x=[0 1 2 2.5 3 3.5 4];
y=[2.5 0.5 0.5 1.5 1.5 1.25 0];

plot(x,y,'bo','LineWidth',2); axis([0 4 0 6]);
pause;

plot(x,y,'ro:','LineWidth',2);
hold on;
pause;

DD=DDtable(x,y);
c=diag(DD);
plotnewtoninterp(x,y,c,'k-','LineWidth',2);
pause;

for j=2:2:(length(x)-1)
  xloc=x(j-1:j+1);
  yloc=y(j-1:j+1);
  DDloc=DDtable(xloc,yloc);
  cloc=diag(DDloc);
  hold on;
  plotnewtoninterp(xloc,yloc,cloc,'g-','LineWidth',2);
  hold off;
end