matlab实现的的knn分类器 有训练样本和测试样本

clear;clc;ticload data.txt;a=data(1:30,1:4);aa=data(31:50,1:4);b=data(51:80,1:4);bb=data(81:100,1:4);c=data(101:130,1:4);cc=data(131:150,1:4);train_sample=cat(1,a,b,c);%组成训练样本（90*4）test_sample=cat(1,aa,bb,cc);%组成测试样本（60*4）k=5;cha=zeros(1,90);sum=0;[i,j]=size(train_sample);[u,v]=size(test_sample);for x=1:u    for y=1:i        result=sqrt((test_sample(x,1)-train_sample(y,1)).^2+(test_sample(x,2)-train_sample(y,2)).^2+(test_sample(x,3)-train_sample(y,3)).^2+(test_sample(x,4)-train_sample(y,4)).^2);        cha(1,y)=result;    end;    [z,ind]=sort(cha);    m1=0;    m2=0;    m3=0;    for n=1:k        if ind(1,n)