MATLAB: Generate the binary sequence

binary sequence

I have a code to generate the binary sequence that only contains m zeros and n ones. For example, m=n=2. then the number of combinations of the binary sequence is 6,nchoosek(4,2). My code was fine to output the 6 combinations, but mostly 2 combinations are the same. My question is how to avoid a combination of sequence show twice?
The code is following:
%  clear all;
m = input('How many zeroes do you need \n');
n = input('how many ones do you need\n');
lnk=nchoosek(m+n,n);
i=n+m;
for kk=1:lnk
   % m = input('How many zeroes do you need \n');
   % n = input('how many ones do you need\n');
   if i<=1
        disp('size of binary sequence is out of range');
   else 
        %Binary sequence contains m zeros and n ones in any order
        x1=zeros(1,i);
        x1(randperm(i,n))=1
        %count down the number of switches in such a Binary sequence x1;
        switches=0;
        for k=1:length(x1)-1
            if x1(k)==0 && x1(k+1)==1
                switches= switches+1;
            elseif x1(k)==1 && x1(k+1)==0 
                switches=switches+1;
            end
        end  
        Av(kk)=switches;
   end   
end
Also, my result shows like:
How many zeroes do you need 
2
how many ones do you need
2
x1 =
     0     0     1     1
x1 =
     0     0     1     1
x1 =
     0     1     1     0
x1 =
     1     0     1     0
x1 =
     1     1     0     0
x1 =
     1     1     0     0
Av =
     1     1     2     3     1     1
tot_combination =
     6

Best Answer

Maybe I'm misunderstanding something but to me it looks like your code is wrong, it's missing for ex. 0 1 0 1 as an output.
The simplest way to obtain all unique permutations of a sequence is:
m = 2; n = 2;
seqs = unique(perms([zeros(1, m) ones(1, n)]), 'rows')
There are indeed 6 combinations, but not the ones you return in your example.
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