// Implement Handler::getBranches().
Branches CxUnivarHandler::getBranches(BrCandPtr cand, DoubleVector &x,
RelaxationPtr , SolutionPoolPtr )
{
double minFromBds = 0.1;
BrVarCandPtr vcand = boost::dynamic_pointer_cast <BrVarCand> (cand);
VariablePtr v = vcand->getVar();
double xval = x[v->getIndex()];
double value = xval; // Make sure branch value is not too close to an end point
double len = v->getUb() - v->getLb();
if (value < v->getLb() + minFromBds*len) {
value = v->getLb() + minFromBds*len;
} else if (value > v->getUb() - minFromBds*len) {
value = v->getUb() - minFromBds*len;
}
// can't branch on something that is at its bounds.
if (!(value > v->getLb()+1e-8 && value < v->getUb()-1e-8)) {
std::cerr << "Warning! Branching on variable with bounds/value: [" <<
v->getLb() << " , " << value << " " << v->getUb() << " ]" << std::endl;
//assert(value > v->getLb()+1e-8 && value < v->getUb()-1e-8);
}
Branches branches = (Branches) new BranchPtrVector();
BranchPtr branch = (BranchPtr) new Branch();
VarBoundModPtr mod = (VarBoundModPtr) new VarBoundMod(v, Upper, value);
assert(!"add Mod correctly here.");
branch->addPMod(mod);
branch->setActivity((v->getUb()-value)/len);
branches->push_back(branch);
branch = (BranchPtr) new Branch();
mod = (VarBoundModPtr) new VarBoundMod(v, Lower, value);
assert(!"add Mod correctly here.");
branch->addPMod(mod);
branch->setActivity((value - v->getLb())/len);
branches->push_back(branch);
logger_->msgStream(LogDebug2) << "branching on " << v->getName();
logger_->msgStream(LogDebug2) << " <= " << value << " or "
<< " >= " << value << std::endl;
#if defined(DEBUG_CXUNIVARHANDLER)
std::cout << "branching on " << v->getName();
std::cout << " <= " << value << " or " << " >= " << value << std::endl;
#endif
return branches;
}
BranchPtr
MultilinearTermsHandler::doBranch_(BranchDirection UpOrDown, ConstVariablePtr v,
double bvalue)
{
BranchPtr branch;
BoundType lu;
VariableType vtype = v->getType();
#if defined(DEBUG_MULTILINEARTERMS_HANDLER)
std::cout << "Branching: " << (UpOrDown == DownBranch ? "Down" : "Up")
<< " at value: " << bvalue << " on: " << std::endl;
v->write(std::cout);
#endif
branch = (BranchPtr) new Branch();
double branching_value = bvalue;
// Change bounds on the x var (called v here)
if (UpOrDown == DownBranch) {
lu = Upper;
if (vtype != Continuous) branching_value = floor(bvalue);
}
else {
lu = Lower;
if (vtype != Continuous) branching_value = ceil(bvalue);
}
VarBoundModPtr vmod = (VarBoundModPtr) new VarBoundMod(v, lu, branching_value);
assert(!"check whether this needs to be addRMod instead");
branch->addPMod(vmod);
branch->setActivity(0.5);// TODO: set this correctly
return branch;
}
