[Numpy-discussion] tensor ops in dim > 3?

Dr. Dmitry Gokhman gokhman at sphere.math.utsa.edu
Tue Aug 27 16:11:04 CDT 2002


I have a rank three n-dim tensor A.  For two of the axes I want to perform
v^t A v (a quadratic form with scalar output, where v is a vector). The
final output should be a vector.  I also need to compute the derivative of
this with respect to v.  This involves symmetrizing and matrix-vector
multiplication (2 sym(A)v using two axes of A only, which gives a vector)
with the final result being a matrix.

Is there something elegant I can do short of extending numpy with fortrash
routines? Perhaps something like SciPy's 3-d tensor ops but for n-dim?

Thanks in advance for any tips, - d

PS One more dumb question: I just installed the ScientificPython-2.4.1 rpm
on my reincarnated Mandrake linux machine running python2.2.  Do I need to
do something to configure it?  My scripts aren't finding things (e.g.
indexing.py).





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