exkernelknn1.m

关于svm的例程

clear all
close all

n = 50; 

sigma=1;
[xapp,yapp,xtest,ytest, xtest1, xtest2]=dataset('gaussian',n,0,sigma);
[xapp]=normalizemeanstd(xapp);


 



valY=[-1 1];
k=3;
kernel='gaussian';
kerneloption=0.1;

[xtest1 xtest2]  = meshgrid([-4:.4:4],[-4:0.4:4]); 
nn = length(xtest1); 
xtest = [reshape(xtest1 ,nn*nn,1) reshape(xtest2 ,nn*nn,1)]; 
[ypred,tabkppv,distance]=kernelknn(xapp,yapp,valY,kernel,kerneloption,xtest,k);
[ypred2,tabkppv,distance]=kernelknn(xapp,yapp,valY,'poly',1,xtest,k);


ypred = reshape(ypred,nn,nn); 
ypred2 = reshape(ypred2,nn,nn); 

%--------------- plotting-------------------------%
figure(1); 
clf; 
hold on
[cc,hh]=contour(xtest1,xtest2,ypred,[0 0],'k');
clabel(cc,hh); 
[cc,hh]=contour(xtest1,xtest2,ypred2,[0 0],'g');
clabel(cc,hh); 
h1=plot(xapp(yapp==1,1),xapp(yapp==1,2),'+b'); 
set(h1,'LineWidth',2);
h2=plot(xapp(yapp==-1,1),xapp(yapp==-1,2),'dr'); 
set(h2,'LineWidth',2);
axis([-4 4 -4 4]);