The package nicematrix∗

F. Pantigny
fpantigny@wanadoo.fr
April 28, 2025

Abstract
The LaTeX package nicematrix provides new environments similar to the classical environ-
ments {tabular}, {array} and {matrix} of array and amsmath but with extended features.

dimensions (cm)

Price
C1 C2 Cn Product
L l h
 
L1 a11 a12 a1n
L2  a21
 a22 a2n 
 small 3 5.5 1 30
  standard 5.5 8 1.5 50.5
premium
 
Ln an1 an2 ann 8.5 10.5 2 80
extra 8.5 10 1.5 85.5
special 12 12 0.5 70

The package nicematrix is entirely contained in the file nicematrix.sty. This file may be put in the
current directory or in a texmf tree. However, the best is to install nicematrix with a TeX distribution
such as MiKTeX, TeX Live or MacTeX.
Remark
If you use LaTeX via Internet with, for example, Overleaf, you can upload the file nicematrix.sty
in the repertory of your project in order to take full advantage of the latest version de nicematrix.1
This package can be used with xelatex, lualatex, pdflatex but also by the classical workflow
latex-dvips-ps2pdf (or Adobe Distiller). However, the file nicematrix.dtx of the present documen-
tation should be compiled with LuaLaTeX.
This package requires and loads the packages l3keys2e, array, amsmath, pgfcore and the module shapes
of pgf (tikz, which is a layer over pgf, is not loaded). The final user only has to load the package
with \usepackage{nicematrix}.
The idea of nicematrix is to create pgf nodes under the cells and the positions of the rules of the
tabular created by array and to use these nodes to develop new features. As usual with pgf, the
coordinates of these nodes are written in the aux to be used on the next compilation and that’s why
nicematrix may need several compilations2 . One must not use the command \nofiles (which
prevents the creation of the aux file).
Most features of nicematrix may be used without explicit use of pgf or TikZ (which, in fact, is not
loaded by default).
A command \NiceMatrixOptions is provided to fix the options (the scope of the options fixed by
this command is the current TeX group: they are semi-global).

∗ This document corresponds to the version 7.1c of nicematrix, at the date of 2025/04/28.
1 The latest version of the file nicematrix.sty may be downloaded on the Github depot of nicematrix:
https://github.com/fpantigny/nicematrix/releases
2 If you use Overleaf, Overleaf will do automatically a sufficient number of compilations.

1
1 The environments of this package

The package nicematrix defines the following new environments.

{NiceTabular} {NiceArray} {NiceMatrix}
{NiceTabular*} {pNiceArray} {pNiceMatrix}
{NiceTabularX} {bNiceArray} {bNiceMatrix}
{BNiceArray} {BNiceMatrix}
{vNiceArray} {vNiceMatrix}
{VNiceArray} {VNiceMatrix}
The environments {NiceArray}, {NiceTabular} and {NiceTabular*} are similar to the environ-
ments {array}, {tabular} and {tabular*} of the package array (which is loaded by nicematrix).
The environments {pNiceArray}, {bNiceArray}, etc. have no equivalent in array.
The environments {NiceMatrix}, {pNiceMatrix}, etc. are similar to the corresponding environments
of amsmath (which is loaded by nicematrix): {matrix}, {pmatrix}, etc.
The environment {NiceTabularX} is similar to the environment {tabularx} from the eponymous
package.3 .
It’s recommended to use primarily the classical environments and to use the environ-
ments of nicematrix only when some feature provided by these environments is used (this
will save memory).
All the environments of the package nicematrix accept, between square brackets, an optional list of
key=value pairs. There must be no space before the opening bracket ([) of this list of
options.

2 The vertical space between the rows

It’s well known that some rows of the arrays created by default with LaTeX are, by default, too close
to each other. Here is a classical example.
$\begin{pmatrix}
\frac{1}{2} & -\frac{1}{2} \\
1
− 12

2
\frac{1}{3} & \frac{1}{4} \\ 1
3
1
4
\end{pmatrix}$

Inspired by the package cellspace which deals with that problem, the package nicematrix provides two
keys cell-space-top-limit and cell-space-bottom-limit similar to the parameters of cellspace
called \cellspacetoplimit and \cellspacebottomlimit.
There is also a key cell-space-limits to set both parameters at once.
The initial value of these parameters is 0 pt in order to have for the environments of nicematrix the
same behaviour as those of array and amsmath. However, a value of 1 pt would probably be a good
choice and we suggest to set them with \NiceMatrixOptions.4
\NiceMatrixOptions{cell-space-limits = 1pt}
$\begin{pNiceMatrix}
\frac12 & -\frac12 \\
!
1
2 − 12
\frac13 & \frac14 \\ 1 1
3 4
\end{pNiceMatrix}$

3 In fact, it’s possible to use directly the X columns in the environment {NiceTabular} (and the required width for

the tabular is fixed by the key width): cf. p. 28

4 One should remark that these parameters apply also to the columns of type S of siunitx whereas the package

cellspace is not able to act on such columns of type S.

2
It’s also possible to change these parameters for only a few rows by using the command \RowStyle
provided by nicematrix (cf. p. 26).

3 The vertical position of the arrays

The package nicematrix provides a option baseline for the vertical position of the arrays. This
option takes in as value an integer which is the number of the row on which the array will be aligned.
$A = \begin{pNiceMatrix}[baseline=2]
1
\frac{1}{\sqrt{1+p^2}} & p & 1-p \\ p 1−p
p 
1+p2
1 & 1 & 1 \\ A= 1 1 1 
1 & p & 1+p 1 p 1+p
\end{pNiceMatrix}$

It’s also possible to use the option baseline with one of the special values t, c or b. These letters
may also be used absolutely like the option of the environments {tabular} and {array} of array.
The initial value of baseline is c.
In the following example, we use the option t (equivalent to baseline=t) immediately after an \item
of list. One should remark that the presence of a \hline at the beginning of the array doesn’t prevent
the alignment of the baseline with the baseline of the first row (with {tabular} or {array} of array,
one must use \firsthline).
\begin{enumerate}
\item an item
\smallskip
\item \renewcommand{\arraystretch}{1.2}
1. an item
$\begin{NiceArray}[t]{lcccccc}
\hline 2. n 0 1 2 3 4 5
n & 0 & 1 & 2 & 3 & 4 & 5 \\
un 1 2 4 8 16 32
u_n & 1 & 2 & 4 & 8 & 16 & 32
\hline
\end{NiceArray}$
\end{enumerate}

However, it’s also possible to use the tools of booktabs5 : \toprule, \bottomrule, \midrule, etc.
\begin{enumerate}
\item an item
\smallskip
\item
$\begin{NiceArray}[t]{lcccccc} 1. an item
\toprule
n & 0 & 1 & 2 & 3 & 4 & 5 \\ 2. n 0 1 2 3 4 5
\midrule un 1 2 4 8 16 32
u_n & 1 & 2 & 4 & 8 & 16 & 32
\bottomrule
\end{NiceArray}$
\end{enumerate}

It’s also possible to use the key baseline to align a matrix on an horizontal rule (drawn by \hline).
In this aim, one should give the value line-i where i is the number of the row following the horizontal
rule.

\NiceMatrixOptions{cell-space-limits=1pt}

5 The extension booktabs is not loaded by nicematrix.

3
$A=\begin{pNiceArray}{cc|cc}[baseline=line-3]
\dfrac{1}{A} & \dfrac{1}{B} & 0 & 0 \\ 1 1
 
0 0
\dfrac{1}{C} & \dfrac{1}{D} & 0 & 0 \\ A B 
\hline
1 1 
 0 0
0 & 0 & A & B \\ C D
 
A= 
0 & 0 & D & D \\
0 0 A B
\end{pNiceArray}$ 0 0 D D

4 The blocks

4.1 General case

In the environments of nicematrix, it’s possible to use the command \Block in order to place an
element in the center of a rectangle of merged cells of the array.6
The command \Block must be used in the upper leftmost cell of the cells of the block with two
mandatory arguments.

• The first argument is the size of the block with the syntax i-j where i is the number of rows of
the block and j its number of columns.
If this argument is empty, its default value is 1-1. If the number of rows is not specified, or
equal to *, the block extends until the last row (idem for the columns).

• The second argument is the content of the block. In {NiceTabular}, {NiceTabular*} and
{NiceTabularX}, the content of the block is composed in text mode whereas, in the other
environments, it is composed in math mode.

Here is an example of utilisation of the command \Block in mathematical matrices.

$\begin{bNiceArray}{cw{c}{1cm}c|c}[margin]
\Block{3-3}{A} & & & 0 \\ 
0

& & & \Vdots \\  A 
& & & 0 \\ 



\hline  0 
0 & \Cdots& 0 & 0 0 0 0
\end{bNiceArray}$

One may wish to raise the size of the “A” placed in the block of the previous example. Since this
element is composed in math mode, it’s not possible to use directly a command like \large, \Large
and \LARGE. That’s why the command \Block provides an option between angle brackets to specify
some TeX code which will be inserted before the beginning of the math mode.7
$\begin{bNiceArray}{cw{c}{1cm}c|c}[margin]
\Block{3-3}<\Large>{A} & & & 0 \\ 
0

0 & & & \Vdots \\
& & & 0 \\



A 


\hline  0 
0 & \Cdots& 0 & 0 0 0 0
\end{bNiceArray}$

6 The spaces after a command \Block are deleted.

7 This argument between angular brackets may also be used to insert a command of font such as \bfseries when
the command \\ is used in the content of the block. It’s also possible to put in that optional argument the command
\rotate provided by nicematrix (cf. part 14.5, p. 51).

4
In fact, the command \Block accepts as first optional argument (between square brackets) a list of
pairs key=value.
First, there are keys which are quick tools to control the apperance of the block.

• the key fill takes in as value a color and fills the block with that color;
• the key opacity sets the opacity of the filling color specified by fill;8
• the key draw takes in as value a color and strokes the frame of the block with that color (the
default value of that key is the current color of the rules of the array);
• the key color takes in as value a color and apply that color the content of the block but draws
also the frame of the block with that color;
• the keys hlines, vlines and hvlines draw all the corresponding rules in the block;9
• the key line-width is the width of the rules (is relevant only when one of the keys draw,
hvlines, vlines and hlines is used);
• the key rounded-corners requires rounded corners (for the frame drawn by draw and the shape
drawn by fill) with a radius equal to the value of that key (the default value is 4 pt10 ).

Sometimes, these tools are not sufficient to control the appearance of the block. The following keys
are more powerful but also more difficult to use. Moreover, the require the loading of TikZ by the
user (with \usepackage{tikz}). By default, nicematrix does not load TikZ but only pgf, which is a
sublayer of TikZ.

• The key borders provides the ability to draw only some borders of the blocks; the value of
that key is a (comma-separated) list of elements covered by left, right, top and bottom;
it’s possible, in fact, in the list which is the value of the key borders, to add an entry of
the form tikz={list} where list is a list of couples key=value of TikZ specifying the graphical
characteristics of the lines that will be drawn (for an example, see p. 69).
• When the key tikz is used, the TikZ path corresponding of the rectangle which delimits the
block is executed with TikZ11 by using as options the value of that key tikz (which must be a
list of keys allowed for a TikZ path).
In fact, in the list of the keys provided by the user as value of tikz, it’s possible to put a key
offset . That key is not provided by TikZ but by nicematrix. It will narrow the rectangular
frame corresponding to the block by a margin (horizontally and vertically) equal to the value
(of that key offset). That new frame, a bit narrower, will be executed by TikZ with options
which are the other keys in the list of keys provided as value to the key tikz of \Block.
For examples, cf. p. 63.

There is also some technical keys:

• the key name provides a name to the rectangular TikZ node corresponding to the block; it’s
possible to use that name with TikZ in the \CodeAfter of the environment (cf. p. 39);
• the key respect-arraystretch prevents the setting of \arraystretch to 1 at the beginning
of the block (which is the behaviour by default) ;
• By default, the rules are not drawn in the blocks (see the section about the rules: section 5
p. 11). However, if the key transparent is used, the rules are drawn. For an example, see
section 18.1 on page 63. Caution: that key does not imply that the content of the block will be
transparent!

8 Caution: that feature creates instructions of transparency in the pdf and some readers of pdf don’t support such

instructions.
9 However, the rules are not drawn in the sub-blocks of the block, as always with nicematrix: the rules are not drawn

in the blocks, except when they have the key transparent (cf. section 5 p. 11).
10 This value is the initial value of the rounded corners of TikZ.
11 TikZ should be loaded (by default, nicematrix only loads pgf) and, if it’s not, an error will be raised.

5
There is also keys for the horizontal and vertical positions of the content of the block: cf. 4.5 p. 7.

One must remark that, by default, the commands \Blocks don’t create space. There
is exception only for the blocks mono-column and the blocks mono-row under some conditions as
explained just below.
In the following example, we have had to enlarge by hand the columns 2 and 3 (with the construction
w{c}{...} of array).

\begin{NiceTabular}{cw{c}{2cm}w{c}{3cm}c}
rose & tulip & daisy & dahlia \\
violet
& \Block[draw=red,fill=[RGB]{204,204,255},rounded-corners]{2-2}
{\LARGE Some beautiful flowers} & & marigold \\
& & marigold \\
iris & & & lis \\
arum & periwinkle & forget-me-not & hyacinth
\end{NiceTabular}

rose tulip daisy dahlia

violet
iris Some beautiful flowers marigold
lis
arum periwinkle forget-me-not hyacinth

4.2 The mono-column blocks

The mono-column blocks have a special behaviour.

• The natural width of the contents of these blocks is taken into account for the width of the
current column.
In the columns with a fixed width (columns w{...}{...}, W{...}{...}, p{...}, b{...},
m{...}, V and X), the content of the block is formatted as a paragraph of that width.

• The specification of the horizontal position provided by the type of column (c, r or l) is taken
into account for the blocks. For a block in a column ot type p{...}, b{...}, m{...}, V{...}
ou X, the alignment c will be used by default. However, those types of columns may have an
optional argument for the horizontal alignment (eg: p[l]{...}) and, in that case, that type of
alignement is passed to the block.
Of course, the \Block may also have its own specification of alignment: cf. 4.5 p. 7.
• The specifications of font specified for the column by a construction >{...} in the preamble of
the array are taken into account for the mono-column blocks of that column (this behaviour is
probably expected).

\begin{NiceTabular}{@{}>{\bfseries}lr@{}} \hline
\Block{2-1}{John} & 12 \\ 12
John
& 13 \\ \hline 13
Steph & 8 \\ \hline Steph 8
\Block{3-1}{Sarah} & 18 \\ 18
& 17 \\ Sarah 17
& 15 \\ \hline 15
Ashley & 20 \\ \hline Ashley 20
Henry & 14 \\ \hline Henry 14
\Block{2-1}{Madison} & 15 \\ 15
& 19 \\ \hline Madison
19
\end{NiceTabular}

6
4.3 The mono-row blocks
For the mono-row blocks, the natural height and depth are taken into account for the height and
depth of the current row (as does a standard \multicolumn of LaTeX), except when an option of
vertical position has been used for the block (one of the keys t, b, m, T and B described in the part
4.6, p. 9).

4.4 The mono-cell blocks

A mono-cell block inherits all the properties of the mono-row blocks and mono-column blocks.
At first sight, one may think that there is no point using a mono-cell block. However, there are some
good reasons to use such a block.
• It’s possible to use the command \\ in a (mono-cell) block.
• It’s possible to use the option of horizontal alignment of the block in derogation of the type of
column given in the preamble of the array.

• It’s possible do draw a frame around the cell with the key draw of the command \Block and
to fill the background with rounded corners with the keys fill and rounded-corners.12
• It’s possible to draw one or several borders of the cell with the key borders.

\begin{NiceTabular}{cc}
\toprule
Writer & \Block[l]{}{year\\ of birth} \\ year
Writer
\midrule of birth
Hugo & 1802 \\ Hugo 1802
Balzac & 1799 \\ Balzac 1799
\bottomrule
\end{NiceTabular}

We recall that if the first mandatory argument of \Block is left blank, the block is mono-cell.13

4.5 Horizontal position of the content of the block

The command \Block accepts the keys l , c and r for the horizontal position of its content.
$\begin{bNiceArray}{cw{c}{1cm}c|c}[margin]
\Block[r]{3-3}<\LARGE>{A} & & & 0 \\ 
0

& & & \Vdots \\
& & & 0 \\



A 


\hline  0 
0 & \Cdots& 0 & 0 0 0 0
\end{bNiceArray}$

By default, the horizontal position of the content of a block is computed by using the positions of
the contents of the columns implied in that block. That’s why, in the following example, the header
“First group” is correctly centered despite the instruction !{\qquad} in the preamble which has been
used to increase the space between the columns (this is not the behaviour of \multicolumn).

12 If one simply wishes to color the background of a unique cell, there is no point using the command \Block: it’s

possible to use the command \cellcolor.

13 One may consider that the default value of the first mandatory argument of \Block is 1-1.

7
\begin{NiceTabular}{@{}c!{\qquad}ccc!{\qquad}ccc@{}}
\toprule
Rank & \Block{1-3}{First group} & & & \Block{1-3}{Second group} \\
& 1A & 1B & 1C & 2A & 2B & 2C \\
\midrule
1 & 0.657 & 0.913 & 0.733 & 0.830 & 0.387 & 0.893\\
2 & 0.343 & 0.537 & 0.655 & 0.690 & 0.471 & 0.333\\
3 & 0.783 & 0.885 & 0.015 & 0.306 & 0.643 & 0.263\\
4 & 0.161 & 0.708 & 0.386 & 0.257 & 0.074 & 0.336\\
\bottomrule
\end{NiceTabular}

Rank First group Second group

1A 1B 1C 2A 2B 2C
1 0.657 0.913 0.733 0.830 0.387 0.893
2 0.343 0.537 0.655 0.690 0.471 0.333
3 0.783 0.885 0.015 0.306 0.643 0.263
4 0.161 0.708 0.386 0.257 0.074 0.336

In order to have an horizontal positionning of the content of the block computed with the limits of
the columns of the LaTeX array (and not with the contents of those columns), one may use the key
L , R and C of the command \Block.14
Here is the same example with the key C for the first block.

\begin{NiceTabular}{@{}c!{\qquad}ccc!{\qquad}ccc@{}}
\toprule
Rank & \Block[C]{1-3}{First group} & & & \Block{1-3}{Second group} \\
& 1A & 1B & 1C & 2A & 2B & 2C \\
\midrule
1 & 0.657 & 0.913 & 0.733 & 0.830 & 0.387 & 0.893\\
2 & 0.343 & 0.537 & 0.655 & 0.690 & 0.471 & 0.333\\
3 & 0.783 & 0.885 & 0.015 & 0.306 & 0.643 & 0.263\\
4 & 0.161 & 0.708 & 0.386 & 0.257 & 0.074 & 0.336\\
\bottomrule
\end{NiceTabular}

Rank First group Second group

1A 1B 1C 2A 2B 2C
1 0.657 0.913 0.733 0.830 0.387 0.893
2 0.343 0.537 0.655 0.690 0.471 0.333
3 0.783 0.885 0.015 0.306 0.643 0.263
4 0.161 0.708 0.386 0.257 0.074 0.336

The command \Block supports also the keys p and j. With the key p , the content of the block is
formatted like a paragraph (as in a column of type p). That key may be used in conjunction with
a key l, c or r, and, in that case, the paragraph is formatted with \raggedright, \centering or
\raggedleft (or \RaggedRight, \Centering and \RaggedLeft when ragged2e) est chargée. With
the key j (which inforces the key p), the paragraph is justified.

14 Remark: The keys L, C and R require less computations than the keys l, c and r. If you are concernend about

efficiency, you should use by default \Block[C].

8
It’s possible to put an environment {itemize} or {enumerate} in a block which uses the key p or
j (in the other case, you will have a LaTeX error: Not allowed in LR mode). For the following
example, we have loaded the package enumitem (for the key left of the environment {itemize}).
\begin{NiceTabular}[hvlines]{ccc}
one & two two & three three \\
one &
\Block[p]{*-2}{%
\begin{itemize}[left=0pt]
\item one two three four five
\item two
\item three
\end{itemize}
} \\
one & \\
one & \\
one & \\
one & \\
one & \\
one & \\
\end{NiceTabular}

one two two three three

one
one • one two three four
one five
one
• two
one
one • three
one

4.6 Vertical position of the content of the block

For the vertical position, the command \Blocks accepts the keys m, t, b, T and B.

• With the key m 15 , the content of the block is vertically centered.

• With the key t , the baseline of the content of the block is aligned with the baseline of the first
row concerned by the block.

• with the key b, the baseline of the last row of the content of the block (we recall that the
content of a block may contain several lines of text separated by \\) is aligned with the baseline
of the last of the rows of the array involved in the block.
• With the key T, the content of the block is set upwards.
No vertical margin is added. However, the contents of the block is (always) composed by
nicematrix in a {minipage}, a {tabular} or an {array} and, hence, there will still remain a
margin (in most cases). If needed, it’s always possible to add a \strut...
• With the key B, the content of the block is set downwards.

When no key is given, the key m applies (except in the mono-row blocks).
\NiceMatrixOptions{rules/color=[gray]{0.75}, hvlines}

15 That key has an alias: v-center.

9
\begin{NiceTabular}{ccc}
\Block[fill=red!10,t,l]{4-2}{two\\lines}
& & \Huge Un\\
two
lines
Un
deux
& & deux \\
trois
quatre
& & trois \\
& & \Huge quatre \\
text & text \\ text text
\end{NiceTabular}

\begin{NiceTabular}{ccc}
\Block[fill=red!10,b,r]{4-2}{two\\lines}
& & \Huge Un\\
Un
deux
& & deux \\
trois
quatre
& & trois \\ two
& & \Huge quatre \\ lines
text & text \\ text text
\end{NiceTabular}

\begin{NiceTabular}{ccc}
\Block[fill=red!10,T,L]{4-2}{two\\lines}
& & \Huge Un\\
two
lines Un
deux
& & deux \\
trois
quatre
& & trois \\
& & \Huge quatre \\
text & text \\ text text
\end{NiceTabular}

\begin{NiceTabular}{ccc}
\Block[fill=red!10,B,R]{4-2}{two\\lines}
& & \Huge Un\\
Un
deux
& & deux \\
trois
quatre
& & trois \\ two
& & \Huge quatre \\ lines
text & text \\ text text
\end{NiceTabular}

4.7 \\ and & in the blocks

The extension nicematrix provides the ability to use \\ and & directly in the content of a block (in
order to format its contents) but there is some rectrictions.

• One must not use both \\ and & in the same block.
• For \\, there is no other restriction. It’s possible to use \\ in a block to format a text on several
lines.
• In order to use &, the key ampersand-in-blocks (alias: &-in-blocks ) must been activated16 .
Then, the block is divided in sub-blocks as illustrated below. Be careful: when ampersand-
in-blocks is in force, the (main) argument of the command \Block is syntactically divided
into sub-blocks by splitting on the ampersands &, the ampersands between curly braced are
protected but not those in an environment.17

16 Otherwise, the use of & in the command \Block will raise a TeX error :

! Extra alignment tab has been changed to \cr.

17 It’s not possible to write \Block[ampersand-in-blocks]{}{\begin{array}{cc}1&2\end{array}}. Of course, it’s

possible without the key ampersand-in-blocks.

10
With the ampserand &, it’s possible to divide horizontally a block in sub-blocks of the same size.
\begin{NiceTabular}{ll}%
[hvlines,ampersand-in-blocks]
the five first naturels numbers
& the five first naturels numbers \\
3 one two three
3 & \Block{}{one & two & three} \\
4 & \Block{}{one& two & three & four} \\ 4 one two three four
5 & \Block{}{one & two & three & four & five} \\ 5 one two three four five
\end{NiceTabular}
As we can see, the blocks (which was are in fact mono-cell blocks) are divided into sub-blocks of the
same size. However, maybe the following code would be prefered.
\begin{NiceTabular}{lccccc}%
[hvlines,ampersand-in-blocks]
& \Block{1-5}{the five first the five first natural numbers
natural numbers} \\ 3 one two three
3 & \Block{1-5}{one & two & three} \\ 4 one two three four
4 & \Block{1-5}{one& two & three & four} \\ 5 one two three four five
5 & one & two & three & four & five \\
\end{NiceTabular}

In this code, we have blocks of size 1-5 which are divided into three or four sub-blocks.

5 The rules

The usual techniques for the rules may be used in the environments of nicematrix (except \vline).
However, there is some small differences with the classical environments.

5.1 Some differences with the classical environments

5.1.1 The vertical rules
In the environments of nicematrix, the vertical rules specified by | in the preambles of the environments
are never broken, even by an incomplete row or by a double horizontal rule specified by \hline\hline
(there is no need to use the package hhline).

\begin{NiceTabular}{|c|c|} \hline
First & Second \\ \hline\hline First Second
Peter \\ \hline Peter
Mary & George\\ \hline Mary George
\end{NiceTabular}

However, the vertical rules are not drawn in the blocks (created by \Block: cf. p. 4) nor in the
corners (created by the key corner: cf. p. 14) nor in the potential exterior rows (created by the keys
first-row and last-row: cf. p. 29).

If you use booktabs (which provides \toprule, \midrule, \bottomrule, etc.) and if you actually want
to add vertical rules (which is not in the spirit of booktabs), you should notice that the vertical rules
drawn by nicematrix are compatible with booktabs. Remark that nicematrix does not load booktabs.
$\begin{NiceArray}{c|ccc} \toprule
a & b & c & d \\ \midrule a b c d
1 & 2 & 3 & 4 \\ 1 2 3 4
1 & 2 & 3 & 4 \\ \bottomrule 1 2 3 4
\end{NiceArray}$

11
However, it’s still possible to define a specifier (named, for instance, I) to draw vertical rules with
the standard behaviour of array.

\newcolumntype{I}{!{\vrule}}

5.1.2 The command \cline

The horizontal and vertical rules drawn by \hline and the specifier “|” make the array larger or
wider by a quantity equal to the width of the rule (with array and also with nicematrix).
For historical reasons, this is not the case with the command \cline, as shown by the following
example.
\setlength{\arrayrulewidth}{2pt}
\begin{tabular}{cccc} \hline
A&B&C&D \\ \cline{2-2} A B C D
A&B&C&D \\ \hline A B C D
\end{tabular}

In the environments of nicematrix, this situation is corrected (it’s still possible to go to the standard
behaviour of \cline with the key standard-cline ).
\setlength{\arrayrulewidth}{2pt}
\begin{NiceTabular}{cccc} \hline
A B C D
A&B&C&D \\ \cline{2}
A&B&C&D \\ \hline A B C D
\end{NiceTabular}

In the environments of nicematrix, an instruction \cline{i} is equivalent to \cline{i-i}.

5.2 The thickness and the color of the rules

The environments of nicematrix provide a key rules/width to set the width (in fact the thickness)
of the rules in the current environment. In fact, this key merely sets the value of the standard LaTeX
length \arrayrulewidth.
It’s well known that colortbl provides the command \arrayrulecolor in order to specify the color of
the rules.
With nicematrix, it’s possible to specify the color of the rules even when colortbl is not loaded. For sake
of compatibility, the command is also named \arrayrulecolor. However, nicematrix also provides a
key rules/color, available in \NiceMatrixOptions or in an individual environment, to fix the color
of the rules. This key sets the value locally (whereas \arrayrulecolor acts globally!) and should be
prefered.
\begin{NiceTabular}{|ccc|}[rules/color=[gray]{0.9},rules/width=1pt]
\hline
rose & tulipe & lys \\ rose tulipe lys
arum & iris & violette \\ arum iris violette
muguet & dahlia & souci \\ muguet dahlia souci
\hline
\end{NiceTabular}

In fact, in that example, instead of \hline, it would have a better choice to use \Hline, provided
by nicematrix and described just below, because it ensures a better output in the PDF viewers at the
low levels of zoom.

12
5.3 The tools of nicematrix for the rules
Here are the tools provided by nicematrix for the rules.
• the keys hlines, vlines, hvlines and hvlines-except-borders;

• the specifier “|” in the preamble (for the environments with preamble);
• the command \Hline.

All these tools don’t draw the rules in the blocks nor in the empty corners (when the
key corners is used), nor in the exterior rows and columns.
• These blocks are:
– the blocks created by the command \Block18 presented p. 4;
– the blocks implicitely delimited by the continuous dotted lines created by \Cdots, \Vdots,
etc. (cf. p. 31).
• The corners are created by the key corners explained below (see p. 14).
• For the exterior rows and columns, see p. 29.

In particular, this remark exhibits a first difference between the standard command \hline and the
command \Hline provided by nicematrix.
Moreover, the key \Hline takes in an optional argument (between square brackets) which is a list of
key=value pairs. For the description of those keys, see custom-line on p. 16.19

As well as the command \Hline, the specifier “|” supports an optional argument between square
brackets for the characteristics of the rule.
\begin{NiceTabular}{ | c |[color=blue] c |}
\Hline
a & b \\
\Hline[color=red] a b
c & d \\ c d
\Hline
\end{NiceTabular}

5.3.1 The keys hlines and vlines

The keys hlines and vlines (which draw, of course, horizontal and vertical rules) take in as value
a list of numbers which are the numbers of the rules to draw.20
In fact, for the environments with delimiters (such as {pNiceMatrix} or {bNiceArray}), the key
vlines don’t draw the exterior rules (this is certainly the expected behaviour).
$\begin{pNiceMatrix}[vlines,rules/width=0.2pt]
1 & 2 & 3 & 4 & 5 & 6 \\
 
1 2 3 4 5 6
1 & 2 & 3 & 4 & 5 & 6 \\ 1 2 3 4 5 6
1 & 2 & 3 & 4 & 5 & 6 1 2 3 4 5 6
\end{pNiceMatrix}$

When the key hlines is in force, it’s still possible to use \Hline\Hline to put a double horizontal
rule. As well, it’s possible to put || in the preamble (of an environment with preamble) to put a
double vertical rule, even when the key vlines is in force.

18 And also the command \multicolumn but it’s recommended to use instead \Block in the environments of nicematrix.
19 Technical remark: If the user wants to write a command over the command \Hline, it shall be ensured that this
new command is expandable in the TeX sens (by using, for instance, \NewExpandableDocumentCommand of LaTeX3,
\newcommand of LaTeX or \def of TeX). Example: \NewExpandableDocumentCommand}{}{\Hline[color=red]}
20 It’s possible to put in that list some intervals of integers with the syntax i-j.

13
$\begin{NiceArray}{c||ccccc}[hlines,vlines]
& a & b & c & d & e \\ \Hline\Hline a b c d e
x & 0 & 0 & 0 & 0 & 0 \\ x 0 0 0 0 0
y & 0 & 0 & 0 & 0 & 0 \\ y 0 0 0 0 0
z & 0 & 0 & 0 & 0 & 0 \\ z 0 0 0 0 0
\end{NiceArray}$

5.3.2 The keys hvlines and hvlines-except-borders

The key hvlines (no value) is the conjonction of the keys hlines and vlines.
\setlength{\arrayrulewidth}{1pt}
\begin{NiceTabular}{cccc}[hvlines,rules/color=blue]
rose & tulip & sunflower & lily \\
violet & \Block[draw=red]{2-2}{\LARGE flowers} & & orchid \\
carnation & & & lys \\
daisy & peony & jasmine & magnolia
\end{NiceTabular}

rose tulip sunflower lily

violet orchid
carnation flowers lys
daisy peony jasmine magnolia

It’s worth noting that, when the key rounded-corners is used for the environment {NiceTabular},
the key hvlines draws rounded corners for the exterior frame of the tabular: cf. part 14.1, p. 49.

The key hvlines-except-borders is similar to the key hvlines but does not draw the rules on the
horizontal and vertical borders of the array. For an example of use of that key, see the part “Use
with tcolorbox”, p. 64.

5.3.3 The (empty) corners

The four corners of an array will be designed by NW, SW, NE and SE (north west, south west, north
east and south east).
For each of these corners, we will call empty corner (or simply corner) the reunion of all the empty
rectangles starting from the cell actually in the corner of the array.21
However, it’s possible, for a cell without content, to require nicematrix to consider that cell as not
empty with the command \NotEmpty.

A
A A A
A
In the example on the right (where B is in the center of a A A A A
block of size 2×2), we have colored in blue the four (empty) A A A A A A
corners of the array. A A A A A A
A A A
A
B
A

When the key corners 22 is used, nicematrix computes the (empty) corners and these corners will be
taken into account by the tools for drawing the rules (the rules won’t be drawn in the corners).

21 For sake of completeness, we should also say that a cell contained in a block (even an empty cell) is not taken into

account for the determination of the corners. That behaviour is natural. The precise definition of a “non-empty cell”
is given below (cf. p. 61).
22 The key corners that we describe now has no direct link with the key rounded-corners described in the part 14.1,

p. 49

14
\NiceMatrixOptions{cell-space-top-limit=3pt}
\begin{NiceTabular}{*{6}{c}}[corners,hvlines] A
& & & & A \\ A A A
& & A & A & A \\ A
& & & A \\
A A A A
& & A & A & A & A \\
A & A & A & A & A & A \\ A A A A A A
A & A & A & A & A & A \\ A A A A A A
& A & A & A \\ A A A
& \Block[C]{2-2}{B} & & A \\ A
& & & A \\ B
A
\end{NiceTabular}

It’s also possible to provide to the key corners a (comma-separated) list of corners (designed by NW,
SW, NE and SE).
\NiceMatrixOptions{cell-space-top-limit=3pt}
\begin{NiceTabular}{*{6}{c}}[corners=NE,hvlines] 1
1\\
1 1
1&1\\
1 2 1
1&2&1\\
1&3&3&1\\ 1 3 3 1
1&4&6&4&1\\ 1 4 6 4 1
& & & & &1 1
\end{NiceTabular}

. The corners are also taken into account by the tools provided by nicematrix to color cells, rows
and columns. These tools don’t color the cells which are in the corners (cf. p. 19). The command
\TikzEveryCell available in the \CodeBefore and the \CodeAfter (cf. p. 44) takes also into account
the empty corners.

5.3.4 The command \diagbox

The command \diagbox (inspired by the package diagbox), allows, when it is used in a cell, to slash
that cell diagonally downwards.
$\begin{NiceArray}{*{5}{c}}[hvlines]
\diagbox{x}{y} & e & a & b & c \\ x
y e a b c
e & e & a & b & c \\ e e a b c
a & a & e & c & b \\ a a e c b
b & b & c & e & a \\ b b c e a
c & c & b & a & e c c b a e
\end{NiceArray}$

It’s possible to use the command \diagbox in a \Block.

$\begin{NiceArray}{*{5}{c}}[hvlines]
\Block{2-2}{\diagbox{x}{y}} & & a & b & c \\ y a b c
& & a & b & c \\ x a b c
a & a & e & c & b \\ a a e c b
b & b & c & e & a \\ b b c e a
c & c & b & a & e c c b a e
\end{NiceArray}$

But it’s also possible to use \diagbox for the diagonal rule only (and the labels are put but the usual
way, that is to say in cells of the tabular).

15
$\begin{NiceArray}{*{5}{c}}[hvlines]
\Block{2-2}{\diagbox{}{}} & y & a & b & c \\ y a b c
x & & a & b & c \\ x a b c
a & a & e & c & b \\ a a e c b
b & b & c & e & a \\ b b c e a
c & c & b & a & e c c b a e
\end{NiceArray}$

Nevertheless, it’s always possible to draw whatever rule we wish with TikZ in the \CodeAfter (or
the \CodeBefore) by using the PGF/TikZ nodes created by nicematrix: cf. p. 54.

5.3.5 Commands for customized rules

It’s also possible to define commands and letters for customized rules with the key custom-line
available in \NiceMatrixOptions and in the options of individual environments. That key takes in
as argument a list of key=value pairs. First, there is three keys to define the tools which will be used
to use that new type of rule.

• the key command is the name (without the backslash) of a command that will be created by
nicematrix and that will be available for the final user in order to draw horizontal rules (similarly
to \hline);
• the key ccommand is the name (without the backslash) of a command that will be created by
nicematrix and that will be available for the final user to order to draw partial horizontal rules
(similarly to \cline, hence the name ccommand): the argument of that command is a list of
intervals of columns specified by the syntax i or i-j.23
• the key letter takes in as argument a letter24 that the user will use in the preamble of an
environment with preamble (such as {NiceTabular} in order to specify a vertical rule.

We will now speak of the keys which describe the rule itself. Those keys may also be used in the
(optional) argument of an individual command \Hline or in the (optional) argument of a specifier
“|” in the preamble of an environment.

There is three possibilities.

• First possibility
It’s possible to specify composite rules, with a color and a color for the inter-rule space (as
possible with colortbl for instance).

– the key multiplicity is the number of consecutive rules that will be drawn: for instance,
a value of 2 will create double rules such those created by \hline\hline or || in the
preamble of an environment;
– the key color sets the color of the rules ;
– the key sep-color sets the color between two successive rules (should be used only in
conjonction with multiplicity). The name of that key is inspired by the command
\doublerulesepcolor of colortbl.

That system may be used, in particular, for the definition of commands and letters to draw
rules with a specific color (and those rules will respect the blocks and corners as do all the rules
of nicematrix).

23 It’s recommended to use such commands only once in a row because each use will create space between the rows

corresponding to the total width of the rule.

24 The following letters are forbidden: lcrpmbVX|()[]!@<>

16
 \begin{NiceTabular}{lcIcIc}[custom-line = {letter=I, color=blue}]
\hline
& \Block{1-3}{dimensions} \\
& L & l & h \\
\hline
Product A & 3 & 1 & 2 \\
Product B & 1 & 3 & 4 \\
Product C & 5 & 4 & 1 \\
\hline
\end{NiceTabular}

dimensions
L l H
Product A 3 1 2
Product B 1 3 4
Product C 5 4 1

The key sep-color with the value white may also be used in case of an horizontal double-rule
on the top of a colored cell (if we want the space between both rules above the cell not colored
by the color of the cell).
\NiceMatrixOptions
{
custom-line =
{
command = DoubleRule ,
multiplicity = 2 ,
sep-color = white
one two three
}
} four five six

\begin{NiceTabular}{ccc}
one & two & three \\
\DoubleRule
four & \cellcolor{yellow} five & six \\
\end{NiceTabular}

• Second possibility
It’s possible to use the key tikz (if TikZ is loaded). In that case, the rule is drawn directly
with TikZ by using as parameters the value of the key tikz which must be a list of key=value
pairs which may be applied to a TikZ path.
By default, no space is reserved for the rule that will be drawn with TikZ. It is possible to
specify a reservation (horizontal for a vertical rule and vertical for an horizontal one) with the
key total-width. That value of that key, is, in some ways, the width of the rule that will be
drawn (nicematrix does not compute that width from the characteristics of the rule specified in
tikz).

Here is an example with the key dotted of TikZ.

17
 \NiceMatrixOptions
{
custom-line =
{
letter = I ,
tikz = dotted ,
total-width = \pgflinewidth one two three
} four five six
} seven eight nine

\begin{NiceTabular}{cIcIc}
one & two & three \\
four & five & six \\
seven & eight & nine
\end{NiceTabular}

• Third possibility : the key dotted

As one can see, the dots of a dotted line of TikZ have the shape of a square, and not a circle.
That’s why the extension nicematrix provides in the key custom-line a key dotted which will
draw rounded dots. The initial value of the key total-width is, in this case, equal to the
diameter of the dots (but the user may change the value with the key total-width if needed).
Those dotted rules are also used by nicematrix to draw continuous dotted rules between cells of
the matrix with \Cdots, \Vdots, etc. (cf. p. 31).
In fact, nicematrix defines by default the commands \hdottedline and \cdottedline and the
letter “:” for those dotted rules.25
\NiceMatrixOptions % present in nicematrix.sty
{
custom-line =
{
letter = : ,
command = hdottedline ,
ccommand = cdottedline ,
dotted
}
}
Thus, it’s possible to use the commands \hdottedline and \cdottedline to draw horizontal
dotted rules.
\begin{pNiceMatrix}
1 & 2 & 3 & 4 & 5 \\
\hdottedline

1 2 3 4 5

6 & 7 & 8 & 9 & 10 \\ 6 7 8 9 10
\cdottedline{1,4-5} 11 12 13 14 15
11 & 12 & 13 & 14 & 15
\end{pNiceMatrix}

In the environments with an explicit preamble (like {NiceTabular}, {NiceArray}, etc.), it’s
possible to draw a vertical dotted line with the specifier “:”.
$\left(\begin{NiceArray}{cccc:c}
1 & 2 & 3 & 4 & 5 \\
 
1 2 3 4 5
6 & 7 & 8 & 9 & 10 \\ 6 7 8 9 10
11 & 12 & 13 & 14 & 15 11 12 13 14 15
\end{NiceArray}\right)

25 However, it’s possible to overwrite those definitions with a custom-line (in order, for example, to switch to dashed

lines).

18
6 The color of the background of the rows and columns

6.1 Use of colortbl

We recall that the package colortbl can be loaded directly with \usepackage{colortbl} or by loading
xcolor with the key table: \usepackage[table]{xcolor}.
However, there is two drawbacks:

• The package colortbl patches array, leading to some incompatibilities (for instance with the
command \hdotsfor).
• The package colortbl constructs the array row by row, alterning colored rectangles, rules and
contents of the cells. The resulting pdf is difficult to interpret by some pdf viewers and may
lead to artefacts on the screen.
– Some rules seem to disappear. This is because many PDF viewers give priority to graphical
element drawn posteriorly (which is in the spirit of the “painting model” of PostScript and
PDF). Concerning this problem, MuPDF (which is used, for instance, by SumatraPDF)
gives better results than Adobe Reader.
– A thin white line may appear between two cells of the same color. This phenomenon
occurs when each cell is colored with its own instruction fill (the PostScript operator
fill noted f in PDF). This is the case with colortbl: each cell is colored on its own, even
when \columncolor or \rowcolor is used.
As for this phenomenon, Adobe Reader gives better results than MuPDF (however, it
seems, that, in recent versions of MuPDF, the problem has been solved...).
The package nicematrix provides tools to avoid both problems.

6.2 The tools of nicematrix in the \CodeBefore

The package nicematrix provides some tools to draw the colored panels first, and, then, the content
of the cells and the rules. This strategy is more conform to the “painting model” of the formats
PostScript and pdf and is more suitable for the pdf viewers. However, it requires several compila-
tions.26
The extension nicematrix provides a key code-before for some code that will be executed before the
drawing of the tabular.
An alternative syntax is provided: it’s possible to put the content of that code-before between the
keywords \CodeBefore and \Body at the beginning of the environment.
\begin{pNiceArray}{preamble}
\CodeBefore [options]
instructions of the code-before
\Body
contents of the environment
\end{pNiceArray}
The optional argument between square brackets is a list of key=value pairs which will be presented
progressively in this documentation.27
New commands are available in that \CodeBefore: \cellcolor, \rectanglecolor, \rowcolor,
\columncolor, \rowcolors, \rowlistcolors, \chessboardcolors and \arraycolor.28
The names of these commands are inspired by the names of the commands provided by colortbl.

26 If you use Overleaf, Overleaf will do automatically a sufficient number of compilations.

27 The available keys are create-cell-nodes, sub-matrix (and its subkeys) and delimiters-color.
28 Remark that, in the \CodeBefore, PGF/TikZ nodes of the form “(i-|j)” are also available to indicate the position

to the potential rules: cf. p. 58.

19
These commands don’t color the cells which are in the “corners” if the key corners is used. That
key has been described p. 14.
These commands respect the rounded corners if the key rounded-corners (described in the part 14.1
at the page 49) has been used.
All these commands accept an optional argument, between square brackets and in first position. That
optional argument may contain two elements (separated by a comma)
• the colorimetric space (RGB, rgb, HTML, etc) as specified by the the extension xcolor;

• a specification of opacity of the form opacity = value.29

We describe now in detail those commands.

• The command \cellcolor takes its name from the command \cellcolor of colortbl.
This command takes in as mandatory arguments a color and a list of cells, each of which with
the format i-j where i is the number of the row and j the number of the colummn of the cell.
In fact, despite its name, this command may be used to color a whole row (with the syntax i-)
or a whole column (with the syntax -j).

\begin{NiceTabular}{ccc}[hvlines]
\CodeBefore
\cellcolor[HTML]{FFFF88}{3-1,2-2,-3}
a b c
\Body
a & b & c \\ e f g
e & f & g \\ h i j
h & i & j \\
\end{NiceTabular}

• The command \rectanglecolor takes three mandatory arguments. The first is the color. The
second is the upper-left cell of the rectangle and the third is the lower-right cell of the rectangle.

\begin{NiceTabular}{ccc}[hvlines]
\CodeBefore
\rectanglecolor{blue!15}{2-2}{3-3}
a b c
\Body
a & b & c \\ e f g
e & f & g \\ h i j
h & i & j \\
\end{NiceTabular}

• The command \arraycolor takes in as mandatory argument a color and color the whole
tabular with that color (except the potential exterior rows and columns: cf. p. 29). It’s only a
particular case of \rectanglecolor.

• The command \chessboardcolors takes in as mandatory arguments two colors and it colors
the cells of the tabular in quincunx with these colors.

29 Caution: that feature creates instructions of transparency in the pdf and some readers of pdf don’t support such

instructions.

20
 $\begin{pNiceMatrix}[r,margin]
\CodeBefore
\chessboardcolors{red!15}{blue!15}
\Body  
1 & -1 & 1 \\ 1 −1 1
 −1 1 −1 
-1 & 1 & -1 \\
1 & -1 & 1 1 −1 1
\end{pNiceMatrix}$

We have used the key r which aligns all the columns rightwards (cf. p. 51).

• The command \rowcolor takes its name from the command \rowcolor of colortbl. Its first
mandatory argument is the color and the second is a comma-separated list of rows or interval
of rows with the form a-b (an interval of the form a- represent all the rows from the row a until
the end).

$\begin{NiceArray}{lll}[hvlines]
\CodeBefore
\rowcolor{red!15}{1,3-5,8-}
\Body
a_1 & b_1 & c_1 \\ a1 b1 c1
a_2 & b_2 & c_2 \\ a2 b2 c2
a_3 & b_3 & c_3 \\ a3 b3 c3
a_4 & b_4 & c_4 \\ a4 b4 c4
a_5 & b_5 & c_5 \\ a5 b5 c5
a_6 & b_6 & c_6 \\ a6 b6 c6
a_7 & b_7 & c_7 \\ a7 b7 c7
a_8 & b_8 & c_8 \\ a8 b8 c8
a_9 & b_9 & c_9 \\ a9 b9 c9
a_{10} & b_{10} & c_{10} \\ a10 b10 c10
\end{NiceArray}$

• The command \columncolor takes its name from the command \columncolor of colortbl. Its
syntax is similar to the syntax of \rowcolor.

• The command \rowcolors (with a s) takes its name from the command \rowcolors of colortbl.
The s emphasizes the fact that there is two colors. This command colors alternately the rows
of the tabular with the two colors (provided in second and third argument), beginning with the
row whose number is given in first (mandatory) argument. One of the arguments of color may
be empty (no color is applied in the corresponding rows).
In fact, the first (mandatory) argument is, more generally, a comma separated list of intervals
describing the rows involved in the action of \rowcolors (an interval of the form i- describes
in fact the interval of all the rows of the tabular, beginning with the row i).

The last argument of \rowcolors is an optional list of pairs key=value (the optional argument
in the first position corresponds to the colorimetric space). The available keys are cols, restart
and respect-blocks.

– The key cols describes a set of columns. The command \rowcolors will color only the
cells of these columns. The value is a comma-separated list of intervals of the form i-j
(where i or j may be replaced by *).
– With the key restart , each interval of rows (specified by the first mandatory argument)
begins with the same color.30

30 Otherwise, the color of a given row relies only upon the parity of its absolute number.

21
 – With the key respect-blocks the “rows” alternately colored may extend over several
rows if they have to incorporate blocks (created with the command \Block: cf. p. 4).

\begin{NiceTabular}{clr}[hvlines]
\CodeBefore
\rowcolors[gray]{2}{0.8}{}[cols=2-3,restart]
\Body
\Block{1-*}{Results} \\
Results
John & 12 \\
Stephen & 8 \\ John 12
A
Sarah & 18 \\ Stephen 8
Ashley & 20 \\ Sarah 18
Henry & 14 \\ Ashley 20
B
Madison & 15 Henry 14
\end{NiceTabular} Madison 15

\begin{NiceTabular}{lr}[hvlines]
\CodeBefore
\rowcolors{1}{blue!10}{}[respect-blocks]
12
\Body John
13
\Block{2-1}{John} & 12 \\
Steph 8
& 13 \\
18
Steph & 8 \\
\Block{3-1}{Sarah} & 18 \\ Sarah 17
& 17 \\ 15
& 15 \\ Ashley 20
Ashley & 20 \\ Henry 14
Henry & 14 \\ 15
Madison
\Block{2-1}{Madison} & 15 \\ 19
& 19
\end{NiceTabular}

• The extension nicematrix provides also a command \rowlistcolors. This command generalises
the command \rowcolors: instead of two successive arguments for the colors, this command
takes in an argument which is a (comma-separated) list of colors. In that list, the symbol =
represent a color identical to the previous one.
\begin{NiceTabular}{c}
\CodeBefore
\rowlistcolors{1}{red!15,blue!15,green!15}
\Body Peter
Peter \\ James
James \\ Abigail
Abigail \\ Elisabeth
Elisabeth \\ Claudius
Claudius \\ Jane
Jane \\ Alexandra
Alexandra \\
\end{NiceTabular}

It’s also possible to use in the command \rowlistcolors a color series defined by the command
\definecolorseries of xcolor (and initialized with the command \resetcolorseries31 ).

31 For the initialization, in the following example, you have used the counter iRow (which corresponds to the internal

22
 \begin{NiceTabular}{c}
\CodeBefore
\definecolorseries{BlueWhite}{rgb}{last}{blue}{white}
\resetcolorseries[\value{iRow}]{BlueWhite}
\rowlistcolors{1}{BlueWhite!!+} Peter
\Body James
Peter \\ Abigail
James \\ Elisabeth
Abigail \\ Claudius
Elisabeth \\ Jane
Claudius \\ Alexandra
Jane \\
Alexandra \\
\end{NiceTabular}

We recall that all the color commands we have described don’t color the cells which are in the
“corners”. In the following example, we use the key corners to require the determination of the
corner north east (NE).
\begin{NiceTabular}{ccccccc}[corners=NE,margin,hvlines,first-row,first-col]
\CodeBefore
\rowlistcolors{1}{blue!15, }
0 1 2 3 4 5 6
\Body
0 1
& 0 & 1 & 2 & 3 & 4 & 5 & 6 \\
1 1 1
0 & 1 \\
2 1 2 1
1 & 1 & 1 \\
2 & 1 & 2 & 1 \\ 3 1 3 3 1
3 & 1 & 3 & 3 & 1 \\ 4 1 4 6 4 1
4 & 1 & 4 & 6 & 4 & 1 \\ 5 1 5 10 10 5 1
5 & 1 & 5 & 10 & 10 & 5 & 1 \\ 6 1 6 15 20 15 6 1
6 & 1 & 6 & 15 & 20 & 15 & 6 & 1 \\
\end{NiceTabular}

The previous example uses the keys first-row and first-col which are described in the chapter
concerning the «exterior» rows and columns (cf. p. 29).
As one can see, by default, the coloring commands that we have described don’t apply in those exterior
rows and columns.
However, it may still be possible to color in those rows and columns by providing explicity the numbers
of those rows and columns.
In the following example, we require a color in the column 0 (which is the «first column» and which
exists because the key first-col has been used).

TeX counter \c@iRow) which, when used in the \CodeBefore (and in the \CodeAfter) corresponds to the number of
rows of the array: cf. p 52. That leads to an adjustement of the gradation of the colors to the size of the tabular.

23
\begin{NiceTabular}{ccccccc}[corners=NE,margin,hvlines,first-row,first-col]
\CodeBefore
\rowlistcolors{1}{blue!15, }
\columncolor{red!15}{0} 0 1 2 3 4 5 6
\Body 0 1
& 0 & 1 & 2 & 3 & 4 & 5 & 6 \\ 1 1 1
0 & 1 \\ 2 1 2 1
1 & 1 & 1 \\ 3 1 3 3 1
2 & 1 & 2 & 1 \\ 4 1 4 6 4 1
3 & 1 & 3 & 3 & 1 \\ 5 1 5 10 10 5 1
4 & 1 & 4 & 6 & 4 & 1 \\ 6 1 6 15 20 15 6 1
5 & 1 & 5 & 10 & 10 & 5 & 1 \\
6 & 1 & 6 & 15 & 20 & 15 & 6 & 1 \\
\end{NiceTabular}

One should remark that all the previous commands are compatible with the commands of booktabs
(\toprule, \midrule, \bottomrule, etc). However, booktabs is not loaded by nicematrix.
\begin{NiceTabular}[c]{lSSSS}
\CodeBefore
\rowcolor{red!15}{1-2}
\rowcolors{3}{blue!15}{}
\Body
\toprule
\Block{2-1}{Product} & dimensions (cm)

Price
Product
\Block{1-3}{dimensions (cm)} & & & L l h
\Block{2-1}{\rotate Price} \\
small 3 5.5 1 30
\cmidrule(rl){2-4}
standard 5.5 8 1.5 50.5
& L & l & h \\
premium 8.5 10.5 2 80
\midrule
extra 8.5 10 1.5 85.5
small & 3 & 5.5 & 1 & 30 \\
special 12 12 0.5 70
standard & 5.5 & 8 & 1.5 & 50.5 \\
premium & 8.5 & 10.5 & 2 & 80 \\
extra & 8.5 & 10 & 1.5 & 85.5 \\
special & 12 & 12 & 0.5 & 70 \\
\bottomrule
\end{NiceTabular}

We have used the type of column S of siunitx (which should be loaded by the user).

New 7.1
It’s also possible, in the \CodeBefore, to use the commands \EmptyColumn and \EmptyRow. The
command \EmptyColumn takes in as argument a (comma-separated) list of numbers of columns and
requires that no rules nor background colors will be drawn in the corresponding columns. The
command \EmptyRow is similar for the rows.
\begin{NiceTabular}{ccccc}[hvlines,no-cell-nodes]
\CodeBefore
\rowcolor{blue!15}{1}
\EmptyColumn{3} one two three four
\Body two
one three four
one & two && three & four \\ rows
one & \Block{}{two\\ rows} && three & four \\
\end{NiceTabular}

6.3 Color tools to be used inside the tabular

The extension nicematrix also provides commands to be used directly in the tabular (as does colortbl).

24
These commands are the following several commands available (the first three ones are inspired by
the similar commands of colortbl).

• \cellcolor which colorizes a cell;32

• \rowcolor which must be used in a cell and which colorizes the end of the row;33
• \columncolor which must be used in the preamble of the environment with the same syntax
as the corresponding command of colortbl (however, unlike the command \columncolor of
colortbl, this command \columncolor can appear within another command, itself used in the
preamble of the array; on the other hand, the two final optional arguments for fixing offset are
not supported);
• \rowcolors which takes in as arguments two colors and color the rest of the tabular with those
colors;

• \rowlistcolors which takes in as argument a color and color the rest of the tabular with the
colors of that list of colors.34
These commands are compatible with the commands for the overlays of Beamer (\only, etc.)
\NewDocumentCommand { \Blue } { } { \columncolor{blue!15} }
\begin{NiceTabular}{>{\Blue}c>{\Blue}cc}
\toprule
\rowcolor{red!15}
Last name & First name & Birth day \\
\midrule
Achard & Jacques & 5 juin 1962 \\
Lefebvre & Mathilde & 23 mai 1988 \\
Vanesse & Stephany & 30 octobre 1994 \\
Dupont & Chantal & 15 janvier 1998 \\
\bottomrule
\end{NiceTabular}

Last name First name Birth day

Achard Jacques 5 juin 1962
Lefebvre Mathilde 23 mai 1988
Vanesse Stephany 30 octobre 1994
Dupont Chantal 15 janvier 1998

Each use of the \rowlistcolors (or \rowcolors, which is, in fact, a special case of \rowlistcolors)
stops the potential coloring schemes35 specified by a previous command \rowlistcolors. In par-
ticular, it’s possible to start coloring the rows with \rowlistcolors{...} and stop coloring by a
command \rowlistcolors with an empty argument.

32 That command \cellcolor will delete the following spaces (which does not the command \cellcolor of colortbl).
Moreover, if one wishes to define a command above that command \cellcolor, it must be protected in the TeX
sens (whereas, if it were the command \cellcolor of colortbl, one should, no the contrary, write a fully expandable
command).
33 If you want a commande to color the following n rows, consider the command \RowStyle and its key fillcolor,

p. 26
34 When the command \rowlistcolors (or the command \rowcolors) is used in a cell of the column j of the array,

the command applies only on the columns above j (by design).

35 We say schemes in plural form because it’s possible to start simultaneously several coloring schemes if they apply

on different columns.

25
\begin{NiceTabular}{c}[hvlines]
one \\
two \\ one
\rowlistcolors{red!15} two
three \\ three
four \\ four
five \\ five
\rowlistcolors{} six
six \\ seven
seven \\
\end{NiceTabular}

6.4 The special color “nocolor”

The extension nicematrix provides the special color nocolor which may be used in all the coloring
commands provided by nicematrix (in the \CodeBefore or in the array itself).
The cells marked by this color won’t be colored, whatever the other instructions of coloring which
may apply to these cells.
Therefore, the color nocolor is an easy way to add an exception to a more general coloring command.

7 The command \RowStyle

The command \RowStyle takes in as argument some formatting intructions that will be applied to
each cell on the rest of the current row.
That command also takes in as optional argument (between square brackets) a list of key=value
pairs.
• The key nb-rows sets the number of rows to which the specifications of the current command
will apply (with the special value *, it will apply to all the following rows).
• The keys cell-space-top-limit , cell-space-bottom-limit and cell-space-limits are
available with the same meaning that the corresponding global keys (cf. p. 2).
• The key fill (alias: rowcolor ) sets the color of the background and opacity 36 sets its opacity.
• If the key rounded-corners is used, that background will have rounded-corners.
• The key color sets the color of the text.37
• The key bold enforces bold characters for the cells of the row, both in math and text mode.

\begin{NiceTabular}{cccc}
\hline
\RowStyle[cell-space-limits=3pt]{\rotate}
second

fourth
third

first & second & third & fourth \\

first

\RowStyle[nb-rows=2,fill=blue!50,color=white]{\sffamily}
1 & 2 & 3 & 4 \\ 1 2 3 4
I & II & III & IV I II III IV
\end{NiceTabular}

The command \rotate is described p. 51.

36 Caution: that feature creates instructions of transparency in the pdf and some readers of pdf don’t support such

instructions.
37 The key color uses the command \color but also inserts an instruction \leavevmode before. This instruction

prevents an extra vertical space in the cells which belong to columns of type p, b, m and X (which start in vertical
mode of LaTeX). For the columns V (of varwidth), that’s not enough, except when LuaLaTeX is used with the package
luacolor (see question 460489 on TeX StackExchange).

26
8 The width of the columns

8.1 Basic tools

In the environments with an explicit preamble (like {NiceTabular}, {NiceArray}, etc.), it’s possible
to fix the width of a given column with the standard letters w, W, p, b and m of the package array.
\begin{NiceTabular}{W{c}{2cm}cc}[hvlines]
Paris & New York & Madrid \\ Paris New York Madrid
Berlin & London & Roma \\ Berlin London Roma
Rio & Tokyo & Oslo Rio Tokyo Oslo
\end{NiceTabular}

In the environments of nicematrix, it’s also possible to fix the minimal width of all the columns (except
the potential exterior columns: cf. p. 29) directly with the key columns-width.
$\begin{pNiceMatrix}[columns-width = 1cm]
1 & 12 & -123 \\
 
1 12 −123
12 & 0 & 0 \\  12 0 0 
4 & 1 & 2 4 1 2
\end{pNiceMatrix}$

Note that the space inserted between two columns (equal to 2 \tabcolsep in {NiceTabular} and
to 2 \arraycolsep in the other environments) is not suppressed (of course, it’s possible to suppress
this space by setting \tabcolsep or \arraycolsep equal to 0 pt before the environment).

It’s possible to give the special value auto to the option columns-width: all the columns of the array
will have a width equal to the widest cell of the array.38
$\begin{pNiceMatrix}[columns-width = auto]
1 & 12 & -123 \\
 
1 12 −123
12 & 0 & 0 \\  12 0 0 
4 & 1 & 2 4 1 2
\end{pNiceMatrix}$

Without surprise, it’s possible to fix the minimal width of the columns of all the arrays of a current
scope with the command \NiceMatrixOptions.
\NiceMatrixOptions{columns-width=10mm}
$\begin{pNiceMatrix}
a & b \\ c & d
\end{pNiceMatrix}
   
a b 1 1245
= =
c d 345 2
\begin{pNiceMatrix}
1 & 1245 \\ 345 & 2
\end{pNiceMatrix}$

It’s also possible to fix a zone where all the matrices will have their columns of the same width, equal
to the widest cell of all the matrices. This construction uses the environment {NiceMatrixBlock}
with the option auto-columns-width39 . The environment {NiceMatrixBlock} has no direct link
with the command \Block presented previously in this document (cf. p. 4).

38 The result is achieved with only one compilation (but PGF/TikZ will have written informations in the aux file and

a message requiring a second compilation will appear).

39 At this time, this is the only usage of the environment {NiceMatrixBlock} but it may have other usages in the

future.

27
\begin{NiceMatrixBlock}[auto-columns-width]
$\begin{array}{c}
\begin{bNiceMatrix}  
9 17
9 & 17 \\ -2 & 5
−2 5
\end{bNiceMatrix} \\ \\
\begin{bNiceMatrix}  
1 1245345
1 & 1245345 \\ 345 & 2
345 2
\end{bNiceMatrix} \\
\end{array}$
\end{NiceMatrixBlock}

8.2 The columns X

The environment {NiceTabular} provides X columns similar to those provided by the environment
{tabularx} of the eponymous package.
The required width of the tabular may be specified with the key width (in {NiceTabular} or in
\NiceMatrixOptions). The initial value of this parameter is \linewidth (and not \textwidth).
For sake of similarity with the environment {tabularx}, nicematrix also provides an environment
{NiceTabularX} with a syntax similar to the syntax of {tabularx}, that is to say with a first
mandatory argument which is the width of the tabular.
As with the packages tabu40 and tabularray, the specifier X takes in an optional argument (between
square brackets) which is a list of keys.
• It’s possible to give a weight for the column by providing a positive number directly as argument
of the specifier X. For example, a column X[2] will have a width double of the width of a column X
(which has a weight equal to 1).41
• It’s possible to specify an horizontal alignment with one of the letters l, c and r (which insert
respectively \raggedright, \centering and \raggedleft followed by \arraybackslash).42
• It’s possible to specify a vertical alignment with one of the keys t (alias p), m and b (which
construct respectively columns of type p, m and b). The initial value is t.

\begin{NiceTabular}[width=9cm]{X[c,m]X[0.5,c,m]}[hvlines]
a rather long text which fits on several lines
& a rather long text which fits on several lines \\
a shorter text & a shorter text
\end{NiceTabular}

a rather long
a rather long text which fits on
text which fits on
several lines
several lines
a shorter text a shorter text

8.3 The columns V of varwidth

Let’s recall first the behaviour of the environment {varwidth} of the eponymous package varwidth.
That environment is similar to the classical environment {minipage} but the width provided in the
argument is only the maximal width of the created box. In the general case, the width of the box
constructed by an environment {varwidth} is the natural width of its contents.
That point is illustrated on the following examples.

40 The extension tabu is now considered as deprecated.

41 The negative values of the weight, as provided by tabu (which is now obsolete), are not supported by nicematrix. If
such a value is used, an error will be raised.
42 In fact, when ragged2e is loaded, nicematrix uses the commands \RaggedRight, \Centering and \RaggedLeft of

ragged2e instead of the commands \raggedright, \centering and \raggedleft. That ensures a better output.

28
\fbox{%
\begin{varwidth}{8cm}
\begin{itemize} • first item
\item first item
\item second item • second item
\end{itemize}
\end{varwidth}}

\fbox{%
\begin{minipage}{8cm}
\begin{itemize} • first item
\item first item
\item second item • second item
\end{itemize}
\end{minipage}}

The package varwidth provides also the column type V. A column of type V{hdimi} encapsulates all
its cells in a {varwidth} with the argument hdimi (and does also some tuning).
When the package varwidth is loaded, the columns V of varwidth are supported by nicematrix.
\begin{NiceTabular}[corners=NW,hvlines]{V{3cm}V{3cm}V{3cm}}
& some text & some very very very long text \\
some very very very long text \\
some very very very long text
\end{NiceTabular}

some text some very very very

long text
some very very very
long text
some very very very
long text

Concerning nicematrix, one of the interests of this type of columns is that, for a cell of a column of
type V, the PGF/TikZ node created by nicematrix for the content of that cell has a width adjusted
to the content of the cell : cf. p. 56.

The columns V of nicematrix supports the keys t, p, m, b, l, c and r also supported by the columns
X: see their description in the section 8.2, p. 28.

One should remark that the extension varwidth (at least in its version 0.92) has some problems: for
instance, with LuaLaTeX, it does not work when the content begins with \color.

9 The exterior rows and columns

The options first-row , last-row, first-col and last-col allow the composition of exterior rows
and columns in the environments of nicematrix. It’s particularly interesting for the (mathematical)
matrices.
A potential “first row” (exterior) has the number 0 (and not 1). Idem for the potential “first column”.

29
$\begin{pNiceMatrix}[first-row,last-row,first-col,last-col,nullify-dots]
& C_1 & \Cdots & & C_4 & \\
L_1 & a_{11} & a_{12} & a_{13} & a_{14} & L_1 \\
\Vdots & a_{21} & a_{22} & a_{23} & a_{24} & \Vdots \\
& a_{31} & a_{32} & a_{33} & a_{34} & \\
L_4 & a_{41} & a_{42} & a_{43} & a_{44} & L_4 \\
& C_1 & \Cdots & & C_4 &
\end{pNiceMatrix}$

 C1 C4 
L1 a11 a12 a13 a14 L1
a21 a22 a23 a24 
 
a31 a32 a33 a34 
L4 a41 a42 a43 a44 L4
C1 C4

The dotted lines have been drawn with the tools presented p. 31.

We have several remarks to do.

• For the environments with an explicit preamble (i.e. {NiceTabular}, {NiceArray} and its
variants), no letter must be given in that preamble for the potential first column and the
potential last column: they will automatically (and necessarily) be of type r for the first column
and l for the last one.43

• One may wonder how nicematrix determines the number of rows and columns which are needed
for the composition of the “last row” and “last column”.
– For the environments with explicit preamble, like {NiceTabular} and {pNiceArray}, the
number of columns can obviously be computed from the preamble.
– When the option light-syntax (cf. p. 53) is used, nicematrix has, in any case, to load the
whole body of the environment (and that’s why it’s not possible to put verbatim material
in the array with the option light-syntax). The analysis of this whole body gives the
number of rows and the number of columns.
– In the other cases, nicematrix compute the number of rows and columns during the first
compilation and write the result in the aux file for the next run.
However, it’s possible to provide the number of the last row and the number of the last
column as values of the options last-row and last-col, tending to an acceleration of the
whole compilation of the document. That’s what we will do throughout the rest of the
document.

It’s possible to control the appearance of these rows and columns with options code-for-first-row,
code-for-last-row , code-for-first-col and code-for-last-col. These options specify tokens
that will be inserted before each cell of the corresponding row or column.
\NiceMatrixOptions{code-for-first-row = \color{red},
code-for-first-col = \color{blue},
code-for-last-row = \color{green},
code-for-last-col = \color{magenta}}
\begin{displaymath}
\begin{pNiceArray}{cc|cc}[first-row,last-row=5,first-col,last-col,nullify-dots]
& C_1 & \multicolumn1c{\Cdots} & & C_4 & \\
L_1 & a_{11} & a_{12} & a_{13} & a_{14} & L_1 \\
\Vdots & a_{21} & a_{22} & a_{23} & a_{24} & \Vdots \\
\hline

43 The users wishing exterior columns with another type of alignment should consider the command \SubMatrix

available in the \CodeAfter and in the \CodeBefore (cf. p. 40).

30
 & a_{31} & a_{32} & a_{33} & a_{34} & \\
L_4 & a_{41} & a_{42} & a_{43} & a_{44} & L_4 \\
& C_1 & \multicolumn1c{\Cdots} & & C_4 &
\end{pNiceArray}
\end{displaymath}

 C1 C4 
L1 a11 a12 a13 a14 L1
a21 a22 a23 a24 
 
a31 a32 a33 a34 
L4 a41 a42 a43 a44 L4
C1 C4
Remarks
• As shown in the previous example, the horizontal and vertical rules don’t extend in the exterior
rows and columns. This remark also applies to the customized rules created by the key custom-
line (cf. p. 16).
• A specification of color present in code-for-first-row also applies to a dotted line drawn in
that exterior “first row” (except if a value has been given to xdots/color). Idem for the other
exterior rows and columns.
• Logically, the potential option columns-width (described p. 27) doesn’t apply to the “first
column” and “last column”.
• For technical reasons, it’s not possible to use the option of the command \\ after the “first row”
or before the “last row”. The placement of the delimiters would be wrong. If you are looking for
a workaround, consider the command \SubMatrix in the \CodeAfter (and the \CodeBefore)
described p. 40.

10 The continuous dotted lines

Inside the environments of the package nicematrix, new commands are defined: \Ldots , \Cdots ,
\Vdots , \Ddots and \Iddots . These commands are intended to be used in place of \dots, \cdots,
\vdots, \ddots and \iddots.44
Each of them must be used alone in the cell of the array and it draws a dotted line between the
first non-empty cells45 on both sides of the current cell. Of course, for \Ldots and \Cdots, it’s an
horizontal line; for \Vdots, it’s a vertical line and for \Ddots and \Iddots diagonal ones. It’s possible
to change the color of these lines with the option color.46

\begin{bNiceMatrix}  
a1 a1
a_1 & \Cdots & & & a_1 \\
\Vdots & a_2 & \Cdots & & a_2 \\
 
 a2 a2 
& \Vdots & \Ddots[color=red] \\
 
 
\\
 
 
a_1 & a_2 & & & a_n
 
\end{bNiceMatrix} a1 a2 an

In order to represent the null matrix, one can use the following codage:

44 The command \iddots, defined in nicematrix, is a variant of \ddots with dots going forward. If mathdots is loaded,

the version of mathdots is used. It corresponds to the command \adots of unicode-math.

45 The precise definition of a “non-empty cell” is given below (cf. p. 61).
46 It’s also possible to change the color of all these dotted lines with the option xdots/color (xdots to remind that it

works for \Cdots, \Ldots, \Vdots, etc.): cf. p. 35.

31
\begin{bNiceMatrix}
0 & \Cdots & 0 \\
 
0 0
\Vdots & & \Vdots \\  
0 & \Cdots & 0
 
0 0
\end{bNiceMatrix}

However, one may want a larger matrix. Usually, in such a case, the users of LaTeX add a new row
and a new column. It’s possible to use the same method with nicematrix:

\begin{bNiceMatrix}  
0 0
0 & \Cdots & \Cdots & 0 \\
\Vdots & & & \Vdots \\
 
 
\Vdots & & & \Vdots \\
 
 
0 & \Cdots & \Cdots & 0
 
\end{bNiceMatrix} 0 0

In the first column of this example, there are two instructions \Vdots but, of course, only one dotted
line is drawn.

In fact, in this example, it would be possible to draw the same matrix more easily with the following
code:

\begin{bNiceMatrix}  
0 0
0 & \Cdots & & 0 \\
\Vdots & & & \\
 
 
& & & \Vdots \\
 
 
0 & & \Cdots & 0
 
\end{bNiceMatrix} 0 0

There are also other means to change the size of the matrix. Someone might want to use the optional
argument of the command \\ for the vertical dimension and a command \hspace* in a cell for the
horizontal dimension.47
However, a command \hspace* might interfer with the construction of the dotted lines. That’s why
the package nicematrix provides a command \Hspace which is a variant of \hspace transparent for
the dotted lines of nicematrix.
 
$\begin{bNiceMatrix} 0 0
0 & \Cdots & \Hspace*{1cm} & 0 \\
 
 
\Vdots & & & \Vdots \\[1cm]
 
 
0 & \Cdots & & 0
 
 
\end{bNiceMatrix}$
 
0 0

10.1 The option nullify-dots

Consider the following matrix composed classicaly with the environment {pmatrix} of amsmath.
$A = \begin{pmatrix}
h & i & j & k & l & m \\
 
h i j k l m
x & & & & & x A=
x x
\end{pmatrix}$

If we add \ldots instructions in the second row, the geometry of the matrix is modified.

47 In nicematrix, one should use \hspace* and not \hspace for such an usage because nicematrix loads array. One may

also remark that it’s possible to fix the width of a column by using the environment {NiceArray} (or one of its variants)
with a column of type w or W: see p. 27

32
$B = \begin{pmatrix}
h & i & j & k & l & m \\
 
h i j k l m
x & \ldots & \ldots & \ldots & \ldots & x B=
x ... ... ... ... x
\end{pmatrix}$

By default, with nicematrix, if we replace {pmatrix} by {pNiceMatrix} and \ldots by \Ldots, the
geometry of the matrix is not changed.
$C = \begin{pNiceMatrix}
h & i & j & k & l & m \\
 
h i j k l m
x & \Ldots & \Ldots & \Ldots & \Ldots & x C=
x x
\end{pNiceMatrix}$

However, one may prefer the geometry of the first matrix A and would like to have such a geometry
with a dotted line in the second row. It’s possible by using the option nullify-dots (and only one
instruction \Ldots is necessary).
$D = \begin{pNiceMatrix}[nullify-dots]
h & i & j & k & l & m \\
 
h i j k l m
x & \Ldots & & & & x D=
x x
\end{pNiceMatrix}$

The option nullify-dots smashes the instructions \Ldots (and the variants) horizontally but also
vertically.
Caution: the key nullify-dots has a name that may be confusing; that key does not imply that
the dotted rules won’t be drawn!

10.2 The commands \Hdotsfor and \Vdotsfor

Some people commonly use the command \hdotsfor of amsmath in order to draw horizontal dotted
lines in a matrix. In the environments of nicematrix, one should use instead \Hdotsfor in order to
draw dotted lines similar to the other dotted lines drawn by the package nicematrix.
As with the other commands of nicematrix (like \Cdots, \Ldots, \Vdots, etc.), the dotted line drawn
with \Hdotsfor extends until the contents of the cells on both sides.
$\begin{pNiceMatrix}
1 & 2 & 3 & 4 & 5 \\
 
1 2 3 4 5
1 & \Hdotsfor{3} & 5 \\ 1 5
1 & 2 & 3 & 4 & 5 \\
 
1 2 3 4 5
1 & 2 & 3 & 4 & 5 1 2 3 4 5
\end{pNiceMatrix}$

However, if these cells are empty, the dotted line extends only in the cells specified by the argument
of \Hdotsfor (by design).
$\begin{pNiceMatrix}
1 & 2 & 3 & 4 & 5 \\
 
1 2 3 4 5
& \Hdotsfor{3} \\  
1 & 2 & 3 & 4 & 5 \\
 
1 2 3 4 5
1 & 2 & 3 & 4 & 5 1 2 3 4 5
\end{pNiceMatrix}$

Remark: Unlike the command \hdotsfor of amsmath, the command \Hdotsfor may be used even
when the package colortbl48 is loaded (however, with nicematrix, loading colortbl is rather point-less
since nicematrix provides its own coloring tools: cf. p. 19).

48 We recall that when xcolor is loaded with the option table, the package colortbl is loaded.

33
The package nicematrix also provides a command \Vdotsfor similar to \Hdotsfor but for the vertical
dotted lines. The following example uses both \Hdotsfor and \Vdotsfor:

\begin{bNiceMatrix}
C[a_1,a_1] & \Cdots & C[a_1,a_n]
& \hspace*{20mm} & C[a_1,a_1^{(p)}] & \Cdots & C[a_1,a_n^{(p)}] \\
\Vdots & \Ddots & \Vdots
& \Hdotsfor{1} & \Vdots & \Ddots & \Vdots \\
C[a_n,a_1] & \Cdots & C[a_n,a_n]
& & C[a_n,a_1^{(p)}] & \Cdots & C[a_n,a_n^{(p)}] \\
\rule{0pt}{15mm}\NotEmpty & \Vdotsfor{1} & & \Ddots & & \Vdotsfor{1} \\
C[a_1^{(p)},a_1] & \Cdots & C[a_1^{(p)},a_n]
& & C[a_1^{(p)},a_1^{(p)}] & \Cdots & C[a_1^{(p)},a_n^{(p)}] \\
\Vdots & \Ddots & \Vdots
& \Hdotsfor{1} & \Vdots & \Ddots & \Vdots \\
C[a_n^{(p)},a_1] & \Cdots & C[a_n^{(p)},a_n]
& & C[a_n^{(p)},a_1^{(p)}] & \Cdots & C[a_n^{(p)},a_n^{(p)}]
\end{bNiceMatrix}

(p) (p)
 
C[a1 , a1 ] C[a1 , an ] C[a1 , a1 ] C[a1 , an ]
 
 
 
(p) (p) 
 C[an , a1 ] C[an , an ] C[an , a1 ] C[an , an ] 

 
 
 
 
 
 
 
 
(p) (p) (p) (p) (p) (p) 
C[a1 , a1 ] C[a1 , an ] C[a1 , a1 ] C[a1 , an ]

 
 
 
(p) (p) (p) (p) (p) (p)
C[an , a1 ] C[an , an ] C[an , a1 ] C[an , an ]

10.3 How to generate the continuous dotted lines transparently

Imagine you have a document with a great number of mathematical matrices with ellipsis. You may
wish to use the dotted lines of nicematrix without having to modify the code of each matrix. It’s
possible with the keys. renew-dots and renew-matrix.49

• The option renew-dots

With this option, the commands \ldots, \cdots, \vdots, \ddots, \iddots44 and \hdotsfor
are redefined within the environments provided by nicematrix and behave like \Ldots, \Cdots,
\Vdots, \Ddots, \Iddots and \Hdotsfor; the command \dots (“automatic dots” of amsmath)
is also redefined to behave like \Ldots.

• The option renew-matrix

With this option, the environment {matrix} is redefined and behave like {NiceMatrix}, and
so on for the five variants.

Therefore, with the keys renew-dots and renew-matrix, a classical code gives directly the ouput of
nicematrix.

49 The options renew-dots, renew-matrix can be fixed with the command \NiceMatrixOptions like the other options.

However, they can also be fixed as options of the command \usepackage.

34
\NiceMatrixOptions{renew-dots,renew-matrix}
\begin{pmatrix}
 
1 1
1 & \cdots & \cdots & 1 \\ 
0

0 & \ddots & & \vdots \\

 
\vdots & \ddots & \ddots & \vdots \\
 
 
0 & \cdots & 0 & 1 0 0 1
\end{pmatrix}

10.4 The labels of the dotted lines

The commands \Ldots, \Cdots, \Vdots, \Ddots, \Iddots, \Hdotsfor and \Vdotsfor (and the
command \line in the \CodeAfter which is described p. 39) accept two optional arguments specified
by the tokens _ and ^ for labels positionned below and above the line. The arguments are composed
in math mode with \scriptstyle.
The version 6.22 of nicematrix has introduced a new label, specified by the token “:” for a label placed
on the line. The label is composed on a white background which is put on the line previously drawn
(see example on p. 68).

$\begin{bNiceMatrix}
 
1 0
1 & \hspace*{1cm} & 0 \\[8mm]  n
ti

m
 
& \Ddots^{n \text{ times}} & \\ 
 es


0 & & 1  
\end{bNiceMatrix}$
 
0 1

With the key horizontal-label , the labels stay horizontal.

$\begin{bNiceMatrix}
 
1 0
1 & \hspace*{1cm} & 0 \\[8mm] 
 n times 

& \Ddots[horizontal-label]^{n \text{ times}} & \\ 



0 & & 1  
\end{bNiceMatrix}$
 
0 1

10.5 Customisation of the dotted lines

The dotted lines drawn by \Ldots, \Cdots, \Vdots, \Ddots, \Iddots, \Hdotsfor and \Vdotsfor
(and by the command \line in the \CodeAfter which is described p. 39) may be customized by the
following options (specified between square brackets after the command):
• horizontal-label(s);
• color;
• radius;
• shorten-start, shorten-end and shorten;
• inter;
• line-style.

For an individual command, it’s possible to write horizontal-label (in the singular).
These options may also be fixed with \NiceMatrixOptions, as options of \CodeAfter or at the level
of a given environment but, in those cases, they must be prefixed by xdots (xdots to remind that it
works for \Cdots, \Ldots, \Vdots, etc.), and, thus have for names:
• xdots/horizontal-labels;
• xdots/color;
• xdots/radius;

35
 • xdots/shorten-start, xdots/shorten-end and xdots/shorten;
• xdots/inter;
• xdots/line-style.
For the clarity of the explanations, we will use those names.

With the key xdots/horizontal-labels, the labels (introduced by _, ^ and :) stay horizontal.

The option xdots/color fixes the color or the dotted line. It’s possible to use a color definied “on
the fly” (e.g.: xdots/color = { [RGB]{204,204,255} }). One should remark that the dotted lines
drawn in the exterior rows and columns have a special treatment: cf. p. 29.

The option radius fixes the radius of the dots. The initial value is 0.53 pt.

The keys xdots/shorten-start and xdots/shorten-end fix the margin at the extremities of the
line. The key xdots/shorten fixes both parameters. The initial value is 0.3 em (it is recommanded
to use a unit of length dependent of the current font).50

The option xdots/inter fixes the length between the dots. The initial value is 0.45 em (it is
recommanded to use a unit of length dependent of the current font).

The option xdots/line-style

It should be pointed that, by default, the lines drawn by TikZ with the parameter dotted are
composed of square dots (and not rounded ones).51
\tikz \draw [dotted] (0,0) -- (5,0) ;
In order to provide lines with rounded dots in the style of those provided by \ldots (at least with
the Computer Modern fonts), the package nicematrix embeds its own system to draw a dotted line
(and this system uses pgf and not TikZ). This style is called standard and that’s the initial value
of the parameter xdots/line-style.
However (when TikZ is loaded) it’s possible to use for xdots/line-style any style provided by TikZ,
that is to say any sequence of options provided by TikZ for the TikZ pathes (with the exception of
“color”, “shorten >” and “shorten <”).
Here is for example a tridiagonal matrix with the style loosely dotted:
$\begin{pNiceMatrix}[nullify-dots,xdots/line-style=loosely dotted]
a & b & 0 & & \Cdots & 0 \\
b & a & b & \Ddots & & \Vdots \\
0 & b & a & \Ddots & & \\
& \Ddots & \Ddots & \Ddots & & 0 \\
\Vdots & & & & & b \\
0 & \Cdots & & 0 & b & a
\end{pNiceMatrix}$
 
a b 0 0
b a b 
 
0 b a 
 

 0

 b
0 0 b a

50 In fact, when xdots/shorten, xdots/shorten-start and xdots/shorten-end are used in \NiceMatrixOptions or

at the level of an environment (such as {pNiceMatrix}), those keys only apply to the extremeties of dotted lines
corresponding to a non-empty content of a cell. When they are used for a command such as \Cdots (and, in that case,
their names are shorten, shorten-start and shorten-end), they apply to all the extremities.
51 The first reason of this behaviour is that the pdf format includes a description for dashed lines. The lines specified

with this descriptor are displayed very efficiently by the pdf readers. It’s easy, starting from these dashed lines, to
create a line composed by square dots whereas a line of rounded dots needs a specification of each dot in the pdf file.
Nevertheless, you can have a look at the following page to see how to have dotted rules with rounded dots in TikZ:
https://tex.stackexchange.com/questions/52848/tikz-line-with-large-dots

36
10.6 The commands \Hbrace and \Vbrace
New 7.1
Since, as said in the previous part, it’s possible to use, with the commands \Cdots, \Ldots, \Vdots,
etc. all the styles of lines provided by TikZ, one may wish to use those commands to draw braces
with the decoration brace provided by the library decorations.pathreplacing of TikZ.
In order to facilitate that use, nicematrix provides two commands \Hbrace and \Vbrace . Those
commands are available only if TikZ has been loaded with its library decorations.pathreplacing (before
or after the loading of nicematrix). Otherwise, a (non-fatal) error will be raised.

\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing}

The commands \Hbrace and \Vbrace have the same syntax. Both commands take in three arguments:
• an optional argument, between square brackets, which contains a list of key=value pairs: the
keys allowed are color, horizontal-labels, shorten, shorten-start and shorten-end.
• a mandatory argument which is the number of columns (for \Hbrace) or the number of rows
(for \Vbrace) over which the command applies;

• an mandatory argument which is the label of the curly brace.

As regards the ampersands (&), \Hbrace has the same behavior as the commands \multicolumn,
\hdotsfor, \Hdotsfor, etc.: only one ampersand must be inserted, even if the brace that will be
drawn will extend on several columns.

$\begin{NiceArray}{ccccc}%
[ hvlines ,
first-row ,
last-row = 6,
p q
first-col ,
last-col , 1 1 134 1 1
xdots/horizontal-labels ] p 1 1 134 1 1 p
& \Hbrace{3}{p} & \Hbrace{2}{q} \\ 1 1 13456 1 1
\Vbrace{3}{p} & 1 & 1 & 134 & 1 & 1 & \Vbrace{3}{p} \\ 1 1 134 1 1
q q
& 1 & 1 & 134 & 1 & 1 \\ 1 1 134 1 1
& 1 & 1 & 13456 & 1 & 1 \\ p q
\Vbrace{2}{q} & 1 & 1 & 134 & 1 & 1 & \Vbrace{2}{q}\\
& 1 & 1 & 134 & 1 & 1 \\
& \Hbrace{3}{p} & \Hbrace[color=blue]{2}{q} \\
\end{NiceArray}$

The TikZ style used by nicematrix to draw those braces is called nicematrix/brace. Here is the
initial value of that style:
decoration = { brace , raise = -0.15 em } ,
decorate
The final user can change that style TikZ as he wishes (respecting the structure with the keys
decorate and decoration).
For another example of use of \Hbrace and \Vbrace, see the section “Dotted lines that are no longer
dotted”, p. 67.

10.7 The dotted lines and the rules

The dotted lines determine virtual blocks which have the same behaviour regarding the rules (the
rules specified by the specifier | in the preamble, by the command \Hline, by the keys hlines,

37
vlines, hvlines and hvlines-except-borders and by the tools created by custom-line are not
drawn within the blocks).52
$\begin{bNiceMatrix}[margin,hvlines]
\Block{3-3}<\LARGE>{A} & & & 0 \\
 
0
& \hspace*{1cm} & & \Vdots \\ 
 A 

& & & 0 \\  
0 
0 & \Cdots& 0 & 0

0 0 0
\end{bNiceMatrix}$

11 Delimiters in the preamble of the environment

In the environments with preamble ({NiceArray}, {pNiceArray}, etc.), it’s possible to put vertical
delimiters directly in the preamble of the environment.53
The opening delimiters should be prefixed by the keyword \left and the closing delimiters by the
keyword \right . It’s not mandatory to use \left and \right pair-wise.
All the vertical extensible delimiters of LaTeX are allowed.
Here is a example which uses the delimiters \lgroup and \rgroup.
$\begin{NiceArray}{\left\lgroup ccc\right\rgroup l}
1 & 2 & 3 &
4 & 1 & 6 &
7 & 8 & 9 & \scriptstyle L_3 \gets L_3 + L_1 + L_2
\end{NiceArray}$

1 2 3

 
4 1 6



 


7 8 9 L3 ←L3 +L1 +L2


For this example, it would also have been possible to use the environment {NiceArrayWithDelims}
(cf. the section 14.10, p. 54) and the key last-col (cf. p. 29).

There is a particular case: for the delimiters (, [ and \{54 , and the corresponding closing delimiters,
the prefixes \left et \right are optional.55

Here is an example with a left delimiter \{ in a {NiceTabular} (remark the compatibility with the
key t).

We define $f$ with\quad

\begin{NiceTabular}[t]{\{ll}
$f(x) = 0$ & if $x$ is non positive \\
$f(x) = 1-e^x$ & if $x$ is positive

On définit f par if x is non positive


f (x) = 0
f (x) = 1 − ex if x is positive

When there are two successive delimiters (necessarily a closing one following by an opening one for
another submatrix), a space equal to \enskip is automatically inserted.

52 On the other side, the command \line in the \CodeAfter (cf. p. 39) does not create block.
53 This syntax is inspired by the extension blkarray.
54 For the braces, the protection by a backslash is mandatory (that’s why we have written \{).
55 For the delimiters [ and ], the prefixes remain mandatory when there is a conflict of notation with the square

brackets for the options of some descriptors of columns.

38
$\begin{pNiceArray}{(c)(c)(c)}
a_{11} & a_{12} & a_{13} \\
a_{21} & \displaystyle \int_0^1\dfrac{1}{x^2+1}\,dx & a_{23} \\
a_{31} & a_{32} & a_{33}
\end{pNiceArray}$
   
a11 a12 a13
  1 1 Z  
 a21
  dx  a23 
 
  x 2+1 
0
a31 a32 a33

For more complex constructions, in particular with delimiters spanning only a subset of the rows
of the array, one should consider the command \SubMatrix available in the \CodeAfter (and the
\CodeBefore). See the section 12.2, p. 40.

12 The \CodeAfter

The option code-after may be used to give some code that will be executed after the construction
of the matrix.56
For the legibility of the code, an alternative syntax is provided: it’s possible to give the instructions of
the code-after at the end of the environment, after the keyword \CodeAfter (the key code-after
is of course mandatory in the \AutoNiceMatrix and the similar commands). Although \CodeAfter
is a keyword, it takes in an optional argument (between square brackets).57
The experienced users may, for instance, use the PGF/TikZ nodes created by nicematrix in the
\CodeAfter. These nodes are described further beginning on p. 54.
The \CodeAfter provides several special commands: \line, \SubMatrix, \OverBrace, \UnderBrace
and \TikzEveryCell. We will now present these commands.
One should avoid spurious spaces in that \CodeAfter.58

12.1 The command \line in the \CodeAfter

The command \line draws directly dotted lines between cells or blocks. It takes in two arguments
for the cells or blocks to link. Both argument may be:

• a specification of cell of the form i-j where is the number of the row and j is the number of the
column;
• the name of a block (created by the command \Block with the key name of that command).
The options available for the customisation of the dotted lines created by \Cdots, \Vdots, etc. are
also available for this command (cf. p. 35).

This command may be used, for example, to draw a dotted line between two adjacent cells.

56 There is also a key code-before described p. 19.

57 Here are the keys accepted in that argument: delimiters/color, rules and its sub-keys, sub-matrix (linked to
the command \SubMatrix) and its sub-keys and xdots (for the command \line) and its sub-keys.
58 See: https://tex.stackexchange.com/questions/689336

39
\NiceMatrixOptions{xdots/shorten = 0.6 em}
\begin{pNiceMatrix}  
I 0 0
I & 0 & \Cdots &0 \\
0 & I & \Ddots &\Vdots\\
 
0 I 
\Vdots &\Ddots & I &0 \\
 
 
0 &\Cdots & 0 &I
 I 0
\CodeAfter \line{2-2}{3-3} 0 0 I
\end{pNiceMatrix}

It can also be used to draw a diagonal line not parallel to the other diagonal lines (by default, the
dotted lines drawn by \Ddots are “parallelized”: cf. p. 60).
\begin{bNiceMatrix}
1 & \Cdots & & 1 & 2 & \Cdots & 2 \\
0 & \Ddots & & \Vdots & \Vdots & \hspace*{2.5cm} & \Vdots \\
\Vdots & \Ddots & & & & & \\
0 & \Cdots & 0 & 1 & 2 & \Cdots & 2
\CodeAfter \line[shorten=6pt]{1-5}{4-7}
\end{bNiceMatrix}
 
1 1 2 2
 
0 
 
 
 
0 0 1 2 2

12.2 The command \SubMatrix in the \CodeAfter (and the \CodeBefore)

The command \SubMatrix provides a way to put delimiters on a portion of the array considered as
a submatrix. The command \SubMatrix takes in five arguments:
• the first argument is the left delimiter, which may be any extensible delimiter provided by
LaTeX : (, [, \{, \langle, \lgroup, \lfloor, etc. but also the null delimiter .;
• the second argument is the upper-left corner of the submatrix with the syntax i-j where i the
number of row and j the number of column (the special word last is allowed);
• the third argument is the lower-right corner with the same syntax;
• the fourth argument is the right delimiter;
• the last argument, which is optional, is a list of key=value pairs.59
One should remark that the command \SubMatrix draws the delimiters after the construction of the
array: no space is inserted by the command \SubMatrix itself. That’s why, in the following example,
we have used the key margin and you have added by hand some space between the third and fourth
column with @{\hspace{1.5em}} in the preamble of the array.
\[\begin{NiceArray}{ccc@{\hspace{1.5em}}c}[cell-space-limits=2pt,margin]
1 & 1 & 1 & x \\
\dfrac{1}{4} & \dfrac{1}{2} & \dfrac{1}{4} & y \\
  
1 1 1 x
1 & 2 & 3 & z  1 1 1  
\CodeAfter  4 2 4  y 
  
\SubMatrix({1-1}{3-3}) 1 2 3 z
\SubMatrix({1-4}{3-4})
\end{NiceArray}\]

59 There is no optional argument between square brackets in first position because a square bracket just after

\SubMatrix must be interpreted as the first (mandatory) argument of the command \SubMatrix: that bracket is
the left delimiter of the sub-matrix to construct (eg.: \SubMatrix[{2-2}{4-7}]).

40
Eventually, in this example, it would probably have been easier to put the delimiters directly in the
preamble of {NiceArray} (see section 11, p. 38) with the following construction.
$\begin{NiceArray}{(ccc)(c)}[cell-space-limits=2pt]   
1 1 1 x
1 & 1 & 1 & x \\ 1 1 1
\dfrac{1}{4} & \dfrac{1}{2} & \dfrac{1}{4} & y \\
 
  y 
4 2 4  
1 & 2 & 3 & z
1 2 3 z
\end{NiceArray}$

In fact, the command \SubMatrix also takes in two optional arguments specified by the traditional
symbols ^ and _ for material in superscript and subscript (but no space is reserved for that material).
$\begin{bNiceMatrix}[right-margin=1em]
1 & 1 & 1 \\
1 & a & b \\
 
1 1 1
1 & c & d
T
1 a b 
\CodeAfter 1 c d
\SubMatrix[{2-2}{3-3}]^{T}
\end{bNiceMatrix}$

The options of the command \SubMatrix are as follows:

• left-xshift and right-xshift shift horizontally the delimiters (there exists also the key
xshift which fixes both parameters);
• extra-height adds a quantity to the total height of the delimiters (height \ht + depth \dp);
• delimiters/color fixes the color of the delimiters (also available in \NiceMatrixOptions, in
the environments with delimiters and as option of the keyword \CodeAfter);
• slim is a boolean key: when that key is in force, the horizontal position of the delimiters is
computed by using only the contents of the cells of the submatrix whereas, in the general case,
the position is computed by taking into account the cells of the whole columns implied in the
submatrix (see example below). ;
• vlines contents a list of numbers of vertical rules that will be drawn in the sub-matrix (if this
key is used without value, all the vertical rules of the sub-matrix are drawn);
• hlines is similar to vlines but for the horizontal rules;
• hvlines , which must be used without value, draws all the vertical and horizontal rules;
• code insert code, especially TikZ code, after the construcion of the submatrix. That key is
detailed below.
One should remark that the keys add their rules after the construction of the main matrix: no space
is added between the rows and the columns of the array for theses rules.

All these keys are also available in \NiceMatrixOptions, at the level of the environments of nicematrix
or as option of the command \CodeAfter with the prefix sub-matrix which means that their names
are therefore sub-matrix/left-xshift, sub-matrix/right-xshift, sub-matrix/xshift, etc.

$\begin{NiceArray}{cc@{\hspace{5mm}}l}[cell-space-limits=2pt]
& & \frac{1}{2} \\
& & \frac{1}{4} \\[1mm] 1
!
a & b & \frac{1}{2}a+\frac{1}{4}b \\ 2
c & d & \frac{1}{2}c+\frac{1}{4}d \\
1
4
\CodeAfter
! !
1 1
a b 2a + 4b
\SubMatrix({1-3}{2-3}) 1 1
\SubMatrix({3-1}{4-2}) c d 2c + 4d
\SubMatrix({3-3}{4-3})
\end{NiceArray}$

41
Here is the same example with the key slim used for one of the submatrices.
$\begin{NiceArray}{cc@{\hspace{5mm}}l}[cell-space-limits=2pt]
& & \frac12 \\
& & \frac14 \\[1mm] 1
!
a & b & \frac12a+\frac14b \\ 2
c & d & \frac12c+\frac14d \\
1
4
\CodeAfter
! !
1 1
a b 2a + 4b
\SubMatrix({1-3}{2-3})[slim] 1 1
\SubMatrix({3-1}{4-2}) c d 2c + 4d
\SubMatrix({3-3}{4-3})
\end{NiceArray}$

There is also a key name which gives a name to the submatrix created by \SubMatrix. That name is
used to create PGF/TikZ nodes: cf p. 59.

Despite its name, the command \SubMatrix may also be used within a {NiceTabular}. Here is an
example (which uses \bottomrule and \toprule of booktabs).
\begin{NiceTabular}{@{}ll@{}}
\toprule
Part A & the first part \\
\Block{2-1}{Part B} & a first sub-part \\ Part A  the first part
& a second sub-part \\ a first sub-part
\bottomrule Part B a second sub-part
\CodeAfter
\SubMatrix{\lbrace}{2-2}{3-2}{.}
\end{NiceTabular}

The command \SubMatrix is, in fact, also available in the \CodeBefore. By using \SubMatrix in
the \CodeBefore, the delimiters drawn by those commands \SubMatrix are taken into account to
limit the continuous dotted lines (drawn by \Cdots, \Vdots, etc.) which have an open extremity.
For an example, see voir 18.9 p. 75.

Caution : The following functionnality is fragile and does not work with latex–dvips–ps2pdf.
The key code of the command \SubMatrix allows the insertion of code after the construction of
the submatrix. It’s meant to be used to insert TikZ instructions because, in the TikZ instructions
inserted by that code, the nodes of the form i-j.anchor or i-|j are interpreted with i and j as
numbers of row and column relative to the submatrix.60
$\begin{NiceArray}{ccc@{}w{c}{5mm}@{}ccc}
& & && -1 & 1 & 2 \\
& & && 0 & 3 & 4 \\
& & && 0 & 0 & 5 \\
1 & 2 & 3 && -1 & 7 & 25 \\
0 & 4 & 5 && 0 & 12 & 41 \\
0 & 0 & 6 && 0 & 0 & 30
\CodeAfter
\NewDocumentCommand{\MyDraw}{}{\tikz \draw [blue] (2-|1) -| (3-|2) -|
(4-|3) ;}
\SubMatrix({1-5}{3-7})[code = \MyDraw ]
\SubMatrix({4-1}{6-3})[code = \MyDraw ]
\SubMatrix({4-5}{6-7})[code = \MyDraw ]
\end{NiceArray}$

60 Be careful: the syntax j|-i is not allowed.

42
  
−1 1 2
 0 3 4
  0 0 5
1 2 3 −1 7 25
0 4 5  0 12 41 
0 0 6 0 0 30

As we see, the drawing done by our command \MyDraw is relative to the submatrix to which it is
applied.

12.3 The commands \OverBrace and \UnderBrace in the \CodeAfter

The commands \OverBrace and \UnderBrace provide a way to put horizontal braces on a part of
the array. These commands take in three arguments:
• the first argument is the upper-left corner of the submatrix with the syntax i-j where i the
number of row and j the number of column;
• the second argument is the lower-right corner with the same syntax;
• the third argument is the label of the brace that will be put by nicematrix (with pgf) above the
brace (for the command \OverBrace) or under the brace (for \UnderBrace).
It’s possible to use the command \\ in this third argument in order to format the label on
several lines.

\begin{pNiceMatrix}
1 & 2 & 3 & 4 & 5 & 6 \\ A B
11 & 12 & 13 & 14 & 15 & 16 \\ z }| {z }| {
1 2 3 4 5 6
\CodeAfter
11 12 13 14 15 16
\OverBrace{1-1}{2-3}{A}
\OverBrace{1-4}{2-6}{B}
\end{pNiceMatrix}

Caution: There is no vertical space reserved for those braces and their labels.61

In fact, the commands \OverBrace and \UnderBrace take in an optional argument (in first position
and between square brackets) for a list of key=value pairs. The available keys are:
• left-shorten and right-shorten which do not take in value; when the key left-shorten is
used, the abscissa of the left extremity of the brace is computed with the contents of the cells
of the involved sub-array, otherwise, the position of the potential vertical rule is used (idem for
right-shorten).
• shorten , which is the conjunction of the keys left-shorten and right-shorten;
• yshift , which shifts vertically the brace (and its label);
• color, which sets the color of the brace (and its label).

\begin{pNiceMatrix}
1 & 2 & 3 & 4 & 5 & 6 \\ A B
11 & 12 & 13 & 14 & 15 & 16 \\ z }| { z }| {
1 2 3 4 5 6
\CodeAfter
11 12 13 14 15 16
\OverBrace[shorten,yshift=3pt]{1-1}{2-3}{A}
\OverBrace[shorten,yshift=3pt]{1-4}{2-6}{B}
\end{pNiceMatrix}

61 See: https://tex.stackexchange.com/questions/685755

43
12.4 The command \TikzEveryCell in the \CodeAfter
The command \TikzEveryCell executes with TikZ the rectangular path corresponding to each cell
of the tabular with parameters of TikZ the argument of \TikzEveryCell. That argument must be a
list of key=value pairs which may be applied to a TikZ path. In fact, the command applies to each of
the tabular, except those in the exterior rows and columns (cf. p. 29) and those in the empty corners
(when the key corners is used: cf. p. 14). It applies in fact to each block (excepted those with the
key transparent) and does not apply to the individual cells located within these blocks.
In fact, in the list of keys provided as argument of \TikzEveryCell, it’s possible to put a key
offset . That key is not provided by TikZ but by nicematrix. It will narrow the rectangular frame
corresponding to the block by a margin (horizontally and vertically) equal to the value (of that key
offset). That new frame, a bit narrower, will be executed by TikZ with options which are the other
keys in the argument of \TikzEveryCell.

\renewcommand{\arraystretch}{1.3}
\begin{NiceTabular}{ccc}[corners]
& \Block{1-2}{columns} \\
\Block{2-1}{rows} columns
& cell 1 1 & cell 1 2 \\ cell 1 1 cell 1 2
& cell 2 1 & cell 2 2 rows
cell 2 1 cell 2 2
\CodeAfter
\TikzEveryCell{offset=1pt,draw}
\end{NiceTabular}

The command \TikzEveryCell has two optional keys, available between square brackets.
• with the key empty , the command only acts on the empty cells (the exact definition of an
“empty cell” is given in part 17.2, p. 61);

• with key non-empty , the command only acts on the non-empty cells.

\renewcommand{\arraystretch}{1.4}
\begin{NiceTabular}{cccccc}[hvlines]
P & O & U & R & V & U \\ P O U R V U
O & & & E & I & \\ O E I
M & O & R & F & A & L \\
M O R F A L
E & T & A & L & & E \\
L & A & S & E & R & S \\ E T A L E
O & & E & X & I & T L A S E R S
\CodeAfter
\TikzEveryCell[empty]{fill=gray,draw} O E X I T
\end{NiceTabular}

The commmand \TikzEveryCell is, in fact, also available in the \CodeBefore.

13 Captions and notes in the tabulars

13.1 Caption of a tabular

The environment {NiceTabular} provides the keys caption , short-caption and label which may
be used when the tabular is inserted in a floating environment (typically the environment {table}).
With the key caption, the caption, when it is long, is wrapped at the width of the tabular (except
the potential exterior columns specified by first-col and last-col: cf. 9, p. 29), without the use
of the package threeparttable or the package floatrow.

44
By default, the caption is composed below the tabular. With the key caption-above , available in
\NiceMatrixOptions, the caption will be composed above the tabular.
The key short-caption corresponds to the optional argument of the clasical command \caption
and the key label corresponds, of course, to the command \label.
See table 1, p. 47, for an example of use the keys caption and label.
These functionnalities are compatible with the extension caption.

13.2 The footnotes

The package nicematrix allows, by using footnote or footnotehyper, the extraction of the notes inserted
by \footnote in the environments of nicematrix and their composition in the foot of the page with
the other notes of the document.
If nicematrix is loaded with the option footnote (with \usepackage[footnote]{nicematrix} or
with \PassOptionsToPackage), the package footnote is loaded (if it is not yet loaded) and it is used
to extract the footnotes.
If nicematrix is loaded with the option footnotehyper, the package footnotehyper is loaded (if it is
not yet loaded) ant it is used to extract footnotes.
Caution: The packages footnote and footnotehyper are incompatible. The package footnotehyper is
the successor of the package footnote and should be used preferently. The package footnote has some
drawbacks, in particular: it must be loaded after the package xcolor and it is not perfectly compatible
with hyperref.

13.3 The notes of tabular

The package nicematrix also provides a command \tabularnote which gives the ability to specify
notes that will be composed at the end of the array with a width of text equal to the width of the array
(except the potential exterior columns specified by first-col and last-col: cf. 9, p. 29). With no
surprise, that command is available only in the environments {NiceTabular}, {NiceTabular*} and
{NiceTabularX}.
In fact, this command is available only if the extension enumitem has been loaded (before or after
nicematrix). Indeed, the notes are composed at the end of the array with a type of list provided by
the package enumitem.
\begin{NiceTabular}{@{}llr@{}}
\toprule \RowStyle{\bfseries}
Last name & First name & Birth day \\
\midrule
Achard\tabularnote{Achard is an old family of the Poitou.}
& Jacques & June 5, 2005 \\
Lefebvre\tabularnote{The name Lefebvre is an alteration of the name Lefebure.}
& Mathilde & January 23, 1975 \\
Vanesse & Stephany & October 30, 1994 \\
Dupont & Chantal & January 15, 1998 \\
\bottomrule
\end{NiceTabular}

Last name First name Birth day

a
Achard Jacques June 5, 2005
Lefebvreb Mathilde January 23, 1975
Vanesse Stephany October 30, 1994
Dupont Chantal January 15, 1998
a
Achard is an old family of the Poitou.
b
The name Lefebvre is an alteration of the
name Lefebure.

45
 • If you have several successive commands \tabularnote{...} with no space at all between
them, the labels of the corresponding notes are composed together, separated by commas (this
is similar to the option multiple of footmisc for the footnotes).

• If a command \tabularnote{...} is exactly at the end of a cell (with no space at all after)
and if the alignment mode of the column is c or r, the label of the note is composed in an
overlapping position (towards the right). This structure may provide a better alignment of the
cells of a given column.

• If the key notes/para is used, the notes are composed at the end of the array in a single
paragraph (as with the key para of threeparttable).
• There is a key tabularnote which provides a way to insert some text in the zone of the notes
before the numbered tabular notes.
An alternative syntax is available with the environment {TabularNote}. That environment
should be used at the end of the environment {NiceTabular} (but before a potential instruction
\CodeAfter).
• If the package booktabs has been loaded (before or after nicematrix), the key notes/bottomrule
draws a \bottomrule of booktabs after the notes.
• The command \tabularnote may be used before the environment of nicematrix. Thus, it’s
possible to use it on the title inserted by \caption in an environment {table} of LaTeX (or
in a command \captionof of the package caption). It’s also possible, as expected, to use
the command \tabularnote in the caption provided by the key caption of the environment
{NiceTabaular}.
If several commands \tabularnote are used in a tabular with the same argument, only one
note is inserted at the end of the tabular (but all the labels are composed, of course). It’s
possible to control that feature with the key notes/detect-duplicates.62
• It’s possible to create a reference to a tabular note created by \tabularnote (with the usual
command \label used after the \tabularnote).
• The command \tabularnote has an optional argument (between square brackets) to change
the symbol of the reference of the note.
Example: \tabularnote[$\star$]{A footnote...}

For an illustration of some of those remarks, see table 1, p. 47. This table has been composed with
the following code (the package caption has been loaded in this document).

\begin{table}
\centering
\NiceMatrixOptions{caption-above}
\begin{NiceTabular}{@{}llc@{}
[
caption = A tabular whose caption has been specified by the key
\texttt{caption}\tabularnote[$\star$]{It's possible to put a tabular
note in the caption.} ,
label = t:tabularnote ,
tabularnote = Some text before the notes. ,
notes/bottomrule
]
\toprule
Last name & First name & Length of life \\
\midrule
Churchill & Wiston & 91\\
Nightingale\tabularnote{Considered as the first nurse of history}%
\tabularnote{Nicknamed ``the Lady with the Lamp''.}

62 For technical reasons, the final user is not allowed to put several commands \tabularnote with exactly the same

argument in the caption of the tabular. It’s not a real restriction...

46
& Florence\tabularnote{This note is shared by two references.} & 90 \\
Schoelcher & Victor & 89\tabularnote{The label of the note is overlapping.}\\
Touchet & Marie\tabularnote{This note is shared by two references.} & 89 \\
Wallis & John & 87 \\
\bottomrule
\end{NiceTabular}
\end{table}

Table 1: A tabular whose caption has been

specified by the key caption?

Last name First name Length of life

Churchill Wiston 91
Nightingalea,b Florencec 90
Schoelcher Victor 89d
Touchet Mariec 89
Wallis John 87
Some text before the notes.
?
It’s possible to put a tabular note in the
caption
a
Considered as the first nurse of history.
b
Nicknamed “the Lady with the Lamp”.
c
This note is shared by two references.
d
The label of the note is overlapping.

13.4 Customisation of the tabular notes

The tabular notes can be customized with a set of keys available in \NiceMatrixOptions. The name
of these keys is prefixed by notes.
• notes/para
• notes/bottomrule
• notes/style

• notes/label-in-tabular
• notes/label-in-list
• notes/enumitem-keys

• notes/enumitem-keys-para
• notes/code-before
For sake of commodity, it is also possible to set these keys in \NiceMatrixOptions via a key notes
which takes in as value a list of pairs key=value where the name of the keys need no longer be prefixed
by notes:

47
 \NiceMatrixOptions
{
notes =
{
bottomrule ,
style = ... ,
label-in-tabular = ... ,
enumitem-keys =
{
labelsep = ... ,
align = ... ,
...
}
}
}

We detail these keys.

• The key notes/para requires the composition of the notes (at the end of the tabular) in a
single paragraph.
Initial value: false
That key is also available within a given environment.

• The key notes/bottomrule adds a \bottomrule of booktabs after the notes. Of course, that
rule is drawn only if there is really notes in the tabular. The package booktabs must have been
loaded (before or after the package nicematrix). If it is not, an error is raised.
Initial value: false
That key is also available within a given environment.

• The key notes/style is a command whose argument is specified by #1 and which gives the
style of numerotation of the notes. That style will be used by \ref when referencing a tabular
note marked with a command \label. The labels formatted by that style are used, separated
by commas, when the user puts several consecutive commands \tabularnote. The marker #1
is meant to be the name of a LaTeX counter.
Initial value: \textit{\alph{#1}}
Another possible value should be a mere \arabic{#1}

• The key notes/label-in-tabular is a command whose argument is specified by #1 which is

used when formatting the label of a note in the tabular. Internally, this number of note has
already been formatted by notes/style before sent to that command.
Initial value: \textsuperscript{#1}
In French, it’s a tradition of putting a small space before the label of note. That tuning could
be acheived by the following code:
\NiceMatrixOptions{notes/label-in-tabular = \,\textsuperscript{~#1}}

• The key notes/label-in-list is a command whose argument is specified by #1 which is used

when formatting the label in the list of notes at the end of the tabular. Internally, this number
of note has already been formatted by notes/style before sent to that command.
Initial value: \textsuperscript{#1}
In French, the labels of notes are not composed in upper position when composing the notes.
Such behaviour could be acheived by:
\NiceMatrixOptions{notes/label-in-list = ~#1.\nobreak\hspace{0.25em}}

The command \nobreak is for the event that the option para is used.

48
 • The notes are composed at the end of the tabular by using internally a style of list of enumitem.
This style of list is defined as follows (with, of course, keys of enumitem):
noitemsep , leftmargin = * , align = left , labelsep = 0pt
The specification align = left in that style requires a composition of the label leftwards in
the box affected to that label. With that tuning, the notes are composed flush left, which is
pleasant when composing tabulars in the spirit of booktabs (see for example the table 1, p. 47).

The key notes/enumitem-keys specifies a list of pairs key=value (following the specifications
of enumitem) to customize that style of list (it uses internally the command \setlist* of
enumitem).

• The key notes/enumitem-keys-para is similar to the previous one but corresponds to the type
of list used when the option para is in force. Of course, when the option para is used, a list
of type inline (as called by enumitem) is used and the pairs key=value should correspond to
such a list of type inline.
Initially, the style of list is defined by: afterlabel = \nobreak, itemjoin = \quad

• The key notes/code-before is a token list inserted by nicematrix just before the composition
of the notes at the end of the tabular.
Initial value: empty
For example, if one wishes to compose all the notes in gray and \footnotesize, he should use
that key:

\NiceMatrixOptions{notes/code-before = \footnotesize \color{gray}}

It’s also possible to add \raggedright or \RaggedRight in that key (\RaggedRight is a com-
mand of ragged2e).

• The key notes/detect-duplicates activates the detection of the commands \tabularnotes

with the same argument.
Initial value : true

For an example of customisation of the tabular notes, see p. 65.

13.5 Use of {NiceTabular} with threeparttable

If you wish to use an environment {NiceTabular}, {NiceTabular*} or {NiceTabularX} in an envi-
ronment {threeparttable} of the eponymous package, you have to patch {threeparttable} with
the following code.
\makeatletter
\AddToHook{env/threeparttable/begin}
{\TPT@hookin{NiceTabular}\TPT@hookin{NiceTabular*}\TPT@hookin{NiceTabularX}}
\makeatother
Nevertheless, the use of threeparttable in conjonction with nicematrix seems rather point-less because
of the functionalities provided by nicematrix (see the key caption in the section 13.1, p. 44).

14 Other features

14.1 The key rounded-corners

The key rounded-corners that we will describe now has no direct link with the key corners (which
is used to specify “empty corners”) described in the part 5.3.3, p. 14.

49
The key rounded-corners specifies that the tabular should have rounded corners with a radius equal
to the value of that key (the default value is 4 pt63 ). More precisely, that key has two effects that we
describe now.

• All the commands for coloring the cells, columns and rows (in the \CodeBefore but also directly
in the array will respect those rounded corners.
• When the key hvlines is used, the exterior rules will be drawn with rounded corners.64
That key is available in all the environments and commands (e.g. \pAutoNiceMatrix) of nicematrix
and also in the command \NiceMatrixOptions.

\begin{NiceTabular}
[hvlines,rounded-corners]
{ccc}
\CodeBefore
Last name First name Profession
\rowcolor{red!15}{1}
\Body Arvy Jacques Physicist
Last name & First name & Profession \\ Jalon Amandine Physicist
Arvy & Jacques & Physicist \\
Jalon & Amandine & Physicist
\end{NiceTabular}

14.2 Command \ShowCellNames

The command \ShowCellNames, which may be used in the \CodeBefore and in the \CodeAfter
displays the name (with the form i-j) of each cell. When used in the \CodeAfter, that command
applies a semi-transparent white rectangle to fade the array (caution: some pdf readers don’t support
transparency).
\begin{NiceTabular}{ccc}[hvlines,cell-space-limits=3pt]
\Block{2-2}{} & & test \\
& & blabla \\
1-1 1-2 1-3
test
& some text & nothing
2-1 2-2 2-3
blabla
\CodeAfter \ShowCellNames 3-1 3-2text
some 3-3
nothing
\end{NiceTabular}

14.3 Use of the column type S of siunitx

If the package siunitx is loaded (before or after nicematrix), it’s possible to use the S column type of
siunitx in the environments of nicematrix.
$\begin{pNiceArray}{ScW{c}{1cm}c}[nullify-dots,first-row]
{C_1} & \Cdots & & C_n \\  C1 Cn 
2.3 0 0
2.3 & 0 & \Cdots & 0 \\ 12.4
12.4 & \Vdots & & \Vdots \\

 
 1.45
1.45 \\

7.2 0 0
7.2 & 0 & \Cdots & 0
\end{pNiceArray}$

On the other hand, the d columns of the package dcolumn are not supported by nicematrix.

63 This value is the initial value of the rounded corners of Tikz.

64 Of course, when used in an environment with delimiters ({pNiceMatrix}, {bNiceArray}, etc.), the key hvlines
does not draw the exterior rules.

50
14.4 Default column type in {NiceMatrix}
The environments without preamble ({NiceMatrix}, {pNiceMatrix}, {bNiceMatrix}, etc.) and the
commande \pAutoNiceMatrix (and its variants) provide an option columns-type to specify the type
of column which will be used (the initial value is, of course, c).
The keys l and r are shortcuts for columns-type=l and columns-type=r.
$\begin{bNiceMatrix}[r]
\cos x & - \sin x \\
 
cos x − sin x
\sin x & \cos x sin x cos x
\end{bNiceMatrix}$

The key columns-type is available in \NiceMatrixOptions but with the prefix matrix, which means
that its name is, within \NiceMatrixOptions : matrix/columns-type.

14.5 The command \rotate

The package nicematrix provides a command \rotate . When used in the beginning of a cell, this
command composes the contents of the cell after a rotation of 90° in the direct sens.
In the following command, we use that command in the code-for-first-row.65

\NiceMatrixOptions%
{code-for-first-row = \scriptstyle \rotate \text{image of },

image of e1

image of e2

image of e3
code-for-last-col = \scriptstyle }
$A = \begin{pNiceMatrix}[first-row,last-col=4]
e_1 & e_2 & e_3 \\
1 & 2 & 3 & e_1 \\
 
1 2 3 e1
4 & 5 & 6 & e_2 \\ A = 4 5 6  e2
7 & 8 & 9 & e_3 7 8 9 e3
\end{pNiceMatrix}$

If the command \rotate is used in the “last row” (exterior to the matrix), the corresponding elements
are aligned upwards as shown below.

\NiceMatrixOptions%
{code-for-last-row = \scriptstyle \rotate , 1

2

3 e1
code-for-last-col = \scriptstyle } A = 4 5 6e2
$A = \begin{pNiceMatrix}[last-row=4,last-col=4] 7 8 9 e3
1 & 2 & 3 & e_1 \\
image of e1

e2

e3

4 & 5 & 6 & e_2 \\

7 & 8 & 9 & e_3 \\
\text{image of } e_1 & e_2 & e_3
\end{pNiceMatrix}$

The command \rotate has a key c: \rotate[c] (spaces are deleted after \rotate[c]). When that
key is used, the content is composed in a \vcenter and, therefore, in most cases, we will have a
vertical alignment.

Caution: the command \rotate is designed to be used in a \Block or in columns of type l, r, c, w

ou W; if it is used in other column types (such as p{...}), the result will maybe differ from what is
expected.

65 It can also be used in \RowStyle (cf. p. 26.)

51
14.6 The option small
With the option small, the environments of the package nicematrix are composed in a way similar to
the environment {smallmatrix} of the package amsmath (and the environments {psmallmatrix},
{bsmallmatrix}, etc. of the package mathtools).

$\begin{bNiceArray}{cccc|c}[small,
last-col ,
code-for-last-col = \scriptscriptstyle,
columns-width = 3mm ]
1 & -2 & 3 & 4 & 5 \\
0 & 3 & 2 & 1 & 2 & L_2 \gets 2 L_1 - L_2 \\
0 & 1 & 1 & 2 & 3 & L_3 \gets L_1 + L_3
\end{bNiceArray}$
h1 −2 3 4 5 i
0 3 2 1 2 L2 ←2L1 −L2
0 1 1 2 3 L3 ←L1 +L3

One should note that the environment {NiceMatrix} with the option small is not composed exactly
as the environment {smallmatrix}. Indeed, all the environments of nicematrix are constructed upon
{array} (of the package array) whereas the environment {smallmatrix} is constructed directly with
an \halign of TeX.
In fact, the option small corresponds to the following tuning:
• the cells of the array are composed with \scriptstyle;
• \arraystretch is set to 0.47;
• \arraycolsep is set to 1.45 pt;
• the characteristics of the dotted lines are also modified.

When the key small is in force, some functionalities of nicematrix are no longer available: for example,
it’s no longer possible to put vertical delimiters directly in the preamble of an environment with
preamble (cf. section 11, p. 38).

14.7 The counters iRow and jCol

In the cells of the array, it’s possible to use the LaTeX counters iRow and jCol66 which represent
the number of the current row and the number of the current column. We recall that the exterior
“first row” (if it exists) has the number 0 and that the exterior “first column” (if it exists) has also
the number 0. Of course, the user must not change the value of these counters iRow and jCol which
are used internally by nicematrix.
In the \CodeBefore (cf. p. 19) and in the \CodeAfter (cf. p. 39), iRow represents the total number
of rows (except the potential exterior rows: cf. p. 29) and jCol represents the total number of
columns (except the potential exterior columns).
$\begin{pNiceMatrix}% don’t forget the %
[first-row,
first-col,
code-for-first-row = \mathbf{\alph{jCol}} , a b c d
1 1 2 3 4
code-for-first-col = \mathbf{\arabic{iRow}} ]
25 6 7 8
& & & & \\
3 9 10 11 12
& 1 & 2 & 3 & 4 \\
& 5 & 6 & 7 & 8 \\
& 9 & 10 & 11 & 12
\end{pNiceMatrix}$

66 There counters are actual LaTeX counters: the underlying TeX counters are \c@iRow and \c@jCol

52
If LaTeX counters called iRow and jCol are defined in the document by packages other than nicematrix
(or by the final user), they are shadowed in the environments of nicematrix.

The package nicematrix also provides commands in order to compose automatically matrices from a
general pattern. These commands are \AutoNiceMatrix, \pAutoNiceMatrix, \bAutoNiceMatrix ,
\vAutoNiceMatrix , \VAutoNiceMatrix et \BAutoNiceMatrix.
These commands take in two mandatory arguments. The first is the format of the matrix, with the
syntax n-p where n is the number of rows and p the number of columns. The second argument is the
pattern (it’s a list of tokens which are inserted in each cell of the constructed matrix).
$C = \pAutoNiceMatrix{3-3}{C_{\arabic{iRow},\arabic{jCol}}}$
 
C1,1 C1,2 C1,3
C = C2,1 C2,2 C2,3 
C3,1 C3,2 C3,3
There exists also \AutoNiceArrayWithDelims similar to {NiceArrayWithDelims}.

14.8 The key light-syntax

The option light-syntax (inpired by the package spalign) allows the user to compose the arrays
with a lighter syntax, which gives a better legibility of the TeX source.
When this option is used, one should use the semicolon for the end of a row and spaces or tabulations
to separate the columns. However, as usual in the TeX world, the spaces after a control sequence are
discarded and the elements between curly braces are considered as a whole.
$\begin{bNiceMatrix}[light-syntax,first-row,first-col]
a b
{} a b ;  
a 2 cos a cos a + cos b
a 2\cos a {\cos a + \cos b} ;
b cos a + cos b 2 cos b
b \cos a+\cos b { 2 \cos b }
\end{bNiceMatrix}$

It’s possible to change the character used to mark the end of rows with the option end-of-row. As
said before, the initial value is a semicolon.
When the option light-syntax is used, it is not possible to put verbatim material (for example with
the command \verb) in the cells of the array.67
The key light-syntax-expanded has the same behaviour as the key light-syntax but the body
of the environment is expanded (in the TeX sens68 ) before being splitted in rows (but after the
extraction of a potential \CodeAfter).

14.9 Color of the delimiters

For the environments with delimiters ({pNiceArray}, {pNiceMatrix}, etc.), it’s possible to change
the color of the delimiters with the key delimiters/color .
$\begin{bNiceMatrix}[delimiters/color=red]
1 & 2 \\
 
1 2
3 & 4 3 4
\end{bNiceMatrix}$

This color also applies to the delimiters drawn by the command \SubMatrix (cf. p. 40) and for the
delimiters directly specified in the preamble of the environments with preamble (cf. p. 38).

67 The reason is that, when the option light-syntax is used, the whole content of the environment is loaded as a TeX

argument to be analyzed. The environment doesn’t behave in that case as a standard environment of LaTeX which
only put TeX commands before and after the content.
68 More precisely, it’s a expansion of type e of L3.

53
14.10 The environment {NiceArrayWithDelims}
In fact, the environment {pNiceArray} and its variants are based upon a more general environment,
called {NiceArrayWithDelims} . The first two mandatory arguments of this environment are the left
and right delimiters used in the construction of the matrix.
It’s possible to use {NiceArrayWithDelims} if we want to use atypical or asymetrical delimiters.
$\begin{NiceArrayWithDelims}
{\downarrow}{\uparrow}{ccc}[margin] 
 1
x
2 3
1 & 2 & 3 \\

 
 4 5 6
4 & 5 & 6 \\

 
y 7 8 9
7 & 8 & 9

\end{NiceArrayWithDelims}$

14.11 The command \OnlyMainNiceMatrix

The command \OnlyMainNiceMatrix executes its argument only when it is in the main part of the
array, that is to say when it is not in one of the exterior rows or one of the exterior columns. If it is
used outside an environment of nicematrix, that command is no-op.
For an example of utilisation, see tex.stackexchange.com/questions/488566

15 Use of TikZ with nicematrix

15.1 The nodes corresponding to the contents of the cells

The package nicematrix creates a PGF/TikZ node69 for each (non-empty) cell of the considered array.
These nodes are used to draw the dotted lines between the cells of the matrix (inter alia).
Caution : By default, no node is created in a empty cell.
However, it’s possible to impose the creation of a node with the command \NotEmpty. 70
The creation of those nodes needs time and memory. It’s possible to desactive ponctually the creation
of those nodes with the key no-cell-nodes in order to speed up the compilations. But be careful:
those nodes are used internally but nicematrix for several features. One should use the key no-cell-
nodes only when those feateures are not used. Among these are the key corners and the commands
for the continuous dotted lines (\Cdots, etc.).
The nodes of a document must have distinct names. That’s why the names of the nodes created by
nicematrix contains the number of the current environment. Indeed, the environments of nicematrix
are numbered by a internal global counter.
In the environment with the number n, the node of the row i and column j has for name nm-n-i-j.
The command \NiceMatrixLastEnv provides the number of the last environment of nicematrix (for
LaTeX, it’s a “fully expandable” command and not a counter).
However, it’s advisable to use instead the key name 71 . This key gives a name to the current environ-
ment. When the environment has a name, the nodes are accessible with the name “name-i-j” where
name is the name given to the array and i and j the numbers of row and column. It’s possible to
use these nodes with pgf but the final user will probably prefer to use TikZ (which is a convenient
layer upon pgf). However, one should remind that nicematrix doesn’t load TikZ by default. In the
following examples, we assume that TikZ has been loaded.

69 We recall that TikZ is a layer over PGF. The extension nicematrix loads PGF but does not load TikZ. We speak of

PGF/TikZ nodes to emphase the fact that the PGF nodes created by nicematrix may be used with PGF but also with
TikZ. The final user will probably prefer to use TikZ rather than PGF.
70 One should note that, with that command, the cell is considered as non-empty, which has consequencies for the

continuous dotted lines (cf. p. 31) and the computation of the “corners” (cf. p. 14).
71 The value of the key name is expanded (in the TeX sens).

54
$\begin{pNiceMatrix}[name=mymatrix]
1 & 2 & 3 \\
4 & 5 & 6 \\
 
1 2 3
7 & 8 & 9 4 5 6
\end{pNiceMatrix}$ 7 8 9
\tikz[remember picture,overlay]
\draw (mymatrix-2-2) circle (2mm) ;

Don’t forget the options remember picture and overlay.

In the \CodeAfter, the things are easier : one must refer to the nodes with the form i-j (we don’t
have to indicate the environment which is of course the current environment).
$\begin{pNiceMatrix}
1 & 2 & 3 \\
4 & 5 & 6 \\
 
1 2 3
7 & 8 & 9 4 5 6
\CodeAfter 7 8 9
\tikz \draw (2-2) circle (2mm) ;
\end{pNiceMatrix}$

The nodes of the last column (except the potential “last column” specified by last-col72 ) may also
be indicated by i-last. Similarly, the nodes of the last row may be indicated by last-j.

In the following example, we have underlined all the nodes of the matrix.
 
a a+b a+b+c
a a a+b 
a a a

Since those nodes are PGF nodes, one won’t be surprised to learn that they are drawn by using a
specific PGF style. That style is called nicematrix/cell-node and its definition in the source file
nicematrix.sty is as follows:
\pgfset
{
nicematrix / cell-node /.style =
{
inner sep = 0 pt ,
minimum width = 0 pt
}
}
The final user may modify that style by changing the values of the keys text/rotate, inner xsep,
inner ysep, inner sep, outer xsep, outer ysep, outer sep, minimum width, minimum height
and minimum size.
For an example of utilisation, see part 18.10, p. 76.

15.1.1 The key pgf-node-code

For the experienced users, nicematrix provides the key pgf-node-code which corresponds to
some PGF node that will be executed at the creation, by PGF, of the nodes corresponding to the
cells of the array. More pricisely, the value given to the key pgf-node-code will be passed in the
fifth argument of the command \pgfnode. That value should contain at least an instruction such as
\pgfusepath, \pgfusepathqstroke, \pgfusepathqfill, etc.

72 For the exterior columns, cf. part 9, p. 29.

55
15.1.2 The columns V of varwidth
When the extension varwidth is loaded, the columns of the type V defined by varwidth are supported
by nicematrix. It may be interessant to notice that, for a cell of a column of type V, the PGF/TikZ
node created by nicematrix for the content of that cell has a width adjusted to the content of the cell.
This is in contrast to the case of the columns of type p, m or b for which the nodes have always a
width equal to the width of the column. In the following example, the command \lipsum is provided
by the eponymous package.

\begin{NiceTabular}{V{10cm}}
\bfseries \large
Titre \\
\lipsum[1][1-4]
\CodeAfter
\tikz \draw [rounded corners] (1-1) -| (last-|2) -- (last-|1) |- (1-1) ;
\end{NiceTabular}

Titre
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus
elit, vestibulum ut, placerat ac, adipiscing vitae, felis. Curabitur
dictum gravida mauris. Nam arcu libero, nonummy eget, con-
sectetuer id, vulputate a, magna.

We have used the nodes corresponding to the position of the potential rules, which are described
below (cf. p. 58).

15.2 The “medium nodes” and the “large nodes”

In fact, the package nicematrix can create “extra nodes”: the “medium nodes” and the “large nodes”.
The first ones are created with the option create-medium-nodes and the second ones with the option
create-large-nodes .73
These nodes are not used by nicematrix by default, and that’s why they are not created by default.
The names of the “medium nodes” are constructed by adding the suffix “-medium” to the names of
the “normal nodes”. In the following example, we have underlined the “medium nodes”. We consider
that this example is self-explanatory.
 
a a+b a+b+c
a a a+b 
a a a

The names of the “large nodes” are constructed by adding the suffix “-large” to the names of the
“normal nodes”. In the following example, we have underlined the “large nodes”. We consider that
this example is self-explanatory.74
 
a a+b a+b+c
a a a+b 
a a a

The “large nodes” of the first column and last column may appear too small for some usage. That’s
why it’s possible to use the options left-margin and right-margin to add space on both sides of

73 There is also an option create-extra-nodes which is an alias for the conjonction of create-medium-nodes and

create-large-nodes.
74 There is no “large nodes” created in the exterior rows and columns (for these rows and columns, cf. p. 29).

56
the array and also space in the “large nodes” of the first column and last column. In the following
example, we have used the options left-margin and right-margin.75
 
a a+b a+b+c
 a a a+b 
a a a

It’s also possible to add more space on both side of the array with the options extra-left-margin
and extra-right-margin. These margins are not incorporated in the “large nodes”. It’s possible to
fix both values with the option extra-margin and, in the following example, we use extra-margin
with the value 3 pt.  
a a+b a+b+c
 a a a+b 
a a a

Be careful : These nodes are reconstructed from the contents of the contents cells of the array.
Usually, they do not correspond to the cells delimited by the rules (if we consider that these rules are
drawn).

Here is an array composed with the following code:

\large fraise amande abricot
\begin{NiceTabular}{wl{2cm}ll}[hvlines]
fraise & amande & abricot \\
prune pêche poire
prune & pêche & poire \\[1ex] noix noisette brugnon
noix & noisette & brugnon
\end{NiceTabular}

fraise amande abricot

Here, we have colored all the cells of the array prune pêche poire
with \chessboardcolors.
noix noisette brugnon

fraise amande abricot

Here are the “large nodes” of this array (with- prune pêche poire
out use of margin nor extra-margin).
noix noisette brugnon

The nodes we have described are not available by default in the \CodeBefore (described p. 19).
It’s possible to have these nodes available in the \CodeBefore by using the key create-cell-nodes
of the keyword \CodeBefore (in that case, the nodes are created first before the construction of the
array by using informations written on the aux file and created a second time during the contruction
of the array itself; this mechanism is not activated by default for efficiency reasons).

Here is an example which uses these nodes in the \CodeAfter.

\begin{NiceArray}{c@{\;}c@{\;}c@{\;}c@{\;}c}[create-medium-nodes]
u_1 &-& u_0 &=& r \\
u_2 &-& u_1 &=& r \\
u_3 &-& u_2 &=& r \\

75 The options left-margin and right-margin take dimensions as values but, if no value is given, the default value

is used, which is \arraycolsep (by default: 5 pt). There is also an option margin to fix both left-margin and
right-margin to the same value.

57
 u_4 &-& u_3 &=& r \\
\phantom{u_5} & & \phantom{u_4} &\smash{\vdots} & \\
u_n &-& u_{n-1} &=& r \\[3pt]
\hline
u_n &-& u_0 &=& nr \\
\CodeAfter
\tikz[very thick, red, opacity=0.4, name suffix = -medium]
\draw (1-1.north west) -- (2-3.south east)
(2-1.north west) -- (3-3.south east)
(3-1.north west) -- (4-3.south east)
(4-1.north west) -- (5-3.south east)
(5-1.north west) -- (6-3.south east) ;
\end{NiceArray}

u1 − u0 = r
u2 − u1 = r
u3 − u2 = r
u4 − u3 ..
= r
.
un − un−1 = r
un − u0 = nr

15.3 The nodes which indicate the position of the rules

The package nicematrix creates a PGF/TikZ node merely called i (with the classical prefix) at the
intersection of the horizontal rule of number i and the vertical rule of number i (more specifically
the potential position of those rules because maybe there are not actually drawn). The last node has
also an alias called last.
There are also nodes called i.1, i.2, i.25, i.3, i.4, i.5, i.6, i.7, i.75, i.8 and i.9 between the
node i and the node i + 1.
These nodes are available in the \CodeBefore and the \CodeAfter.
1
1.5
2 tulipe lys
arum 2.5
3 violette mauve
muguet dahlia 3.5
4

If we use TikZ (we remind that nicematrix does not load TikZ by default, by only pgf, which is a
sub-layer of TikZ), we can access, in the \CodeAfter but also in the \CodeBefore, to the intersection
of the (potential) horizontal rule i and the (potential) vertical rule j with the syntax (i-|j).
\begin{NiceMatrix}
\CodeBefore
\tikz \draw [fill=red!15] (7-|4) |- (8-|5) |- (9-|6) |- cycle ;
\Body
1 \\
1 & 1 \\
1 & 2 & 1 \\
1 & 3 & 3 & 1 \\
1 & 4 & 6 & 4 & 1 \\
1 & 5 & 10 & 10 & 5 & 1 \\
1 & 6 & 15 & 20 & 15 & 6 & 1 \\
1 & 7 & 21 & 35 & 35 & 21 & 7 & 1 \\
1 & 8 & 28 & 56 & 70 & 56 & 28 & 8 & 1
\end{NiceMatrix}

58
 1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
1 6 15 20 15 6 1
1 7 21 35 35 21 7 1
1 8 28 56 70 56 28 8 1

The “decimal” nodes (like i.4) may be used, for example to cross a row of a matrix (if TikZ is loaded).
$\begin{pNiceArray}{ccc|c}
2 & 1 & 3 & 0 \\
3 & 3 & 1 & 0 \\
 
2 1 3 0
3 & 3 & 1 & 0 3 3 1 0
\CodeAfter 3 3 1 0
\tikz \draw [red] (3.4-|1) -- (3.4-|last) ;
\end{pNiceArray}$

15.4 The nodes corresponding to the command \SubMatrix

The command \SubMatrix available in the \CodeAfter has been described p. 40.
If a command \SubMatrix has been used with the key name with an expression such as name=MyName
three PGF/TikZ nodes are created with the names MyName-left, MyName and MyName-right.
The nodes MyName-left and MyName-right correspond to the delimiters left and right and the node
MyName correspond to the submatrix itself.
In the following example, we have highlighted these nodes (the submatrix itself has been created with
\SubMatrix\{{2-2}{3-3}\}).
 
121  23 345  345
 45 346 863 444
 
3462 38458 34 294
34 7 78 309

16 API for the developers

The package nicematrix provides two variables which are internal but public76 :
• \g_nicematrix_code_before_tl ;
• \g_nicematrix_code_after_tl.

These variables contain the code of what we have called the “code-before” (usually specified at the
beginning of the environment with the syntax using the keywords \CodeBefore and \Body) and the
“code-after” (usually specified at the end of the environment after the keyword \CodeAfter). The
developer can use them to add code from a cell of the array (the affectation must be global, allowing
to exit the cell, which is a TeX group).
One should remark that the use of \g_nicematrix_code_before_tl needs one compilation more
(because the instructions are written on the aux file to be used during the next run).

76 According to the LaTeX3 conventions, each variable with name beginning with \g_nicematrix ou \l_nicematrix

is public and each variable with name beginning with \g__nicematrix or \l__nicematrix is private.

59
Example : We want to write a command \crossbox to draw a cross in the current cell. This command
will take in an optional argument between square brackets for a list of pairs key-value which will be
given to TikZ before the drawing.
It’s possible to program such command \crossbox as follows, explicitely using the public variable
\g_nicematrix_code_before_tl.
\ExplSyntaxOn
\cs_new_protected:Nn \__pantigny_crossbox:nnn
{
\tikz \draw [ #3 ]
( #1 -| \int_eval:n { #2 + 1 } ) -- ( \int_eval:n { #1 + 1 } -| #2 )
( #1 -| #2 ) -- ( \int_eval:n { #1 + 1 } -| \int_eval:n { #2 + 1 } ) ;
}

\NewDocumentCommand \crossbox { ! O { } }
{
\tl_gput_right:Nx \g_nicematrix_code_before_tl
{
\__pantigny_crossbox:nnn
{ \int_use:c { c@iRow } }
{ \int_use:c { c@jCol } }
{ \exp_not:n { #1 } }
}
\ignorespaces
}
\ExplSyntaxOff

We have used the LaTeX counters iRow and jCol provided by nicematrix (cf. p. 52).

Here is an example of utilisation:

\begin{NiceTabular}{ccc}[hvlines]
\CodeBefore
\arraycolor{gray!10}
merlan requin cabillaud
\Body
merlan & requin & cabillaud \\ baleine morue
baleine & \crossbox[red] & morue \\ mante raie poule
mante & raie & poule
\end{NiceTabular}

17 Technical remarks

First remark: the package underscore must be loaded before nicematrix. If it is loaded after, an error
will be raised.

17.1 Diagonal lines

By default, all the diagonal lines77 of a same array are “parallelized”. That means that the first
diagonal line is drawn and, then, the other lines are drawn parallel to the first one (by rotation
around the left-most extremity of the line). That’s why the position of the instructions \Ddots in
the array can have a marked effect on the final result.
In the following examples, the first \Ddots instruction is written in color.

77 We speak of the lines created by \Ddots and not the lines created by a command \line in the \CodeAfter.

60
Example with parallelization (default):
$A = \begin{pNiceMatrix}
 
1 1
1 & \Cdots & & 1 \\  
a + b
a+b & \Ddots & & \Vdots \\

A= 
\Vdots & \Ddots & & \\
 
 
a+b & \Cdots & a+b & 1 a+b a+b 1
\end{pNiceMatrix}$

$A = \begin{pNiceMatrix}  
1 1
1 & \Cdots & & 1 \\
a+b & & & \Vdots \\
 
a + b 
\Vdots & \Ddots & \Ddots & \\ A=



a+b & \Cdots & a+b & 1
 
\end{pNiceMatrix}$ a+b a+b 1

It’s possible to turn off the parallelization with the option parallelize-diags set to false:
 
1 1
 
a + b
The same example without parallelization:

A= 


 
a+b a+b 1
It’s possible to specify the instruction \Ddots which will be drawn first (and which will be used to
draw the other diagonal dotted lines when the parallelization is in force) with the key draw-first:
\Ddots[draw-first].

17.2 The “empty” cells

The package nicematrix uses, in several circunstancies, the concept of “empty cell’. For example,
an instruction like \Ldots, \Cdots, etc. (cf. p. 31) tries to determine the first non-empty cell on
both sides. In the same way, when the key corners is used (cf. p. 14), nicematrix computes corners
consisting of empty cells.
However, an “empty cell” is not necessarily a cell with no TeX content (that is to say a cell with no
token between the two ampersands &). The precise rules are as follow.

• An implicit cell is empty. For example, in the following matrix:

\begin{pmatrix}
a & b \\
c \\
\end{pmatrix}

the last cell (second row and second column) is empty.

• For the columns of type p, m, b, V78 and X79 , the cell is empty if (and only if) its content in the
TeX code is empty (there is only spaces between the ampersands &).

• For the columns of type c, l, r and w{...}{...}, the cell is empty if (and only if) its TeX
output has a width equal to zero.

• A cell containing the command \NotEmpty is not empty (and a PGF/TikZ node is created in
that cell).

78 The columns of type V are provided by varwidth, which must be loaded: cf. p. 28.
79 See p. 28

61
 • A cell with only a command \Hspace (or \Hspace*) is empty. This command \Hspace is a
command defined by the package nicematrix with the same meaning as \hspace except that
the cell where it is used is considered as empty. This command can be used to fix the width of
some columns of the matrix without interfering with nicematrix.

17.3 The option exterior-arraycolsep

The environment {array} inserts an horizontal space equal to \arraycolsep before and after each
column. In particular, there is a space equal to \arraycolsep before and after the array. This
feature of the environment {array} was probably not a good idea80 . The environment {matrix}
of amsmath and its variants ({pmatrix}, {vmatrix}, etc.) of amsmath prefer to delete these spaces
with explicit instructions \hskip -\arraycolsep81 . The package nicematrix does the same in all
its environments, {NiceArray} included. However, if the user wants the environment {NiceArray}
behaving by default like the environment {array} of array (for example, when adapting an existing
document) it’s possible to control this behaviour with the option exterior-arraycolsep , set by the
command \NiceMatrixOptions. With this option, exterior spaces of length \arraycolsep will be
inserted in the environments {NiceArray} (the other environments of nicematrix are not affected).

17.4 Incompatibilities
There might be incompatibilities between nicematrix and babel with the language which activate (in
the TeX sens) some characters, in particular the character <.
Par exemple, for Spanish, it’s recommended to deactivate the abreviations at load-time with the
instruction:
\usepackage[spanish,es-noshorthands]{babel}

The extension nicematrix is usually not compatible with the classes and packages that redefine the
environments {tabular} and {array}. In particular, it’s the case of the class socg-lipics-v2021.
However, in that case, it’s possible to load the class with the key notab which requires that the
environment {tabular} is not redefined.
The package nicematrix is not compatible with the class ieeeaccess because that class is not compatible
with PGF/TikZ. However, there is a simple workaround by writing:82
\let\TeXyear\year
\documentclass{IEEEaccess}
\let\year\TeXyear

In order to use nicematrix with the class aastex631 (of the American Astronomical Society), you have
to add the following instructions in the preamble of your document :
\BeforeBegin{NiceTabular}{\let\begin\BeginEnvironment\let\end\EndEnvironment}
\BeforeBegin{NiceArray}{\let\begin\BeginEnvironment}
\BeforeBegin{NiceMatrix}{\let\begin\BeginEnvironment}
The package nicematrix is not fully compatible with the packages and classes of LuaTeX-ja: the
detection of the empty corners (cf. p. 14) may be wrong in some circonstances.
The package nicematrix is not fully compatible with the package arydshln (because this package
redefines many internals of array) and does not support the columns V of boldline (because the letter V
is reserved for the columns V of varwidth). By any means, nicematrix provides, with the key custom-
line (cf. part 5.3.5, p. 16), tools to draw dashed rules and rules of different widths.

The columns d of dcolumn are not supported (but it’s possible to use the colums S of siunitx).

80 In the documentation of amsmath, we can read: The extra space of \arraycolsep that array adds on each side is a

waste so we remove it [in {matrix}] (perhaps we should instead remove it from array in general, but that’s a harder
task).
81 And not by inserting @{} on both sides of the preamble of the array. As a consequence, the length of the \hline

is not modified and may appear too long, in particular when using square brackets.
82 See https://tex.stackexchange.com/questions/528975

62
17.5 Compatibility with the Tagging Project of LaTeX
New 7.0
Since the version 7.0, the extension nicematrix is compatible with the Tagging Project of LaTeX (whose
aim is to create tagged PDF). At this time, only simple standard tabulars are correctly tagged.
Here is a example of code which will produce a generate tagged PDF.

\DocumentMetadata{
lang = en,
pdfversion = 2.0,
pdfstandard = ua-2,
pdfstandard = a-4f,
testphase = {phase-III, table, math}
}
\documentclass{article}
\usepackage{lmodern}
\usepackage{nicematrix}

\begin{document}

\begin{center}
\tagpdfsetup{table/header-rows=1}
\begin{NiceTabular}{ccc}[hvlines]
First name & Last name & Age \\
Paul & Imbert & $66$ \\
John & Sarrus & $23$ \\
Liz & Taylor & $100$ \\
George & Adams & $34$
\end{NiceTabular}
\end{center}

\end{document}

18 Examples

18.1 Utilisation of the key “tikz” of the command \Block

The key TikZ of the command \Block is available only when TikZ is loaded.83
For the following example, we also need the TikZ library patterns.

\usetikzlibrary{patterns}

\ttfamily \small
\begin{NiceTabular}{X[m]X[m]X[m]}[hvlines,cell-space-limits=3pt,rounded-corners]
\Block[tikz={pattern=grid,pattern color=lightgray}]{}
{pattern = grid,\\ pattern color = lightgray}
& \Block[tikz={pattern = north west lines,pattern color=blue}]{}
{pattern = north west lines,\\ pattern color = blue}
& \Block[tikz={outer color = red!50, inner color=white }]{2-1}
{outer color = red!50,\\ inner color = white} \\
\Block[tikz={pattern = sixpointed stars, pattern color = blue!15}]{}
{pattern = sixpointed stars,\\ pattern color = blue!15}
& \Block[tikz={left color = blue!50}]{}
{left color = blue!50} \\
\end{NiceTabular}

83 By default, nicematrix only loads pgf, which is a sub-layer of TikZ.

63
 pattern = grid, pattern = north west lines,
pattern color = lightgray pattern color = blue outer color = red!50,
pattern = sixpointed stars, inner color = white
left color = blue!50
pattern color = blue!15

In the following example, we use the key tikz to hatch a row of the tabular. Remark that you use
the key transparent of the command \Block in order to have the rules drawn in the block.84
\begin{NiceTabular}{ccc}[hvlines]
\CodeBefore
\columncolor[RGB]{169,208,142}{2}
\Body
one & two & three \\
\Block[transparent, tikz={pattern = north west lines, pattern color = gray}]{1-*}{}
four & five & six \\
seven & eight & nine
\end{NiceTabular}

one two three

four five six
seven eight nine

18.2 Use with tcolorbox

Here is an example of use of {NiceTabular} within a command \tcbox of tcolorbox. We have used
the key hvlines-except-borders in order to draw all the rules, except on the borders (which are,
of course, added by tcolorbox).
\tcbset
{
colframe = blue!50!black ,
colback = white ,
fonttitle = \bfseries ,
nobeforeafter ,
center title
}

\tcbox
[
left = 0mm ,
right = 0mm ,
top = 0mm ,
bottom = 0mm ,
boxsep = 0mm ,
toptitle = 0.5mm ,
bottomtitle = 0.5mm ,
title = My table
]
{
\renewcommand{\arraystretch}{1.2}% <-- the % is mandatory here
\begin{NiceTabular}{rcl}[hvlines-except-borders,rules/color=blue!50!black]
\CodeBefore
\rowcolor{red!15}{1}
\Body

84 By default, the rules are not drawn in the blocks created by the command \Block (cf. section 5 p. 11): with the

key transparent, they are drawn (the block becomes transparent to the exterior rules).

64
 One & Two & Three \\
Men & Mice & Lions \\
Upper & Middle & Lower
\end{NiceTabular}
}

My table
One Two Three
Men Mice Lions
Upper Middle Lower

18.3 Notes in the tabulars

The tools provided by nicematrix for the composition of the tabular notes have been presented in the
section 13 p. 44.
Let’s consider that we wish to number the notes of a tabular with stars.85
First, we write a command \stars similar to the well-known commands \arabic, \alph, \Alph, etc.
which produces a number of stars equal to its argument86 .
\ExplSyntaxOn
\NewDocumentCommand { \stars } { m }
{ \prg_replicate:nn { \value { #1 } } { \( \star \) } }
\ExplSyntaxOff
Of course, we change the style of the labels with the key notes/style. However, it would be
interesting to change also some parameters in the type of list used to compose the notes at the
end of the tabular. First, we required a composition flush right for the labels with the setting
align=right. Moreover, we want the labels to be composed on a width equal to the width of the
widest label. The widest label is, of course, the label with the greatest number of stars. We know
that number: it is equal to \value{tabularnote} (because tabularnote is the LaTeX counter used
by \tabularnote and, therefore, at the end of the tabular, its value is equal to the total number of
tabular notes). We use the key widest* of enumitem in order to require a width equal to that value:
widest*=\value{tabularnote}.
\NiceMatrixOptions
{
notes =
{
style = \stars{#1} ,
enumitem-keys =
{
widest* = \value{tabularnote} ,
align = right
}
}
}
\begin{NiceTabular}{@{}llr@{}}
\toprule \RowStyle{\bfseries}
Last name & First name & Birth day \\
\midrule
Achard\tabularnote{Achard is an old family of the Poitou.}
& Jacques & 5 juin 1962 \\
Lefebvre\tabularnote{The name Lefebvre is an alteration of the name Lefebure.}
& Mathilde & 23 mai 1988 \\

85 Of course, it’s realistic only when there is very few notes in the tabular.
86 In fact: the value of its argument.

65
Vanesse & Stephany & 30 octobre 1994 \\
Dupont & Chantal & 15 janvier 1998 \\
\bottomrule
\end{NiceTabular}

Last name First name Birth day

Achard? Jacques June 5, 2005
Lefebvre?? Mathilde January 23, 1975
Vanesse Stephany October 30, 1994
Dupont Chantal January 15, 1998
?
Achard is an old family of the Poitou.
??
The name Lefebvre is an alteration of the
name Lefebure.

18.4 Dotted lines

An example with the resultant of two polynoms:

\setlength{\extrarowheight}{1mm}
\[\begin{vNiceArray}{cccc:ccc}[columns-width=6mm]
a_0 & && &b_0 & & \\
a_1 &\Ddots&& &b_1 &\Ddots& \\
\Vdots&\Ddots&& &\Vdots &\Ddots&b_0 \\
a_p & &&a_0 & & &b_1 \\
&\Ddots&&a_1 &b_q & &\Vdots\\
& &&\Vdots & &\Ddots& \\
& &&a_p & & &b_q
\end{vNiceArray}\]

a0 b0
a1 b1
b0
ap a0 b1
a1 bq

ap bq

An example for a linear system:

$\begin{pNiceArray}{*6{c}|c}[nullify-dots,last-col,code-for-last-col=\scriptstyle]
1 & 1 & 1 &\Cdots & & 1 & 0 & \\
0 & 1 & 0 &\Cdots & & 0 & & L_2 \gets L_2-L_1 \\
0 & 0 & 1 &\Ddots & & \Vdots & & L_3 \gets L_3-L_1 \\
& & &\Ddots & & & \Vdots & \Vdots \\
\Vdots & & &\Ddots & & 0 & \\
0 & & &\Cdots & 0 & 1 & 0 & L_n \gets L_n-L_1
\end{pNiceArray}$

66
  
1 1 1 1 0
0 1 0 0 L2 ←L2 −L1
 
0 0 1 L3 ←L3 −L1
 
 
 
 0 
0 0 1 0 Ln ←Ln −L1

18.5 Dotted lines which are no longer dotted

The option line-style controls the style of the lines drawn by \Ldots, \Cdots, etc. Thus, it’s
possible with these commands to draw lines which are not longer dotted (TikZ should be loaded).

\setcounter{MaxMatrixCols}{12}
\newcommand{\blue}{\color{blue}}
\[\begin{pNiceMatrix}[last-row,last-col,nullify-dots,xdots/line-style={dashed,blue}]
1& & & \Vdots & & & & \Vdots \\
& \Ddots[line-style=standard] \\
& & 1 \\
\Cdots & & & \blue 0 & \Cdots & & & \blue 1 & & & \Cdots & \blue \leftarrow i \\
& & & & 1 \\
& & &\Vdots & & \Ddots[line-style=standard] & & \Vdots \\
& & & & & & 1 \\
\Cdots & & & \blue 1 & \Cdots & & \Cdots & \blue 0 & & & \Cdots & \blue \leftarrow j \\
& & & & & & & & 1 \\
& & & & & & & & & \Ddots[line-style=standard] \\
& & & \Vdots & & & & \Vdots & & & 1 \\
& & & \blue \overset{\uparrow}{i} & & & & \blue \overset{\uparrow}{j} \\
\end{pNiceMatrix}\]

 
1
 
 

 1 

 0 1 ← i
 

 1 

 
 

 1 

 1 0 ← j
 

 1 

 
1
↑ ↑
i j

67
In fact, it’s even possible to draw solid lines with the commands \Cdots, \Vdots, etc.87
\NiceMatrixOptions{xdots={horizontal-labels,line-style = <->}}
$\begin{pNiceArray}{ccc|cc}[first-row,last-col,margin]
\Hdotsfor{3}^{3} & \Hdotsfor{2}^{2} \\ 3 2

2 & 1 & 1 & 1 & 1 & \Vdotsfor{3}^{3}\\

 
2 1 1 1 1
1 & 1 & 1 & 1 & 1 \\  1 1 1 1 1  3
1 & 1 & 1 & 1 & 1 \\
 
 1 1 1 1 1 
\Hline
 
 1 1 1 1 1 
2
1 & 1 & 1 & 1 & 1 & \Vdotsfor{2}^{2} \\ 1 1 1 1 1
1 & 1 & 1 & 1 & 1 \\
\end{pNiceArray}$

If you want the label on the line, you should use the special token “:” instead of “^”:
\NiceMatrixOptions{xdots={horizontal-labels,line-style = <->}}
$\begin{pNiceArray}{ccc|cc}[first-row,last-col,margin]
\Hdotsfor{3}:{3} & \Hdotsfor{2}:{2} \\
2 & 1 & 1 & 1 & 1 & \Vdotsfor{3}:{3} \\  3 2 
2 1 1 1 1
1 & 1 & 1 & 1 & 1 \\
1 1 1 1 1 3
1 & 1 & 1 & 1 & 1 \\

 
1 1 1 1 1
\Hline
 
 
1 1 1 1 1
1 & 1 & 1 & 1 & 1 & lignes
 
2
\Vdotsfor{2}:{2 \rlap{ \smash{rows}}} \\ 1 1 1 1 1
1 & 1 & 1 & 1 & 1 \\
\end{pNiceArray}$

If one prefers the braces of the library decorations.pathreplacing of TikZ, the best way is to use the
commands \Hbrace and \Vbrace provided by nicematrix (cf. p. 37).88
\NiceMatrixOptions{xdots/horizontal-labels}
$\begin{pNiceArray}{ccc|cc}[first-row,last-col,margin] 3 2
\Hbrace{3}{3} & \Hbrace{2}{2} \\  
2 1 1 1 1
2 & 1 & 1 & 1 & 1 & \Vbrace{3}{3} \\
1 1 1 1 1 3
1 & 1 & 1 & 1 & 1 \\
 
 
1 1 1 1 1
1 & 1 & 1 & 1 & 1 \\
 
 
\Hline
 1 1 1 1 1 
2
1 & 1 & 1 & 1 & 1 & \Vbrace{2}{2} \\ 1 1 1 1 1
1 & 1 & 1 & 1 & 1 \\
\end{pNiceArray}$

87 Inthis document, the TikZ library arrows.meta has been loaded, which impacts the shape of the arrow tips.
88 Remark that those commands are available only if TikZ has been loaded with the library decorations.pathreplacing:
\usepackage{TikZ} \usetikzlibrary{decorations.pathreplacing}.

68
It’s possible to change the TikZ style of those braces by changing the TikZ style nicematrix/brace.
In the following example, we assume that the TikZ extension calligraphy has been loaded:

\usetikzlibrary{calligraphy}

\NiceMatrixOptions{xdots/horizontal-labels}
\tikzset
{
nicematrix/brace/.style =
{
decoration =
{
calligraphic brace ,
amplitude = 0.4 em ,
raise = -0.25 em
} ,
line width = 0.1 em ,
decorate ,
}
}
$\begin{pNiceArray}{ccc|cc}[first-row,last-col,margin]
\Hbrace{3}{3} & \Hbrace{2}{2} \\ 3 2

2 & 1 & 1 & 1 & 1 & \Vbrace{3}{3} \\

 
2 1 1 1 1
1 & 1 & 1 & 1 & 1 \\  1 1 1 1 1  3
1 & 1 & 1 & 1 & 1 \\
 
 1 1 1 1 1 
\Hline
 
 1 1 1 1 1 
2
1 & 1 & 1 & 1 & 1 & \Vbrace{2}{2} \\ 1 1 1 1 1
1 & 1 & 1 & 1 & 1 \\
\end{pNiceArray}$

If one prefers the curly braces of the current mathematical font of LaTeX, one should use the com-
mands \SubMatrix, \OverBrace and \UnderBrace in the \CodeAfter.
$\begin{pNiceArray}{ccc|cc}[margin,last-col]
2 & 1 & 1 & 1 & 1 & \Block{3-1}{\quad 3} \\
1 & 1 & 1 & 1 & 1 \\ 3 2
1 & 1 & 1 & 1 & 1 \\ z }| { z }| {
\Hline
 
2 1 1 1 1 
1 & 1 & 1 & 1 & 1 & \Block{2-1}{\quad 2} \\  1 1 1 1 1  3
1 & 1 & 1 & 1 & 1 \\
 
 1 1 1 1 1 
\CodeAfter
 
 1 1 1 1 1 
\OverBrace[shorten,yshift=1.5mm]{1-1}{1-3}{3} 2
1 1 1 1 1
\OverBrace[shorten,yshift=1.5mm]{1-4}{1-5}{2}
\SubMatrix{.}{1-1}{3-5}{\rbrace}[xshift=3.5mm]
\SubMatrix{.}{4-1}{5-5}{\rbrace}[xshift=3.5mm]
\end{pNiceArray}$

Or course, the output may seem disappointing. That’s why, for this type of use, we recommend
the use of the commands \Hbrace and \Vbrace (provided by nicematrix), as shown in the previous
examples.

18.6 Dashed rules

In the following example, we use the command \Block to draw dashed rules. For that example, TikZ
should be loaded (by \usepackage{tikz}).

69
\begin{pNiceMatrix}
\Block[borders={bottom,right,tikz=dashed}]{2-2}{}
1 & 2 & 0 & 0 & 0 & 0 \\
4 & 5 & 0 & 0 & 0 & 0 \\
0 & 0 & \Block[borders={bottom,top,right,left,tikz=dashed}]{2-2}{}
7 & 1 & 0 & 0 \\
0 & 0 & -1 & 2 & 0 & 0 \\
0 & 0 & 0 & 0 & \Block[borders={left,top,tikz=dashed}]{2-2}{}
3 & 4 \\
0 & 0 & 0 & 0 & 1 & 4
\end{pNiceMatrix}
 
1 2 0 0 0 0
4 5 0 0 0 0
 
0 0 7 1 0 0
 
0
 0 −1 2 0 0
0 0 0 0 3 4
0 0 0 0 1 4

18.7 Stacks of matrices

We often need to compose mathematical matrices on top on each other (for example for the resolution
of linear systems).
In order to have the columns aligned one above the other, it’s possible to fix a width for all the
columns. That’s what is done in the following example with the environment {NiceMatrixBlock}
and its option auto-columns-width.
\begin{NiceMatrixBlock}[auto-columns-width]
\NiceMatrixOptions
{
light-syntax,
last-col, code-for-last-col = \color{blue}\scriptstyle,
vlines = 5 ,
matrix/columns-type = r ,
no-cell-nodes % only for speedup
}
\setlength{\extrarowheight}{1mm}

\quad $\begin{pNiceMatrix}
12 -8 7 5 3 {} ;
3 -18 12 1 4 ;
-3 -46 29 -2 -15 ;
9 10 -5 4 7
\end{pNiceMatrix}$

\smallskip
\quad $\begin{pNiceMatrix}
12 -8 7 5 3 ;
0 64 -41 1 19 { L_2 \gets L_1-4L_2 } ;
0 -192 123 -3 -57 { L_3 \gets L_1+4L_3 } ;
0 -64 41 -1 -19 { L_4 \gets 3L_1-4L_4 } ;
\end{pNiceMatrix}$

\smallskip
\quad $\begin{pNiceMatrix}
12 -8 7 5 3 ;
0 64 -41 1 19 ;
0 0 0 0 0 { L_3 \gets 3 L_2 + L_3 }
\end{pNiceMatrix}$

\smallskip

70
\quad $\begin{pNiceMatrix}
12 -8 7 5 3 {} ;
0 64 -41 1 19 ;
\end{pNiceMatrix}$
\end{NiceMatrixBlock}
 
12 −8 7 5 3
 

 3 −18 12 1 4

 −3 −46 29 −2 −15
9 10 −5 4 7
 
12 −8 7 5 3
 

 0 64 −41 1 19L2 ←L1 −4L2

 0 −192 123 −3 −57L3 ←L1 +4L3
0 −64 41 −1 −19 L4 ←3L1 −4L4
 
12 −8 7 5 3
0 64 −41 1 19
 

0 0 0 0 0 L3 ←3L2 +L3
!
12 −8 7 5 3
0 64 −41 1 19

However, one can see that the last matrix is not perfectly aligned with others. That’s why, in LaTeX,
the parenthesis have not exactly the same width (smaller parenthesis are a bit slimer).
In order the solve that problem, it’s possible to require the delimiters to be composed with the
maximal width, thanks to the boolean key delimiters/max-width .
\begin{NiceMatrixBlock}[auto-columns-width]
\NiceMatrixOptions
{
delimiters/max-width,
light-syntax,
last-col, code-for-last-col = \color{blue}\scriptstyle,
vlines = 5 ,
matrix/columns-type = r ,
no-cell-nodes % only for speedup
}
\setlength{\extrarowheight}{1mm}

\quad $\begin{pNiceMatrix}
12 -8 7 5 3 {} ;
3 -18 12 1 4 ;
-3 -46 29 -2 -15 ;
9 10 -5 4 7
\end{pNiceMatrix}$
...
\end{NiceMatrixBlock}
 
12 −8 7 5 3
 

 3 −18 12 1 4


 −3 −46 29 −2 −15

9 10 −5 4 7
 
12 −8 7 5 3
 

 0 64 −41 1 19
L2 ←L1 −4L2

 0 −192 123 −3 −57
L3 ←L1 +4L3
0 −64 41 −1 −19 L4 ←3L1 −4L4

71
  
12 −8 7 5 3
0 64 −41 1 19
 

0 0 0 0 0 L3 ←3L2 +L3
!
12 −8 7 5 3
0 64 −41 1 19

If you wish an alignment of the different matrices without the same width for all the columns, you can
construct a unique array and place the parenthesis with commands \SubMatrix in the \CodeAfter.
Of course, that array can’t be broken by a page break.
\setlength{\extrarowheight}{1mm}
\[\begin{NiceMatrix}[r, last-col=6, code-for-last-col = \scriptstyle \color{blue}]
12 & -8 & 7 & 5 & 3 \\
3 & -18 & 12 & 1 & 4 \\
-3 & -46 & 29 &-2 &-15 \\
9 & 10 &-5 &4 & 7 \\[1mm]
12 & -8 & 7 &5 & 3 \\
0 & 64 &-41 & 1 & 19 & L_2 \gets L_1-4L_2 \\
0 & -192 &123 &-3 &-57 & L_3 \gets L_1+4L_3 \\
0 & -64 & 41 &-1 &-19 & L_4 \gets 3L_1-4L_4 \\[1mm]
12 & -8 &7 &5 & 3 \\
0 & 64 &-41 &1 &19 \\
0 & 0 &0 &0 & 0 & L_3 \gets 3L_2+L_3 \\[1mm]
12 & -8 &7 &5 & 3 \\
0 & 64 &-41 & 1 & 19 \\
\CodeAfter [sub-matrix/vlines=4]
\SubMatrix({1-1}{4-5})
\SubMatrix({5-1}{8-5})
\SubMatrix({9-1}{11-5})
\SubMatrix({12-1}{13-5})
\end{NiceMatrix}\]

 
12 −8 7 5 3
 3 −18 12 1 4
 
 
 −3 −46 29 −2 −15 
9 10 −5 4 7
 
12 −8 7 5 3
 0 64 −41 1 19  L2 ←L1 −4L2
 
 
 0 −192 123 −3 −57  L3 ←L1 +4L3
0 −64 41 −1 −19 L4 ←3L1 −4L4
 
12 −8 7 5 3
64 −41
 
 0 1 19 
0 0 0 0 0 L3 ←3L2 +L3
!
12 −8 7 5 3
0 64 −41 1 19

In this tabular, the instructions \SubMatrix are executed after the composition of the tabular and,
thus, the vertical rules are drawn without adding space between the columns.

In fact, it’s possible, with the key vlines-in-sub-matrix , to choice a letter in the preamble of the
array to specify vertical rules which will be drawn in the \SubMatrix only (by adding space between
the columns).

72
\setlength{\extrarowheight}{1mm}
\[\begin{NiceArray}
[
vlines-in-sub-matrix=I,
last-col,
code-for-last-col = \scriptstyle \color{blue}
]
{rrrrIr}
12 & -8 & 7 & 5 & 3 \\
3 & -18 & 12 & 1 & 4 \\
-3 & -46 & 29 &-2 &-15 \\
9 & 10 &-5 &4 & 7 \\[1mm]
12 & -8 & 7 &5 & 3 \\
0 & 64 &-41 & 1 & 19 & L_2 \gets L_1-4L_2 \\
0 & -192 &123 &-3 &-57 & L_3 \gets L_1+4L_3 \\
0 & -64 & 41 &-1 &-19 & L_4 \gets 3L_1-4L_4 \\[1mm]
12 & -8 &7 &5 & 3 \\
0 & 64 &-41 &1 &19 \\
0 & 0 &0 &0 & 0 & L_3 \gets 3L_2+L_3 \\[1mm]
12 & -8 &7 &5 & 3 \\
0 & 64 &-41 & 1 & 19 \\
\CodeAfter
\SubMatrix({1-1}{4-5})
\SubMatrix({5-1}{8-5})
\SubMatrix({9-1}{11-5})
\SubMatrix({12-1}{13-5})
\end{NiceArray}\]

 
12 −8 7 5 3
 3 −18 12 1 4
 
 
 −3 −46 29 −2 −15 
9 10 −5 4 7
 
12 −8 7 5 3
 0 64 −41 1 19  L2 ←L1 −4L2
 
 
 0 −192 123 −3 −57  L3 ←L1 +4L3
0 −64 41 −1 −19 L4 ←3L1 −4L4
 
12 −8 7 5 3
64 −41
 
 0 1 19 
0 0 0 0 0 L3 ←3L2 +L3
!
12 −8 7 5 3
0 64 −41 1 19

18.8 How to highlight cells of a matrix

In order to highlight a cell of a matrix, it’s possible to “draw” that cell with the key draw of the
command \Block (this is one of the uses of a mono-cell block89 ).

89 We recall that, if the first mandatory argument of the command \Block is left empty, that means that the block is

a mono-cell block

73
$\begin{pNiceArray}{>{\strut}cccc}[margin,rules/color=blue,no-cell-nodes]
\Block[draw]{}{a_{11}} & a_{12} & a_{13} & a_{14} \\
a_{21} & \Block[draw]{}{a_{22}} & a_{23} & a_{24} \\
a_{31} & a_{32} & \Block[draw]{}{a_{33}} & a_{34} \\
a_{41} & a_{42} & a_{43} & \Block[draw]{}{a_{44}} \\
\end{pNiceArray}$
 
a11 a12 a13 a14
 a21
 a22 a23 a24 

 a31 a32 a33 a34 
a41 a42 a43 a44
We should remark that the rules we have drawn are drawn after the construction of the array and thus,
they don’t spread the cells of the array. We recall that, on the other side, the commands \hline and
\Hline, the specifier “|” and the options hlines, vlines, hvlines and hvlines-except-borders
spread the cells.90

It’s possible to color a row with \rowcolor in the code-before (or with \rowcolor in the first cell
of the row.
\begin{pNiceArray}{>{\strut}cccc}% <-- % mandatory
[margin, extra-margin=2pt,no-cell-nodes]
\rowcolor{red!15}A_{11} & A_{12} & A_{13} & A_{14} \\
A_{21} & \rowcolor{red!15}A_{22} & A_{23} & A_{24} \\
A_{31} & A_{32} & \rowcolor{red!15}A_{33} & A_{34} \\
A_{41} & A_{42} & A_{43} & \rowcolor{red!15}A_{44}
\end{pNiceArray}
 
A11 A12 A13 A14
 A21 A22 A23 A24 
 
 A31 A32 A33 A34 
A41 A42 A43 A44

However, it’s not possible to do a fine tuning. That’s why we describe now a method to highlight a
row of the matrix.
That example and the following ones require TikZ (by default, nicematrix only loads pgf, which is
a sub-layer of TikZ) and the TikZ library fit. The following instructions in the preamble of your
document do the job:
\usepackage{tikz}
\usetikzlibrary{fit}

We create a rectangular TikZ node which encompasses the nodes of the second row by using the tools
of the TikZ library fit. Those nodes are not available by default in the \CodeBefore (for efficiency).
We have to require their creation with the key create-cell-nodes of the keyword \CodeBefore.
\tikzset{highlight/.style={rectangle,
fill=red!15,
rounded corners = 0.5 mm,
inner sep=1pt,
fit=#1}}

$\begin{bNiceMatrix}
\CodeBefore [create-cell-nodes]
\tikz \node [highlight = (2-1) (2-last)] {} ;

90 For the command \cline, see the remark p. 12.

74
\Body
0 & \Cdots & 0 \\
1 & \Cdots & 1 \\
0 & \Cdots & 0 \\
\end{bNiceMatrix}$
 
0 0
1 1
0 0

We consider now the following matrix. If we want to highlight each row of this matrix, we can use
the previous technique three times.
\begin{pNiceArray}{ccc}[last-col, margin = 2pt]
\CodeBefore [create-cell-nodes]
\begin{tikzpicture}
\node [highlight = (1-1) (1-last)] {} ;
\node [highlight = (2-1) (2-last)] {} ;
\node [highlight = (3-1) (3-last)] {} ;
\end{tikzpicture}
\Body
a & a + b & a + b + c & L_1 \\
a & a & a + b & L_2 \\
a & a & a & L_3
\end{pNiceArray}
 
a a + b a + b + c L1
a a a + b L2
a a a L3

The result may seem disappointing. We can improve it by using the “medium nodes” instead of the
“normal nodes”.
\[\begin{pNiceArray}{ccc}[last-col, margin = 2pt, create-medium-nodes]
\CodeBefore [create-cell-nodes]
\begin{tikzpicture} [name suffix = -medium]
\node [highlight = (1-1) (1-last)] {} ;
\node [highlight = (2-1) (2-last)] {} ;
\node [highlight = (3-1) (3-last)] {} ;
\end{tikzpicture}
\Body
a & a + b & a + b + c & L_1 \\
a & a & a + b & L_2 \\
a & a & a & L_3
\end{pNiceArray}\]
 
a a + b a + b + c L1
a a a + b L2
a a a L3

18.9 Utilisation of \SubMatrix in the \CodeBefore

In the following example, we illustrate the mathematical product of two matrices.
The whole figure is an environment {NiceArray} and the three pairs of parenthesis have been added
with \SubMatrix in the \CodeBefore.

75
 Cj
 
b11 b1j b1n
 
 

 bkj 

 
bn1 bnj bnn
  
a11 a1n
  
  
 ai1
Li  aik ain  cij
 
 
  
an1 ann

\tikzset{highlight/.style={rectangle,
fill=red!15,
rounded corners = 0.5 mm,
inner sep=1pt,
fit=~#1}}
\[\begin{NiceArray}{*{6}{c}@{\hspace{6mm}}*{5}{c}}[nullify-dots]
\CodeBefore [create-cell-nodes]
\SubMatrix({2-7}{6-last})
\SubMatrix({7-2}{last-6})
\SubMatrix({7-7}{last-last})
\begin{tikzpicture}
\node [highlight = (9-2) (9-6)] { } ;
\node [highlight = (2-9) (6-9)] { } ;
\end{tikzpicture}
\Body
& & & & & & & & \color{blue}\scriptstyle C_j \\
& & & & & & b_{11} & \Cdots & b_{1j} & \Cdots & b_{1n} \\
& & & & & & \Vdots & & \Vdots & & \Vdots \\
& & & & & & & & b_{kj} \\
& & & & & & & & \Vdots \\
& & & & & & b_{n1} & \Cdots & b_{nj} & \Cdots & b_{nn} \\[3mm]
& a_{11} & \Cdots & & & a_{1n} \\
& \Vdots & & & & \Vdots & & & \Vdots \\
\color{blue}\scriptstyle L_i
& a_{i1} & \Cdots & a_{ik} & \Cdots & a_{in} & \Cdots & & c_{ij} \\
& \Vdots & & & & \Vdots \\
& a_{n1} & \Cdots & & & a_{nn} \\
\CodeAfter
\tikz \draw [gray,shorten > = 1mm, shorten < = 1mm] (9-4.north) to [bend left] (4-9.west) ;
\end{NiceArray}\]

18.10 A triangular tabular

In the following example, we use the style PGF/TikZ nicematrix/cell-node to rotate the contents
of the cells (and, then, we compensate that rotation by a rotation of the whole tabular with the
command \adjustbox of the eponymous package, which must be loaded previously).
\pgfset
{
nicematrix/cell-node/.append style =
{ text/rotate = 45, minimum size = 6 mm }
}

\setlength{\tabcolsep}{0pt}

\adjustbox{rotate = -45, set depth = 6mm + 1.414 \arrayrulewidth}

76
{\begin{NiceTabular} [ hvlines, corners=SE, baseline = line-9 ] { cccccccc }
\CodeBefore
\chessboardcolors{red!15}{blue!15}
\Body
1 & 1 & 1 & 1 & 1 & 1 & 1 & 1 \\
1 & 2 & 3 & 4 & 5 & 6 & 7 \\
1 & 3 & 6 & 10 & 15 & 21 \\
1 & 4 & 10 & 20 & 35 \\
1 & 5 & 15 & 35 \\
1 & 6 & 21 \\
1 & 7 \\
1
\end{NiceTabular}}

1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
1 6 15 20 15 6 1
1 7 21 35 35 21 7 1

77
19 History

The development of the package nicematrix is done in the following GitHub depot:
https://github.com/fpantigny/nicematrix
The successive versions of the file nicematrix.sty provided by TeXLive are also available on the
svn server of TeXLive:
https:www.tug.org/svn/texlive/trunk/Master/texmf-dist/tex/latex/nicematrix/nicematrix.sty

Changes between version 7.0 and 7.1

New commands \Hbrace and \Vbrace.
New commands \EmptyColumn and \EmptyRow in the \CodeBefore.

Changes between version 6.29 and 7.0

The package nicematrix is now compatible (for the tabulars) with the Tagging Project.

Changes between version 6.28 and 6.29

Modification in order to be compatible with the next version of array (v. 2.6g).

Changes between version 6.27 and 6.28

Sub-blocks with the character & (when the key ampersand-in-block is in force).
Keys p and j for the command \Block.
PGF nodes i.1, i.2, i.3, etc.

Changes between version 6.26 and 6.27

New key light-syntax-expanded.

Changes between version 6.25 and 6.26

Special color nocolor.

Changes between version 6.24 and 6.25

Correction of several bugs.
An instruction \rowlistcolors in the tabular stops the effect of a previous \rowlistcolors.

Changes between version 6.23 and 6.24

New command \TikzEveryCell available in the \CodeAfter and the \CodeBefore to apply the same
TikZ instruction to all the cells and blocks of the array.
New key offset in the key tikz of a command \Block.

Changes between version 6.22 and 6.23

The specifier “|” in the preambles of the environments has now an optional argument.
Correction of several bugs.

78
Changes between version 6.21 and 6.22
Key opacity for the command \Block.
It’s now possible to put a label on a “continuous dotted line” with the specifier “:”.

Changes between version 6.20a and 6.21

Key c for the command \tabularnote.
New commands \rowcolors and \rowlistcolors available in the array itself (previously, there were
only two commands \rowcolors and \rowlistcolors available in the \CodeBefore.

Changes between version 6.20 and 6.20a

The value of the key name of an environment of nicematrix is expanded (in the TeX sens).
The labels of the tabular notes (created by the command \tabularnote) are now composed in an
overlapping position only when the horizontal alignment mode of the column is c or r.

Changes between version 6.19 and 6.20

New key xdots/horizontal-labels.

Changes between version 6.18 and 6.19

The command \tabularnote now supports an optional argument (between square brackets) to change
the symbol of the reference of the note.

Changes between version 6.17 and 6.18

New key opacity in the commands to color cells, rows and columns.
New key rounded-corners for a whole tabular.

Changes between version 6.16 and 6.17

New PGF/TikZ style nicematrix/cell-node.
New key pgf-node-code

Changes between version 6.15 and 6.16

It’s now possible to put any LaTeX extensible delimiter (\lgroup, \langle, etc.) in the preamble of
an environment with preamble (such as {NiceArray}) by prefixing them by \left and \right.
New key code for the command \SubMatrix in the \CodeAfter.

Changes between version 6.14 and 6.15

New key transparent for the command \Block (with that key, the rules are drawn within the block).

Changes between version 6.13 and 6.14

New keys for the command \Block for the vertical position of the content of that block.

79
Changes between version 6.12 and 6.13
New environment {TabularNote} in {NiceTabular} with the same semantic as the key tabularnote
(for legibility).
The command \Hline nows accepts options (between square brackets).

Changes between version 6.11 and 6.12

New keys caption, short-caption and label in the environment {NiceTabular}.
In {NiceTabular}, a caption specified by the key caption is wrapped to the width of the tabular.
Correction of a bug: it’s now possible to use \OverBrace and \UnderBrace with unicode-math (with
XeLaTeX or LuaLaTeX).

Changes between version 6.10 and 6.11

New key matrix/columns-type to specify the type of columns of the matrices.
New key ccommand in custom-line and new command \cdottedline.

Changes between version 6.9 and 6.10

New keys xdots/shorten-start and xdots/shorten-end.
It’s possible to use \line in the \CodeAfter between two blocks (and not only two cells).

Changes between version 6.8 and 6.9

New keys xdots/radius and xdots/inter for customisation of the continuous dotted lines.
New command \ShowCellNames available in the \CodeBefore and in the \CodeAfter.

Changes between version 6.7 and 6.8

In the notes of a tabular (with the command \tabularnote), the duplicates are now detected: when
several commands \tabularnote are used with the same argument, only one note is created at the
end of the tabular (but all the labels are present, of course).

Changes between version 6.6 and 6.7

Key color for \OverBrace and \UnderBrace in the \CodeAfter
Key tikz in the key borders of a command \Block

Changes between version 6.5 and 6.6

Keys tikz and width in custom-line.

Changes between versions 6.4 and 6.5

Key custom-line in \NiceMatrixOptions.
Key respect-arraystretch.

Changes between versions 6.3 and 6.4

New commands \UnderBrace and \OverBrace in the \CodeAfter.
Correction of a bug of the key baseline (cf. question 623258 on TeX StackExchange).
Correction of a bug with the columns V of varwidth.
Correction of a bug: the use of \hdottedline and : in the preamble of the array (or another letter
specified by letter-for-dotted-lines) was incompatible with the key xdots/line-style.

80
Changes between versions 6.2 and 6.3
Keys nb-rows, rowcolor and bold for the command \RowStyle
Key name for the command \Block.
Support for the columns V of varwidth.

Changes between versions 6.1 and 6.2

Better compatibility with the classes revtex4-1 (deprecated) and revtex4-2.
Key vlines-in-sub-matrix.

Changes between versions 6.0 and 6.1

Better computation of the widths of the X columns.
Key \color for the command \RowStyle.

81
Index

Symbols \CodeAfter, 39–44, 75

&-in-blocks, 10 \CodeBefore...\Body, 19, 75, 76
color
A for the delimiters of the matrices, 53
ampersand-in-blocks, 10 key for dotted rules, 35
\arraycolor (command of \CodeBefore), 19 key of \Block, 5
\arrayrulecolor, 12 key of \OverBrace and \UnderBrace, 43
\arrayrulewidth, 12 key of \RowStyle, 26
auto-columns-width key of “custom-line”, 16
(clé de {NiceMatrixBlock}), 71 colortbl (package), 19
(key of {NiceMatrixBlock}), 27 Colour
\AutoNiceMatrix, 53 of the cells, 19
of the delimiters of the matrices, 53
B
of the rules, 12
baseline (key for an environment), 3
cols (key of \rowcolors of \CodeBefore), 21
\BAutoNiceMatrix, 53
\columncolor
\bAutoNiceMatrix, 53
command in the preamble of an environment,
blkarray (package), 38
24
\Block, 4
command of \CodeBefore, 19, 64
Blocks in the tabulars, 4–11
columns-type (key of {NiceMatrix}, etc.), 51
\Body, see \CodeBefore
columns-width, 27
bold (key of \RowStyle), 26
command (key of “custom-line”), 16
booktabs (package), 11
corners (key of an environment), 14, 23
borders (key of \Block), 5
Corners (rounded —)
bottomrule (subkey of “notes”), 47
for a block, 5
brace (nicematrix/brace is a TikZ style
for a tabular, 49
used by \Hbrace et \Vbrace), 37
Corners (the empty —), 14, 76
C create-cell-nodes (key of \CodeBefore), 57, 75
Captions of the tabulars, 44 create-extra-nodes, 56
caption (key of {NiceTabular}), 44 create-large-nodes, 56
caption-above, 44 create-medium-nodes, 56, 75
ccommand (key of “custom-line”), 16 \crossbox (defined in an example), 60
\Cdots, 31 custom-line, 16–19
\cdottedline, 18
D
cell-space-bottom-limit, 2, 26
\Ddots, 31, 60, 66
cell-space-limits, 2, 26
\definecolorseries (command of xcolor), 22
cell-space-top-limit, 2, 26
delimiters
\cellcolor
—/color for an environment, 53
command in tabular, 24
—/color pour \SubMatrix, 41
command of \CodeBefore, 19
—/max-width, 71
cellspace (package), 2
delimiters in the preambles, 38
\chessboardcolors
detect-duplicates (subkey of “notes”), 47
(commande du \CodeBefore), 19, 76
\diagbox, 15
\cline (LaTeX command), 12
Dotted lines, 31–38, 66
code (key of \SubMatrix), 41
dotted (key of “custom-line”), 18
code-after, 39
draw (key of \Block), 5, 73
code-before
key for an environment, 19 E
subkey of “notes”, 47 empty (key of \TikzEveryCell), 44
code-for-first-col, 30 \EmptyColumn (command of \CodeBefore), 24
code-for-first-row, 30, 51, 67 \EmptyRow (command of \CodeBefore), 24
code-for-last-col, 30, 51, 66, 67 end-of-row (to be used with light-syntax), 53
code-for-last-row, 30, 51

82
enumitem (package required to use left-xshift (key of \SubMatrix), 41
\tabularnote), 45, 65 letter (key of “custom-line”), 16
enumitem-keys (subkey of “notes”), 47, 65 light-syntax, 53
enumitem-keys-para (subkey of “notes”), 47 light-syntax-expanded, 53
exterior-arraycolsep, 62 \line (command of \CodeAfter), 39
extra-height (key of \SubMatrix), 41 line-style (key for dotted rules), 35
extra-left-margin, 56 line-style (key for the dotted rules), 67
extra-right-margin, 56 line-width (key of \Block), 5
Lines in the tabulars, see Rules
F
fill M
key of \Block, 5 mathdots (package), 31
key of \RowStyle, 26 max-width (subkey of “delimiters”), 71
first-col, 29 multiplicity (key of “custom-line”), 16
first-row, 29, 51
footnote (package), 45 N
footnote (key), 45 name
footnotehyper (package), 45 key for an environment, 54
footnotehyper (key), 45 key of \Block, 5
key of \SubMatrix, 59
H nb-rows (key of \RowStyle), 26
\Hbrace, 37 {NiceArrayWithDelims}, 54
\Hdotsfor, 33 {NiceMatrixBlock}, 27, 70
\hdottedline, 18 \NiceMatrixOptions, 1
highlight (TikZ style defined in {NiceTabularX}, 28
an example), 74 no-cell-nodes, 54
\Hline, 13 nocolor, 26
hlines, see Rules Nodes of PGF/TikZ, 54–59
key for an environment, 13 non empty (key of \TikzEveryCell), 44
key of \Block, 5 Notes in the tabulars, 45–49, 65
key of \SubMatrix, 41 \NotEmpty, 61
horizontal-label(s) (key for dotted rules), 35 notes (key to customize the notes of a
\Hspace, 32 tabular), 65
hvlines, see Rules nullify-dots, 32
key for an environment, 14
key of \Block, 5 O
key of \SubMatrix, 41 \OnlyMainNiceMatrix, 54
hvlines-except-borders, 14, 65 opacity
key of \Block, 5
I key of \RowStyle, 26
\Iddots, 31, 60 key of commands such as
Incompatibilities, 62 \rowcolor, etc., 20
inter (key for dotted rules), 35 \OverBrace (command of \CodeAfter
iRow (LaTeX counter), 52 and \CodeBefore), 43

J P
jCol (LaTeX counter), 52 para (subkey of “notes”), 47
parallelize-diags, 60
L \pAutoNiceMatrix, 53
label (key of {NiceTabular}), 44 pgf-node-code, 55, 76
label-in-list (subkey of “notes”), 47
label-in-tabular (subkey of “notes”), 47 R
last-col, 29, 51, 66 radius (key for dotted rules), 35
last-row, 29, 51 \rectanglecolor (in \CodeBefore), 19
\Ldots, 31 renew-dots, 34
\left : used by nicematrix for renew-matrix, 34
delimiters in the preambles, 38 \resetcolorseries (command of xcolor), 22
left-margin, 56 respect-arraystretch (key of \Block), 5
left-shorten (key of \OverBrace and respect-blocks (key of \rowcolors du
\UnderBrace), 43 \CodeBefore), 21

83
restart (key of \rowcolors of \CodeBefore), 21 U
\right : used by nicematrix for \UnderBrace (command of \CodeAfter
delimiters in the preambles, 38 and \CodeBefore), 43
right-margin, 56
right-shorten (key of \OverBrace and V
\UnderBrace), 43 V (the columns V of varwidth), 28, 56
right-xshift (key of \SubMatrix), 41 v-center (key of \Block), 9
\rotate, 24, 26, 51 varwidth (package), 28, 56
rounded-corners \VAutoNiceMatrix, 53
key of \Block, 5 \vAutoNiceMatrix, 53
key of \RowStyle, 26 \Vbrace, 37
key of {NiceTabular}, 49 \Vdots, 31
\rowcolor \Vdotsfor, 33
command in tabular, 24, 74 vlines, see Rules
command of \CodeBefore, 19, 65 key for an environment, 13
rowcolor (key of \RowStyle), 26 key of \Block, 5
\rowcolors (command of \CodeBefore), 19 key of \SubMatrix, 41
\rowlistcolors (command of \CodeBefore), 19 vlines-in-sub-matrix, 72
\RowStyle, 26
Rules in the tabulars, 11–19 W
rules (key for an environment), 12, 65 width
key of {NiceTabular}, 28
S subkey of “rules”, 12
S (the columns S of siunitx), 24, 50 Width of the columns, 27–29
sep-color (key of “custom-line”), 16
short-caption, 44 X
shorten (key for dotted rules), 35 X (the columns X), 28
shorten-end (key for dotted rules), 35 xdots (and its subkeys), 31
shorten-start (key for dotted rules), 35 xshift (key of \SubMatrix), 41
\ShowCellNames (command of \CodeAfter
Y
and \CodeBefore), 50
yshift (key of \OverBrace and \UnderBrace), 43
siunitx (package), 50
slim (key of \SubMatrix), 41
small (key for an environment), 52
{smallmatrix} (environment of amsmath), 52
standard-cline, 12
style (subkey of “notes”), 47, 65
sub-matrix (key of \CodeAfter, with subkeys), 39
\SubMatrix (command of \CodeAfter
and \CodeBefore), 40, 59, 72, 75

T
\tabularnote, 45, 65
{TabularNote}, 46
tabularnote (key of {NiceTabular}), 46
tabularx (package), 28
Tagging Project, 63
tcolorbox (package), 64
threeparttable (package), 49
tikz-braces (key at load-tome of nicematrix), 37
TikZ (utilisation with nicematrix), 54
\TikzEveryCell (command of \CodeAfter
and \CodeBefore), 44
tikz
key of \Block, 5, 63
key of “borders” de \Block, 5, 69
key of “custom-line”, 17
total-width (key of “custom-line”), 17
transparent (key of \Block), 5, 64

84
Contents
1 The environments of this package 2

2 The vertical space between the rows 2

3 The vertical position of the arrays 3

4 The blocks 4
4.1 General case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2 The mono-column blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.3 The mono-row blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.4 The mono-cell blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.5 Horizontal position of the content of the block . . . . . . . . . . . . . . . . . . . . . . 7
4.6 Vertical position of the content of the block . . . . . . . . . . . . . . . . . . . . . . . 9
4.7 \\ and & in the blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

5 The rules 11
5.1 Some differences with the classical environments . . . . . . . . . . . . . . . . . . . . 11
5.1.1 The vertical rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1.2 The command \cline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2 The thickness and the color of the rules . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.3 The tools of nicematrix for the rules . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.3.1 The keys hlines and vlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.3.2 The keys hvlines and hvlines-except-borders . . . . . . . . . . . . . . . . . . . . 14
5.3.3 The (empty) corners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.3.4 The command \diagbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.3.5 Commands for customized rules . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6 The color of the background of the rows and columns 19

6.1 Use of colortbl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.2 The tools of nicematrix in the \CodeBefore . . . . . . . . . . . . . . . . . . . . . . . 19
6.3 Color tools to be used inside the tabular . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.4 The special color “nocolor” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

7 The command \RowStyle 26

8 The width of the columns 27

8.1 Basic tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
8.2 The columns X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
8.3 The columns V of varwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

9 The exterior rows and columns 29

10 The continuous dotted lines 31

10.1 The option nullify-dots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
10.2 The commands \Hdotsfor and \Vdotsfor . . . . . . . . . . . . . . . . . . . . . . . . . 33
10.3 How to generate the continuous dotted lines transparently . . . . . . . . . . . . . . . 34
10.4 The labels of the dotted lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
10.5 Customisation of the dotted lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
10.6 The commands \Hbrace and \Vbrace . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
10.7 The dotted lines and the rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

11 Delimiters in the preamble of the environment 38

12 The \CodeAfter 39
12.1 The command \line in the \CodeAfter . . . . . . . . . . . . . . . . . . . . . . . . . . 39
12.2 The command \SubMatrix in the \CodeAfter (and the \CodeBefore) . . . . . . . . . 40
12.3 The commands \OverBrace and \UnderBrace in the \CodeAfter . . . . . . . . . . . 43
12.4 The command \TikzEveryCell in the \CodeAfter . . . . . . . . . . . . . . . . . . . . 44

85
13 Captions and notes in the tabulars 44
13.1 Caption of a tabular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
13.2 The footnotes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
13.3 The notes of tabular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
13.4 Customisation of the tabular notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
13.5 Use of {NiceTabular} with threeparttable . . . . . . . . . . . . . . . . . . . . . . . . 49

14 Other features 49
14.1 The key rounded-corners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
14.2 Command \ShowCellNames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
14.3 Use of the column type S of siunitx . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
14.4 Default column type in {NiceMatrix} . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
14.5 The command \rotate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
14.6 The option small . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
14.7 The counters iRow and jCol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
14.8 The key light-syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
14.9 Color of the delimiters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
14.10 The environment {NiceArrayWithDelims} . . . . . . . . . . . . . . . . . . . . . . . . 54
14.11 The command \OnlyMainNiceMatrix . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

15 Use of TikZ with nicematrix 54

15.1 The nodes corresponding to the contents of the cells . . . . . . . . . . . . . . . . . . 54
15.1.1 The key pgf-node-code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
15.1.2 The columns V of varwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
15.2 The medium nodes and the large nodes . . . . . . . . . . . . . . . . . . . . . . . . . 56
15.3 The nodes which indicate the position of the rules . . . . . . . . . . . . . . . . . . . 58
15.4 The nodes corresponding to the command \SubMatrix . . . . . . . . . . . . . . . . . 59

16 API for the developers 59

17 Technical remarks 60
17.1 Diagonal lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
17.2 The empty cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
17.3 The option exterior-arraycolsep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
17.4 Incompatibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
17.5 Compatibility with the Tagging Project of LaTeX . . . . . . . . . . . . . . . . . . . . 63

18 Examples 63
18.1 Utilisation of the key ’tikz’ of the command \Block . . . . . . . . . . . . . . . . . . . 63
18.2 Use with tcolorbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
18.3 Notes in the tabulars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
18.4 Dotted lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
18.5 Dotted lines which are no longer dotted . . . . . . . . . . . . . . . . . . . . . . . . . 67
18.6 Dashed rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
18.7 Stacks of matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
18.8 How to highlight cells of a matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
18.9 Utilisation of \SubMatrix in the \CodeBefore . . . . . . . . . . . . . . . . . . . . . . 75
18.10 A triangular tabular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

19 History 78

Index 82

86