analog circuit simulator

for the mock-up version check https://codeberg.org/zoomlogo/aacs

build instructions:
git clone https://github.com/zoomlogo/zspice
cd zspice
cmake .
make
./bin/test_run           # to run the tests
./bin/zspice             # actual program

resources:
= https://guitorri.github.io/qucs-web/docs/technical.pdf
= https://www2.eecs.berkeley.edu/Pubs/TechRpts/1973/ERL-m-382.pdf
= https://cheever.domains.swarthmore.edu/Ref/mna/MNA_All.html
= https://en.wikipedia.org/wiki/Modified_nodal_analysis
= https://ngspice.sourceforge.io/docs/ngspice-45-manual.pdf