ThePEGLesHouchesInterface.cc

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#include <algorithm>
#include <iostream>
#include <sstream>
#include <string>
#include <memory>
#include <set>

#include <boost/shared_ptr.hpp>

#include <ThePEG/Interface/ClassDocumentation.h>
#include <ThePEG/Interface/InterfacedBase.h>
#include <ThePEG/Interface/Parameter.h>
#include <ThePEG/Utilities/ClassTraits.h>

#include <ThePEG/LesHouches/LesHouches.h>
#include <ThePEG/LesHouches/LesHouchesReader.h>

#include "FWCore/Utilities/interface/Exception.h"

#include "SimDataFormats/GeneratorProducts/interface/LesHouches.h"

#include "GeneratorInterface/LHEInterface/interface/LHERunInfo.h"
#include "GeneratorInterface/LHEInterface/interface/LHEEvent.h"
#include "GeneratorInterface/LHEInterface/interface/LHEProxy.h"

using namespace lhef;

namespace ThePEG {

class LesHouchesInterface : public LesHouchesReader {
    public:
    LesHouchesInterface();
    ~LesHouchesInterface() override;

    static void Init();

    protected:      
    IBPtr clone() const override { return new_ptr(*this); }
    IBPtr fullclone() const override { return new_ptr(*this); }

    private:
    void open() override;
    void close() override;
    long scan() override;

    virtual double eventWeight();
    virtual double reweight();
    double getEvent() override;
    bool doReadEvent() override;

    LHEProxy::ProxyID   proxyID;
    bool            initialized;

    static ClassDescription<LesHouchesInterface> initLesHouchesInterface;
};

// registration with ThePEG plugin system

template<>
struct BaseClassTrait<LesHouchesInterface, 1> : public ClassTraitsType {
    typedef LesHouchesReader NthBase;
};

template<>
struct ClassTraits<LesHouchesInterface> :
            public ClassTraitsBase<LesHouchesInterface> {
    static string className() { return "ThePEG::LesHouchesInterface"; }
    static string library() { return "pluginGeneratorInterfaceThePEGHadronisation.so"; }
};

} // namespace ThePEG

using namespace ThePEG;

LesHouchesInterface::LesHouchesInterface() :
    initialized(false)
{
}

LesHouchesInterface::~LesHouchesInterface()
{
}

long LesHouchesInterface::scan()
{
    return 1000000000;
}

void LesHouchesInterface::open()
{
    const LHERunInfo *runInfo = LHEProxy::find(proxyID)->getRunInfo().get();
    const lhef::HEPRUP &orig = *runInfo->getHEPRUP();

    heprup.IDBMUP   = orig.IDBMUP;
    heprup.EBMUP    = orig.EBMUP;
    heprup.PDFGUP   = orig.PDFGUP;
    heprup.PDFSUP   = orig.PDFSUP;
    heprup.NPRUP    = orig.NPRUP;
    heprup.LPRUP    = orig.LPRUP;
    heprup.XSECUP   = orig.XSECUP;
    heprup.XERRUP   = orig.XERRUP;
    heprup.XMAXUP   = orig.XMAXUP;

    // We are cheating here, ThePEG does not need to know the real
    // weighting method, as it complains about anything but 3 anyway.
    // We just need to trick ThePEG into just processing each event
    // passed without doing anything fancy with it (and shut up).
    heprup.IDWTUP = 1;
}

void LesHouchesInterface::close()
{
}

double LesHouchesInterface::eventWeight()
{
    return 1.0;
}

// no reweighting
double LesHouchesInterface::reweight()
{
    preweight = 1.0;
    return 1.0;
}

// overwrite parent routine doing fancy stuff and just pass the event
double LesHouchesInterface::getEvent()
{
    reset();

    if (!doReadEvent())
        return 0.0;

    if (!initialized && !checkPartonBin())
        throw cms::Exception("ThePEGLesHouchesInterface")
            << "Found event which cannot be handled by "
            << "the assigned PartonExtractor." << std::endl;
    initialized = true;

    fillEvent();
    getSubProcess();

    return 1.0;
}

bool LesHouchesInterface::doReadEvent()
{
    reset();

    boost::shared_ptr<LHEEvent> event =
                LHEProxy::find(proxyID)->releaseEvent();
    if (!event)
        throw Stop();

    hepeup.XPDWUP.first = hepeup.XPDWUP.second = 0;

    const lhef::HEPEUP &orig = *event->getHEPEUP();

    hepeup.NUP  = orig.NUP;
    hepeup.IDPRUP   = orig.IDPRUP;
    hepeup.SCALUP   = orig.SCALUP;
    hepeup.AQEDUP   = orig.AQEDUP;
    hepeup.AQCDUP   = orig.AQCDUP;
        
        //workaround, since Herwig++ is not passing LHE weights to the hepmc product anyways
        //as currently run in CMSSW
        hepeup.XWGTUP   = 1.0;
        
    hepeup.resize();

    std::copy(orig.IDUP.begin(), orig.IDUP.end(), hepeup.IDUP.begin());
    hepeup.ISTUP    = orig.ISTUP;
    hepeup.MOTHUP   = orig.MOTHUP;
    hepeup.ICOLUP   = orig.ICOLUP;
    hepeup.VTIMUP   = orig.VTIMUP;
    hepeup.SPINUP   = orig.SPINUP;

    for(int i = 0; i < hepeup.NUP; i++)
        std::copy(&orig.PUP[i].x[0], &orig.PUP[i].x[5],
                  hepeup.PUP[i].begin());

    fillEvent();

    return true;
}

// register with ThePEG plugin system

ClassDescription<LesHouchesInterface> LesHouchesInterface::initLesHouchesInterface;

void LesHouchesInterface::Init() {
    typedef LHEProxy::ProxyID ProxyID;

    static ClassDocumentation<LesHouchesInterface> documentation
        ("ThePEG::LesHouchesInterface interfaces with LHEInterface");

    static Parameter<LesHouchesInterface, ProxyID> interfaceProxyID
        ("ProxyID", "The ProxyID.",
         &LesHouchesInterface::proxyID, ProxyID(),
         ProxyID(), ProxyID(), false, false, false);

    interfaceProxyID.rank(11);
}