org.epiga.problem

Class Problem<R extends Representation<?>>

java.lang.Object

org.epiga.problem.Problem<R>

Type Parameters:

R - the representation type

Direct Known Subclasses:

AbstractOnemaxProblem, IntmaxProblem, MKProblem

public abstract class Problem<R extends Representation<?>>
extends java.lang.Object

The base class for defining problems.

Author:

Daniel H. Stolfi

Constructor Summary

Constructors

Constructor and Description
Problem(int size, boolean cache) Constructor.

Method Summary

Modifier and Type	Method and Description
abstract int	compare(double d1, double d2) Comparator which defines if it's a minimization or maximization problem.
abstract void	crossover(R r1, R r2, java.util.BitSet n) Epigenetic crossover of two solutions.
abstract R	generateSolution() Generate a new solution of the Problem.
int	getEvaluations() Returns the number of evaluations done.
double	getFitness(R representation) Compute and return the fitness value.
int	getSize() Returns the size of the solution vector of the problem.
boolean	isBetter(double d1, double d2) Returns true if the first fitness value is better than the second one, according to the comparison function.
abstract void	methilate(R r, java.util.BitSet n, float eprobability) Epigenetic methilation of a solution.
abstract void	save(R representation, java.lang.String file) Saves the problem representation to a file.
java.lang.String	toString() Returns the String representation of the Problem

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Problem

public Problem(int size,
               boolean cache)

Constructor.

Parameters:

size - the problem size.

cache - true if a hash table will be used as a evaluation cache.

Method Detail

generateSolution

public abstract R generateSolution()

Generate a new solution of the Problem.

Returns:

the new solution generated.

toString

public java.lang.String toString()

Returns the String representation of the Problem

Overrides:

toString in class java.lang.Object

getFitness

public double getFitness(R representation)

Compute and return the fitness value.

Parameters:

representation - the representation to be evaluated.

Returns:

the fitness value

getEvaluations

public int getEvaluations()

Returns the number of evaluations done.

Returns:

the number of evaluations done.

getSize

public int getSize()

Returns the size of the solution vector of the problem.

Returns:

the size of the solution vector of the problem.

crossover

public abstract void crossover(R r1,
                               R r2,
                               java.util.BitSet n)

Epigenetic crossover of two solutions.

Parameters:

r1 - the representation of the first solution

r2 - the representation of the second solution

n - the nucleosome vector

methilate

public abstract void methilate(R r,
                               java.util.BitSet n,
                               float eprobability)

Epigenetic methilation of a solution.

Parameters:

r - the representation of the solution

n - the nucleosome vector

eprobability - the epigenetic probability

isBetter

public boolean isBetter(double d1,
                        double d2)

Returns true if the first fitness value is better than the second one, according to the comparison function.

Parameters:

d1 - the first fitness value

d2 - the second fitness value

Returns:

true if the first fitness value is better than the second one.

compare

public abstract int compare(double d1,
                            double d2)

Comparator which defines if it's a minimization or maximization problem.

Parameters:

d1 - the first fitness value

d2 - the second fitness value

Returns:

true or false depending on the use of minimizingComparator of maximizingComparator.

save

public abstract void save(R representation,
                          java.lang.String file)
                   throws java.io.FileNotFoundException

Saves the problem representation to a file.

Parameters:

representation - the representation

file - the filename

Throws:

java.io.FileNotFoundException - If the file cannot be saved