[PYTHON MATRIX-SIG] Matrix multiplication

[Konrad HINSEN]

> I may have missed any previous discussion on the implementation of
> matrix multiplication in Numerical Python. Anyway, I understand that
> the current implementation of .matrixMultiply() requires arrays to be
> 2-dimensional (has this changed?).

True. As a temporary solution, I can offer a (slow) Python function
that is more general:

def dot(a1, a2):
    r1 = len(a1.shape)-1
    r2 = len(a2.shape)-1
    axes = [r1] + range(r1)
    a1 = a1.transpose(axes).copy()
    f = a1.reshape
    a1 = apply(f, a1.shape + r2*(1,))
    a2 = a2.copy()
    f = a2.reshape
    a2 = apply(f, a2.shape[0:1] + r1*(1,) + a2.shape[1:])
    return Numeric.add.reduce(a1*a2)

-------------------------------------------------------------------------------
Konrad Hinsen                     | E-Mail: hinsenk@ere.umontreal.ca
Departement de chimie             | Tel.: +1-514-343-6111 ext. 3953
Universite de Montreal            | Fax:  +1-514-343-7586
C.P. 6128, succ. Centre-Ville     | Deutsch/Esperanto/English/Nederlands/
Montreal (QC) H3C 3J7             | Francais (phase experimentale)
-------------------------------------------------------------------------------

=================
MATRIX-SIG  - SIG on Matrix Math for Python

send messages to: matrix-sig@python.org
administrivia to: matrix-sig-request@python.org
=================