function [dx,ct]= h_kmeans(x,N)
[m,n]=size(x);
ct=zeros(m,n);
ct=x(ceil(rand(m,1)*m),:);
D=zeros(m,n);
dx=0;
while any(ct~=dx)
ct=dx;
for i=1:N
q=zeros(m,1);
for j=1:N
q=q+(x(:,j)-ct(i,j)).^2;
end
D(:,j)=dx;
end
[z,dx]=min(D,[],2);
for i=1:m
idx=mean(x(dx==i,:));
end
end
return
end