User talk:Tamfang/Archive 2013

Latest comment: 11 years ago by Tomruen in topic Ditrigonary polyhedra


tamfang auf Behasa Indonesian

Hi INTP (I'm INTJ). I know an Indonesian & will ask them tonight & let you know what means. p.s. Enjoyed looking your page -- amusing & smart! Ihardlythinkso (talk) 20:58, 23 January 2013 (UTC)

Thanks! —Tamfang (talk) 21:03, 23 January 2013 (UTC)

Okay, here's what I got back from my "Indonesian connection" to my Email inquiry:

maybe wrong spelling TAMFANG? I do not know that word, check the spelling?

The responder is native Indonesian (grew up in Jakarta). Anyway, ... "them's the facts!" Cheers, Ihardlythinkso (talk) 03:32, 25 January 2013 (UTC)

Swell. I can remove that sentence! —Tamfang (talk) 03:42, 25 January 2013 (UTC)

Copy-edit?

Hi Anton, if you'd like to take a look, I expanded some material to clear up some ambiguity at: Henagon#In_spherical_geometry. Also discussion on the talk page. Tom Ruen (talk) 02:01, 16 February 2013 (UTC)

Enclave and exclave

Hi. The recent introduction of Wikidata and its use for recording interwiki links has lead me to question the wisdom of covering two different (even if highly related) concepts in one article, as Enclave and exclave does. I've said more at Talk:Enclave and exclave#Reconsideration of merge of enclave and exclave, you may to comment there. -- chris_j_wood (talk) 16:28, 24 February 2013 (UTC)

Ned Sparks

Don't be a smart ass. Beyond My Ken (talk) 11:47, 27 February 2013 (UTC)

More noncompact hyperbolic tilings

Can you make *34∞, *44∞, *4∞∞? Double sharp (talk) 15:49, 27 February 2013 (UTC)

What does ya wants 'em fer? —Tamfang (talk) 07:18, 28 February 2013 (UTC)

Blank rows are left at [1]. Actually if batch-style I wouldn't mind having all the finite ones too from this fundamental domain center perspective: 2<=p<=q<=r<=9. How many sets would that be? Uh oh, 100+! Maybe 2<=p<=q<=r<=6..8 or so? ~30 families, that's better! At your convenience! :) Tom Ruen (talk) 20:34, 27 February 2013 (UTC)

≤7 : 44; ≤8 : 71; ≤9 : 106. —Tamfang (talk) 07:32, 28 February 2013 (UTC)
Tom, kindly consult me before you rearrange a table that has my name on top. The sequence was not random, as inspection of the source code shows. —Tamfang (talk) 06:07, 28 February 2013 (UTC)
I'm sorry Anton. My enthusiasm made me rude. I saw you uploaded the 3 infinite families. Thanks so much! Tom Ruen (talk) 20:44, 28 February 2013 (UTC)


WOW! I knew there was an overachiever in you Anton! Tables look wonderful, including merged domains of the even-order sets! :) [2]

p.s. Your "other" category isn't complete if sometime you'd like to look further for merge rules. Like (642) has 6 subgroups by removing any single mirror or any pair of mirrors. Shown here. File:Hyperbolic 642 subgroups-small.png So 642, 662, 444, i42, 644, 664, 666, i44, ii2, ii4 all could have 6 sets instead of 3. The mirror removal between branches both orders above two is what creates new quad domains (like hand-recolored File:Hyperbolic domains i222.png from (∞ 4 2) is one instance your rules miss), otherwise similar to another triangle domain family. I assume you skipped iii intentionally, but it also ought to have 6 subgroup! I imagine you just pick 100 or 1000 for infinity? At least that trick can work with Tyler Applet for visually sufficient approximations. [3] Tom Ruen (talk) 23:49, 3 March 2013 (UTC)

"other" consists, so far, of what happens when the "checkers" code (first column) is altered to count flips (mod 2) over only one of the three mirrors, rather than the sum of all three. (This gives neat results only if both adjacent angle-divisors are even. When the present death-march is done, I'll look at counting mod another common factor if any.)
Haven't skipped iii (∞ ∞ ∞); the generating script hasn't reached it yet. — No, I literally use the angle π/∞ = 0. —Tamfang (talk) 03:22, 4 March 2013 (UTC)
Some octagonal ones are still missing... Double sharp (talk) 11:41, 4 March 2013 (UTC)
No shit. My computer has been grinding for five days now (the programs aren't as efficient as they would be in an ideal world) and I've been putting things up in batches. Not that I know why anyone would want all of this. —Tamfang (talk) 21:13, 4 March 2013 (UTC)
THANK YOU!!! Tom Ruen (talk) 22:29, 4 March 2013 (UTC)

Can you make fractional ones like (7 7/2 2), (9 9/2 2), (7/2 3 3), (7 7/3 3), (7/2 4 4), (5/2 4 4), (∞ 7/3 2)... (just throwing a few out) Double sharp (talk) 11:12, 4 March 2013 (UTC)

No I'm sure - star tilings don't have simple interiors to fill. Tom Ruen (talk) 19:27, 4 March 2013 (UTC)

Shouldn't all this gay badinage be at commons:User talk:Tamfang? —Tamfang (talk) 21:21, 4 March 2013 (UTC)

Tri-infinite hyperbolic tilings

Hi Anton, if you want a challenge sometime, here's a table I'd love completed as an example of noncompact hyperbolic tiling family! SockPuppetForTomruen (talk) 20:14, 26 December 2012 (UTC)

Paracompact uniform tilings in [∞,3] family
Symmetry: [∞,3], (*∞32) [∞,3]+
(∞32)
[1+,∞,3]
(*∞33)
[∞,3+]
(3*∞)
                                                                 
     
=     
     
=     
     
=     
            =
     or     
      =
     or     
     
=     
                   
{∞,3} t{∞,3} r{∞,3} t{3,∞} {3,∞} rr{∞,3} tr{∞,3} sr{∞,3} h{∞,3} h2{∞,3} s{3,∞}
Uniform duals
                                                           
                 
V∞3 V3.∞.∞ V(3.∞)2 V6.6.∞ V3 V4.3.4.∞ V4.6.∞ V3.3.3.3.∞ V(3.∞)3 V3.3.3.3.3.∞

Like

Uniform hexagonal/triangular tilings
Symmetry: [6,3], (*632) [6,3]+
(632)
[6,3+]
(3*3)
{6,3} t{6,3} r{6,3} t{3,6} {3,6} rr{6,3} tr{6,3} sr{6,3} s{3,6}
                                                     
                 
63 3.122 (3.6)2 6.6.6 36 3.4.6.4 4.6.12 3.3.3.3.6 3.3.3.3.3.3
Uniform duals
                 
V63 V3.122 V(3.6)2 V63 V36 V3.4.6.4 V.4.6.12 V34.6 V36

p.s. Another tiling family of interest unrepresented in the hyperbolic tiling images, symmetry *2223 in orbifold notation. I see the fundamental domain can be bisected by a mirror into two triangles as *642, although there's apparently a degree of freedom in *2223 that the fundamental domain may not be symmetry, just like rectangular symmetry *2222 is only divisible into *442 if the domain is a square, while *2223 would be a kite domain to have reflective symmetry. Anyway, It would be great to have some examples if you're up for it! Tom Ruen (talk) 04:07, 7 January 2013 (UTC)

I tried a hand-coloring of *642 fundamental domains (or bicolored version), combining triangles in 6 permutations of mirror removal, including symmetry orbifold *222222. So these are just a way to construct non-triangular reflection domains, and each has a set of uniform tilings that can be generated! Tom Ruen (talk) 03:16, 8 January 2013 (UTC)
If I understood orbifold notation ... —Tamfang (talk) 03:29, 19 January 2013 (UTC)
 

Hey Anton, perhaps I could make some use from your Python code to generate the hyperbolic tilings? Do you have it conveniently available? No hurry, just a thought! Tom Ruen (talk) 02:01, 19 January 2013 (UTC)

See my Commons page – or (now) any of the image pages. —Tamfang (talk) 03:30, 19 January 2013 (UTC)
Found it! [4] Tom Ruen (talk) 23:54, 19 January 2013 (UTC)

p.s. Not enough patience with me with your source code, but I did (partially) hand-recolor your *∞∞2 triangle "checkerboard" domains into an infinite square checkerboard domain *∞∞∞∞! (and *∞42 into *2∞2∞) I'm not sure how to play chess or checkers on either board, although perhaps *3333 or *4444 would be fun! Tom Ruen (talk) 23:32, 28 January 2013 (UTC)

   
*2222
*3333
*4444


I don't think there is a real problem with defining rules for chess on any non-infinite board. Considering a square tiling of the form {4,2n} (*nnnnn):

  • Rook: Moves from any square to any adjacent square of a different colour, and continues that way indefinitely.
  • Bishop: Same as rook, but must go to a square of the same colour instead.
  • Queen: Rook plus bishop.
  • King: Same as queen, but only moves one square.
  • Knight: A single-square rook move, followed by a single square-bishop move going outwards. Can jump.
  • Pawn: A single (double on first move) square rook move forward (towards where the enemy is at the start of the game). A single-move bishop capture forward. Promotes at enemy's back rank.

Castling and en passant are readily definable.

You should start from a central vertex, and remove all tiles that need five or more king moves to access from the central vertex to get an "8×8"(???) board. When that is done, you can add the pieces. (I have not yet figured out an ideal arrangement.)

There are many more squares on a {4,6} than on a {4,4} board, so perhaps you could make a "6×6" board by clipping tiles four or more king moves from the central vertex instead. I would recommend not playing on anything higher than {4,8} unless you want a very long game. (All the pieces seem to benefit equally from the curvature, so the game should be playable using Chess with different armies, unless some pieces win material tactically right out of the opening position.)

If you want a diagram of the starting position and piece moves, ask me. It will make me figure out a good arrangement and think about whether to follow chess with an "8×8" board or make a "mini-mega-chess" with a "6×6" board. (4×4 is obviously too small.)

I don't play checkers, but the rules seem readily extendable to such boards.

For boards that are not composed of squares, look at Hexagonal chess and Triangular Chess for the Euclidean versions. They can then be extended to hyperbolic versions using what I wrote above.

Spherical boards do not have enough squares to make a very interesting game. There is also the danger of being attacked from behind, so I think you should use Betza's Peace Bump Chess rule for such a game (retracting moves across a side's own baseline cannot be captures). I also think that only the icosahedron (and perhaps the dodecahedron) gives a good game.

A large hosohedron might be an interesting idea, on the other hand. Double sharp (talk) 08:58, 2 February 2013 (UTC)

Postscript: Anton! Your bitmap hyperbolic tilings and checkerboards were a great success for my symmetry work. I did my first experimental table using them to show subgroups of *642 symmetry, using edge-detection on the checkerboards to isolate mirror lines.I used lightened checkerboards to show rotational symmetry, and mirrors on top for mixed groups. I included glide reflections in (32×) as narrow lines, but would be better as dashed lines. I have a similar table for Euclidean *442 at User:Tomruen/temp1, and explicitly labeled gyration point orders there. So anyway, thanks again! Sadly I don't think I'm prepared to automate these manipulations for all the hyperbolic familes, although I'll do a few more by hand. Tom Ruen (talk) 01:43, 14 April 2013 (UTC)

Mystery ideal triangle tiling

How can we distinguish between these two? Perhaps ideal triangles have a computable area, and Anton's are equal-area as (p,p,p) as p-->oo, while the second ones are not?! Tom Ruen (talk) 02:32, 4 February 2013 (UTC)

   
Found at Ideal triangle
Both are equal-area (π/2 - 3*0 = π/2 in each case) but the other pattern lacks reflection symmetries. —Tamfang (talk) 02:36, 4 February 2013 (UTC)
I can't see what the symmetry, or what mirrors exist outside the center. Here's a blog that has a similar tessellation [5]. Tom Ruen (talk) 02:44, 4 February 2013 (UTC)
Mine is generated by hyperbolic mirrors; the other appears to be generated in the manner of a compass rose. —Tamfang (talk) 02:56, 4 February 2013 (UTC)
I knew infinity was trouble! If it was drawn in dynamic viewer, you could translate the center, and move a different triangle to the center and I expect central symmetry would disappear. Tom Ruen (talk) 03:08, 4 February 2013 (UTC)
Yes, I believe so. —Tamfang (talk) 04:00, 4 February 2013 (UTC)

Terr. of US

Thanks for the clean-up at Territories of US' listing territorial Members of Congress. At the time of posting, the existence of territorial Members of Congress was contested at 'United States:Talk' --- so I added the .gov links expecting another two-month fight on the 'Terr. of US:Talk' page. I enumerated because naturalized US citizens and their children are editor-denied legitimacy on American Samoa, #5. -- all that who-shot-John is old news. Now the edit-style is more conventional and the inline reference reads better without appearing self-promotional for the Members. Thanks.

Modern era territories do not meet the 'rights and privileges' of states, so some deny them inclusion in the United States at 'United States:Talk'; but previously 'incorporated' territories have never had state-only privileges --- possession populations for 200 years are incorporated in places preparing for statehood --- equality has gone to US citizenship in territories --- people not places, territories have never been equal to states constitutionally, though their citizens may have rights equivalent to those in states.

Though reverted as recently as last week, at 'United States' I would "include territories" of former Spanish, German and Danish colony non-citizens and their descendants --- who now one hundred years later, accept US local self-government, citizenship and territorial Member of Congress. Their acceptance in referendum and locally elected legislature is dismissed without sources as "irrelevant". I would admit US secondary government and scholarly sources to allow the WP article to include territories as does USG report itself. Interesting ongoing experiment, October 2012 - April 2013 to date. Contested daily at talk, walls of it. I fear that colors some of my posts unnecessarily. Thanks again for the fresh eyes-on-the-page at 'Territories of US'. cheers. TheVirginiaHistorian (talk) 10:19, 8 April 2013 (UTC)

Merger/move proposal

I have proposed a "merger/move request" between List of U.S. state partition proposals and List of proposed states of the United States, because I feel there is considerable overlap. If you are interested participating in the discussion, please feel free to do so here. Thank you. Green Giant (talk) 22:21, 16 April 2013 (UTC)

Symmetries of 5-cell

Hi Anton! I'm looking again at 4D symmetries, and expanded this section in tetrahedron, isometries of irregular tetrahedra, basically added a table and 2D edge-colorings to show matching edges. So this gives me a clue that the same thing can be done for 4D. So far I've found no online evidence that anyone has attempted this, although it seems unlikely. Part of the problem is 4D point groups are rather a mess of notations, so even if the irregular 4-simplices were enumerated as permutations, their symmetry doesn't have a standard notation to share. I'm partial towards Coxeter_notation, but Coxeter didn't fully map them back to other notations, and Conway's efforts were equally incomplete. So the mess has been left at User:Tomruen/polychoral_groups. ANYWAY, if you see a way to enumerate unique symmetry diagrams of the 5-cell, like my colored diagrams for 8 tetrahedra, we could at least see what's there. How many could there be?! :) Tom Ruen (talk) 00:25, 16 May 2013 (UTC)

Negative Low Tides

Hello. I came here just to mention that I tried to answer your two-year-old question regarding "Negative Low Tide" in the Talk pages of Wikipedia's Tides article. But I see from topics on this page that you are a mathematician. If I had known, I would have offered a much briefer and much more succinct attempt answer to your "tidal" question. Please forgive any condescension in the tone of my reply there. If you have any tidal modeling interests, the current mathematical model used in America for tide prediction is simply the sum of around 37 sine wave functions, whose amplitude, cyclic period, and phase lag is different for each very specific location. The list of sine wave parameters for all locations covered by NOAA are listed here. Selecting one place will reveal a list of sine wave parameter sets used to model the tide at that location. Furthermore, NOAA can provide some computer programs for tide prediction, although entirely without support and often written in ancient languages like FORTRAN (sadly, the language used for my Mathematics Ph.D. long ago). If it is the long term historical tidal data and analysis that interests you, there is that too at NOAA, but the world authority for that is formally assigned to the Permanent Service for Mean Sea Level in Liverpool, England. It is a part of the British Government National Oceanography Centre located within Southampton University on the south coast of England. Cheers, from ChrisJBenson (talk) 02:57, 29 June 2013 (UTC)

I'm not a mathematician so much as a tinkerer with mathematical toys tools.
I too have written the odd bit of Fortran. Most recently, I amused myself by trying to translate the Fortran code from Robert Axelrod's iterated prisoner's dilemma tournament (1979?) into C or Python. Wasn't able to run it, mind you ... —Tamfang (talk) 03:28, 29 June 2013 (UTC)
Axelrod and I both used to teach at UC Berkeley, though not at the same time. The winner of the original (truly non-communicating) 1979 Axelrod competition was the simplest strategy: If it's the first iteration, cooperate, else duplicate the opponent's last iteration. I have a fondness for "simplest wins", which (as an accidental but actual bias) appears to have been ignored in studies of this intersection between game theory (me), economics theory (my daughter at U Penn), and the real human Darwin-evolution of a co-operation bias. Feel free to delete this section and/or leave messages for me here. Cheers from ChrisJBenson (talk) 03:15, 2 July 2013 (UTC)

Buffy, "Restless"

Hey Tamfang, an editor recently added a citation needed tag to a portion in the Restless (Buffy the Vampire Slayer) article, and I'd appreciative your assistance if you may. I originally thought that was already cited in the article, but I was wrong. And it got me thinking actually, is the "730" foreshadowing referring to Dawn's first appearance or Buffy's death or both? I couldn't think of another Buffy editor in which I've been in contact before, so I've turned to you. Any chance you could help, with a reference, or clarification. Thanks. Drovethrughosts (talk) 14:50, 2 July 2013 (UTC)

Glory must use the Key on a specific date to open the portal; likely she knew that date before Graduation Day. Maybe that's what 730 is about, rather than Buffy's death in specific. It clearly isn't Dawn's arrival.
If "Be back before dawn/Dawn" is foreshadowing, it's rather lame foreshadowing; it would be significant if something bad happens because Buffy is away when Dawn shows up, which ain't the case.
Maybe there's a scholarly source, or a statement by Joss, that Tara's obscure remarks are foreshadowing (and of what); but without such authority, I'd make the sentence in question more tentative ("may foreshadow") and hope that satisfies Orangemike.
It's handled better in the main body, where the coincidences are listed without expressly saying that they are intentional symbols. —Tamfang (talk) 17:45, 2 July 2013 (UTC)
I readded it, per the Slayage source (paragraph 15), and a featurette found on the season 5 DVD ("Spotlight on Dawn"), in which both Whedon and David Fury comment on Little Miss Muffet being Dawn. As for the two years thing (the end of season 5, not the beginning), in "Restless" Tara says "That clock's completely wrong", because Dawn appears in the following episode. Again, per the Slayage source. Drovethrughosts (talk) 21:07, 3 July 2013 (UTC)
Sigh: what do we do when a secondary source thinks 16 months (between "Graduation Day" and "Buffy vs Dracula") have 730 days? Invoking JW's "I suck at math" is a (re)solution but less than satisfactory. —Tamfang (talk) 22:29, 3 July 2013 (UTC)

WP Heraldry and Vexillology in the Signpost

The WikiProject Report would like to focus on WikiProject Heraldry and Vexillology for a Signpost article. This is an excellent opportunity to draw attention to your efforts and attract new members to the project. Would you be willing to participate in an interview? If so, here are the questions for the interview. Just add your response below each question and feel free to skip any questions that you don't feel comfortable answering. Multiple editors will have an opportunity to respond to the interview questions, so be sure to sign your answers. If you know anyone else who would like to participate in the interview, please share this with them. Have a great day. –Mabeenot (talk) 15:51, 7 September 2013 (UTC)

Ditrigonary polyhedra

Hi Anton, if you'd like to use your editing skills or geometry knowledge, seeing a couple dead links I added a new article: ditrigonary polyhedra. Tom Ruen (talk) 06:21, 13 October 2013 (UTC)