org.jgap
Class CachedFitnessFunction

java.lang.Object
  org.jgap.FitnessFunction
      org.jgap.CachedFitnessFunction

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, ICloneable

Direct Known Subclasses:

MinimizingFitnessFunctionCached

public abstract class CachedFitnessFunction
extends FitnessFunction

The cached fitness function extends the original FitnessFunction functionality in order to reduce evaluating something twice.

Since:

3.2

See Also:

Serialized Form

Field Summary

Fields inherited from class org.jgap.FitnessFunction

DELTA, NO_FITNESS_VALUE

Constructor Summary

CachedFitnessFunction()
Default Constructor ensuring downward compatibility.

CachedFitnessFunction(java.util.Map<java.lang.String,java.lang.Double> cache)
Constructor that allows to use a custom java.util.Map implementation as cache.

Method Summary

protected java.lang.String	getBusinessKey(IChromosome a_subject) Retrieves the business key of a chromosome instance.
double	getFitnessValue(IChromosome a_subject) Cached fitness value function.

Methods inherited from class org.jgap.FitnessFunction

clone, evaluate, getLastComputedFitnessValue

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CachedFitnessFunction

public CachedFitnessFunction()

Default Constructor ensuring downward compatibility.

Since:

3.3.2

CachedFitnessFunction

public CachedFitnessFunction(java.util.Map<java.lang.String,java.lang.Double> cache)

Constructor that allows to use a custom java.util.Map implementation as cache.
E.g. for multi-threaded fitness calculations one could use one instance of java.util.concurrent.ConcurrentHashMap for all instances of the fitness function.

Parameters:

cache - java.util.Map data structure used to cache the fitness values

Since:

3.3.2

Method Detail

getFitnessValue

public final double getFitnessValue(IChromosome a_subject)

Cached fitness value function.

Overrides:

getFitnessValue in class FitnessFunction

Parameters:

a_subject - the chromosome to evaluate

Returns:

fitness value, from cache if available

Since:

3.2

getBusinessKey

protected java.lang.String getBusinessKey(IChromosome a_subject)

Retrieves the business key of a chromosome instance.

Parameters:

a_subject - the chromosome to retrieve the key for

Returns:

the business key of the chromosome

Since:

3.2