#!/usr/bin/env gawk
#
# pure awk stats computing from https://unix.stackexchange.com/a/13779
# with stdev
# need to be used with "sort -n" 

BEGIN {
    c = 0;
    sum = 0;
  }
  $1 ~ /^(\-)?[0-9]*(\.[0-9]*)?$/ {
    a[c++] = $1;
    sum += $1;
    sumsq += $1^2;
  }
  END {
    ave = sum / c;
    stdev = sqrt((sumsq-sum^2/NR)/NR)
    if( (c % 2) == 1 ) {
      median = a[ int(c/2) ];
    } else {
      median = ( a[c/2] + a[c/2-1] ) / 2;
    }
    OFS="\t";
    print sum, c, ave, median, stdev, a[0], a[c-1];
  }