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How do I find the submatrix of a matrix?

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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 :)

Accepted Answer

Jos (10584)
Jos (10584) on 2 Jun 2016
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)
  1 Comment
Sloke Shrestha
Sloke Shrestha on 14 Jun 2019
Hello,
Could you explain how this algorithm works?
Thank you!

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More Answers (1)

giannit
giannit on 15 Aug 2021
Edited: giannit on 15 Aug 2021
[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

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