LHAupLesHouches.cc

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#include <algorithm>
#include <iostream>
#include <iterator>
#include <sstream>
#include <string>
#include <memory>
#include <cassert>

#include "GeneratorInterface/Pythia8Interface/plugins/LHAupLesHouches.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"

using namespace Pythia8;

bool LHAupLesHouches::setInit() {
  if (!runInfo)
    return false;
  const lhef::HEPRUP &heprup = *runInfo->getHEPRUP();

  setBeamA(heprup.IDBMUP.first, heprup.EBMUP.first, heprup.PDFGUP.first, heprup.PDFSUP.first);
  setBeamB(heprup.IDBMUP.second, heprup.EBMUP.second, heprup.PDFGUP.second, heprup.PDFSUP.second);
  setStrategy(heprup.IDWTUP);

  for (int i = 0; i < heprup.NPRUP; i++)
    addProcess(heprup.LPRUP[i], heprup.XSECUP[i], heprup.XERRUP[i], heprup.XMAXUP[i]);

  //hadronisation->onInit().emit();

  //runInfo.reset();

  //fill SLHA header information if available
  std::vector<std::string> slha = runInfo->findHeader("slha");
  if (!slha.empty()) {
    std::string slhaheader;
    for (std::vector<std::string>::const_iterator iter = slha.begin(); iter != slha.end(); ++iter) {
      slhaheader.append(*iter);
    }
    infoPtr->setHeader("slha", slhaheader);
  }

  //will be used to work around missing initialization inside pythia8
  if (!fEvAttributes) {
    fEvAttributes = new std::map<std::string, std::string>;
  } else {
    fEvAttributes->clear();
  }

  return true;
}

bool LHAupLesHouches::setEvent(int inProcId) {
  if (!event)
    return false;

  if (event->getReadAttempts() > 0)
    return false;  // record already tried

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

  if (!hepeup.NUP)
    return false;

  setProcess(hepeup.IDPRUP, hepeup.XWGTUP, hepeup.SCALUP, hepeup.AQEDUP, hepeup.AQCDUP);

  const std::vector<float> &scales = event->scales();

  unsigned int iscale = 0;
  for (int i = 0; i < hepeup.NUP; i++) {
    //retrieve scale corresponding to each particle
    double scalein = -1.;

    //handle clustering scales if present,
    //applies to outgoing partons only
    if (setScalesFromLHEF_ && !scales.empty() && hepeup.ISTUP[i] == 1) {
      if (iscale >= scales.size()) {
        edm::LogError("InvalidLHEInput") << "Pythia8 requires"
                                         << "cluster scales for all outgoing partons or for none" << std::endl;
      }
      scalein = scales[iscale];
      ++iscale;
    }

    addParticle(hepeup.IDUP[i],
                hepeup.ISTUP[i],
                hepeup.MOTHUP[i].first,
                hepeup.MOTHUP[i].second,
                hepeup.ICOLUP[i].first,
                hepeup.ICOLUP[i].second,
                hepeup.PUP[i][0],
                hepeup.PUP[i][1],
                hepeup.PUP[i][2],
                hepeup.PUP[i][3],
                hepeup.PUP[i][4],
                hepeup.VTIMUP[i],
                hepeup.SPINUP[i],
                scalein);
  }

  if (!infoPtr->eventAttributes) {
    fEvAttributes->clear();
    infoPtr->eventAttributes = fEvAttributes;
  } else {
    infoPtr->eventAttributes = fEvAttributes;  // make sure still there
    infoPtr->eventAttributes->clear();
  }

  //fill parton multiplicities if available
  int npLO = event->npLO();
  int npNLO = event->npNLO();

  //default value of -99 indicates tags were not present in the original LHE file
  //don't pass to pythia in this case to emulate pythia internal lhe reader behaviour
  if (npLO != -99) {
    char buffer[100];
    snprintf(buffer, 100, "%i", npLO);
    (*infoPtr->eventAttributes)["npLO"] = buffer;
  }
  if (npNLO != -99) {
    char buffer[100];
    snprintf(buffer, 100, "%i", npNLO);
    (*infoPtr->eventAttributes)["npNLO"] = buffer;
  }

  //add #rwgt info from comments
  const std::vector<std::string> &comments = event->getComments();
  for (unsigned i = 0; i < comments.size(); i++) {
    if (comments[i].rfind("#rwgt", 0) == 0)
      (*infoPtr->eventAttributes)["#rwgt"] = comments[i];
  }

  const lhef::LHEEvent::PDF *pdf = event->getPDF();
  if (pdf) {
    this->setPdf(pdf->id.first,
                 pdf->id.second,
                 pdf->x.first,
                 pdf->x.second,
                 pdf->scalePDF,
                 pdf->xPDF.first,
                 pdf->xPDF.second,
                 true);
  } else {
    this->setPdf(hepeup.IDUP[0],
                 hepeup.IDUP[1],
                 hepeup.PUP[0][3] / runInfo->getHEPRUP()->EBMUP.first,
                 hepeup.PUP[1][3] / runInfo->getHEPRUP()->EBMUP.second,
                 0.,
                 0.,
                 0.,
                 false);
  }

  event->attempted();

  return true;
}