Re: [Numpy-discussion] Dot product threading?

[Pau G. <pau...@gm...>]

> Pau, can you confirm that this is the same
> as the routine you're interested in?
>
> def dot2(a,b):
>     '''Returns dot product of last two dimensions of two 3-D arrays,
>     threaded over first dimension.'''
>     try:
>         assert a.shape[1] =3D=3D b.shape[2]
>         assert a.shape[0] =3D=3D b.shape[0]
>     except AssertionError:
>         print "incorrect input shapes"
>     res =3D zeros( (a.shape[0], a.shape[1], a.shape[1]), dtype=3Dfloat )
>     for i in range(a.shape[0]):
>         res[i,...] =3D dot( a[i,...], b[i,...] )
>     return res
>

yes, that is what I would like. I would like it even with more
dimensions and with all the broadcasting rules ;-)
These can probably be achieved by building actual 'arrays of matrices'
(an array of matrix objects) and then using the ufunc machinery.
But I think that a simple dot2 function (with an other name of course)
will still very useful.

pau