Class UniformCrossover<T>
- java.lang.Object
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- org.apache.commons.math4.legacy.genetics.UniformCrossover<T>
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- Type Parameters:
T- generic type of theAbstractListChromosomes for crossover
- All Implemented Interfaces:
CrossoverPolicy
public class UniformCrossover<T> extends Object implements CrossoverPolicy
Perform Uniform Crossover [UX] on the specified chromosomes. A fixed mixing ratio is used to combine genes from the first and second parents, e.g. using a ratio of 0.5 would result in approximately 50% of genes coming from each parent. This is typically a poor method of crossover, but empirical evidence suggests that it is more exploratory and results in a larger part of the problem space being searched.This crossover policy evaluates each gene of the parent chromosomes by choosing a uniform random number
pin the range [0, 1]. Ifp<ratio, the parent genes are swapped. This means with a ratio of 0.7, 30% of the genes from the first parent and 70% from the second parent will be selected for the first offspring (and vice versa for the second offspring).This policy works only on
AbstractListChromosome, and therefore it is parameterized by T. Moreover, the chromosomes must have same lengths.- Since:
- 3.1
- See Also:
- Crossover techniques (Wikipedia), Crossover (Obitko.com), Uniform crossover
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Constructor Summary
Constructors Constructor Description UniformCrossover(double ratio)Creates a newUniformCrossoverpolicy using the given mixing ratio.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description ChromosomePaircrossover(Chromosome first, Chromosome second)Perform a crossover operation on the given chromosomes.doublegetRatio()Returns the mixing ratio used by thisCrossoverPolicy.
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Constructor Detail
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UniformCrossover
public UniformCrossover(double ratio) throws OutOfRangeException
Creates a newUniformCrossoverpolicy using the given mixing ratio.- Parameters:
ratio- the mixing ratio- Throws:
OutOfRangeException- if the mixing ratio is outside the [0, 1] range
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Method Detail
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getRatio
public double getRatio()
Returns the mixing ratio used by thisCrossoverPolicy.- Returns:
- the mixing ratio
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crossover
public ChromosomePair crossover(Chromosome first, Chromosome second) throws DimensionMismatchException, MathIllegalArgumentException
Perform a crossover operation on the given chromosomes.- Specified by:
crossoverin interfaceCrossoverPolicy- Parameters:
first- the first chromosome.second- the second chromosome.- Returns:
- the pair of new chromosomes that resulted from the crossover.
- Throws:
MathIllegalArgumentException- iff one of the chromosomes is not an instance ofAbstractListChromosomeDimensionMismatchException- if the length of the two chromosomes is different
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