# PCA
dat<-read.table("zeroyield.txt",header=T)
dat1<-dat[-1,]-dat[-length(dat1[,1]),]
(ans<-prcomp(dat1))
summary(ans)
x1<-as.numeric(ans$rotation[,1])
x2<-as.numeric(ans$rotation[,2])
x3<-as.numeric(ans$rotation[,3])
plot(x1,x2,type="n")
text(x1,x2,colnames(dat1))
plot(x1,x3,type="n")
text(x1,x3,colnames(dat1))
plot(x2,x3,type="n")
text(x2,x3,colnames(dat1))
