#!/usr/bin/perl -w
use strict;

my $col = shift @ARGV;
if (!defined $col) { 
   print "usage: basicStats.pl #colNum0based < infile > outfile\n";
   exit;
}

my $sum = 0;
my $cnt = 0;
my @num;
my $min;
my $max;
while (<>) {
    chomp;
    my @f = split(/\t/);
    if (scalar @f < $col) { #try splitting on spaces
       @f = split(/\s/);
    }
    if ($f[$col] !~ /^-?[0-9]+\.?\d*$/) {
        if ($f[$col] !~ /^\d\.\d+e-\d+$/) { #allow scientific nums 8.25218682951e-05
        print "ERROR selected column is not a number $f[$col]\n";
        exit;
        }
    }
    $sum += $f[$col];
    push(@num, $f[$col]);
    $cnt++;
    if (!defined $min) {
       $min = $f[$col];
       $max = $f[$col];
    }else {
       if ($f[$col] < $min) { $min = $f[$col]; }
       if ($f[$col] > $max) { $max = $f[$col]; }
    }
}

@num = sort { $a <=> $b } @num;
my $m = int($cnt/2);
print "Found $cnt numbers with min $min and max $max\n",
      "sum ", $sum, "\n",
      "average ", $sum/$cnt, "\n",
      "median ", $num[$m], "\n";
my $q = int($cnt/4);
print "first quartile ", $num[$q], "\n";
$q = 3*$q;
print "third quartile ", $num[$q], "\n";