#22904 closed defect (fixed)
numerical noise in sage/matrix/matrix_double_dense.pyx
Reported by: | fbissey | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-8.0 |
Component: | numerical | Keywords: | |
Cc: | strogdon | Merged in: | |
Authors: | François Bissey | Reviewers: | Steven Trogdon |
Report Upstream: | N/A | Work issues: | |
Branch: | a945232 (Commits, GitHub, GitLab) | Commit: | |
Dependencies: | Stopgaps: |
Description
I get the following doctest failures in sage-on-gentoo
sage -t --long /usr/lib64/python2.7/site-packages/sage/matrix/matrix_double_dense.pyx ********************************************************************** File "/usr/lib64/python2.7/site-packages/sage/matrix/matrix_double_dense.pyx", line 628, in sage.matrix.matrix_double_dense.Matrix_double_dense.condition Failed example: A.condition(p=Infinity) # tol 2e-14 Expected: 22738.50000000045 Got: 22738.499999999945 Tolerance exceeded: 22738.50000000045 vs 22738.499999999945, tolerance 2e-14 > 2e-14 ********************************************************************** File "/usr/lib64/python2.7/site-packages/sage/matrix/matrix_double_dense.pyx", line 1787, in sage.matrix.matrix_double_dense.Matrix_double_dense.solve_left Failed example: x = A.solve_left(b); x.zero_at(1e-17) # fix noisy zeroes Expected: (0.666666666..., 0.0, 0.333333333...) Got: (0.6666666666666666, 1.50030138462859e-17, 0.3333333333333332) **********************************************************************
At first I thought it was caused by a difference in openblas version but it turns out out not to be the case. Probably hardware tuning related.
This ticket will raise the tolerance of these tests a little bit to accomodate the failure
Change History (4)
comment:1 Changed 5 years ago by
- Branch set to u/fbissey/numerical_noise_in_double_dense
- Cc strogdon added
- Commit set to a94523201b5af8275380ced16193cfd5bc44e471
- Status changed from new to needs_review
comment:2 Changed 5 years ago by
- Reviewers set to Steven Trogdon
- Status changed from needs_review to positive_review
I suppose you get the same with vanilla. Here my SoG and vanilla are identical for the first example. There are only minor difference for the second, but no noise in the zero
value. Openblas version does not seem to affect results here. I have had similar problems with this particular test in the past.
comment:3 Changed 5 years ago by
- Branch changed from u/fbissey/numerical_noise_in_double_dense to a94523201b5af8275380ced16193cfd5bc44e471
- Resolution set to fixed
- Status changed from positive_review to closed
comment:4 Changed 5 years ago by
- Commit a94523201b5af8275380ced16193cfd5bc44e471 deleted
Note: See
TracTickets for help on using
tickets.
Hi Steve,
would you mind reviewing this? This is fairly minor.
New commits:
fix numerical noise in matrix_double_dense