MATLAB: How to find an element in a subset of a matrix as well as its index in the matrix

Question

Hi,

I am trying to find an element in a subset of a matrix (e.g. A) and the index of that element in matrix A.

Here is an example: let A be 6×6 matrix. I want to find a zero between rows 1 and 3, and columns 1 and 3.

I tried q = (find(A(1:3,1:3) == 0)

The answer I get is an array of 1 and 0, giving me an index of each 0 in terms of the subset of A that I defined. How can I find the index in terms of A?

thank you, i.

Answer 1

 subset=false(size(A));
  subset(1:3,1:3)=true;
 indexLogical=(A==0) & subset;
 q = find(indexLogical);