[Octave-bug-tracker] [bug #53823] svd for fat single complex matrices crashes octave

[Marco Caliari]

URL:
  <http://savannah.gnu.org/bugs/?53823>

                 Summary: svd for fat single complex matrices crashes octave
                 Project: GNU Octave
            Submitted by: caliari
            Submitted on: Thu 03 May 2018 02:53:45 PM UTC
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Segfault, Bus Error, etc.
                  Status: Patch Submitted
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.4.0
        Operating System: GNU/Linux

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Details:

As reported in the maintainers mailing list


svd(single(randn(30,50) + i*randn(30,50)))


crashes octave. The problem is with the dimension of lrwork. As written here

https://github.com/Reference-LAPACK/lapack/blob/master/SRC/cgesdd.f

and

https://github.com/Reference-LAPACK/lapack/blob/master/SRC/zgesdd.f

LAPACK <= 3.6 (which is not so old) has a bug and requires lrwork = 7*min_mn.
The attached changeset fixes the problem for me.



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File Attachments:


-------------------------------------------------------
Date: Thu 03 May 2018 02:53:45 PM UTC  Name: svd.diff  Size: 1KiB   By:
caliari

<http://savannah.gnu.org/bugs/download.php?file_id=44076>

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