R/ClusterEntropy.R

In IntNMF: Integrative Clustering of Multiple Genomic Dataset

# Cluster Entropy
ClusterEntropy <- function(ComputedClusters, TrueClasses) {
  cross.tab <- table(ComputedClusters,TrueClasses)
  # Compute the inner sum for each clusters
  inner.sum <- apply(cross.tab,1,function(x){
  c.size <- sum(x)
  sum(x * ifelse(x!=0,log2(x/c.size),0))})
  # Calculate entropy
  - sum(inner.sum)/(sum(cross.tab) * log2(ncol(cross.tab)))
}