#!/usr/local/bin/perl

# calculate mean and sd

# first line is labels
$_ = <>;
@labels = split;
shift @labels;	# remove "subjects" label

# next are data
while (<>) {
	chop;
	@line = split;

	shift @line; # remove subject name

	foreach $i (0 .. $#line) {
		$sum[$i] += $line[$i];
		$ssq[$i] += $line[$i] * $line[$i];	
	}

	$n++;
}

foreach $i (0 .. $#line) {
	$mean[$i] = $sum[$i] / $n;
	$var[$i] = ($ssq[$i] - $sum[$i]*$sum[$i]/$n) / ($n-1);
	($var[$i] > 0) || ($var[$i] = 0);
	$stderr[$i] = sqrt($var[$i] / $n);
}

# labels
foreach $i (0 .. $#line) {
	$x = $labels[$i];
	print "$x\t";
}
print "\n";

# means
foreach $i (0 .. $#line) {
	$x = $mean[$i];
	printf ("%.3f\t" , $x);
}
print "\n";		 

# standard errors
foreach $i (0 .. $#line) {
	$x = $stderr[$i];
	printf ("%.3f\t" , $x);
}
print "\n";