Substituting values in a matrix

Say I have the following two matrices:

    >> x = [1 4 3; 6 4 3; 6 9 3; 2 4 3; 5 4 0; 5 3 1; 6 4 7];
    >> y = [0 0 1; 1 1 0; 1 1 0; 0 1 1; 0.2 0.8 0.54; 1 1 1; 0 0 0];

Where you can think of `x` as some image, and `y` the *degree of membership* of of each element of `x` to some region of interest.

Say I set those elements in `x` that have degree of membership = 1 to `1` and the other elements to `0` as follows:

    x = zeros(size(y));
    x(y==1) = 1;

In which case I will have the following output:

         0     0     1
         1     1     0
         1     1     0
         0     1     1
         0     0     0
         1     1     1
         0     0     0

Now, for the elements of `0`, how can I substitute their values with the value of `y` in the corresponding location?

Thanks.

Answer 1

[Walter Roberson]

x(x==0) = y(x==0)