How to operate block matrices?

15 views (last 30 days)
Noemi ZM
Noemi ZM on 7 Oct 2022
Commented: Noemi ZM on 7 Oct 2022
I'd like to operate matrix in which each element is composed by two numbers. For instance,
If I have a matrix B=[1,2; 3,4] for instance, I'd like to have
Someone have some idea?
Thank you!

Accepted Answer

Rik on 7 Oct 2022
Perhaps a function like pagemtimes does what you need.
You will have to store your matrix as a 3-D matrix. Even if pagemtimes is not what you want, that will make it easier to write a loop to apply the operation you do want.
Image Analyst
Image Analyst on 7 Oct 2022
Can you explain exactly what was multiplied by what, and summed, to get the output matrixes?

Sign in to comment.

More Answers (1)

Paul on 7 Oct 2022
One can always store block matrices in cell arrays and then roll code to implement the block matrix algebra. Maybe there is a submittal on the FEX for a block matrix class?
A = {[1 2] , [3 4]; [3 5] , [4 2]};
B = {1 , 2; 3, 4};
C = blockmtimes(B,A)
C = 2×2 cell array
{[ 7 12]} {[ 11 8]} {[15 26]} {[25 20]}
function C = blockmtimes(A,B)
[m,n] = size(A);
[n,s] = size(B);
for ii = 1:m
for jj = 1:n
C{ii,jj} = zeros(size(A{ii,jj},1),size(B{ii,jj},2));
for kk = 1:n
C{ii,jj} = C{ii,jj} + A{ii,kk}*B{kk,jj};


Find more on Matrices and Arrays in Help Center and File Exchange




Community Treasure Hunt

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

Start Hunting!