matrix multiplication

[Dan Stromberg]

On Mon, Feb 26, 2018 at 8:53 AM, Seb <spluque at gmail.com> wrote:
> On Sun, 25 Feb 2018 18:52:14 -0500,
> Terry Reedy <tjreedy at udel.edu> wrote:
>
> [...]
>
>> numpy has a matrix multiply function and now the '@' matrix multiply
>> operator.
>
> Yes, but what I was wondering is whether there's a faster way of
> multiplying each row (1x3) of a matrix by another matrix (3x3), compared
> to looping through the matrix row by row as shown in the code.  Perhaps
> I'm not understanding how to use the broadcasting features of `matmul`.

I'm a bit of a numpy newb, but this sounds like numpy's "broadcasting" feature:
http://lmgtfy.com/?q=numpy+broadcasting