在另一个矩阵matlab中删除具有相应零的元素

Question

I have two matrices A & B in Matlab, for example

A=[0,0,1,2,3,0,4,2,0]
B=[2,3,1,2,2,3,4,4,1]

What I want to do is to set elements in B to zero where they have the same position as zero elements in A. So in my example:

A=[0,0,1,2,3,0,4,2,0]
B=[2,3,1,2,2,3,4,4,1]

I want B to be like this:

B=[0,0,1,2,2,0,4,4,0]

Any idea?

Answer 1

You can do it using logical indexing like so: B(A==0) = 0

EDIT:

You can also do it like this: B.*(A~=0) which will be easier to generalise to higher dimensions using bsxfun as per your comment below.

Answer 2

The only problem with doing something that Dan suggests is if A and B are not the same size. You can still however do this with a little bit of extra work.

indices = find(A==0);
indices = indices(indices <= length(B));
B(indices) = 0;