[SciPy-Dev] ANN: SciPy 0.9.0 release candidate 2

[josef.pktd at gmail.com]

On Wed, Feb 2, 2011 at 9:50 AM, Pauli Virtanen <pav at iki.fi> wrote:
> Wed, 02 Feb 2011 09:43:04 -0500, josef.pktd wrote:
> [clip]
>> From this it looks like the problem is more general, but until now we
>> have seen it only on Win32.
>
> If the matter is data alignment, perhaps this is because of memory
> allocators or the BLAS library functioning differently on different
> platforms.
>
> To get a definite answer if the issue is data alignment, one can perhaps
> check if the different results are correlated with
>
>        input_array.__array_interface__['data'][0] % 16
>
> (assuming no copies are made inside dot()).

alignment alternates, same script as on numpy mailinglist (numpy.dot)
with additional print

    print (y[0], m.__array_interface__['data'][0] % 16,
           x.__array_interface__['data'][0] % 16)

using lapack
(array([  5.00486230e-06]), 8, 0)
(array([  5.00486408e-06]), 0, 0)
(array([  5.00486230e-06]), 8, 0)
(array([  5.00486408e-06]), 0, 0)
(array([  5.00486230e-06]), 8, 0)
(array([  5.00486408e-06]), 0, 0)
(array([  5.00486230e-06]), 8, 0)
(array([  5.00486408e-06]), 0, 0)
(array([  5.00486230e-06]), 8, 0)
(array([  5.00486408e-06]), 0, 0)

in some runs alignment doesn't change in iterations
using lapack
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)
(array([  5.00486230e-06]), 8, 8)

Josef

>
> --
> Pauli Virtanen
>
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