[Numpy-discussion] speed of numpy vs matlab on dot product

[Rob Hooft]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

JJ wrote:
> python
> import numpy
> import scipy
> a = scipy.random.normal(0,1,[10000,2000])
> b = scipy.random.normal(0,1,[10000,2000])
> c = scipy.dot(a,scipy.transpose(b))

Hi,

My experience with the old Numeric tells me that the first thing I would
try to speed this up is to copy the transposed b into a fresh array. It
might be that the memory access in dot is very inefficient due to the
transposed (and hence large-stride) array.

Of course I may be completely wrong.

Rob

- --
Rob W.W. Hooft  ||  rob at hooft.net  ||  http://www.hooft.net/people/rob/
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFEi9TdH7J/Cv8rb3QRAgXYAJ9EcJtfUeX3H0ZWf22AapOvC3dgTwCgtF5r
QW6si4kqTjCvifCfTc/ShC0=
=uuUY
-----END PGP SIGNATURE-----