Opened 3 years ago

Closed 2 years ago

Last modified 2 years ago

#29186 closed enhancement (fixed)

Add simplicity and simpliciality to polyhedra

Reported by: gh-kliem Owned by:
Priority: major Milestone: sage-9.1
Component: geometry Keywords: simplicity, simpliciality, polytopes
Cc: jipilab, gh-LaisRast Merged in:
Authors: Jonathan Kliem Reviewers: Jean-Philippe Labbé
Report Upstream: N/A Work issues:
Branch: 573dbfc (Commits, GitHub, GitLab) Commit: 573dbfc89f7b67015c6779e986159dcddf894c87
Dependencies: Stopgaps:

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Description

In #27086 we have implemented simplicity and simpliciality for combinatorial polyhedra. We expose this methods in Polyhedron_base.

The methods return the largest k such that the polytope is k-simple/simplicial. In case of unbounded polyhedra a NotImplementedError is raised.

A polytope is k-simplicial if every k-face is a simplex. It is k-simple if its dual/polar is k-simplicial.

Change History (9)

comment:1 Changed 3 years ago by gh-kliem

  • Branch set to public/29186
  • Commit set to 34068512da0d10e02d27c32812d868517aba3a35
  • Status changed from new to needs_review

New commits:

3406851added simplicity and simpliciality to polyhedra

comment:2 Changed 3 years ago by jipilab

  • Reviewers set to Jean-Philippe Labbé
  • Status changed from needs_review to needs_work

Some comments:

-        Return the largest `k` such that the polytope is `k`-simple.
-
-        Return the dimension in case of a simplex.
-
-        A polytope `P` is `k`-simple, if every `(d-1-k)`-face
-        is contained in exactly `k+1` facets of `P` for `1 <= k <= d-1`.
-
-        Equivalently it is `k`-simple if the polar/dual polytope is `k`-simplicial.
+        Return the largest integer `k` such that the polytope is `k`-simple.
+
+        A polytope `P` is `k`-simple, if every `(d-1-k)`-face
+        is contained in exactly `k+1` facets of `P` for `1 <= k <= d-1`.
+        Equivalently it is `k`-simple if the polar/dual polytope is `k`-simplicial.
+        If `self` is a simplex, it returns its dimension.

similarly:

-        Return the largest `k` such that the polytope is `k`-simplicial.
-
-        Return the dimension in case of a simplex.
-
-        A polytope is `k`-simplicial, if every `k`-face is a simplex.
+        Return the largest interger `k` such that the polytope is `k`-simplicial.
+
+        A polytope is `k`-simplicial, if every `k`-face is a simplex.
+        If `self` is a simplex, returns its dimension.

Once this is fixed and the bots gives a green light, you can set this on positive review on my behalf.

comment:3 Changed 3 years ago by gh-kliem

  • Branch changed from public/29186 to public/29186-reb
  • Commit changed from 34068512da0d10e02d27c32812d868517aba3a35 to 297c6869b2a25f1508c5923d71ba6a2cbbf608f7
  • Status changed from needs_work to needs_review

New commits:

c9ff832added simplicity and simpliciality to polyhedra
297c686improved documentation

comment:4 Changed 2 years ago by mkoeppe

  • Milestone changed from sage-9.1 to sage-9.2

Batch modifying tickets that will likely not be ready for 9.1, based on a review of the ticket title, branch/review status, and last modification date.

comment:5 Changed 2 years ago by jipilab

  • Status changed from needs_review to needs_work

Small things:

+        is contained in exactly `k+1` facets of `P` for `1 <= k <= d-1`.

You can use \leq there.

Otherwise, looks good, once this is done you can put this on positive review on my behalf.

Last edited 2 years ago by jipilab (previous) (diff)

comment:6 Changed 2 years ago by gh-kliem

  • Branch changed from public/29186-reb to public/29186-reb2
  • Commit changed from 297c6869b2a25f1508c5923d71ba6a2cbbf608f7 to 573dbfc89f7b67015c6779e986159dcddf894c87

New commits:

d6e1bf6added simplicity and simpliciality to polyhedra
f4689d3improved documentation
573dbfclatex \lex

comment:7 Changed 2 years ago by gh-kliem

  • Status changed from needs_work to positive_review

comment:8 Changed 2 years ago by vbraun

  • Branch changed from public/29186-reb2 to 573dbfc89f7b67015c6779e986159dcddf894c87
  • Resolution set to fixed
  • Status changed from positive_review to closed

comment:9 Changed 2 years ago by mkoeppe

  • Milestone changed from sage-9.2 to sage-9.1
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