Re: [Numpy-discussion] Matrix dot product over an axis(for a 3d array/list of matrices)

2010-07-15 Thread Emmanuel Bengio
I get about 60% of the original execution times for about any size of stack. On 15 July 2010 14:09, Charles R Harris wrote: > > > On Thu, Jul 15, 2010 at 12:00 PM, Emmanuel Bengio wrote: > >> Ok I get it. Thanks! >> >> Numpy syntax that works for me: >>

Re: [Numpy-discussion] Matrix dot product over an axis(for a 3d array/list of matrices)

2010-07-15 Thread Emmanuel Bengio
Ok I get it. Thanks! Numpy syntax that works for me: numpy.sum(a[:,:,:,numpy.newaxis]*b[:,numpy.newaxis,:,:],axis=-2) On 15 July 2010 13:46, Charles R Harris wrote: > > > On Thu, Jul 15, 2010 at 11:32 AM, Emmanuel Bengio wrote: > >> >Could you place all Rot's into

Re: [Numpy-discussion] Matrix dot product over an axis(for a 3d array/list of matrices)

2010-07-15 Thread Emmanuel Bengio
x27;s into the same array and all the Trans's into the > same array? If you have the first index of each array refer to which array > it is numpy.dot should work fine, since numpy.dot just does the dot product > over the second to last and last indexes. > http://docs.scipy.org/doc/n

[Numpy-discussion] Matrix dot product over an axis(for a 3d array/list of matrices)

2010-07-15 Thread Emmanuel Bengio
Hello, I have a list of 4x4 transformation matrices, that I want to "dot with" another list of the same size (elementwise). Making a for loop that calculates the dot product of each is extremely slow, I thought that maybe it's due to the fact that I have thousands of matrices and it's a python fo