Opened 6 months ago

Closed 4 months ago

#31253 closed defect (fixed)

Put equations in stable position for backend cdd

Reported by: gh-kliem Owned by:
Priority: major Milestone: sage-9.3
Component: geometry Keywords: cdd, combinatorial polyhedron
Cc: jipilab, gh-LaisRast, mkoeppe Merged in:
Authors: Jonathan Kliem Reviewers: Matthias Koeppe
Report Upstream: N/A Work issues:
Branch: 1c6c90a (Commits, GitHub, GitLab) Commit: 1c6c90acb6f4848bd5cae4a2a40812c0b2f6a12c
Dependencies: Stopgaps:

Status badges

Description

Currently, equations positions in Hrepresentation of backend cdd depends on the input: 

sage: P = polytopes.permutahedron(2, backend='cdd')                                                                                                                                 
sage: P.Hrepresentation()                                                                                                                                                           
(An equation (1, 1) x - 3 == 0,
 An inequality (0, 1) x - 1 >= 0,
 An inequality (1, 0) x - 1 >= 0)
sage: Q = Polyhedron(P.vertices(), backend='cdd')                                                                                                                                   
sage: Q.Hrepresentation()                                                                                                                                                           
(An inequality (-1, 0) x + 2 >= 0,
 An inequality (1, 0) x - 1 >= 0,
 An equation (1, 1) x - 3 == 0)

This leads to the following failure: 

sage: [x.ambient_Hrepresentation() for x in P.facets()]                                                                                                                             
[(An inequality (1, 0) x - 1 >= 0, An inequality (0, 1) x - 1 >= 0),
 (An inequality (1, 0) x - 1 >= 0, An equation (1, 1) x - 3 == 0)]

We fix this by putting equations always in the same position.

Change History (3)

comment:1 Changed 6 months ago by gh-kliem

  • Branch set to public/31253
  • Commit set to 1c6c90acb6f4848bd5cae4a2a40812c0b2f6a12c
  • Status changed from new to needs_review

New commits:

​1c6c90astable position for equations for backend cdd

comment:2 Changed 4 months ago by mkoeppe

  • Reviewers set to Matthias Koeppe
  • Status changed from needs_review to positive_review

LGTM.

comment:3 Changed 4 months ago by vbraun

  • Branch changed from public/31253 to 1c6c90acb6f4848bd5cae4a2a40812c0b2f6a12c
  • Resolution set to fixed
  • Status changed from positive_review to closed
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