Opened 7 years ago
Closed 7 years ago
#17937 closed defect (fixed)
Cannot compute integral points of 0-dimensional Polyhedron
Reported by: | jdemeyer | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-6.6 |
Component: | geometry | Keywords: | |
Cc: | ncohen | Merged in: | |
Authors: | Jeroen Demeyer | Reviewers: | Nathann Cohen |
Report Upstream: | N/A | Work issues: | |
Branch: | eb6ba85 (Commits, GitHub, GitLab) | Commit: | eb6ba858894c3c3f77b2278115198bfe9076adf0 |
Dependencies: | Stopgaps: |
Description
A trivial case, but it should work anyway:
sage: P = Polyhedron([[]]) sage: P A 0-dimensional polyhedron in ZZ^0 defined as the convex hull of 1 vertex sage: P.integral_points() --------------------------------------------------------------------------- IndexError Traceback (most recent call last) <ipython-input-13-2abbf2adff15> in <module>() ----> 1 P.integral_points() /usr/local/src/sage-git/local/lib/python2.7/site-packages/sage/geometry/polyhedron/base.pyc in integral_points(self, threshold) 3826 box_points<threshold: 3827 from sage.geometry.integral_points import rectangular_box_points -> 3828 return rectangular_box_points(box_min, box_max, self) 3829 3830 # for more complicate polytopes, triangulate & use smith normal form /usr/local/src/sage-git/src/sage/geometry/integral_points.pyx in sage.geometry.integral_points.rectangular_box_points (build/cythonized/sage/geometry/integral_points.c:4761)() 531 v = vector(ZZ, d) 532 if not return_saturated: --> 533 for p in loop_over_rectangular_box_points(box_min, box_max, inequalities, d, count_only): 534 # v = vector(ZZ, orig_perm.action(p)) # too slow 535 for i in range(0,d): /usr/local/src/sage-git/src/sage/geometry/integral_points.pyx in sage.geometry.integral_points.loop_over_rectangular_box_points (build/cythonized/sage/geometry/integral_points.c:5605)() 580 while True: 581 inequalities.prepare_inner_loop(p) --> 582 i_min = box_min[0] 583 i_max = box_max[0] 584 # Find the lower bound for the allowed region IndexError: list index out of range
Change History (6)
comment:1 Changed 7 years ago by
- Cc ncohen added
comment:2 Changed 7 years ago by
- Branch set to u/jdemeyer/cannot_compute_integral_points_of_0_dimensional_polyhedron
comment:3 Changed 7 years ago by
- Commit set to eb6ba858894c3c3f77b2278115198bfe9076adf0
- Status changed from new to needs_review
comment:4 follow-up: ↓ 5 Changed 7 years ago by
- Reviewers set to Nathann Cohen
- Status changed from needs_review to positive_review
Looks good. I pondered a bit over the "single point in zero dimension", but well. Sounds like a valid convention.
Thanks,
Nathann
comment:5 in reply to: ↑ 4 Changed 7 years ago by
Replying to ncohen:
Looks good. I pondered a bit over the "single point in zero dimension", but well. Sounds like a valid convention.
The zero dimensional vector space consists of one element: the zero element. There are two polytopes in this space: the empty polytope and the polytope with one vertex, namely the zero element.
comment:6 Changed 7 years ago by
- Branch changed from u/jdemeyer/cannot_compute_integral_points_of_0_dimensional_polyhedron to eb6ba858894c3c3f77b2278115198bfe9076adf0
- Resolution set to fixed
- Status changed from positive_review to closed
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New commits:
Fix integral_points() for polyhedra in 0 dimensions