matlab-模式识别-非参数判别分类法--------两分法

先来个例子：clear;
clc;
a=10;
b=10;
n=100;
cxd1=a*rand(n,1)-5;
cxd2=b*rand(n,1)-5;
cxd=[cxd1 cxd2];
figure(1);
plot(cxd1,cxd2,'o');
title('随机生成的模式点图');
d12=-2.*cxd1-3.*cxd2-3;
d13=-10.*cxd1-cxd2-1;
d23=-cxd1+cxd2-1;
w1=[];w2=[];w3=[];wir=[];
for i=1:1:length(cxd)
    if(d12(i)>0&d13(i)>0)
        w1=[w1;cxd(i,:)];
    else if(d12(i)<0&d23(i)>0)
            w2=[w2;cxd(i,:)];
        else if (d13(i)<0&d23(i)<0)
                w3=[w3;cxd(i,:)];
            else
                wir=[wir;cxd(i,:)];
            end
        end
    end
end
figure(2);
x=-5:1:5;
y1=-(2/3).*x-1;
y2=-10.*x-1;
y3=x+1;
plot(x,y1,'r');hold on
plot(x,y2,'b');
plot(x,y3,'g');
axis([-5 5 -5 5]);
xlabel('x1');ylabel('x2');title('分类结果图');
if(~isempty(w1))
    plot(w1(:,1),w1(:,2),'o');
end
if(~isempty(w2))
    plot(w2(:,1),w2(:,2),'*');
end
if(~isempty(w3))
    plot(w3(:,1),w3(:,2),'^');

legend('d12(x)=0','d13(x)=0','d23(x)=0','w1','w2','w3');
end
if(isempty(wir))
    plot(wir(:,1),wir(:,2),'.');
   legend('d12(x)=0','d13(x)=0','d23(x)=0','w1 类','w2 类','w3 类','IR 区');

end