/** Initializes map of genotypes to probabilities */
private void initGeneMap() {
int size = genotype.getGeneList().size();
for (int i = 0; i < size; i++) {
geneProbMap.put(i, 1);
}
geneProbSum = size;
}
/**
* Clones the genotype passed in and mutates it in one of three ways. The step size as well as the
* probabilities increase.
*
* @return Returns mutated genotype.
*/
public Genotype mutate() {
int newVal;
Genotype clone = genotype.cloneForMutation();
Mutation cloneMut = new Mutation(clone);
// Initializes trees
cloneMut.initWith(this);
Type mutationType = randType(); // chooses random mutation type
// int mutationGeneIndex = randGeneIndex(); //chooses random index
int mutationGeneIndex = rand.nextInt(clone.getGeneList().size());
float stepSize = stepSize();
Vector3f mutationVector = randVector().normalize().mult(stepSize);
switch (mutationType) {
case REMOVE_BLOCK:
// Filter illegal removals
// if only 2 or less genes left
// if trying to remove the root gene
if (clone.getNumberOfGenes() > 2 && mutationGeneIndex != 0) {
System.out.println("REMOVE_BLOCK");
System.out.println("mutationGeneIndex: " + mutationGeneIndex);
clone.removeGeneByIndex(mutationGeneIndex);
// Creates probability that this is chosen again
newVal = cloneMut.typeProbMap.get(Type.REMOVE_BLOCK) + 1;
cloneMut.typeProbMap.put(Type.REMOVE_BLOCK, newVal);
}
break;
case ADD_BLOCK:
System.out.println("ADD_BLOCK");
clone.addChildBlock(mutationGeneIndex);
// updates probability that this is chosen again
newVal = cloneMut.typeProbMap.get(Type.ADD_BLOCK) + 1;
cloneMut.typeProbMap.put(Type.ADD_BLOCK, newVal);
break;
case MODIFY_BLOCK:
System.out.println("MODIFY_BLOCK");
clone.mutateGeneByIndex(mutationGeneIndex, mutationVector);
// updates probability that this is chosen again
newVal = cloneMut.typeProbMap.get(Type.MODIFY_BLOCK) + 1;
cloneMut.typeProbMap.put(Type.MODIFY_BLOCK, newVal);
// Uses definition of step size in spec
if (stepSize < maxStepSize / 2) {
cloneMut.maxStepSize *= STEP_ADJUST_RATE; // arbitrary value
} else {
cloneMut.maxStepSize /= STEP_ADJUST_RATE;
}
// Decides whether modifying the block will make it bigger or smaller
cloneMut.xMean += (mutationVector.x - xMean) / 2;
cloneMut.yMean += (mutationVector.y - yMean) / 2;
cloneMut.zMean += (mutationVector.z - zMean) / 2;
break;
}
clone.setMutation(cloneMut);
return clone;
}
