畫 coxeter graph 的工具

By Stembridge:
http://www.math.lsa.umich.edu/~jrs/archive.html

Coxeter graph paper

If you've ever worked with affine reflection groups, you've probably wasted
lots of time drawing the reflecting hyperplanes of the rank 2 groups on
scraps of paper.

You may also have wished you had pads of graph paper with
these lines drawn in for you. If so, you've come to the right place.

Behold!
Coxeter graph paper!

    * A2 paper (22K PostScript).
      http://www.math.lsa.umich.edu/%7Ejrs/data/A2.ps
    * B2 paper (24K PostScript).
      http://www.math.lsa.umich.edu/%7Ejrs/data/B2.ps
    * G2 paper (38K PostScript).
      http://www.math.lsa.umich.edu/%7Ejrs/data/G2.ps

Want more? Check out affhyp (New! recently updated for Maple VR4), the Maple
program that produced this paper. Requires the coxeter package.

Affhyp can do lots more
--here are some samples of snazzy 3D graphics it produced:

    * The hyperplanes corresponding to the root systems A3 (27K gif)
     
      and B3 (23K gif).
     

    * The "sandwich" arrangements for A3 (27K gif),
     
      B3 (27K gif),
     
      and C3 (26K gif).