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

[kliem]

Description changed:

--- 
+++ 
@@ -9,3 +9,5 @@
 ```
 
 The bug was introduced in #27926.
+
+We fix this and add a method `_test_lawrence` to systematically test the lawrence construction.

[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