Dual for combinatorial polyhedron

[kliem]

We implement a method of CombinatorialPolyhedron that obtains the polar/dual. We name it dual and create an alias polar to be consistent with Polyhedron_base.

This is obtained by simply copying and interchanging the bitrepresentation of facets and vertices. The object is purely combinatorial and does not have vertex or facet names. A ValueError is raised for the unbounded case.

Along the way we implement a __copy__ method for ListOfFaces and allow initializing CombinatorialPolyhedron from a tuple consisting of two ListOfFaces.

CC: @jplab @LaisRast

Component: geometry

Keywords: polar, dual, combinatorial polyhedron

Author: Jonathan Kliem

Branch/Commit: 73cf39f

Reviewer: Laith Rastanawi

Issue created by migration from https://trac.sagemath.org/ticket/29190

[kliem]

Branch: public/29190

[kliem]

New commits:

bc51430	copy for ListOfFaces
5078b6e	add polar for combinatorial polyhedron

[kliem]

Commit: 5078b6e

[LaisRast]

comment:2

• Maybe add CombinatorialPolyhedron: abbrevations Hrepr -> Hrep etc. #28608 as a dependency here and change the code accordingly.
• In the documentation of CombinatorialPolyhedron. add to far_face the option when data is a tuple consisting of facets and vertices (of class ListOfFaces).
• A typo:

-       * or a tuple consting of facets and vertices as two
+       * or a tuple consisting of facets and vertices as two

[kliem]

Dependencies: #28608

[kliem]

comment:4

I'm just going to wait until #28608 is merged, otherwise it's a pain to review.

[kliem]

Changed commit from 5078b6e to 8beef7c

[kliem]

Changed branch from public/29190 to public/29190-reb

[kliem]

New commits:

328c16d	copy for ListOfFaces
8beef7c	add polar for combinatorial polyhedron

[kliem]

Changed dependencies from #28608 to none

[LaisRast]

comment:6

• I would suggest renaming the method name to dual (since this is purely combinatorial) and put polar as an alias to dual to be consistent with Polyhedron_base.

• Add

        .. SEEALSO::

            :meth:`~sage.geometry.polyhedron.base.Polyhedron_base.polar`.

Otherwise, the ticket is good to go.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

23b87ed	copy for ListOfFaces
309150b	add polar for combinatorial polyhedron
586bc82	renamed polar to dual
73cf39f	fixing doctest

[sagetrac-git]

Changed commit from 8beef7c to 73cf39f

[kliem]

Reviewer: Laith Rastanawi

[LaisRast]

comment:9

I think it is good to go.

[vbraun]

Changed branch from public/29190-reb to 73cf39f