Say I have two matrices of the form A = [1 0 0 1 0 1] (1 x 6 row vector) and B = [ a b c] (1 x 3 row vector). The number of elements in B = number of 1s in A. Is there any matrix operation that could be done on A and B that would give me C = [a 0 0 b 0 c]? That is the 1's of A should be replaced with the values in B and zeros left as it is. I am looking for operations that would not access the individual elements separately (i.e. I am not looking for things like if A(1)==1, C(1)=A(1)*b(1) etc... or inserting zeros.) I am looking for some operation like A*B that would give this result. Sorry about the cryptic title. I can't really describe it without examples.