filename ='iris.csv';
data =csvread(filename);
rawdata =data(:,2:5)
a =data(data(:,1)==0,:);
a =a(:,2:5);
b =data(data(:,1)==1,:);
b =b(:,2:5);
c =data(data(:,1)==2,:);
c =c(:,2:5);[coefs,scores,variances,t2]=princomp(rawdata);
a=a*coefs(:,1:2);
b=b*coefs(:,1:2);
c=c*coefs(:,1:2);plot(a(:,1),a(:,2),'r.','markersize',20);
hold on
plot(b(:,1),b(:,2),'g.','markersize',20);
hold on
plot(c(:,1),c(:,2),'b.','markersize',20);
hold off
xlabel('1st Principal Component');ylabel('2nd Principal Component');
