R/ca.intern.R

In clusterMI: Cluster Analysis with Missing Values by Multiple Imputation

#' @keywords internal
ca.intern <- function(X, tol=10^-7,ncp.max = 100){
  df <- X/sum(X)
  row.w <- col.w <- apply(df, 1, sum)
  w.sqrt <- sqrt(col.w)
  df <- df/row.w
  df <- sweep(df, 2, col.w, "/") - 1
  df.ori <- df
  df <- df * w.sqrt
  df <- sweep(df, 2, w.sqrt, "*")
  df <- Rfast::Crossprod(df, df)
  res.eigen <- Rfast::eigen.sym(df, k= min(ncp.max,ncol(X)-1))
  eig <- res.eigen$values
  rank <- sum((eig/eig[1]) > tol)
  auxi <- res.eigen$vectors[, seq.int(rank)]/w.sqrt
  auxi2 <- sweep(df.ori, 2, col.w, "*")
  auxi2 <- Rfast::mat.mult(auxi2,auxi)
  return(auxi2)
}