Read these:
And then check this out:
>> A = randi(9,1,9)
A =
4 7 7 4 5 4 7 3 1
>> B = rand(1,9)
B =
0.610330 0.959444 0.900687 0.967633 0.010723 0.783159 0.016694 0.609336 0.980585
>> idx = A<5;
>> A(idx)
ans =
4 4 4 3 1
>> B(idx)
ans =
0.61033 0.96763 0.78316 0.60934 0.98059
