function [sita,n]=esti(n,sita)
global s T y u my t n0 ty m
lambda=0.9;                        % forgetting factor "lambda"
uni=ones(1,my);
delta=zeros(my,1); 
delta(y(s,t))=1;
n(:,ty)=lambda*(n(:,ty)+delta)+(1-lambda)*n0(:,ty);
%n(y(s,t),ty)=lambda*(n(y(s,t),ty)+1)+(1-lambda)*n0(y(s,t),ty);
sita(:,ty)=n(:,ty)/(uni*n(:,ty));