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java.lang.Objectec.BreedingSource
ec.BreedingPipeline
ec.gp.GPBreedingPipeline
ec.gp.breed.MutatePromotePipeline
MutatePromotePipeline works very similarly to the PromoteNode algorithm described in Kumar Chellapilla, "A Preliminary Investigation into Evolving Modular Programs without Subtree Crossover", GP98, and is also similar to the "deletion" operator found in Una-May O'Reilly's thesis, "An Analysis of Genetic Programming".
MutatePromotePipeline tries tries times to find a tree that has at least one promotable node. It then picks randomly from all the promotable nodes in the tree, and promotes one. If it cannot find a valid tree in tries times, it gives up and simply copies the individual.
"Promotion" means to take a node n whose parent is m, and replacing the subtree rooted at m with the subtree rooted at n.
A "Promotable" node means a node which is capable of promotion given the existing type constraints. In general to promote a node foo, foo must have a parent node, and must be type-compatible with the child slot that its parent fills.
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.tree.0 0 < int < (num trees in individuals), if exists |
(tree chosen for mutation; if parameter doesn't exist, tree is picked at random) |
Default Base
gp.breed.mutate-demote
Field Summary | |
static int |
NUM_SOURCES
|
static java.lang.String |
P_MUTATEPROMOTE
|
static java.lang.String |
P_NUM_TRIES
|
Fields inherited from class ec.gp.GPBreedingPipeline |
P_NODESELECTOR, P_TREE, TREE_UNFIXED |
Fields inherited from class ec.BreedingPipeline |
DYNAMIC_SOURCES, mybase, P_NUMSOURCES, P_SOURCE, sources, V_SAME |
Fields inherited from class ec.BreedingSource |
CHECKBOUNDARY, DEFAULT_PRODUCED, NO_PROBABILITY, P_PROB, probability, UNUSED |
Constructor Summary | |
MutatePromotePipeline()
|
Method Summary | |
Parameter |
defaultBase()
Returns the default base for this prototype. |
int |
numSources()
Returns the number of sources to this pipeline. |
int |
produce(int min,
int max,
int start,
int subpopulation,
Individual[] inds,
EvolutionState state,
int thread)
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. |
void |
setup(EvolutionState state,
Parameter base)
Sets up the BreedingPipeline. |
Methods inherited from class ec.gp.GPBreedingPipeline |
produces |
Methods inherited from class ec.BreedingPipeline |
finishProducing, individualReplaced, maxChildProduction, minChildProduction, preparePipeline, prepareToProduce, protoClone, sourcesAreProperForm, typicalIndsProduced |
Methods inherited from class ec.BreedingSource |
getProbability, pickRandom, protoCloneSimple, setProbability, setupProbabilities |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
public static final java.lang.String P_MUTATEPROMOTE
public static final java.lang.String P_NUM_TRIES
public static final int NUM_SOURCES
Constructor Detail |
public MutatePromotePipeline()
Method Detail |
public Parameter defaultBase()
Prototype
public int numSources()
BreedingPipeline
numSources
in class BreedingPipeline
public void setup(EvolutionState state, Parameter base)
BreedingSource
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}.
setup
in interface Prototype
setup
in class BreedingPipeline
public int produce(int min, int max, int start, int subpopulation, Individual[] inds, EvolutionState state, int thread) throws java.lang.CloneNotSupportedException
BreedingSource
produce
in class BreedingSource
java.lang.CloneNotSupportedException
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