Producing random numbers in Matlab?

How can I produce random binary numbers with exact number of zeros or ones? for example:

[0 1 0 1 0 1 0 0 1 0]  ===> number of ones are 4, 
[1 1 0 0 1 0 0 1 0 0]  ===> again number of ones are 4,  
[1 0 0 1 0 0 0 0 0 1]  ===> number of ones are 3, which is not allowed.

I just want exact number of ones in output of random sets.

Answer 1

[Azzi Abdelmalek]

n=4
a=randperm(2*n)
out=a>n

Answer 2

[Torsten]

x=zeros(10);
[y,idx]=datasample(1:10,4,'Replace',false);
x(idx)=1;

Best wishes

Torsten.

Answer 3

[david O]

 x=zeros(10,1,1);
for i=1:4
    x(randi(10))=1;
end

[Azzi Abdelmalek]

This doesn't work

[Azzi Abdelmalek]

With randi, you can get the same number more then once

Answer 4

[Azzi Abdelmalek]

Using rand

n=4
m=6
a=[ones(1,n), zeros(1,m)]
[~,idx]=sort(rand(1,m+n))
out=a(idx)