combination.m

Active approach - TOA combin

function C=combination(n,k)
%
% C=kombinacie(n,k)
% 
% Function creates the matrix of the ones and zeros. 
% Just k ones are in every row and the rows are not repeated.
%
% n - selection set
% k - number of ones in every row
%
% C - output matrix (n over k)*n

%tato funkcia vytvori maticu rozmerov (n nad k)*n obsahujucu 1 a 0,
%kde v kazdom riadku bude prave k jednotiek a riadky sa neopakuju 

C=zeros(factorial(n)/(factorial(n-k)*factorial(k)),n);
P=zeros(2^n,n);
g=1;
for i=1:n
    for j=1:2^(n-i)
        for h=0:g-1
        P(j+h*(2^(n-i+1)),i)=1;
        end
    end
    g=2*g;
end
P;

suma=sum(P');
[rows columns] = size(suma);
j=1;
for i=1:columns
    if (abs(suma(1,i)-k)<(10^(-10)))
        for h=1:n
        C(j,h)=P(i,h);
        end
        j=j+1;
    end
end

%% Date: 03.04.2007
%% Author: Maria Riskova