#! /usr/bin/perl
# varianz - Stichproben-Standardabweichung errechnen
@SAVEDARGV = @ARGV;
while(<>) {
if(/(\d+) (\d+.*)/) {
$count++;
$xval = $1;
$ysum += $2;
if($count == 1) {
$ymin = $2;
}
if($2 < $ymin) {
$ymin = $2;
}
if($2 > $ymax) {
$ymax = $2;
}
}
}
$ymittel = $ysum / $count;
@ARGV = @SAVEDARGV;
while(<>) {
if(/(\d+) (\d+)/) {
$sum+= ($2 - $ymittel) * ($2 - $ymittel)
}
}
$varianz = $sum / ($count - 1);
printf "%d %.2f %.2f %.2f %.2f\n", $xval, $ymittel, $ymin, $ymax, sqrt($varianz);