EnginePtr getNLPEngine(EnvPtr env, ProblemPtr p)
{
EngineFactory *efac = new EngineFactory(env);
EnginePtr e = EnginePtr(); // NULL
bool cont=false;
p->calculateSize();
if (p->isLinear()) {
e = efac->getLPEngine();
if (e) {
delete efac;
return e;
} else {
cont = true;
}
}
if (true==cont || p->isQP()) {
e = efac->getQPEngine();
if (e) {
delete efac;
return e;
} else {
cont = true;
}
}
e = efac->getNLPEngine();
assert (e || (!"No engine available for this problem."));
delete efac;
return e;
}
PresolverPtr presolve(EnvPtr env, ProblemPtr p, size_t ndefs,
HandlerVector &handlers)
{
PresolverPtr pres = PresolverPtr(); // NULL
const std::string me("qg: ");
p->calculateSize();
if (env->getOptions()->findBool("presolve")->getValue() == true) {
LinearHandlerPtr lhandler = (LinearHandlerPtr) new LinearHandler(env, p);
handlers.push_back(lhandler);
if (p->isQP() || p->isQuadratic() || p->isLinear() ||
true==env->getOptions()->findBool("use_native_cgraph")->getValue()) {
lhandler->setPreOptPurgeVars(true);
lhandler->setPreOptPurgeCons(true);
lhandler->setPreOptCoeffImp(true);
} else {
lhandler->setPreOptPurgeVars(false);
lhandler->setPreOptPurgeCons(false);
lhandler->setPreOptCoeffImp(false);
}
if (ndefs>0) {
lhandler->setPreOptDualFix(false);
} else {
lhandler->setPreOptDualFix(true);
}
if (!p->isLinear() &&
true==env->getOptions()->findBool("use_native_cgraph")->getValue() &&
true==env->getOptions()->findBool("nl_presolve")->getValue()
) {
NlPresHandlerPtr nlhand = (NlPresHandlerPtr) new NlPresHandler(env, p);
handlers.push_back(nlhand);
}
// write the names.
env->getLogger()->msgStream(LogExtraInfo) << me
<< "handlers used in presolve:" << std::endl;
for (HandlerIterator h = handlers.begin(); h != handlers.end();
++h) {
env->getLogger()->msgStream(LogExtraInfo) << me
<< (*h)->getName() << std::endl;
}
}
pres = (PresolverPtr) new Presolver(p, env, handlers);
pres->standardize();
if (env->getOptions()->findBool("presolve")->getValue() == true) {
pres->solve();
}
return pres;
}