#!/bin/bash

# calculate fprob from indices and fprob matrix
# output: average feature's feature probability and average non-feature's feature probability

bidx=$1
fprob=$2
n=$3

script=$(cat - <<EOS
BEGIN {
  type = 0;  # 0: bidx, 1: fprob

  nprob     = 0;
  nprob_max = 0;
  pprob     = 0;
  pprob_max = 0;
}

{
  if (type == 0) {
    split("", feats);

    for (i = 1; i <= NF; ++i) {
      feats[i] = \$i;
    }

    type = 1;
  } else if (type == 1) {
    sum = 0;
    for (i = 1; i <= NF; ++i) {
      sum += \$i;
    }

    lprob = 0;
    for (i = 1; i <= length(feats); ++i) {
      lprob += \$(feats[i]+1);
    }

    nprob += sum-lprob;
    pprob += lprob;

    nprob_max += NF-length(feats)
    pprob_max += length(feats)

    type  = 0;
  }
}

END {
  print pprob/pprob_max, nprob/nprob_max;
}
EOS
)
paste -d "\n" $bidx $fprob | head -n$((n*2)) | awk "$script"