change a logical array value based on the index of another matrix

I have a logical matrix the same size as matrix A.

If A has a value above a threshold, I want to change the corresponding index in the logical matrix to 1.

A = [1 2 3 4 5];
x = [0 0 0 0 0];

%based on A >= 4 change x to 1 ;
%so x would be [0 0 0 1 1]

Answer 1

[John D'Errico]

If you want to create x on the fly, then just do this:

x = A > 4;

If you for some reason really want to modify an existing vector x, then do this:

x(A > 4) = true;

[raheem mian]

omg so simple. Thank you