Package ec.select

# Class TopSelection

java.lang.Object
ec.BreedingSource
ec.SelectionMethod
ec.select.TopSelection

All Implemented Interfaces:
  `Prototype`, `Setup`, `RandomChoiceChooserD`, `Serializable`, `Cloneable`

public class TopSelection extends SelectionMethod
Returns the single fittest individual in the population, breaking ties randomly.

The individual can be cached so it is not recomputed every single time; the cache is cleared after `prepareToProduce(...)` is called. Note that this means that if there are multiple individuals with the top fitness, and we're caching, only one of them will be returned throughout the series of multiple produce(...) calls.

Typical Number of Individuals Produced Per `produce(...)` call
Always 1.

Parameters

base.`cache` bool = `true` or `false` (default) | (should we cache the individual?)

Default Base
select.top

See Also:
  - Serialized Form

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final String`
  `P_CACHE`
  `static final String`
  `P_TOP`
  Default base

  ### Fields inherited from class ec.SelectionMethod

  `INDS_PRODUCED, KEY_PARENTS`

  ### Fields inherited from class ec.BreedingSource

  `NO_PROBABILITY, P_PROB, probability`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `TopSelection()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `cacheBest(int subpopulation, EvolutionState state, int thread)`
  `Parameter`
  `defaultBase()`
  Returns the default base for this prototype.
  `void`
  `prepareToProduce(EvolutionState s, int subpopulation, int thread)`
  A default version of prepareToProduce which does nothing.
  `int`
  `produce(int subpopulation, EvolutionState state, int thread)`
  An alternative form of "produce" special to Selection Methods; selects an individual from the given subpopulation and returns its position in that subpopulation.
  `void`
  `setup(EvolutionState state, Parameter base)`
  Sets up the BreedingPipeline.

  ### Methods inherited from class ec.SelectionMethod

  `finishProducing, produce, produces, produceWithoutCloning, typicalIndsProduced`

  ### Methods inherited from class ec.BreedingSource

  `clone, fillStubs, getProbability, pickRandom, preparePipeline, setProbability, setupProbabilities`

  ### Methods inherited from class java.lang.Object

  `equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### P_TOP

    public static final String P_TOP
    Default base
    See Also:
      - Constant Field Values

  - ### P_CACHE

    public static final String P_CACHE
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### TopSelection

    public TopSelection()

- ## Method Details

  - ### defaultBase

    public Parameter defaultBase()
    Description copied from interface: `Prototype`
    Returns the default base for this prototype. This should generally be implemented by building off of the static base() method on the DefaultsForm object for the prototype's package. This should be callable during setup(...).

  - ### setup

    public void setup(EvolutionState state, Parameter base)
    Description copied from class: `BreedingSource`
    Sets up the BreedingPipeline. You can use state.output.error here because the top-level caller promises to call exitIfErrors() after calling setup. Note that probability might get modified again by an external source if it doesn't normalize right.

    The most common modification is to normalize it with some other set of probabilities, then set all of them up in increasing summation; this allows the use of the fast static BreedingSource-picking utility method, BreedingSource.pickRandom(...). In order to use this method, for example, if four breeding source probabilities are {0.3, 0.2, 0.1, 0.4}, then they should get normalized and summed by the outside owners as: {0.3, 0.5, 0.6, 1.0}.

    Specified by:
      `setup` in interface `Prototype`
    Specified by:
      `setup` in interface `Setup`
    Overrides:
      `setup` in class `BreedingSource`
    See Also:
      - `Prototype.setup(EvolutionState,Parameter)`

  - ### prepareToProduce

    public void prepareToProduce(EvolutionState s, int subpopulation, int thread)
    Description copied from class: `SelectionMethod`
    A default version of prepareToProduce which does nothing.
    Overrides:
      `prepareToProduce` in class `SelectionMethod`

  - ### cacheBest

    public void cacheBest(int subpopulation, EvolutionState state, int thread)

  - ### produce

    public int produce(int subpopulation, EvolutionState state, int thread)
    Description copied from class: `SelectionMethod`
    An alternative form of "produce" special to Selection Methods; selects an individual from the given subpopulation and returns its position in that subpopulation.
    Specified by:
      `produce` in class `SelectionMethod`