BinaryMutMix.cpp

#include "../ECF_base.h"
#include "Binary.h"
 
namespace Binary
{
 
void BinaryMutMix::registerParameters(StateP state)
{
    myGenotype_->registerParameter(state, "mut.mix", (voidP) new double(0), ECF::DOUBLE);
}
 
 
bool BinaryMutMix::initialize(StateP state)
{
    voidP sptr = myGenotype_->getParameterValue(state, "mut.mix");
    probability_ = *((double*)sptr.get());
    return true;
}
 
 
bool BinaryMutMix::mutate(GenotypeP gene)
{
    Binary* bin = (Binary*) (gene.get());
 
    uint dimension = state_->getRandomizer()->getRandomInteger((uint) bin->variables.size());
    
    // make sure indexSmaller < indexBigger
    uint bitIndexSmaller = state_->getRandomizer()->getRandomInteger((uint) bin->getNumBits());
    uint bitIndexBigger;
    do {
        bitIndexBigger = state_->getRandomizer()->getRandomInteger((uint) bin->getNumBits());
    }while(bitIndexBigger == bitIndexSmaller);
    
    uint tmp = bitIndexSmaller;
    if(bitIndexSmaller > bitIndexBigger) {
      bitIndexSmaller = bitIndexBigger;
      bitIndexBigger = tmp;
    }
 
    // count 1's and 0's
    int counter0 = 0;
    int counter1 = 0;
    
    for(uint i = bitIndexSmaller; i <= bitIndexBigger; i++) {
        if(bin->variables[dimension][i]) counter1++;
        else counter0++;
    }
    
    int fairness0 = counter0;
    int fairness1 = counter1;
    
    // mix bits in [indexSmaller, indexBigger]
    for(uint i = bitIndexSmaller; i <= bitIndexBigger; i++) {
        int random = state_->getRandomizer()->getRandomInteger(1, fairness0 + fairness1);
        if(random <= fairness1) {
            if(counter1 > 0) {
                bin->variables[dimension][i] = true;
                counter1--;
            }
            else {
                bin->variables[dimension][i] = false;
                counter0--;
            }
        }
        else {
            if(counter0 > 0) {
                bin->variables[dimension][i] = false;
                counter0--;
            }
            else {
                bin->variables[dimension][i] = true;
                counter1--;
            }
        }
    }
    
    bin->update();
 
    return true;
}
 
}