How to efficiently calculate a weighted sum of 3 dimensional matrix through a vector in matlab

A is a 3 dimensional matrix (M*N*K), b is a vector with length K. I need to calculate

, which is a 2 dimensional matrix (M*N). But i don't want to write it by a explicit summation because it is too slow. Is there any way to calculate it efficiently through matlab? Please attach the code if convenience.

[Dyuman Joshi]

%Random data
A = rand(3,4,5);
b = rand(5,1);

C = sum(A.*reshape(b,1,1,[]), 3)

C = 3×4

0.7003 1.2789 0.8012 1.0967 0.6957 0.7521 1.0241 0.7907 0.8766 1.2873 1.2261 1.1794

[Hancheng Zhu]

Your code is very good and concise, bro. But it spends more time than the latter answer below. Thanks for your kindly help.

[Matt J]

@Hancheng Zhu If that means you've settled on one of the answers below, please Accept-click one of them.

Answer 1

[Bruno Luong]

This uses matrix multiplication so it should be well optimized and fast.

[m,n] = size(A, [1 2]);
C = reshape(A,m*n, []) * B(:);
C = reshape(C, m, n);

Answer 2

[Matt J]

C=tensorprod(A,b,3,1)