Matrix multiplication between 2d matrix and slice of 3d array

I have two matrices A (3,3,x) and B (3,3) where x is a variable, known value and typically on the order of thousands. I need to compute the matrix multiplication of these two, I know this can be done by

function [ out ] = mat_mult( A,B )
    [~,~,np] = size(A);
    out = zeros(size(A));
    for i=1:np
        out(:,:,i) = A(:,:,i)*B;
    end
end

but I figure there is a more efficient way to do this than for loops, especially for MATLAB. Unforunately, I am not quite sure how to vectorize this.

Answer 1

[Athul Prakash]

Hey Morten,

You can check out 'MULTIPROD' - from File Exchange (linked below). It covers your requirements exactly,

https://in.mathworks.com/matlabcentral/fileexchange/8773-multiple-matrix-multiplications-with-array-expansion-enabled

( Please note that tools available on File Exchange are provided by the community and not created by Mathworks. The Mathworks does not provide any guarantees for such tools.)