http://www.perlmonks.org?node_id=175816

Recent discussion of Pascal's triangle reminded me of a cool 1-D Cellular Automata and Wolfram's famous Rule 30.

Try $rule = 18, 22, 30, 45, 54, 110, or 150 for some snazzy Pascal's Triangle variations.

RuleFoo

update: Also rules 122, 126, 129, 146, 151

#!/usr/bin/perl use strict; my $rule = shift || 30; my $wide = shift || 80; my $high = shift || 60; my $binary = reverse(substr(sprintf("%8.8b", $rule), -8, 8)); $binary =~ tr/01/ */; #print "$binary\n"; my (%rules, $key, $i); for ($i = 7; $i >= 0; $i--) { $key = sprintf("%3.3b", $i); $key =~ tr/01/ */; $rules{$key} = substr($binary, $i, 1); #print "$key $rules{$key}\n"; } my ($str, @chs); for (1..$wide) { if (rand(2) < 1) { $str .= ' '; } else { $str .= '*'; } } for (1..$high) { @chs = split('', $str); print "$str\n"; $str = ''; for ($i = 0; $i < $wide; $i++) { $key = "$chs[$i-1]$chs[$i]$chs[($i+1)%@chs]"; $str .= $rules{$key}; } }