This is a random collection of TikZ examples. I wrote most of the code for some reason or another and decided to share the result – perhaps it is even useful for someone out there ...
The included pdf files are not meant to serve as documentation, they are there for convenience and should be viewed side by side with the source files if you wanna understand the TeX code. I tried to comment all crucial parts of the latter, although most if it should be pretty self-explanatory.
The macro \drawGraph{n}
draws the Cayley graph of F2 = Z ∗ Z up to the n
-th branching point.
See Cayley graph on Wikipedia for details about Cayles graphs. Note that the (geometric realization of the) Cayley graph of F2 is also the universal covering space of the "figure eight" space S1 v S1.
Compilation of cay.tex takes a while which is due to \drawGraph{9}
in the middle (about eight minutes with pdflatex at my machine). If you can, use lualatex to compile because it is (at least here) twice as fast as pdflatex. Alternatively replace 9 by a smaller value.
There are
\subdiv
which draws the (first) barycentric subdivision of a triangle and\subdivrec
which does the same for the n-th barycentric subdivision.\nikolausresidenz{n}
draws a "Haus vom Nikolaus" in itsn
-th barycentric subdivision. (Note that pdflatex's default memory limitation is too restrictive forn=4
or higher. Therefore i compiled nikolausresidenz_n4.tex with lualatex.)
The macro \shuffle{p}{q}
draws all (p,q)
-shuffles, i.e. all shortest paths through a p x q
integer lattice (from one edge to the diagonally opposite).