d  <- read.table("inp_iris.txt",header=TRUE)
mm <- ncol(d)-1

#Standardization
dat <- d[,1:mm]
#dat <- sweep(dat,2,apply(dat,2,mean),FUN="-")
#dat <- sweep(dat,2,apply(dat,2,sd),FUN="/")

#Principal Coponent Analysis
eigen(cor(dat[,1:mm]))
plt <- as.matrix(dat[,1:mm]) %*% eigen(cor(dat[,1:mm]))$vectors[1:mm,]
pairs(
  plt,
  diag.panel=NULL,
  pch=21,
  bg=c("red","green","blue")[unclass(d$Species)]
  )