Aitken method for interpolation

I have written aitken's method for interpolation in octave/matlab.

I would like know if it's right. Because i get this result if I call
Code:
drawint(4)
.

Here is the code, feel free to modify for correcting.

Code:
function w = aitken(t,x,y) % t is a vector of x axis values of points where we want to interpolate % x and y are vectors of known points % return value w is a vector of calculated points (aitken method) on y axis        n=length(y);        Z=zeros(n);        Z(1,:)=y;        temp=zeros(1,length(t)); for k=1:1:length(t) for j=1:n-1 for i=j+1:n                                Z(j+1,i)=(Z(j,i)*(t(k)-x(j))-Z(j,j)*(t(k)-x(i)))/(x(i)-x(j)); end end                temp(k)=Z(n,n); end        w=temp;endfunction drawint(m)        x=0:pi/20:pi; figure; clf; plot(x,sin(x)); hold on;        step=(pi/m);        xf=0:step:pi;        yf=aitken(xf,x,sin(x)) plot(xf,yf,'r');end