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Published 20 hours ago • verified publisher icon Reference-LAPACK

Solution could not be computed in dsysv_aa

Open yhfeng opened this issue 8 years ago • 5 comments

If I choose well conditioned matrix A from reference [http://epubs.siam.org/doi/10.1137/100801548 ],

the solution can't be computed, which contradicts with A is nonsingular.

yhfeng avatar Apr 28 '17 17:04 yhfeng

Matrix A is the following form: screen shot 2017-04-28 at 11 39 24 am

when using dsysv_aa on this matrix, then info > 0 in dsytrf_aa.

yhfeng avatar Apr 28 '17 18:04 yhfeng

@iyamazaki, can you have a look?

langou avatar Apr 29 '17 12:04 langou

Excellent Ichi (@iyamazaki). Thanks for the fix. @yhfeng: Thanks for the bug report. Please let us know if further problem. I am closing the issue.

langou avatar May 01 '17 19:05 langou

Hi all,

I am reopening the issue.

(1) The comments of the INFO parameter in DSYTRF_AA are not correct.

(2) We are currently discussing the meaning of INFO > 0 in DSYTRF_AA. It is not clear we want INFO > 0 at all. If we decide to remove INFO > 0 case (my preference), this will mean that we have to edit the test suite. So some work ahead.

I am reopening the issue so that we do not forget to work on this.

Opinions welcome on (2).

Julien.

langou avatar May 05 '17 12:05 langou

INFO > 0 was removed from DSYTRF_AA in 3ba9cdf7cf4fb924a3e7904fe396692028959c3f. Should we close this issue? This commit had no updates in the test suite.

weslleyspereira avatar May 23 '23 20:05 weslleyspereira