URL:
<http://savannah.gnu.org/bugs/?45797>
Summary: Possible problem with LAPACK Fortran routine ZGESVD
Project: GNU Scientific Library
Submitted by: andrewm
Submitted on: Wed 19 Aug 2015 11:39:09 AM GMT
Category: Accuracy problem
Severity: 3 - Normal
Operating System: Ubuntu Linux
Status: None
Assigned to: None
Open/Closed: Open
Release: 2.6.32-40
Discussion Lock: Any
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Details:
Error in some singular vectors that appear in the standard library release for
this version of Ubuntu using Fortran routine ZGESVD. Was not present in
standard release for 2.6.31-16.
Test routine supplied for a 4x4 complex matrix and two log files. The first
log file when compiled under Linux version 2.6.31-16 (correct), the second
when compiled under Linux version 2.6.32-40 (incorrect).
The test routine is compiled by "make" with executable "svdtest"
This generates the singular values and vectors and reconstitutes the original
complex matrix. The error appears in the imaginary part of one of the left
singular vectors. Check the differences in the log files.
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File Attachments:
-------------------------------------------------------
Date: Wed 19 Aug 2015 11:39:09 AM GMT Name: svdcheck.zip Size: 9kB By:
andrewm
zipped directory containing Fortran test program and log files
<http://savannah.gnu.org/bugs/download.php?file_id=34678>
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