Stem-and-leaf plot/Data generator

From Rosetta Code

Written to generate data sets for the Stem-and-leaf plot task. Statistics aren't my field or area of significant expertise, so some of the variable names might represent my homebrew understanding more than official terminology. --Michael Mol 19:34, 14 December 2009 (UTC)

<lang perl>#!/usr/bin/perl use strict;

  1. The shuffle is taken from http://rosettacode.org/wiki/Knuth_shuffle

sub shuffle

{my @a = @_;
 foreach my $n (1 .. $#a)
    {my $k = int rand $n + 1;
     $k == $n or @a[$k, $n] = @a[$n, $k];}
 return @a;}
  1. The greater your pointcount to your width, the more sparse your result.

sub genhump { my ($offset, $width, $pointcount, $slope) = @_;

my $diecount = $slope; my $range = $width / $diecount;

my @ret; foreach (1 .. $pointcount) { my $point = $offset; foreach (1 .. $diecount) { $point += rand($range * 10000) / 10000; }

push @ret, int($point); }

return @ret; }

my @list = (&genhump(8, 3, 5, 3),

           &genhump(12, 3, 5, 6));

my @shuffled = &shuffle(@list);

print "@shuffled\n";</lang>