[Pkg-octave-devel] Bug#525113: Bug#525113: Bug#525113: Inconsistant complex matrix multiplication

[Laurent Mazet]

Hi Thomas,

you was right, my problem is inthe atlas library:

$ LD_LIBRARY_PATH=/usr/lib /usr/bin/octave -q --eval '[1 2; 3 4] * [1; 1i]'
ans =
    1 + 2i
    3 + 4i

$ lmt-linux ~ $ /usr/bin/octave -q --eval '[1 2; 3 4] * [1; 1i]'
ans =
    1.0000 + 0.0000i
    3.0000 + 0.0000i

$ ldd /usr/bin/octave | grep -i lapack
	liblapack.so.3gf => /usr/lib/sse2/atlas/liblapack.so.3gf (0xb653f000)
$ dpkg -S /usr/lib/sse2/atlas/liblapack.so.3gf
libatlas3gf-sse2: /usr/lib/sse2/atlas/liblapack.so.3gf
$ dpkg -l libatlas3gf-sse2
...
+++-==============-==============-============================================
ii  libatlas3gf-ss 3.6.0-24       Automatically Tuned Linear Algebra Software,

Does I need to make a follow-up to the atlas package bug-report system?

Regards,

      Laurent

Quoting Thomas Weber <thomas.weber.mail at gmail.com>:

> On Wed, Apr 22, 2009 at 11:04:14PM +0200, Thomas Weber wrote:
>> On Wed, Apr 22, 2009 at 12:01:19PM +0200, Laurent Mazet wrote:
>> > Package: octave3.0
>> > Version: 1:3.0.1-7
>> > Arch: i386
>> > Severity: grave
>> >
>> > Hi,
>> >
>> > I've just realized that I can multiply a real 2x2 matrix by a  
>> complex vector.
>>
>> Uh, yes. Why shouldn't this work? Or in other words, how do you
>> distinguish the real matrix from a complex matrix with its complex
>> coefficients being zero
>>
>> [ 1, 2; 3,4] is the same as [1+0i, 2+0i; 3+0i, 4+0i], isn't it?
>
> Sorry, I just realized that the problem was the result, not the act of
> multiplication. Anyway, which BLAS/ATLAS libraries are installed on your
> system?
>
> 	Thomas
>



-- 
Dr. Laurent Mazet   -=-  "Use the source, Luke"  -=-   mazet at softndesign.org