Polar of integer polytopes does not respect backend

[kliem]

Currently, polytopes over the integers have there own method for polar, which does not respect the given backend:

sage: polytopes.cube(backend='normaliz').polar().backend()
'ppl'

We add the backend to the constructor to fix this. Any backend that can handle ZZ can also handle QQ.

CC: @jplab @LaisRast

Component: geometry

Keywords: polytopes, polar

Author: Jonathan Kliem

Branch/Commit: 50bbb76

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/28851

[kliem]

Description changed:

--- 
+++ 
@@ -1,7 +1,8 @@
-Currently, polytopes over the integers have there own method for `polar`, which does not respect the current backend:
+Currently, polytopes over the integers have there own method for `polar`, which does not respect the given backend:
 
 ```
 sage: polytopes.cube(backend='normaliz').polar().backend()
 'ppl'
 ```
-We change this by constructing a new polytope from the parent. Just like the overwritten method.
+
+We add the backend to the constructor to fix this. Any backend that can handle `ZZ` can also handle `QQ`.

[kliem]

Commit: 50bbb76

[kliem]

Branch: public/28851

[kliem]

New commits:

50bbb76

polar of polytope over integers respects backend

[tscrim]

comment:2

LGTM.

[tscrim]

Reviewer: Travis Scrimshaw

[vbraun]

Changed branch from public/28851 to 50bbb76