Try this:
A = randi(9, 4); % Integer Array
idx = randperm(16,5);
A(idx) = A(idx)+rand(1,5) % Some Non-Integer Elements
NotInteger = A(rem(A,1) ~= 0)
producing:
A =
6.0000 3.0000 2.1174 9.0000
2.0000 8.0000 3.5079 4.0000
3.0000 2.0000 4.3188 2.2967
5.0000 3.4242 3.0000 9.0000
NotInteger =
3.4242
2.1174
3.5079
4.3188
2.2967
It works because the rem (or mod) of any number with the denominator of 1 produces the fractional part of the argument. If that is zero, the element is an integer.
