1 /**************************************************************************
2 * Copyright(c) 1998-2007, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
16 //-----------------------------------------------------------------------
17 // Particle generator according to 4 correlated variables : here
18 // z, ptot, r, theta. The input is a THnSparse object included in
19 // the root file (path and name to be set via the SetTHnSparse method).
20 // This class is similar to AliGenFunction.
21 //-----------------------------------------------------------------------
22 // Author : X. Lopez - LPC Clermont (fr)
23 //-----------------------------------------------------------------------
25 Example for generation :
26 AliGenTHnSparse *gener = new AliGenTHnSparse();
27 gener->SetNumberParticles(10);
28 gener->SetPart(13,kTRUE); // for generating id 13 and -13
29 gener->SetThnSparse("file_name","thn_name");
35 #include "THnSparse.h"
37 #include "AliGenTHnSparse.h"
42 #include "AliGenEventHeader.h"
45 ClassImp(AliGenTHnSparse)
47 //_______________________________________________________________________
48 AliGenTHnSparse::AliGenTHnSparse():
55 // Default constructor
56 SetNumberParticles(1);
59 //_______________________________________________________________________
60 AliGenTHnSparse::AliGenTHnSparse(const AliGenTHnSparse& func):
68 SetNumberParticles(1);
71 //_______________________________________________________________________
72 AliGenTHnSparse & AliGenTHnSparse::operator=(const AliGenTHnSparse& func)
75 if(&func == this) return *this;
84 //_______________________________________________________________________
85 AliGenTHnSparse::~AliGenTHnSparse()
91 //_______________________________________________________________________
92 void AliGenTHnSparse::Generate()
94 // Generate Npart of id Ipart
97 Double_t rand[4]; // z, ptot, r, theta
98 Float_t pos[3], phi, ptot, theta, pt, z, r;
102 for (Int_t ipart = 0; ipart < fNpart && naccepted<fNpart; ipart++) {
104 fHn->GetRandom(rand);
110 // Phi: same for position and momemtum
112 phi=(-180+gRandom->Rndm()*360)*TMath::Pi()/180;
114 // position at production
116 pos[0] = r*TMath::Cos(phi);
117 pos[1] = r*TMath::Sin(phi);
120 // momentum at production
122 pt = ptot*TMath::Sin(theta);
123 mom[0] = pt*TMath::Cos(phi);
124 mom[1] = pt*TMath::Sin(phi);
125 mom[2] = ptot*TMath::Cos(theta);
129 Float_t polarization[3] = {0,0,0};
132 // Part and anti-part
135 Double_t sign = gRandom->Rndm();
136 if(sign < 0.5) pdg = -fIpart;
140 PushTrack(fTrackIt,-1,pdg,mom, pos, polarization,0,kPPrimary,nt);
144 AliGenEventHeader* header = new AliGenEventHeader("THn");
145 gAlice->SetGenEventHeader(header);
150 //_______________________________________________________________________
151 void AliGenTHnSparse::Init()
154 // Initialisation, check consistency of selected file
155 printf("************ AliGenTHnSparse ****************\n");
156 printf("*********************************************\n");
158 AliFatal("THnSparse file not specified");
164 //_______________________________________________________________________
165 void AliGenTHnSparse::SetThnSparse(char *file_name, char *thn_name)
168 // Open the file and get object
169 fFile = new TFile(file_name);
170 fHn = (THnSparseF*)(fFile->Get(thn_name));