int Reproduction::breed(System* system, Population* src, vector<Program>* newpop, int index)
{
// Big complex mess
// First select individuals
vector<Program*> p = getSelections(1, src, index);
Program* a = p[0];
// Swap subtrees rooted at a and b to form new nodes
newpop->push_back(Program(system));
Program* dsta=&newpop->at(newpop->size()-1);
a->copy(*dsta);
#ifdef DEBUG
if (!a->checkConsistency())
throw runtime_error("Resulting program from architecture altering operation is not consistent");
#endif
return 1;
}
int Crossover::breed(System* system, Population* src, vector<Program>* newpop, int index)
{
// Big complex mess
// First select individuals
vector<Program*> prgms=getSelections(2, src, index);
Program* a = prgms[0];
Program* b = prgms[1];
// Subtree selection
int branch=rand()%(a->branch.size());
int i,j;
vector<int> strees=getSelectionTrees(branch, &prgms);
i=strees[0];
j=strees[1];
if (i<0 || j<0)
return 0;
// Detect early on if crossover will be unsuccessful due to depth limits
if (system->maxdepth>0)
{
// Only need to check the new branch to see if it exceeds the limit
int deptha=b->branch[branch][j].parentOffset;
int depthb=a->branch[branch][i].parentOffset;
int parent;
parent=i;
while (parent>0)
{
parent+=a->branch[branch][parent].parentOffset;
deptha++;
}
parent=j;
while (parent>0)
{
parent+=b->branch[branch][parent].parentOffset;
depthb++;
}
if (deptha>system->maxdepth || depthb>system->maxdepth)
return 0;
}
if (system->maxnodes>0)
{
// Check if either program will have too many nodes
if (a->branch[branch][0].nodes-a->branch[branch][i].nodes+b->branch[branch][j].nodes>system->maxnodes)
return 0;
if (b->branch[branch][0].nodes-b->branch[branch][j].nodes+a->branch[branch][i].nodes>system->maxnodes)
return 0;
}
// Swap subtrees rooted at a and b to form new nodes
newpop->push_back(Program(system));
newpop->push_back(Program(system));
Program* dsta=&newpop->at(newpop->size()-2);
Program* dstb=&newpop->at(newpop->size()-1);
a->copy(*dsta);
b->copy(*dstb);
copyTree(TreeNodeIter(&dsta->branch[branch], i), TreeNodeIter(&b->branch[branch], j));
copyTree(TreeNodeIter(&dstb->branch[branch], j), TreeNodeIter(&a->branch[branch], i));
#ifdef DEBUG
if (!a->checkConsistency())
throw runtime_error("Resulting program from architecture altering operation is not consistent");
if (!b->checkConsistency())
throw runtime_error("Resulting program from architecture altering operation is not consistent");
#endif
return 2;
}
