Documentation of 'ec.gp.breed.InternalCrossoverPipeline' Java class
InternalCrossoverPipeline
Skip navigation links
ec.gp.breed

Class InternalCrossoverPipeline

  • All Implemented Interfaces:
    Prototype, Setup, SteadyStateBSourceForm, RandomChoiceChooserD, java.io.Serializable, java.lang.Cloneable

    public class InternalCrossoverPipeline
extends GPBreedingPipeline
    InternalCrossoverPipeline picks two subtrees from somewhere within an individual, and crosses them over. Before doing so, it checks to make sure that the subtrees come from trees with the same tree constraints, that the subtrees are swap-compatible with each other, that the new individual does not violate depth constraints, and that one subtree does not contain the other. It tries tries times to find a valid subtree pair to cross over. Failing this, it just copies the individual.

    Typical Number of Individuals Produced Per produce(...) call
    ...as many as the source produces

    Number of Sources
    1

    Parameters

    base.tries
    int >= 1    		 (number of times to try finding valid pairs of nodes)
    base.maxdepth
    int >= 1    		 (maximum valid depth of the crossed-over individual's trees)
    base.ns.0
    classname, inherits and != GPNodeSelector    		 (GPNodeSelector for subtree 0.
    base.ns.1
    classname, inherits and != GPNodeSelector,
    or String same    		 (GPNodeSelector for subtree 1. If value is same, then ns.1 a copy of whatever ns.0 is)
    base.tree.0
    0 < int < (num trees in individuals), if exists    		 (first tree for the crossover; if parameter doesn't exist, tree is picked at random)
    base.tree.1
    0 < int < (num trees in individuals), if exists    		 (second tree for the crossover; if parameter doesn't exist, tree is picked at random. This tree must have the same GPTreeConstraints as tree.0, if tree.0 is defined.)

    Default Base
    gp.breed.internal-xover

    Parameter bases

    base.ns.n
    		nodeselectn (n is 0 or 1)
    See Also:
    Serialized Form

    • Field Detail

      • P_INTERNALCROSSOVER

        public static final java.lang.String P_INTERNALCROSSOVER
        See Also:
        Constant Field Values

      • nodeselect0

        public GPNodeSelector nodeselect0
        How the pipeline chooses the first subtree

      • nodeselect1

        public GPNodeSelector nodeselect1
        How the pipeline chooses the second subtree

      • numTries

        public int numTries
        How many times the pipeline attempts to pick nodes until it gives up.

      • maxDepth

        public int maxDepth
        The deepest tree the pipeline is allowed to form. Single terminal trees are depth 1.

      • tree1

        public int tree1
        Is the first tree fixed? If not, this is -1

      • tree2

        public int tree2
        Is the second tree fixed? If not, this is -1

    • Constructor Detail

      • InternalCrossoverPipeline

        public InternalCrossoverPipeline()

    • Method Detail

      • 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(...).

      • numSources

        public int numSources()
        Description copied from class: BreedingPipeline
        Returns the number of sources to this pipeline. Called during BreedingPipeline's setup. Be sure to return a value > 0, or DYNAMIC_SOURCES which indicates that setup should check the parameter file for the parameter "num-sources" to make its determination.
        Specified by:
        numSources in class BreedingPipeline

      • clone

        public java.lang.Object clone()
        Description copied from interface: Prototype
        Creates a new individual cloned from a prototype, and suitable to begin use in its own evolutionary context.

        Typically this should be a full "deep" clone. However, you may share certain elements with other objects rather than clone hem, depending on the situation:

        • If you hold objects which are shared with other instances, don't clone them.
        • If you hold objects which must be unique, clone them.
        • If you hold objects which were given to you as a gesture of kindness, and aren't owned by you, you probably shouldn't clone them.
        • DON'T attempt to clone: Singletons, Cliques, or Groups.
        • Arrays are not cloned automatically; you may need to clone an array if you're not sharing it with other instances. Arrays have the nice feature of being copyable by calling clone() on them.

        Implementations.

        • If no ancestor of yours implements clone(), and you have no need to do clone deeply, and you are abstract, then you should not declare clone().
        • If no ancestor of yours implements clone(), and you have no need to do clone deeply, and you are not abstract, then you should implement it as follows: 

           public Object clone() 
     {
     try
         { 
         return super.clone();
         }
     catch ((CloneNotSupportedException e)
         { throw new InternalError(); } // never happens
     }
        • If no ancestor of yours implements clone(), but you need to deep-clone some things, then you should implement it as follows: 

           public Object clone() 
     {
     try
         { 
         MyObject myobj = (MyObject) (super.clone());

         // put your deep-cloning code here...
         }
     catch ((CloneNotSupportedException e)
         { throw new InternalError(); } // never happens
     return myobj;
     }
        • If an ancestor has implemented clone(), and you also need to deep clone some things, then you should implement it as follows: 

           public Object clone() 
     { 
     MyObject myobj = (MyObject) (super.clone());

     // put your deep-cloning code here...

     return myobj;
     }
        Specified by:
        clone in interface Prototype
        Overrides:
        clone in class BreedingPipeline

      • 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 BreedingPipeline
        See Also:
        Prototype.setup(EvolutionState,Parameter)

      • produce

        public int produce(int min,
                   int max,
                   int start,
                   int subpopulation,
                   Individual[] inds,
                   EvolutionState state,
                   int thread)
        Description copied from class: BreedingSource
        Produces n individuals from the given subpopulation and puts them into inds[start...start+n-1], where n = Min(Max(q,min),max), where q is the "typical" number of individuals the BreedingSource produces in one shot, and returns n. max must be >= min, and min must be >= 1. For example, crossover might typically produce two individuals, tournament selection might typically produce a single individual, etc.
        Specified by:
        produce in class BreedingSource
Skip navigation links

DMelt 3.0 © DataMelt by jWork.ORG

You see the box below because you did not login.