숫자들의 표준 편차를 구하는 스크립트

standard_deviation.pl

#! /usr/bin/perl

use strict;
use warnings;

use POSIX qw/floor ceil/;

my @data;
while ( <> ) {
    chomp;
    push @data, $_;
}

my $total = 0;
foreach ( @data ) {
    $total += $_;
}

print "number of data = ", $#data + 1, "\n";

my $avg = $total / @data;       # 평균

print "average = $avg\n";

my $sum_of_dev = 0;
my $sum_of_dev_sqr = 0;
foreach ( @data ) {
    my $deviation = $_ - $avg;
    $sum_of_dev += $deviation;
    $sum_of_dev_sqr += $deviation * $deviation;
}
print "sum of dev = $sum_of_dev\n";
print "sum of dev square = $sum_of_dev_sqr\n";

my $variance = $sum_of_dev_sqr / $#data;

print "variance = $variance\n"; # 분산

my $standard_deviation = sqrt $variance;

print "standard deviation = $standard_deviation\n";     # 표준 편차

1;