[Numpy-discussion] A basic question on the dot function

Julien Hillairet julien.hillairet at gmail.com
Tue Oct 16 15:55:06 EDT 2007


2007/10/16, Bill Baxter <wbaxter at gmail.com>:
>
> dot() also serves as Numpy's matrix multiply function.  So it's trying
> to interpret that as a (3,N) matrix times a (3,N) matrix.
>
> See examples here:
>
> http://www.scipy.org/Numpy_Example_List_With_Doc#head-2a810f7dccd3f7c700d1076f15078ad1fe3c6d0d
>
> --bb
>

2007/10/16, Charles R Harris <charlesr.harris at gmail.com>:
>
>
>
> Dot is matrix multiplication, not the "dot" product you were expecting. It
> is also a bit ambiguous, as you see with the 1-D vectors, where you got what
> you expected.
>
> Chuck
>


2007/10/16, Robert Kern <robert.kern at gmail.com>:
>
> When given two 2-D arrays, dot() essentially does matrix multiplication.
> The
> last dimension of the first argument is matched with the next-to-last
> dimension
> of the second argument.
>
> --
> Robert Kern


Thank you for your answers. So, is there a "proper" solution to do the dot
product as I had expected it ?

Cheers,

JH
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