RosettaCodeData/Task/Statistics-Normal-distribution/Perl/statistics-normal-distribut...

32 lines
842 B
Perl

use constant pi => 3.14159265;
use List::Util qw(sum reduce min max);
sub normdist {
my($m, $sigma) = @_;
my $r = sqrt -2 * log rand;
my $theta = 2 * pi * rand;
$r * cos($theta) * $sigma + $m;
}
$size = 100000; $mean = 50; $stddev = 4;
push @dataset, normdist($mean,$stddev) for 1..$size;
my $m = sum(@dataset) / $size;
print "m = $m\n";
my $sigma = sqrt( (reduce { $a + $b **2 } 0,@dataset) / $size - $m**2 );
print "sigma = $sigma\n";
$hash{int $_}++ for @dataset;
my $scale = 180 * $stddev / $size;
my @subbar = < >;
for $i (min(@dataset)..max(@dataset)) {
my $x = ($hash{$i} // 0) * $scale;
my $full = int $x;
my $part = 8 * ($x - $full);
my $t1 = '█' x $full;
my $t2 = $subbar[$part];
print "$i\t$t1$t2\n";
}