lagrange.m

数值分析各种公式的解法

function f=lagrange(x,fx,inx)
n=length(x)
m=length(inx)
for i=1:m
    z=inx(i);
    s=0.0;
    for k=1:n
        p=1.0;
        for j=1:n
            if j~=k
                p=p*(z-x(j))/(x(k)-x(j));
            end
        end
        s=p*fx(k)+s;
    end
    f(i)=s;
end