LHAPDF5.cxx

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//____________________________________________________________________________
/*
 Copyright (c) 2003-2025, The GENIE Collaboration
 For the full text of the license visit http://copyright.genie-mc.org
 
 Costas Andreopoulos <c.andreopoulos \at cern.ch>
 University of Liverpool
*/
//____________________________________________________________________________
 
#include <cstdlib>
 
#include <TSystem.h>
#include <TMath.h>
 
#include "Framework/Conventions/GBuild.h"
#include "Physics/PartonDistributions/LHAPDF5.h"
#include "Framework/Messenger/Messenger.h"
 
#ifdef __GENIE_LHAPDF5_ENABLED__
#include "LHAPDF/LHAPDF.h"
#endif
 
using namespace genie;
 
//____________________________________________________________________________
LHAPDF5::LHAPDF5() :
PDFModelI("genie::LHAPDF5")
{
  this->Initialize();
}
//____________________________________________________________________________
LHAPDF5::LHAPDF5(string config) :
PDFModelI("genie::LHAPDF5", config)
{
  LOG("LHAPDF5", pDEBUG) << "LHAPDF5 configuration:\n " << this->GetConfig();
 
  this->Initialize();
}
//____________________________________________________________________________
LHAPDF5::~LHAPDF5()
{
 
}
//____________________________________________________________________________
void LHAPDF5::Initialize(void) const
{
#ifdef __GENIE_LHAPDF5_ENABLED__
  bool lhapath_ok = true;
  const char * lhapath = gSystem->Getenv("LHAPATH");
  if(!lhapath) lhapath_ok = false;
  else {
      void *dirp = gSystem->OpenDirectory(lhapath);
      if (dirp) gSystem->FreeDirectory(dirp);
      else lhapath_ok = false;
  }
  if(!lhapath_ok) {
   LOG("LHAPDF5", pFATAL)
     << "\n"
     << "** LHAPDF won't be able to read-in the PDF data. \n"
     << "** The LHAPATH env. variable is not properly (or at all) defined. \n"
     << "** Please, set LHAPATH to <lhapdf_top_dir>/PDFsets/ \n"
     << "** See http://projects.hepforge.org/lhapdf/ for more details. \n\n";
   gAbortingInErr = true;
   exit(1);
  }
#endif
}
//____________________________________________________________________________
void LHAPDF5::SetPDFSetFromConfig(void) const
{
// Get PDF spec (particle type, pdf group/set) from configuration registry.
// For definitions, have a look at PDFLIB and LHAPDF manuals
 
#ifdef __GENIE_LHAPDF5_ENABLED__
  string name   = "";
  int    type   = 0;
  int    memset = 0;
 
  this->GetParam("name_lhapdf",   name);
  this->GetParam("type_lhapdf",   type);
  this->GetParam("memset_lhapdf", memset);
 
  LHAPDF::SetType stype = (type==0) ? LHAPDF::LHPDF :  LHAPDF::LHGRID;
 
  LHAPDF::initPDFByName(name, stype, memset);
  LHAPDF::extrapolate(false);
#endif
}
//____________________________________________________________________________
double LHAPDF5::UpValence(double x, double Q2) const
{
  return AllPDFs(x,Q2).uval;
}
//____________________________________________________________________________
double LHAPDF5::DownValence(double x, double Q2) const
{
  return AllPDFs(x,Q2).dval;
}
//____________________________________________________________________________
double LHAPDF5::UpSea(double x, double Q2) const
{
  return AllPDFs(x,Q2).usea;
}
//____________________________________________________________________________
double LHAPDF5::DownSea(double x, double Q2) const
{
  return AllPDFs(x,Q2).dsea;
}
//____________________________________________________________________________
double LHAPDF5::Strange(double x, double Q2) const
{
  return AllPDFs(x,Q2).str;
}
//____________________________________________________________________________
double LHAPDF5::Charm(double x, double Q2) const
{
  return AllPDFs(x,Q2).chm;
}
//____________________________________________________________________________
double LHAPDF5::Bottom(double x, double Q2) const
{
  return AllPDFs(x,Q2).bot;
}
//____________________________________________________________________________
double LHAPDF5::Top(double x, double Q2) const
{
  return AllPDFs(x,Q2).top;
}
//____________________________________________________________________________
double LHAPDF5::Gluon(double x, double Q2) const
{
  return AllPDFs(x,Q2).gl;
}
//____________________________________________________________________________
PDF_t LHAPDF5::AllPDFs(
#ifdef __GENIE_LHAPDF5_ENABLED__
  double x, double Q2
#else
  double, double
#endif
) const
{
  PDF_t pdf;
 
#ifdef __GENIE_LHAPDF5_ENABLED__
  // QCD scale
  double Q = TMath::Sqrt( TMath::Abs(Q2) );
 
  vector<double> pdfs = LHAPDF::xfx(x, Q);
  pdf.uval = pdfs[8] - pdfs[4];
  pdf.dval = pdfs[7] - pdfs[5];
  pdf.usea = pdfs[4];
  pdf.dsea = pdfs[5];
  pdf.str  = pdfs[9];
  pdf.chm  = pdfs[10];
  pdf.bot  = pdfs[11];
  pdf.top  = pdfs[12];
  pdf.gl   = pdfs[6];;
#endif
 
  return pdf;
}
//____________________________________________________________________________
void LHAPDF5::Configure(const Registry & config)
{
  Algorithm::Configure(config);
 
  this->Initialize();
  this->SetPDFSetFromConfig();
 
  fAllowReconfig=false;
}
//____________________________________________________________________________
void LHAPDF5::Configure(string config)
{
  Algorithm::Configure(config);
 
  this->Initialize();
  this->SetPDFSetFromConfig();
 
  fAllowReconfig=false;
}
//____________________________________________________________________________