lagr1.m

实现10次lagrange插值L（x）和三次样条插值

function y = lagr1(x0,y0,x)
n=length(x0);m=length(x);
for i=1:m
    z = x(i);
    s = 0.0;
    for k = 1:n
        p = 1.0;
        for j = 1:n
            if j ~= k
                p = p*(z-x0(j))/(x0(k)-x0(j));
            end
        end
        s=s+p*y0(k);
    end
    y(i) = s;
end