hampel_weight.m

基于M估计的迭代最小二乘算法

function [weight] = Hampel_weight(z)
%Hampel_weight  Calculate weight value based on Hampel's 17A function where
%a=1.7, b=3.4 and c =8.5.
a=1.7;
b=3.4;
c=8.5;
if(abs(z)<=a)
    weight=1;
else if(abs(z)>a&&abs(z)<=b)
        weight=a/abs(z);
    else if(abs(z)>b&&abs(z)<=c)
            weight=a*(c-abs(c))/(abs(z)*(c-b));
        else 
            weight=0;
        end
    end
end