"nchoosek" function for a matrix whose all elements are 0 or 1

I have a matrix A whose all elements are 0 or 1. For example, the first row of A is:

[   0     0     1     0     0     1     0     1     0     0]

I want to use nchoosek function to find the combinations of (total number of 1's in a row) -1. Here, n= 3, k=n-1=2 (always k=n-1). How can I apply this function to all the rows of the matrix or at least, for the above vector.

The output should be as:

[   0     0     1     0     0     1     0     0     0     0]
[   0     0     1     0     0     0     0     1     0     0]
[   0     0     0     0     0     1     0     1     0     0]

nchoosek (3,2)=3.

Thanks

[the cyclist]

For the example

A = [0 0 1 0 0 1 0 1 0 0]

you want all possible rows that have two 1's and how many 0's?

[Ismaeel]

Thanks, yes all possible 1's without considering the 0's. But I want the locations of these possible 1's to be kept.

Answer 1

[James Tursa]

E.g., using a loop:

f = find(A);
n = numel(f);
result = repmat(A,n,1);
for k=1:n
    result(k,f(k)) = 0;
end

Or if the order matters:

    result(k,f(n-k+1)) = 0;

[Ismaeel]

So Cool, thank you so much James.

[Ismaeel]

Can we modify the code in case if A is a matrix instead of a vector? let's say: A=[0 0 1 0 0 1 0 1 0 0] [0 1 0 0 0 1 0 0 0 0] Thanks once again