function [Q]=aitken(x,y,xval)

n=length(x);
P=zeros(n);
P(1,:)=y;
for j=1:n-1
    for i=j+1:n
        P(j+1,i)=(P(j,i)*(xval-x(j))-P(j,j)*(xval-x(i)))/(x(i)-x(j));
    end
end
Q=P(n,n);

for i=1:n
    disp([x(i) P(1:i,i)']);
end