larg.m

牛顿插值法

function s=larg(x,y,x0);
  t=0;  
  nx=length(x);
for k=1:nx
      u=1;
    for j=1:nx
        if j~=k;
            u=u*(x0-x(j))/(x(k)-x(j));
        end 
    end 
    t=u*y(k) +t;
end
s=t