my loop is too slow

[Tim Hochberg]

Some time ago Tim Hochberg (me) wrote:

>>from Numeric import *
>>a = a + dot(c, f) * dot(c, transpose(f))


John E. Davis then wrote:

>Are you sure about this?
[SNIP]
>where `#' denotes matrix multiplication and ' represents the
>transpose.  So, I would code this as:
>
>  a = a + (c#f)*(c#f')
>
>where `*' represents an element by element multiply and `+' represents
>an element by element addition.


We agree. Really. Numeric.dot acts as a matrix multiply on 2D matrices. At
some point, Numeric.matrixmultiply got marked as deprecated and new code was
supposed to use dot. (I don't recall why, you'd have to search the old
Numeric mailing list archives).

-tim