bug in lawrence_extension

[LaisRast]

The method lawrence_extension of Polyhedron does not work when the point at which we do the lawrence_extension has a different base_ring than the Polyhedron:

sage: polytopes.cube().lawrence_extension([5/2,0,0])
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
...
TypeError: no conversion of this rational to integer

The bug was introduced in #27926.

We fix this and add a method _test_lawrence to systematically test the lawrence construction.

CC: @jplab @kliem

Component: geometry

Keywords: polytope, lawrence_extension

Author: Jonathan Kliem

Branch/Commit: 539930e

Reviewer: Laith Rastanawi

Issue created by migration from https://trac.sagemath.org/ticket/30293

[kliem]

comment:1

-parent = self.parent().change_ring(self.base_ring(), ambient_dim = self.ambient_dim() +  1)
+parent = self.parent().base_extend(v, ambient_dim=self.ambient_dim() +  1)

I think this should to the job.

And this ticket shows again that we should test more methods.

[kliem]

Author: Jonathan Kliem

[kliem]

New commits:

1f00faa

fix lawrence extension with base extension; add test method for lawrence construction

[kliem]

Commit: 1f00faa

[kliem]

Branch: public/30293

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

740a654	avoid very long tests
b831f3f	add some long time warnings

[sagetrac-git]

Changed commit from 1f00faa to b831f3f

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

a96a977

run lawrence_polytope test for cdd and normaliz

[sagetrac-git]

Changed commit from b831f3f to a96a977

[LaisRast]

comment:5

It looks good to me.

[LaisRast]

Reviewer: Laith Rastanawi

[kliem]

comment:6

Thank you.

[vbraun]

comment:7

Merge conflict

[kliem]

comment:8

This is the merge conflict, which has an obvious solution.

++<<<<<<< HEAD
 +            sage: TestSuite(id).run(skip=["_test_is_combinatorially_isomorphic", "_test_pyramid"])
++=======
+             sage: TestSuite(id).run(skip=["_test_is_combinatorially_isomorphic", "_test_lawrence"])
++>>>>>>> 1f00faa1c3... fix lawrence extension with base extension; add test method for lawrence construction

[kliem]

Changed commit from a96a977 to 539930e

[kliem]

comment:9

Trivial merge conflict.

---

New commits:

eaeba9a	fix lawrence extension with base extension; add test method for lawrence construction
0c1a2da	avoid very long tests
d7e07af	add some long time warnings
539930e	run lawrence_polytope test for cdd and normaliz

[kliem]

Changed branch from public/30293 to public/30293-reb

[vbraun]

Changed branch from public/30293-reb to 539930e