#!/usr/bin/perl
# Simple averages and medians
# (c) 2003 Martin Mares <mj@ucw.cz>, GPL'ed

use strict;
use warnings;

`sort >avg.tmp`; $? && die;
open I, "avg.tmp" or die;
my $n = 0;
my $sum = 0;
my $max = 0;
my $min;
while (<I>) {
	chomp;
	$n++;
	$sum += $_;
	$max = $_;
	$min = $_ if !defined $min;
}
$n || die "No data found";
seek(I, 0, 0);
my $median = 0;
for (my $i=0; $i<$n/2; $i++) {
	$median = <I>;
	chomp $median;
}
my $avg = $sum/$n;
my $qsum = 0;
seek (I, 0, 0);
while (<I>) {
	chomp;
	my $d = $_ - $avg;
	$qsum += $d*$d;
}
my $var = $qsum/$n;
my $stdd = sqrt($var);
printf "Number of records:	%d\n", $n;
printf "Average:		%.3f\n", $avg;
printf "Variance:		%.3f\n", $var;
printf "Std. deviation:		%.3f\n", $stdd;
printf "Median:			%.3f\n", $median;
printf "Minimum:		%.3f\n", $min;
printf "Maximum:		%.3f\n", $max;
;