Re: Sampling From a Histogram Distribution

[davido]

Another approach: Use Bytes::Random::Secure's string_from method. Supply it with the following "bag" string: "aaaaoooooooooooooooooooppppppppppccccc", and draw as many random characters as you need. The distribution will be appropriately weighted.

Update: Here's how it would look. I'm not convinced that I care for it aesthetically, but the randomness is high quality, and the source is well tested.

use Bytes::Random::Secure;

my $rng    = Bytes::Random::Secure->new( NonBlocking => 1 );
my %weight = ( apples => 4, oranges => 19, pairs => 10, peaches => 5 )
+;
my %map    = ( qw/ apples a oranges o pairs p peaches c / );
my %rmap   = reverse %map;

my $bag = join '', map { ( $map{$_} ) x $weight{$_} } keys %weight;

print $rmap{$rng->string_from($bag,1)}, $_% 8 == 0 ? "\n" : "\t"
  for 1 .. 100;

print "\n";

Sample output:

$ ./mytest.pl
pairs    oranges    oranges    oranges    pairs    apples    oranges  
+  apples
oranges    pairs    oranges    oranges    pairs    peaches    peaches 
+   apples
peaches    pairs    oranges    oranges    oranges    pairs    oranges 
+   oranges
peaches    peaches    peaches    oranges    oranges    peaches    oran
+ges    oranges
... and so on ...

When that module was created, it was an intentional design decision that duplicate characters in the "bag" string would increase the weighting of those characters.