How do I find the submatrix of a matrix?

I'm new to Matlab so bear with me.

If I have a 2D matrix A and a submatrix B of A. How can I check if B is a submatrix of A?

I basically want to search for matrix B in A.

An example with code would be appreciated :)

Answer 1

[Jos (10584)]

Here is a simple for-loop that would work for 2D cases

A = magic(6) 
B = A(2:3,4:5) 

% engine
szA = size(A) ;
szB = size(B) ;
szS = szA - szB + 1 
tf = false(szA) ;
for r = 1:szS(1)
    for c = 1:szS(2)
        tf(r,c) = isequal(A(r:r+szB(1)-1,c:c+szB(2)-1),B) ;
    end
end
[rout,cout] = find(tf)

[Sloke Shrestha]

Hello,

Could you explain how this algorithm works?

Thank you!

Answer 2

[giannit]

[R,P] = ismember(B,A)

if R contains all ones then B is a submatrix of A and P contains the indices of A where B is located, ie A(P) = B