WeaselMutator (Jenetics 6.3.0)

java.lang.Object
- io.jenetics.AbstractAlterer<G,C>
- - io.jenetics.Mutator<G,C>
  - - io.jenetics.ext.WeaselMutator<G,C>

Type Parameters:

G - the gene type

C - the fitness result type

All Implemented Interfaces:

Alterer<G,C>
```
public class WeaselMutator<G extends Gene<?,G>,C extends Comparable<? super C>>
extends Mutator<G,C>
```
Mutator implementation which is part of the Weasel program algorithm. The Weasel program is an thought experiment by Richard Dawkins to illustrate the functioning of the evolution: random mutation combined with non-random cumulative selection.
The mutator mutates the genes of every chromosome of every genotype in the population with the given mutation probability.
Engine setup for the Weasel program:
final Engine<CharacterGene, Integer> engine = Engine.builder(problem) // Set the 'WeaselSelector'. .selector(new WeaselSelector<>()) // Disable survivors selector. .offspringFraction(1) // Set the 'WeaselMutator'. .alterers(new WeaselMutator<>(0.05)) .build();

Since:

3.5

Version:

5.0

See Also:

Weasel program, WeaselSelector

Field Summary
- Fields inherited from class io.jenetics.AbstractAlterer
  _probability
- Fields inherited from interface io.jenetics.Alterer
  DEFAULT_ALTER_PROBABILITY

Constructor Summary

Constructors
Constructor	Description
`WeaselMutator()`	Create a new weasel mutator with the default mutation probability of `0.05`.
`WeaselMutator(double probability)`	Create a new weasel mutator with the given mutation probability.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`AltererResult<G,C>`	`alter(Seq<Phenotype<G,C>> population, long generation)`
`protected MutatorResult<Genotype<G>>`	`mutate(Genotype<G> genotype, double p, Random random)`
`String`	`toString()`

Methods inherited from class io.jenetics.Mutator
mutate, mutate, mutate

Methods inherited from class io.jenetics.AbstractAlterer
probability

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface io.jenetics.Alterer
andThen, compose

- Constructor Detail
  - WeaselMutator
```
public WeaselMutator(double probability)
```
    Create a new weasel mutator with the given mutation probability.
    
    Parameters:
    
    probability - the mutation probability
    
    Throws:
    
    IllegalArgumentException - if the probability is not in the valid range of [0, 1].
  - WeaselMutator
```
public WeaselMutator()
```
    Create a new weasel mutator with the default mutation probability of 0.05.
- Method Detail
  - alter
```
public AltererResult<G,C> alter(Seq<Phenotype<G,C>> population,
                                      long generation)
```
    Specified by:
    
    alter in interface Alterer<G extends Gene<?,G>,C extends Comparable<? super C>>
    
    Overrides:
    
    alter in class Mutator<G extends Gene<?,G>,C extends Comparable<? super C>>
  - mutate
```
protected MutatorResult<Genotype<G>> mutate(Genotype<G> genotype,
                                            double p,
                                            Random random)
```
    Overrides:
    
    mutate in class Mutator<G extends Gene<?,G>,C extends Comparable<? super C>>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Mutator<G extends Gene<?,G>,C extends Comparable<? super C>>