MATLAB Answers

3D Matrix Multiplication

24 views (last 30 days)
Hi I have created two large matrices of which I have reshaped to create the following:
A = 3x1x4 double
B = 3x3x4 double
C = B * A ????
I was wondering how I could multiply each 3x3 matrix from B with each 3x1 matrix from A? The aim is to create a new 3x1x4 matrix in the end. Note: I don't have R2020b so don't have access to the pagemtimes function.
Any help is greatly appreciated, thanks!

Accepted Answer

the cyclist
the cyclist on 24 Feb 2021
Edited: the cyclist on 24 Feb 2021
You can do it straightforwardly with a for loop:
% Some made-up input data
A = rand(3,1,4);
B = rand(3,3,4);
[mA,nA,pA] = size(A);
[mB,nB,pB] = size(B);
C = zeros(mB,nA,pA);
for np = 1:pA
C(:,:,np) = B(:,:,np) * A(:,:,np);
end
  1 Comment
Rahul Marwaha
Rahul Marwaha on 25 Feb 2021
Thanks, that worked perfectly!

Sign in to comment.

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!