Table of Contents
The Watchmaker Framework for Evolutionary Computation is an extensible, high-performance, object-oriented framework for implementing platform-independent evolutionary algorithms in Java. It is freely available under a permissive Open Source licence. It can be downloaded from http://watchmaker.uncommons.org.
This chapter introduces the core components of the Watchmaker Framework and shows how they can be used to implement simple evolutionary algorithms such as the "Hello World" example outlined in the previous chapter.
The central object of an evolutionary program built with the Watchmaker Framework is the evolution engine.
The framework provides multiple implementations of the
EvolutionEngine interface, but the one that you will
usually want to use is GenerationalEvolutionEngine. This is a
general-purpose implementation of the evolutionary algorithm outline from chapter 1.
An EvolutionEngine has a single generic type parameter
that indicates the type of object that it can evolve.
For the "Hello World" program we need to be able to evolve Java strings.
Code that creates an engine that can evolve strings would look something like this:
EvolutionEngine<String> engine
= new GenerationalEvolutionEngine<String>(candidateFactory,
evolutionaryOperator,
fitnessEvaluator,
selectionStrategy,
rng);
Once you have created an EvolutionEngine, your program
is as simple as calling the evolve method with appropriate
arguments.
However, as you can see from the code snippet above, there is a little bit of work to
be done first in order to create an EvolutionEngine that
is configured appropriately for the given problem.
The constructor of the GenerationalEvolutionEngine class requires
five objects. These are: