function correlagram(data,n,color)
maxk = n;
u = mean(data);
N = numel(data);
for k=1:maxk
       for j=k+1:N
               r(k,j) = (data(j)-u)*(data(j-k)-u);
       end
       R(k) = sum(r(k,:))/(var(data)*N);
end
plot(1:maxk,R,color)
hold on;
plot(1:maxk,1.96/sqrt(N),'r');

end