Overlaps corrected, new shape of sectors
[u/mrichter/AliRoot.git] / EVGEN / AliGenThetaSlice.cxx
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56b2bd7e 1/**************************************************************************
2 * Copyright(c) 1998-1999, 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
803d1ab0 16/* $Id$ */
88cb7938 17
0af12c00 18
19// Generates n particles with in the same phi angle, varies theta
56b2bd7e 20// in equidistant intervals
21// This class is intended to use for studies of TPC response
22// via merging with background event.
56b2bd7e 23// Note that for a given theta pt and p are not independent
24// Range for only one variable (pt or p) should be given.
25// Based on the AliGenBox class written by andreas.morsch@cern.ch
26//
27// Comments and suggestions: Jiri.Chudoba@cern.ch
0af12c00 28
56b2bd7e 29
116cbefd 30#include <TPDGCode.h>
31
32#include "AliConst.h"
56b2bd7e 33#include "AliGenThetaSlice.h"
34#include "AliRun.h"
56b2bd7e 35
36ClassImp(AliGenThetaSlice)
37
38//_____________________________________________________________________________
39AliGenThetaSlice::AliGenThetaSlice()
1c56e311 40 :AliGenerator(),
41 fIpart(0)
56b2bd7e 42{
43 //
44 // Default constructor
45 //
56b2bd7e 46}
47
48//_____________________________________________________________________________
49AliGenThetaSlice::AliGenThetaSlice(Int_t npart)
1c56e311 50 :AliGenerator(npart),
51 fIpart(kProton)
56b2bd7e 52{
53 //
54 // Standard constructor
55 //
56 fName = "ThetaSlice";
57 fTitle = "Particle generator - const. phi, slices in theta";
56b2bd7e 58}
59
60//_____________________________________________________________________________
61
62void AliGenThetaSlice::Generate()
63{
64 //
65 // Generate one trigger
66 //
67
68 Float_t polar[3]= {0,0,0};
69 Float_t origin[3];
21391258 70 Float_t time;
56b2bd7e 71 Float_t p[3];
72 Int_t i, j, nt;
73 Double_t pmom, theta, phi, pt;
74 Float_t random[6];
75
76 if (fNpart == 0) return;
77
78 for (j=0;j<3;j++) origin[j]=fOrigin[j];
21391258 79 time = fTimeOrigin;
56b2bd7e 80 if(fVertexSmear==kPerEvent) {
81 Rndm(random,6);
82 for (j=0;j<3;j++) {
83 origin[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
84 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
85 }
21391258 86 Rndm(random,2);
87 time += fOsigma[2]/TMath::Ccgs()*
88 TMath::Cos(2*random[0]*TMath::Pi())*
89 TMath::Sqrt(-2*TMath::Log(random[1]));
56b2bd7e 90 }
91 Float_t thetaInterval = 0.;
92 if (fNpart > 1) {
93 thetaInterval = (fThetaMax-fThetaMin)/(fNpart-1);
94 }
95 Rndm(random,1);
96 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
97 for(i=0;i<fNpart;i++) {
98 Rndm(random,1);
99 theta=fThetaMin+i*thetaInterval;
100 if(TestBit(kMomentumRange)) {
101 pmom=fPMin+random[0]*(fPMax-fPMin);
102 pt=pmom*TMath::Sin(theta);
103 } else {
104 pt=fPtMin+random[0]*(fPtMax-fPtMin);
105 pmom=pt/TMath::Sin(theta);
106 }
107 p[0] = pt*TMath::Cos(phi);
108 p[1] = pt*TMath::Sin(phi);
109 p[2] = pmom*TMath::Cos(theta);
110
111 if(fVertexSmear==kPerTrack) {
112 Rndm(random,6);
113 for (j=0;j<3;j++) {
114 origin[j]=fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
115 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
116 }
21391258 117 Rndm(random,2);
118 time = fTimeOrigin + fOsigma[2]/TMath::Ccgs()*
119 TMath::Cos(2*random[0]*TMath::Pi())*
120 TMath::Sqrt(-2*TMath::Log(random[1]));
56b2bd7e 121 }
21391258 122 PushTrack(fTrackIt,-1,fIpart,p,origin,polar,time,kPPrimary,nt);
56b2bd7e 123 }
124}
125
126//_____________________________________________________________________________
127
128void AliGenThetaSlice::Init()
129{
130// Initialisation, check consistency of selected ranges
131 if(TestBit(kPtRange)&&TestBit(kMomentumRange))
132 Fatal("Init","You should not set the momentum range and the pt range!\n");
133 if((!TestBit(kPtRange))&&(!TestBit(kMomentumRange)))
134 Fatal("Init","You should set either the momentum or the pt range!\n");
135}
136