How to keep the values for particular dimension of a matrix and rest of the dimension will be zeros?

I have a matrix A with dimension 496 by 48. I want to keep the values with dimension A(350:400, 20:35) as it is and rest of the dimension of A will be zeros.

Answer 1

[Walter Roberson]

Easy way:

B = zeros(size(A), 'like', A);
B(350:400,20:35) = A(350:400,20:35);

Now B is A with all the other elements zeroed.

A different approach:

mask = true(size(A));
mask(350:400,20:35) = false;
A(mask) = 0;

A third approach:

A(1:349,:) = 0; A(401:end,:) = 0;
A(:,1:19) = 0; A(:,36:end) = 0;

[AS]

Thanks

Answer 2

[Bruno Luong]

A single line solution

A(~(ismember(1:size(A,2),350:400) & ismember((1:size(A,1))',20:35))) = 0

[AS]

Thanks