TreeMutPermutation.cpp

#include "../ECF_base.h"
#include "Tree.h"
#include "TreeMutPermutation.h"
#include <stdio.h>
 
 
namespace Tree
{
 
void TreeMutPermutation::registerParameters(StateP state)
{
    myGenotype_->registerParameter(state, "mut.permutation", (voidP) new double(0), ECF::DOUBLE);
}
 
 
bool TreeMutPermutation::initialize(StateP state)
{
    voidP sptr = myGenotype_->getParameterValue(state, "mut.permutation");
    probability_ = *((double*)sptr.get());
    return true;
}
 
 
bool TreeMutPermutation::mutate(GenotypeP gene)
{
    Tree* tree = (Tree*) (gene.get());
 
    // try to select a node with >1 args
    uint iNode, nArgs;
    uint tries = 0;
    do {
        iNode = state_->getRandomizer()->getRandomInteger((int) tree->size());
        tries++;
    } while((nArgs = tree->at(iNode)->primitive_->getNumberOfArguments()) < 2 && tries < 4);
 
    if(nArgs < 2)
        return false;
 
    // build permutation vector
    std::vector<uint> permutation;
    permutation.resize(nArgs);
 
    for(uint i = 0; i < nArgs; i++) {
        permutation[i] = i;
    }
    uint ind1, ind2, temp;
    for(uint i = 0; i < nArgs - 1; i++) {
        ind1 = permutation[i];
        ind2 = state_->getRandomizer()->getRandomInteger((int) i, (int) nArgs - 1);
        temp = permutation[ind1];
        permutation[ind1] = permutation[ind2];
        permutation[ind2] = temp;
    }
 
    // record original children node's offsets
    std::vector<uint> offsets;
    offsets.push_back(1);
    for(uint i = 1; i < nArgs; i++) {
        offsets.push_back(offsets[i - 1] + tree->at(iNode + offsets[i - 1])->size_);
    }
 
    // reorder mutated nodes
    std::vector<NodeP> mutNodes;
    mutNodes.assign(tree->begin() + iNode, tree->begin() + iNode + tree->at(iNode)->size_);
 
    uint iCopiedTo = 1;
    for(uint iArg = 0; iArg < nArgs; iArg++) {
        uint nNodes = mutNodes[offsets[permutation[iArg]]]->size_;
        for(uint i = 0; i < nNodes; i++, iCopiedTo++) {
            tree->at(iNode + iCopiedTo) = mutNodes[offsets[permutation[iArg]] + i];
        }
    }
 
    return true;
}
 
}