R/Fraction.R

In villardon/MultBiplotR: Multivariate Analysis Using Biplots in R

Fraction <- function(data,confidence=1){
  center=apply(data,2,mean)
  n=dim(data)[1]
  datacen=(diag(n)-matrix(1, n, n)/n) %*% data
  DE=svd(datacen)
  K=DE$u
  d=matrix(0,n,1)
  for (i in 1:n)
    d[i]=sqrt(sum(K[i,]^2))
  radius = quantile(d,confidence)
  
  data2=data[which(d<=radius),]
  res=list(data=data, fraction=data2, confidence=confidence, center=center)
  class(res)<-"fraction"
  return(res)
}