Polyhedron_base.vertex_adjacency_matrix: Do not use face_lattice

[mkoeppe]

instead just go through self.combinatorial_polyhedron().edges()

This should be faster - and only avoids an indirect dependency of sage.geometry.polyhedron.plot on sage.combinat

CC: @kliem

Component: geometry

Author: Jonathan Kliem

Branch/Commit: 2cd253c

Reviewer: Frédéric Chapoton, Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/32666

[kliem]

New commits:

7db923e	compute vertex adjacency matrix from edges
21a6c94	remove code duplications

[kliem]

Author: Jonathan Kliem

[kliem]

Commit: 21a6c94

[kliem]

Branch: public/32666

[fchapoton]

Reviewer: Frédéric Chapoton

[fchapoton]

comment:2

ok, looks good

[mkoeppe]

comment:3

Thanks for working on this!

[kliem]

comment:4

Thanks for the review.
This change turned out to be surprisingly uncomplicated.

[mkoeppe]

comment:5

how about

--- a/src/sage/geometry/polyhedron/combinatorial_polyhedron/base.pyx
+++ b/src/sage/geometry/polyhedron/combinatorial_polyhedron/base.pyx
@@ -1276,7 +1276,7 @@ cdef class CombinatorialPolyhedron(SageObject):
             sage: polytopes.cube().vertex_adjacency_matrix().is_immutable()
             True
         """
-        from sage.rings.all import ZZ
+        from sage.rings.integer_ring import ZZ
         from sage.matrix.constructor import matrix

[sagetrac-git]

Changed commit from 21a6c94 to 2cd253c

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1 and set ticket back to needs_review. New commits:

2cd253c

more specific import