epclust/tests/testthat/helper.clustering.R

   1 #shorthand: map 1->1, 2->2, 3->3, 4->1, ..., 149->2, 150->3, ... (is base==3)
   2 I = function(i, base)
   3     (i-1) %% base + 1
   4
   5 # NOTE: medoids can be a big.matrix
   6 computeDistortion = function(series, medoids)
   7 {
   8     n = nrow(series) ; L = ncol(series)
   9     distortion = 0.
  10     if (bigmemory::is.big.matrix(medoids))
  11         medoids = medoids[,]
  12     for (i in seq_len(n))
  13         distortion = distortion + min( colSums( sweep(medoids,1,series[,i],'-')^2 ) / L )
  14     distortion / n
  15 }