[u/mrichter/AliRoot.git] / TEPEMGEN / TEpEmGen.cxx

/**************************************************************************
 * Copyright(c) 1998-2002, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 *                                                                        *
 *                                                                        *
 * Copyright(c) 1997, 1998, 2002, Adrian Alscher and Kai Hencken          *
 * See $ALICE_ROOT/EpEmGen/diffcross.f for full Copyright notice          *
 *                                                                        *
 *                                                                        *
 * Copyright(c) 2002 Kai Hencken, Yuri Kharlov, Serguei Sadovsky          *
 * See $ALICE_ROOT/EpEmGen/epemgen.f for full Copyright notice            *
 *                                                                        *
 **************************************************************************/
//------------------------------------------------------------------------
// TEpEmGen is an interface class to fortran event generator of
// single e+e- pair production in ultraperipheral PbPb collisions
// at 5.5 GeV/c
//%
// Yuri.Kharlov@cern.ch
// 9 October 2002
//------------------------------------------------------------------------

#include "TRandom.h"

#include "TEpEmGen.h"
#include "TClonesArray.h"
#include "TParticle.h"
#include "TEcommon.h"

#ifndef WIN32
# define ee_init  ee_init_
# define ee_event ee_event_
# define eernd    eernd_
#else
# define ee_init  EE_INIT
# define ee_event EE_EVENT
# define eernd    EERND
#endif

extern "C" {
  void ee_init  (Double_t &ymin, Double_t &ymax, Double_t &xmin, Double_t &xmax);
  void ee_event (Double_t &ymin, Double_t &ymax, Double_t &xmin, Double_t &xmax,
	         Double_t &yE,   Double_t &yP,   Double_t &xE,   Double_t &xP, 
		 Double_t &phi,  Double_t &w);
  Double_t eernd(Int_t*) {
    Double_t r;
    do r=gRandom->Rndm(); while(0 >= r || r >= 1);
    return r;
  }
}

ClassImp(TEpEmGen)

//------------------------------------------------------------------------------
TEpEmGen::TEpEmGen() : TGenerator("TEpEmGen","TEpEmGen")
{
// TEpEmGen constructor: creates a TClonesArray in which it will store all
// particles. Note that there may be only one functional TEpEmGen object
// at a time, so it's not use to create more than one instance of it.

  delete fParticles; // was allocated as TObjArray in TGenerator
  fParticles = new TClonesArray("TParticle",2);

}

//------------------------------------------------------------------------------
TEpEmGen::~TEpEmGen()
{
  // Destroys the object, deletes and disposes all TParticles currently on list.
  if (fParticles) {
    fParticles->Delete();
    delete fParticles;
    fParticles = 0;
  }
}

//______________________________________________________________________________
void TEpEmGen::GenerateEvent(Double_t ymin, Double_t ymax, Double_t ptmin, Double_t ptmax,
			     Double_t &yElectron, Double_t &yPositron,
			     Double_t &xElectron, Double_t &xPositron,
			     Double_t &phi12,     Double_t &weight)
{
  //produce one event
  ee_event(ymin,ymax,ptmin,ptmax,
	   yElectron,yPositron,xElectron,xPositron,
	   phi12,weight);
}

//______________________________________________________________________________
void TEpEmGen::Initialize(Double_t ymin, Double_t ymax, Double_t ptmin, Double_t ptmax)
{
  // Initialize EpEmGen
  Double_t ptminMeV = ptmin*1000;
  Double_t ptmaxMeV = ptmax*1000;
  ee_init(ymin,ymax,ptminMeV,ptmaxMeV);
}

//______________________________________________________________________________
Double_t TEpEmGen::GetXsection()
{
  // Return cross section accumulated so far
  return EEVENT.Xsecttot;
}

//______________________________________________________________________________
Double_t TEpEmGen::GetDsection()
{
  // Return cross section error accumulated so far
  return EEVENT.Dsecttot;
}
Commit	Line	Data
c9c6bd3b	1	/**************************************************************************
	2	* Copyright(c) 1998-2002, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	* *
	15	* *
	16	* Copyright(c) 1997, 1998, 2002, Adrian Alscher and Kai Hencken *
	17	* See $ALICE_ROOT/EpEmGen/diffcross.f for full Copyright notice *
	18	* *
	19	* *
	20	* Copyright(c) 2002 Kai Hencken, Yuri Kharlov, Serguei Sadovsky *
	21	* See $ALICE_ROOT/EpEmGen/epemgen.f for full Copyright notice *
	22	* *
	23	**************************************************************************/
	24	//------------------------------------------------------------------------
	25	// TEpEmGen is an interface class to fortran event generator of
	26	// single e+e- pair production in ultraperipheral PbPb collisions
	27	// at 5.5 GeV/c
	28	//%
	29	// Yuri.Kharlov@cern.ch
	30	// 9 October 2002
	31	//------------------------------------------------------------------------
	32
63e30ba9	33	#include "TRandom.h"
63e30ba9	34
c9c6bd3b	35	#include "TEpEmGen.h"
	36	#include "TClonesArray.h"
	37	#include "TParticle.h"
	38	#include "TEcommon.h"
	39
	40	#ifndef WIN32
	41	# define ee_init ee_init_
	42	# define ee_event ee_event_
63e30ba9	43	# define eernd eernd_
c9c6bd3b	44	#else
	45	# define ee_init EE_INIT
	46	# define ee_event EE_EVENT
63e30ba9	47	# define eernd EERND
c9c6bd3b	48	#endif
	49
	50	extern "C" {
	51	void ee_init (Double_t &ymin, Double_t &ymax, Double_t &xmin, Double_t &xmax);
	52	void ee_event (Double_t &ymin, Double_t &ymax, Double_t &xmin, Double_t &xmax,
	53	Double_t &yE, Double_t &yP, Double_t &xE, Double_t &xP,
	54	Double_t &phi, Double_t &w);
63e30ba9	55	Double_t eernd(Int_t*) {
	56	Double_t r;
	57	do r=gRandom->Rndm(); while(0 >= r \|\| r >= 1);
	58	return r;
	59	}
c9c6bd3b	60	}
	61
	62	ClassImp(TEpEmGen)
	63
	64	//------------------------------------------------------------------------------
	65	TEpEmGen::TEpEmGen() : TGenerator("TEpEmGen","TEpEmGen")
	66	{
	67	// TEpEmGen constructor: creates a TClonesArray in which it will store all
	68	// particles. Note that there may be only one functional TEpEmGen object
	69	// at a time, so it's not use to create more than one instance of it.
	70
	71	delete fParticles; // was allocated as TObjArray in TGenerator
	72	fParticles = new TClonesArray("TParticle",2);
	73
	74	}
	75
	76	//------------------------------------------------------------------------------
	77	TEpEmGen::~TEpEmGen()
	78	{
	79	// Destroys the object, deletes and disposes all TParticles currently on list.
	80	if (fParticles) {
	81	fParticles->Delete();
	82	delete fParticles;
	83	fParticles = 0;
	84	}
	85	}
	86
	87	//______________________________________________________________________________
	88	void TEpEmGen::GenerateEvent(Double_t ymin, Double_t ymax, Double_t ptmin, Double_t ptmax,
	89	Double_t &yElectron, Double_t &yPositron,
	90	Double_t &xElectron, Double_t &xPositron,
	91	Double_t &phi12, Double_t &weight)
	92	{
	93	//produce one event
	94	ee_event(ymin,ymax,ptmin,ptmax,
	95	yElectron,yPositron,xElectron,xPositron,
	96	phi12,weight);
	97	}
	98
	99	//______________________________________________________________________________
	100	void TEpEmGen::Initialize(Double_t ymin, Double_t ymax, Double_t ptmin, Double_t ptmax)
	101	{
	102	// Initialize EpEmGen
	103	Double_t ptminMeV = ptmin*1000;
	104	Double_t ptmaxMeV = ptmax*1000;
	105	ee_init(ymin,ymax,ptminMeV,ptmaxMeV);
	106	}
	107
	108	//______________________________________________________________________________
	109	Double_t TEpEmGen::GetXsection()
	110	{
	111	// Return cross section accumulated so far
	112	return EEVENT.Xsecttot;
	113	}
	114
	115	//______________________________________________________________________________
	116	Double_t TEpEmGen::GetDsection()
	117	{
	118	// Return cross section error accumulated so far
	119	return EEVENT.Dsecttot;
	120	}