io.jenetics

Enum Optimize

java.lang.Object

java.lang.Enum<Optimize>

io.jenetics.Optimize

All Implemented Interfaces:

Serializable, Comparable<Optimize>

public enum Optimize
extends Enum<Optimize>

This enum determines whether the GA should maximize or minimize the fitness function.

Since:

1.0

Version:

3.0

Author:

Franz Wilhelmstötter

Enum Constant Summary

Enum Constants

Enum Constant and Description
MAXIMUM GA maximization
MINIMUM GA minimization

Method Summary

Modifier and Type	Method and Description
<T extends Comparable<? super T>> Comparator<T>	ascending() Create an appropriate comparator of the given optimization strategy.
<C extends Comparable<? super C>> C	best(C a, C b) Return the best value, according to this optimization direction.
abstract <T extends Comparable<? super T>> int	compare(T a, T b) Compares two comparable objects.
<T extends Comparable<? super T>> Comparator<T>	descending() Create an appropriate comparator of the given optimization strategy.
static Optimize	valueOf(String name) Returns the enum constant of this type with the specified name.
static Optimize[]	values() Returns an array containing the constants of this enum type, in the order they are declared.
<C extends Comparable<? super C>> C	worst(C a, C b) Return the worst value, according to this optimization direction.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

MINIMUM

public static final Optimize MINIMUM

GA minimization

MAXIMUM

public static final Optimize MAXIMUM

GA maximization

Method Detail

values

public static Optimize[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Optimize c : Optimize.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Optimize valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

compare

public abstract <T extends Comparable<? super T>> int compare(T a,
                                                              T b)

Compares two comparable objects. Returns a negative integer, zero, or a positive integer as the first argument is better than, equal to, or worse than the second.

Type Parameters:

T - the comparable type

Parameters:

a - the first object to be compared.

b - the second object to be compared.

Returns:

a negative integer, zero, or a positive integer as the first argument is better than, equal to, or worse than the second.

Throws:

NullPointerException - if one of the arguments is null.

descending

public <T extends Comparable<? super T>> Comparator<T> descending()

Create an appropriate comparator of the given optimization strategy. A collection of comparable objects with the returned comparator will be sorted in descending order, according to the given definition of better and worse.

final Population<DoubleGene, Double> population = ... population.sort(Optimize.MINIMUM.<Double>descending());

The code example above will populationSort the population according it's fitness values in ascending order, since lower values are better in this case.

Type Parameters:

T - the type of the objects to compare.

Returns:

a new Comparator for the type T.

ascending

public <T extends Comparable<? super T>> Comparator<T> ascending()

Create an appropriate comparator of the given optimization strategy. A collection of comparable objects with the returned comparator will be sorted in ascending order, according to the given definition of better and worse.

final Population<DoubleGene, Double> population = ... population.sort(Optimize.MINIMUM.<Double>ascending());

The code example above will populationSort the population according it's fitness values in descending order, since lower values are better in this case.

Type Parameters:

T - the type of the objects to compare.

Returns:

a new Comparator for the type T.

best

public <C extends Comparable<? super C>> C best(C a,
                                                C b)

Return the best value, according to this optimization direction.

Type Parameters:

C - the fitness value type.

Parameters:

a - the first value.

b - the second value.

Returns:

the best value. If both values are equal the first one is returned.

worst

public <C extends Comparable<? super C>> C worst(C a,
                                                 C b)

Return the worst value, according to this optimization direction.

Type Parameters:

C - the fitness value type.

Parameters:

a - the first value.

b - the second value.

Returns:

the worst value. If both values are equal the first one is returned.