UniformCrossover (Apache Commons Math 4.0-beta1)

java.lang.Object
- org.apache.commons.math4.legacy.genetics.UniformCrossover<T>

Type Parameters:

T - generic type of the AbstractListChromosomes 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 p in the range [0, 1]. If p < 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

Constructor Summary

Constructors
Constructor Description

UniformCrossover(double ratio)
Creates a new UniformCrossover policy using the given mixing ratio.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`ChromosomePair`	`crossover(Chromosome first, Chromosome second)`	Perform a crossover operation on the given chromosomes.
`double`	`getRatio()`	Returns the mixing ratio used by this `CrossoverPolicy`.

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

- Constructor Detail
  - UniformCrossover
```
public UniformCrossover(double ratio)
                 throws OutOfRangeException
```
    Creates a new UniformCrossover policy using the given mixing ratio.
    
    Parameters:
    
    ratio - the mixing ratio
    
    Throws:
    
    OutOfRangeException - if the mixing ratio is outside the [0, 1] range
- Method Detail
  - getRatio
```
public double getRatio()
```
    Returns the mixing ratio used by this CrossoverPolicy.
    
    Returns:
    
    the mixing ratio
  - crossover
```
public ChromosomePair crossover(Chromosome first,
                                Chromosome second)
                         throws DimensionMismatchException,
                                MathIllegalArgumentException
```
    Perform a crossover operation on the given chromosomes.
    
    Specified by:
    
    crossover in interface CrossoverPolicy
    
    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 of AbstractListChromosome
    
    DimensionMismatchException - if the length of the two chromosomes is different