main22.asv

最小二乘估计

clear;
clc;
comp=nchoosek(1:1:101,3);%求排列数
[row,col]=size(comp);
UNI=importdata('UNI.txt'); 

for i=1:1:row
    UNIF=[UNI(comp(i,1),:);UNI(comp(i,2),:);UNI(comp(i,3),:)];
    A=[10*ones(3,1)';UNIF(:,2)']';
    L=UNIF(:,1);
    X=inv(A'*A)*A'*L;
    r=UNI*X-YN;
    r2=r.^2;
    medrn(i,1)=median(r2);
end   
d=min(medrn);
for i=1:1:row
    if medrn(i,1)==d
        j=i
    end    
end

UNIFO=[UNI(comp(j,1),:);UNI(comp(j,2),:);UNI(comp(j,3),:)];
AO=[10*ones(3,1)';UNIFO(:,2)']';
LO=UNIFO(:,1);
XO=inv(AO'*AO)*AO'*LO;
%M估计
rO=UNIN*XO-YN;
det=sqrt(rO'*rO/8)