[Numpy-discussion] Speed of matrix multiplication

Travis E. Oliphant oliphant@enthought....
Mon Apr 21 09:02:16 CDT 2008


Keith Goodman wrote:
> Why is a.T*b slower than M.dot(a.T, b)? Does it take longer to parse
> or something?
>   
The issue I think is that a is a Python class and so takes a bit longer 
to do all the things being done which includes:

1) running the Python __mul__ function
2) creating a new array (including running the __array_finalize__ Python 
function).

-Travis




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