stats

# Convert the Y coordinate to an average

eval "exec perl -sS $0 $*"
	if 0;

@values = ();
$sum = $n = 0;
$min = 1.7E+308;
$max = 2.2E-308;
while (<>) {
	next if /^[%#]/;
	split;
	if ($_[0] > 1000000) {
		#warn "$file: ignoring $_";
		next;
	}
	if ($#_ >= 1) {
		$val = $_[1];
	} else {
		$val = $_[0];
	}
	push(@values, $val);
	$sum += $val;
	$min = $val if $val < $min;
	$max = $val if $val > $max;
	$n++;
}
# Do some statistics.
@s = sort(@values);
if ($n & 1) {	
	$median = $s[($n + 1)/2];
} else {
	$i = $n / 2;
	$median = ($s[$i] + $s[$i+1]) / 2;
}
$avg = $sum/$n;
$avgdev = $var = 0;
foreach $_ (@values) {
	$var += ($_ - $median) ** 2;
	$tmp = $_ - $median;
	$avgdev += $tmp > 0 ? $tmp : -$tmp;
}
$var /= $n - 1;
$stddev = sqrt($var);
$avgdev /= $n;
#printf("%8s %8s %8s %8s %8s %4s %8s\n", "Min", "Max", "Average", "Median", "Std Dev", "%", "Avg Dev");
#printf "%8.2f %8.2f %8.2f %8.2f %8.2f %4.1f%% %8.2f\n", $min, $max, $avg, $median, $stddev, $stddev/$median*100, $avgdev;
printf "%4.1f%%\n", $stddev/$median*100;
exit 0;