Charlie 0.6.0 Released - A genetic algorithms library

Hi all,

I’m pleased to announce the second public release of charlie, a
genetic algorithms library for Ruby.

This release includes a TreeGenotype, making the library useful for
genetic programming. This is still an early version with very limited
mutation options, and I would really appreciate suggestions on how to
extend these.
It also includes several performance improvements, changes for ruby
1.9, convergence checks and improved mutator/crossover operators for

Ruby 1.9 Compatibility

This release is mostly compatible with Ruby 1.9.
However, there is a bug in Ruby (#16493) that makes a lot of tests,
and some benchmark examples fail.
To avoid this bug, don’t have two or more results of a function that
returns a module in the same array (e.g. don’t have something like
“crossover PCross(0.5,SinglePointCrossover),
PCross(0.5,UniformCrossover)” in your benchmarks).


  • Quickly develop GAs by combining several parts (genotype, selection,
    crossover, mutation) provided by the library.
  • Sensible defaults are provided with any genotype, so often you only
    need to define a fitness function.
  • Easily replace any of the parts by your own code.
  • Test different strategies in GA, and generate reports comparing
    them. Example report:


This example finds a polynomial which approximates cos(x)

class Cos < TreeGenotype([proc{3rand-1.5},:x], [:+,:,:-], [:[email protected]])
def fitness
-[0,0.33,0.66,1].map{|x| (eval_genes(:x=>x) - Math.cos(x)).abs }.max
use TournamentSelection(4)

Several other simple examples are included in the gem/tarball.


  • sudo gem install charlie



MIT license.

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