/data/refman/pasoursint/CMSSW_4_1_8_patch12/src/GeneratorInterface/ThePEGInterface/src/ThePEGInterface.cc

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#include <iostream>
#include <sstream>
#include <cstdlib>
#include <memory>
#include <cmath>
#include <stdlib.h>

#include <boost/shared_ptr.hpp>
#include <boost/filesystem.hpp>

#include <HepMC/GenEvent.h>
#include <HepMC/PdfInfo.h>
#include <HepMC/IO_GenEvent.h>

#include <ThePEG/Utilities/DynamicLoader.h>
#include <ThePEG/Repository/Repository.h>
#include <ThePEG/Handlers/EventHandler.h>
#include <ThePEG/Handlers/XComb.h>
#include <ThePEG/EventRecord/Event.h>
#include <ThePEG/EventRecord/Particle.h> 
#include <ThePEG/EventRecord/Collision.h>
#include <ThePEG/EventRecord/TmpTransform.h>
#include <ThePEG/Config/ThePEG.h>
#include <ThePEG/PDF/PartonExtractor.h>
#include <ThePEG/PDF/PDFBase.h>
#include <ThePEG/Utilities/UtilityBase.h>

#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include "GeneratorInterface/Core/interface/ParameterCollector.h"

#include "GeneratorInterface/ThePEGInterface/interface/Proxy.h"
#include "GeneratorInterface/ThePEGInterface/interface/RandomEngineGlue.h"
#include "GeneratorInterface/ThePEGInterface/interface/HepMCConverter.h"
#include "GeneratorInterface/ThePEGInterface/interface/ThePEGInterface.h"

using namespace std;
using namespace gen;

ThePEGInterface::ThePEGInterface(const edm::ParameterSet &pset) :
        randomEngineGlueProxy_(ThePEG::RandomEngineGlue::Proxy::create()),
        dataLocation_(ParameterCollector::resolve(pset.getParameter<string>("dataLocation"))),
        generator_(pset.getParameter<string>("generatorModule")),
        run_(pset.getParameter<string>("run")),
        dumpConfig_(pset.getUntrackedParameter<string>("dumpConfig", "")),
        skipEvents_(pset.getUntrackedParameter<unsigned int>("skipEvents", 0))
{
        // Write events in hepmc ascii format for debugging purposes
        string dumpEvents = pset.getUntrackedParameter<string>("dumpEvents", "");
        if (!dumpEvents.empty()) {
                iobc_.reset(new HepMC::IO_GenEvent(dumpEvents.c_str(), ios::out));
                edm::LogInfo("ThePEGSource") << "Event logging switched on (=> " << dumpEvents << ")";
        }
        // Clear dumpConfig target
        if (!dumpConfig_.empty())
                ofstream cfgDump(dumpConfig_.c_str(), ios_base::trunc);
}

ThePEGInterface::~ThePEGInterface()
{
        if (eg_)
                eg_->finalize();
        edm::LogInfo("ThePEGInterface") << "Event generator finalized";
}

string ThePEGInterface::dataFile(const string &fileName) const
{
        if (fileName.empty() || fileName[0] == '/')
                return fileName;
        else
                return dataLocation_ + "/" + fileName;
}

string ThePEGInterface::dataFile(const edm::ParameterSet &pset,
                                 const string &paramName) const
{
        const edm::Entry &entry = pset.retrieve(paramName);
        if (entry.typeCode() == 'F')
                return entry.getFileInPath().fullPath();
        else
                return dataFile(entry.getString());
}

void ThePEGInterface::initRepository(const edm::ParameterSet &pset) const
{
        /* Initialize the repository from
         * 1. the repository file (default values)
         * 2. the ThePEG config files
         * 3. the CMSSW config blocks
         */
        stringstream logstream;

        // Read the repository of serialized default values
        string repository = dataFile(pset, "repository");
        if (!repository.empty()) {
                edm::LogInfo("ThePEGInterface") << "Loading repository (" << repository << ")";
                ThePEG::Repository::load(repository);
        }

        if (!getenv("ThePEG_INSTALL_PATH")) {
                vector<string> libdirlist = ThePEG::DynamicLoader::allPaths();
                for(vector<string>::const_iterator libdir = libdirlist.begin();
                    libdir < libdirlist.end(); ++libdir) {
                        if (libdir->empty() || (*libdir)[0] != '/')
                                continue;
                        if (boost::filesystem::exists(*libdir +
                                        "/../../share/ThePEG/PDFsets.index")) {
                                setenv("ThePEG_INSTALL_PATH",
                                       libdir->c_str(), 0);
                                break;
                        }
                }
        }

        // Read ThePEG config files to read
        vector<string> configFiles = pset.getParameter<vector<string> >("configFiles");

        // Loop over the config files
        for(vector<string>::const_iterator iter = configFiles.begin();
            iter != configFiles.end(); ++iter) {
                edm::LogInfo("ThePEGInterface") << "Reading config file (" << *iter << ")";
                ThePEG::Repository::read(dataFile(*iter), logstream);
                edm::LogInfo("ThePEGSource") << logstream.str();
        }

        // Read CMSSW config file parameter sets starting from "parameterSets"

        ofstream cfgDump;
        ParameterCollector collector(pset);
        ParameterCollector::const_iterator iter;
        if (!dumpConfig_.empty()) {
                cfgDump.open(dumpConfig_.c_str(), ios_base::app);
                iter = collector.begin(cfgDump);
        } else
                iter = collector.begin();

        for(; iter != collector.end(); ++iter) {
                string out = ThePEG::Repository::exec(*iter, logstream);
                if (!out.empty()) {
                        edm::LogInfo("ThePEGInterface") << *iter << " => " << out;
                        cerr << "Error in ThePEG configuration!\n"
                                "\tLine: " << *iter << "\n" << out << endl;
                }
        }

        if (!dumpConfig_.empty()) {
                cfgDump << "saverun " << run_ << " " << generator_ << endl;
                cfgDump.close();
        }

        // write the ProxyID for the RandomEngineGlue to fill its pointer in
        ostringstream ss;
        ss << randomEngineGlueProxy_->getID();
        ThePEG::Repository::exec("set " + generator_ +
                                 ":RandomNumberGenerator:ProxyID " + ss.str(),
                                 logstream);

        // Print the directories where ThePEG looks for libs
        vector<string> libdirlist = ThePEG::DynamicLoader::allPaths();
        for(vector<string>::const_iterator libdir = libdirlist.begin();
            libdir < libdirlist.end(); ++libdir)
                edm::LogInfo("ThePEGInterface") << "DynamicLoader path = " << *libdir << endl;

        // Output status information about the repository
        ThePEG::Repository::stats(logstream);
        edm::LogInfo("ThePEGInterface") << logstream.str();
}

void ThePEGInterface::initGenerator()
{
        // Get generator from the repository and initialize it
        ThePEG::BaseRepository::CheckObjectDirectory(generator_);
        ThePEG::EGPtr tmp = ThePEG::BaseRepository::GetObject<ThePEG::EGPtr>(generator_);
        if (tmp) {
                eg_ = ThePEG::Repository::makeRun(tmp, run_);
                eg_->initialize();
                edm::LogInfo("ThePEGInterface") << "EventGenerator initialized";
        } else
                throw cms::Exception("ThePEGInterface")
                        << "EventGenerator could not be initialized!" << endl;

        // Skip events
        for (unsigned int i = 0; i < skipEvents_; i++) {
                flushRandomNumberGenerator();
                eg_->shoot();
                edm::LogInfo("ThePEGInterface") << "Event discarded";
        }
}

void ThePEGInterface::flushRandomNumberGenerator()
{
        ThePEG::RandomEngineGlue *rnd = randomEngineGlueProxy_->getInstance();

        if (!rnd)
                edm::LogWarning("ProxyMissing")
                        << "ThePEG not initialised with RandomEngineGlue.";
        else
                rnd->flush();
}

auto_ptr<HepMC::GenEvent> ThePEGInterface::convert(
                                        const ThePEG::EventPtr &event)
{
        return std::auto_ptr<HepMC::GenEvent>(
                ThePEG::HepMCConverter<HepMC::GenEvent>::convert(*event));
}

void ThePEGInterface::clearAuxiliary(HepMC::GenEvent *hepmc,
                                     HepMC::PdfInfo *pdf)
{
        if (hepmc) {
                hepmc->set_event_scale(-1.0);
                hepmc->set_alphaQCD(-1.0);
                hepmc->set_alphaQED(-1.0);
        }
        if (pdf) {
                pdf->set_id1(-100);
                pdf->set_id2(-100);
                pdf->set_x1(-1.0);
                pdf->set_x2(-1.0);
                pdf->set_scalePDF(-1.0);
                pdf->set_pdf1(-1.0);
                pdf->set_pdf2(-1.0);
        }
}

void ThePEGInterface::fillAuxiliary(HepMC::GenEvent *hepmc,
                                    HepMC::PdfInfo *pdf,
                                    const ThePEG::EventPtr &event)
{
        if (!event->primaryCollision())
                return;

        ThePEG::tcEHPtr eh = ThePEG::dynamic_ptr_cast<ThePEG::tcEHPtr>(
                                event->primaryCollision()->handler());
        double scale = eh->lastScale();

        if (hepmc) {
                if (hepmc->event_scale() < 0 && scale > 0)
                        hepmc->set_event_scale(std::sqrt(scale) / ThePEG::GeV);

                if (hepmc->alphaQCD() < 0)
                        hepmc->set_alphaQCD(eh->lastAlphaS());
                if (hepmc->alphaQED() < 0)
                        hepmc->set_alphaQED(eh->lastAlphaEM());
        }

        if (pdf) {
                const ThePEG::PPair &beams = eh->lastParticles();
                const ThePEG::PPair &partons = eh->lastPartons();
                ThePEG::tcPDFPtr pdf1 = eh->lastExtractor()->getPDF(
                                                beams.first->dataPtr());
                ThePEG::tcPDFPtr pdf2 = eh->lastExtractor()->getPDF(
                                                beams.second->dataPtr());
                double x1, x2;

                if (pdf->id1() == -100) {
                        int id = partons.first->id();
                        pdf->set_id1(id == 21 ? 0 : id);
                }
                if (pdf->id2() == -100) {
                        int id = partons.second->id();
                        pdf->set_id2(id == 21 ? 0 : id);
                }

                if (pdf->scalePDF() < 0)
                        pdf->set_scalePDF(std::sqrt(scale) / ThePEG::GeV);
                else
                        scale = ThePEG::sqr(pdf->scalePDF()) * ThePEG::GeV;

                if (pdf->x1() < 0) {
                        x1 = eh->lastX1();
                        pdf->set_x1(x1);
                } else
                        x1 = pdf->x1();

                if (pdf->x2() < 0) {
                        x2 = eh->lastX2();
                        pdf->set_x2(x2);
                } else
                        x2 = pdf->x2();

                if (pdf1 && pdf->pdf1() < 0) {
                        double v = pdf1->xfx(beams.first->dataPtr(),
                                             partons.first->dataPtr(),
                                             scale, x1);
                        if (v > 0 && x1 > 0)
                                pdf->set_pdf1(v / x1);
                        else
                                pdf->set_pdf2(-1.0);
                }
                if (pdf2 && pdf->pdf2() < 0) {
                        double v = pdf2->xfx(beams.first->dataPtr(),
                                             partons.first->dataPtr(),
                                             scale, x2);
                        if (v > 0 && x2 > 0)
                                pdf->set_pdf2(v / x2);
                        else
                                pdf->set_pdf2(-1.0);
                }
        }

}

double ThePEGInterface::pthat(const ThePEG::EventPtr &event)
{
        using namespace ThePEG;

        if (!event->primaryCollision())
                return -1.0;

        tSubProPtr sub = event->primaryCollision()->primarySubProcess();
        TmpTransform<tSubProPtr> tmp(sub, Utilities::getBoostToCM(
                                                        sub->incoming()));

        double pthat = (*sub->outgoing().begin())->momentum().perp();
        for(PVector::const_iterator it = sub->outgoing().begin();
            it != sub->outgoing().end(); ++it)
                pthat = std::min(pthat, (*it)->momentum().perp());

        return pthat / ThePEG::GeV;
}