Random numbers

I have a problem regarding random numbers. Suppose I have a zero vector with length 10. I want to generate random numbers only on position 1,2,4,7,8. How do I generate random numbers only on these positions ? Is there any command ?

Answer 1

[Andrei Bobrov]

idx = [1,2,4,7,8];
out = zeros(10,1);
out(idx)=rand(numel(idx),1);