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[Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of
From: |
Marco Caliari |
Subject: |
[Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem |
Date: |
Tue, 24 Apr 2018 05:04:03 -0400 (EDT) |
User-agent: |
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:59.0) Gecko/20100101 Firefox/59.0 |
Update of bug #53719 (project octave):
Status: In Progress => Patch Submitted
_______________________________________________________
Follow-up Comment #5:
I decided for two patches. The first is about the segmentation fault.
Moreover, it fixes some conditions in the subfunction select in eigs.m. It
should certainly be applied (eigs1.diff).
The second changes the switch between using ARPACK or eig inside eigs.m.
Unfortunately, it was not as easy as I thought in comment #3. In fact, we
should compare p and rows (a). By default, p is 2 * k, but it can be
overwritten by opts.p. I also changed a lot of BIST tests in order to really
use ARPACK and not eig. Since the default number of eigenvalues is 6, and the
default Krylov dimension is 2 * 6, I forced eigs to use eig when rows (a) < 13
(it was rows (a) < 9). This second patch (eigs2.diff) needs an accurate review
(we should be sure that all tests pass again on different platforms) and does
not solve the undetected ill-conditioning of the problem in this bug report.
When eig is used, the output argument flag is set to 0. What about setting it
to -0 in order to know when eig was used instead of ARPACK?
(file #44003, file #44004)
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Additional Item Attachment:
File name: eigs1.diff Size:2 KB
File name: eigs2.diff Size:11 KB
_______________________________________________________
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- [Octave-bug-tracker] [bug #53719] eigs delivers wron result in case of complex valued general eigenvalue problem, Michael Asam, 2018/04/23
- [Octave-bug-tracker] [bug #53719] eigs delivers wron result in case of complex valued general eigenvalue problem, Dan Sebald, 2018/04/23
- [Octave-bug-tracker] [bug #53719] eigs delivers wron result in case of complex valued general eigenvalue problem, Marco Caliari, 2018/04/23
- [Octave-bug-tracker] [bug #53719] eigs delivers wron result in case of complex valued general eigenvalue problem, Marco Caliari, 2018/04/23
- [Octave-bug-tracker] [bug #53719] eigs delivers wron result in case of complex valued general eigenvalue problem, Rik, 2018/04/23
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Rik, 2018/04/23
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem,
Marco Caliari <=
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, John W. Eaton, 2018/04/24
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Rik, 2018/04/24
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Marco Caliari, 2018/04/25
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Dan Sebald, 2018/04/25
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Marco Caliari, 2018/04/26
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Marco Caliari, 2018/04/26
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Dan Sebald, 2018/04/26
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Marco Caliari, 2018/04/26
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Marco Caliari, 2018/04/26
- [Octave-bug-tracker] [bug #53719] eigs delivers wrong result in case of complex valued general eigenvalue problem, Dan Sebald, 2018/04/26