Differences
This shows you the differences between two versions of the page.
Next revision | Previous revision | ||
tutorial:face_lattice_tutorial [2011/11/07 18:17] – created joswig | user_guide:tutorials:face_lattice_tutorial [2019/02/04 22:55] (current) – external edit 127.0.0.1 | ||
---|---|---|---|
Line 1: | Line 1: | ||
- | ====== Face lattices (of Polytopes) ====== | + | {{page>.:latest: |
- | + | ||
- | By definition the face lattice of a polytope contains all the combinatorial information about a polytope. | + | |
- | + | ||
- | < | + | |
- | polytope > $p = n_gon(5); | + | |
- | polytope > $HD = $p-> | + | |
- | polytope > print $HD-> | + | |
- | {} | + | |
- | {0} | + | |
- | {1} | + | |
- | {2} | + | |
- | {3} | + | |
- | {4} | + | |
- | {1 2} | + | |
- | {2 3} | + | |
- | {3 4} | + | |
- | {0 4} | + | |
- | {0 1} | + | |
- | {0 1 2 3 4} | + | |
- | </code> | + | |
- | + | ||
- | The obvious question is: How to interpret that output? | + | |
- | + | ||
- | Very often just a part of the face lattice is interesting. | + | |
- | < | + | |
- | polytope > for (my $k=$HD-> | + | |
- | {1 2}{2 3}{3 4}{0 4}{0 1} | + | |
- | </ | + | |
- | The above works as described since DIMS return an array with the first nodes of each dimension. | + | |
- | + | ||