libthepeg-dev 1.8.0-1.1 / usr / include / ThePEG / LesHouches / MadGraphReader.h

// -*- C++ -*-
//
// MadGraphReader.h is a part of ThePEG - Toolkit for HEP Event Generation
// Copyright (C) 1999-2011 Leif Lonnblad
//
// ThePEG is licenced under version 2 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef THEPEG_MadGraphReader_H
#define THEPEG_MadGraphReader_H
// This is the declaration of the MadGraphReader class.

#include "ThePEG/LesHouches/LesHouchesFileReader.h"

namespace ThePEG {

/**
 * MadGraphReader inherits from LesHouchesFileReader and is able to
 * read event files produced by the MadGraph/MadEvent program.
 *
 * @see \ref MadGraphReaderInterfaces "The interfaces"
 * defined for MadGraphReader.
 */
class MadGraphReader: public LesHouchesFileReader {

public:

   /** @name Standard constructors and destructors. */
  //@{
  /**
   * Default constructor.
   */
  MadGraphReader()
    : fixedScale(91.188*GeV), fixedAEM(0.007546772), fixedAS(0.12),
      doInitCuts(false) {}
  //@}

public:

  /** @name Virtual functions specified by the LesHouchesReader base class. */
  //@{
  /**
   * Open a file or stream with events and read in the run information
   * into the corresponding protected variables.
   */
  virtual void open();

  /**
   * Scan the file or stream to obtain information about cross section
   * weights and particles etc. This function should fill the
   * variables corresponding to the /HEPRUP/ common block. The
   * function returns the number of events scanned. This version calls
   * the base class function and the readjusts the values in HEPRUP to
   * cure some inconsistencies in the MadGraph files.
   */
  virtual long scan();

  /**
   * Read the next event form the file or stream into the
   * corresponding protected variables. Return false if there is no
   * more events.
   */
  virtual bool doReadEvent();
  //@}

public:

  /** @name Functions used by the persistent I/O system. */
  //@{
  /**
   * Function used to write out object persistently.
   * @param os the persistent output stream written to.
   */
  void persistentOutput(PersistentOStream & os) const;

  /**
   * Function used to read in object persistently.
   * @param is the persistent input stream read from.
   * @param version the version number of the object when written.
   */
  void persistentInput(PersistentIStream & is, int version);
  //@}

  /**
   * Standard Init function used to initialize the interfaces.
   */
  static void Init();

protected:

  /** @name Clone Methods. */
  //@{
  /**
   * Make a simple clone of this object.
   * @return a pointer to the new object.
   */
  virtual IBPtr clone() const;

  /** Make a clone of this object, possibly modifying the cloned object
   * to make it sane.
   * @return a pointer to the new object.
   */
  virtual IBPtr fullclone() const;
  //@}

protected:

  /** @name Standard Interfaced functions. */
  //@{

  /**
   * Initialize this object after the setup phase before saving an
   * EventGenerator to disk.
   * @throws InitException if object could not be initialized properly.
   */
  virtual void doinit();

  /**
   * Called from doinit() to extract cuts from the event file and add
   * the corresponding objects to the current EventGenerator.
   */
  CutsPtr initCuts();

  /**
   * Called from LesHouchesReader::doinit() to extract PDFs from the
   * event file and add the corresponding objects to the current
   * EventGenerator.
   */
  virtual void initPDFs();

  /**
   * Return true if this object needs to be initialized before all
   * other objects because it needs to extract cuts from the event file.
   */
  virtual bool preInitialize() const;

  /**
   * Finalize this object. Called in the run phase just after a
   * run has ended. Used eg. to write out statistics.
   */
  virtual void dofinish() {
    LesHouchesFileReader::dofinish();
    if ( stats.accepted() > 0 ) useMe();
  }
  //@}

protected:

  /**
   * Interface function to scan a madgraph file and extract
   * information about used cuts. The corresponding cut objects are
   * created in the Repository and assigned to this reader.
   */
  string scanCuts(string);

  /**
   *  Function to extract the number of events from a string
   */
  long numberOfEvents(string);

protected:

  /**
   * Fixed scale. Old MadGraph files do not necessarily contain
   * information about the factorization (or renormalization)
   * scale. In this case this is used instead.
   */
  Energy fixedScale;

  /**
   * Fixed \f$\alpha_{EM}\f$.  Old MadGraph files do not necessarily
   * contain information about the value of \f$\alpha_{EM}\f$. In this
   * case this is used instead.
   */
  double fixedAEM;

  /**
   * Fixed \f$\alpha_S\f$.  Old MadGraph files do not necessarily
   * contain information about the value of \f$\alpha_S\f$. In this
   * case this is used instead.
   */
  double fixedAS;

  /**
   * New MadGraph files contain suitable information about cuts used
   * in the generation. The non-zero ones are stored in this map.
   */
  map<string,double> cuts;
  
  /**
   * If true, cuts may be extracted from the event file during initialization.
   */
  bool doInitCuts;

public:

  /**
   * Exception class used to inform about inability to work with some
   * weighted event files.
   */
  struct WeightedException: public Exception {};

private:

  /**
   * Describe a concrete class with persistent data.
   */
  static ClassDescription<MadGraphReader> initMadGraphReader;

  /**
   * Private and non-existent assignment operator.
   */
  MadGraphReader & operator=(const MadGraphReader &);

};

}


#include "ThePEG/Utilities/ClassTraits.h"

namespace ThePEG {

/** @cond TRAITSPECIALIZATIONS */

/**
 * This template specialization informs ThePEG about the
 * base class of MadGraphReader.
 */
template <>
struct BaseClassTrait<MadGraphReader,1>: public ClassTraitsType {
  /** Typedef of the base class of MadGraphReader. */
  typedef LesHouchesFileReader NthBase;
};

/**
 * This template specialization informs ThePEG about the name of the
 * MadGraphReader class and the shared object where it is
 * defined.
 */
template <>
struct ClassTraits<MadGraphReader>
  : public ClassTraitsBase<MadGraphReader> {
  /** Return the class name. */
  static string className() { return "ThePEG::MadGraphReader"; }
  /** Return the name of the shared library to be loaded to get
   * access to the MadGraphReader class and every other class it uses
   * (except the base class). */
  static string library() { return "MadGraphReader.so"; }

};

/** @endcond */

}

#endif /* THEPEG_MadGraphReader_H */