clear;
clc;


n=5;
X=[-1.32; -0.84; -0.41 ; 0.16; 0.33; 1.09];
Y=[-2.12; -2.09; 1.07; 0.51; -0.27; 1.51];
x_bar=0.25;



function y=W(x, n, X, Y)
    for j=0:n
        S(j+1)=Y(j+1)*phi(j,x,X,n);
    end;
    y=sum(S);
endfunction;

function y=omega(x,n,X);
    y=1;
    for i=0:n
        y=y*(x-X(i+1));
    end;
endfunction;

D=zeros(n+1,n+1);
D(:,1)=Y;

for k=1:n
        for i=0:(n-k)
            D(i+1,k+1)=(D(i+2,k)-D(i+1,k))/(X(i+k+1)-X(i+1));
        end;
end;

Tmp(i+1)=D(1,1);

for i=1:k
        Tmp(i+1)=D(1,i+1)*omega(x_bar,i-1,X);
end;
    Wn=sum(Tmp);




disp(Wn,"Wn=");