Opened 8 years ago
Closed 6 years ago
#10037 closed defect (fixed)
cddlib/Polyhedron bug
Reported by: | mhampton | Owned by: | mhampton |
---|---|---|---|
Priority: | major | Milestone: | sage-5.10 |
Component: | geometry | Keywords: | cddlib, polyhedron, polyhedra |
Cc: | vbraun, dimpase, novoselt | Merged in: | sage-5.10.beta1 |
Authors: | Volker Braun | Reviewers: | Andrey Novoseltsev |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | #14479 | Stopgaps: |
Description (last modified by )
The following causes cddlib to crash; I'm not sure if this is fixable without patching the cddlib source:
p4 = polytopes.permutahedron(5,project=True) pn4 = p4.projection() p3 = pn4.schlegel() verts = p3.transformed_coords edges = p3.lines topes = [] for q in p4.facial_incidences(): topes.append([verts[i] for i in q[1]]) Polyhedron(vertices=topes[3], field=RDF, verbose=True)
output ends with:
Facet graph *Error: Possibly an LP cycling occurs. Use the Criss-Cross method.
Apply trac_10037_polyhedron_bug.patch to the sage library
Attachments (1)
Change History (8)
comment:1 Changed 8 years ago by
comment:2 Changed 8 years ago by
It fails for me on an intel mac, OS X 10.6. It does work for me on linux (64 bit Ubuntu 9.10).
comment:3 Changed 6 years ago by
- Dependencies set to #14479
- Status changed from new to needs_review
#14479 adds raising a proper error, so I consider this fixed. Use rationals for exact arithmetic.
Patch is for a regression in calling schlegel()
without specifying the direction.
comment:4 Changed 6 years ago by
- Description modified (diff)
comment:6 Changed 6 years ago by
- Milestone set to sage-5.10
- Reviewers set to Andrey Novoseltsev
- Status changed from needs_review to positive_review
comment:7 Changed 6 years ago by
- Merged in set to sage-5.10.beta1
- Resolution set to fixed
- Status changed from positive_review to closed
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This one actually works for me (Fedora 13 x86_64):
Just out of curiosity, which arch is that failing on?
I think the way to go is to implement vertex/facet adjacencies ourselves with a modern LP solver, either cvxopt or PPL.
I've opened #10039 as a first step to switch to PPL.