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1、functionBayes2%为了提高实验样本测试的精度,故采用多次模拟求平均值的方法N=input('实验模拟次数N(N最好为奇数)=');Result(1:3,1:3)=0; %判别矩阵的初始化fork=1:N %控制程序模拟次数N %生成二维正态分布的样本2XN维的矩阵 X1=mvnrnd([12],[40;06],300)'; %2XN X2=mvnrnd([53],[50;01],200)'; X3=mvnrnd([47],[20;09],500)'; %样本程序 %---
2、------------------------------------------------% %测试样本 X10=mvnrnd([12],[40;06],100)'; %2XN X20=mvnrnd([53],[50;01],100)'; X30=mvnrnd([47],[20;09],100)'; %先验概率 P(1)=length(X1)/(length(X1)+length(X2)+length(X3)); P(2)=length(X2)/(length(X1)+length(X2)+leng
3、th(X3)); P(3)=length(X3)/(length(X1)+length(X2)+length(X3)); %计算相关量 cov(X):协方差矩阵Ave:均值 %--------------------------------------------------------% W1=-1/2*inv(cov(X1'));W2=-1/2*inv(cov(X2'));W3=-1/2*inv(cov(X3'));% Ave1=(sum(X1')/length(X1))';Ave2=(sum(X2')/lengt
4、h(X2))'; Ave3=(sum(X3')/length(X3))';%计算平均值(2维列向量) w1=inv(cov(X1'))*Ave1;w2=inv(cov(X2'))*Ave2;w3=inv(cov(X3'))*Ave3;%2 w10=-1/2*Ave1'*inv(cov(X1'))*Ave1-1/2*log(det(cov(X1')))+log(P(1)); w20=-1/2*Ave2'*inv(cov(X2'))*Ave2-1/2*log(det(cov(X2')))+log(P(2)); w30=-1
5、/2*Ave3'*inv(cov(X3'))*Ave3-1/2*log(det(cov(X3')))+log(P(3)); %-----------------------------------------------------------% fori=1:3 forj=1:100 ifi==1 g1=X10(:,j)'*W1*X10
6、(:,j)+w1'*X10(:,j)+w10; g2=X10(:,j)'*W2*X10(:,j)+w2'*X10(:,j)+w20; g3=X10(:,j)'*W3*X10(:,j)+w3'*X10(:,j)+w30; ifg1>=g2&g1>=g3 Result(1,1)=Result(1,1)+1; elseifg2>=g1&g2>=g3
7、Result(1,2)=Result(1,2)+1;%记录误判情况 else Result(1,3)=Result(1,3)+1;%记录误判情况 end elseifi==2 g1=X20(:,j)'*W1*X20(:,j)+w1'*X20(:,j)+w10; g2=X20(:,j)'*W2*X20(:,j)+w2'*X20(:,j)+w20;
8、g3=X20(:,j)'*W3*X20(:,j)+w3'*X20(:,j)+w30; ifg2>=g1&g2>=g3 Resul