First version of macros for lego_train
[u/mrichter/AliRoot.git] / PWG2 / RESONANCES / AliRsnValuePair.cxx
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2895972e 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
16////////////////////////////////////////////////////////////////////////////////
17//
18// This class contains all code which is used to compute any of the values
19// which can be of interest within a resonance analysis. Besides the obvious
20// invariant mass, it allows to compute other utility values on all possible
21// targets, in order to allow a wide spectrum of binning and checks.
22// When needed, this object can also define a binning in the variable which
23// it is required to compute, which is used for initializing axes of output
24// histograms (see AliRsnFunction).
25// The value computation requires this object to be passed the object whose
26// informations will be used. This object can be of any allowed input type
27// (track, pair, event), then this class must inherit from AliRsnTarget.
28// Then, when value computation is attempted, a check on target type is done
29// and computation is successful only if expected target matches that of the
30// passed object.
31// In some cases, the value computation can require a support external object,
32// which must then be passed to this class. It can be of any type inheriting
33// from TObject.
34//
35// authors: A. Pulvirenti (alberto.pulvirenti@ct.infn.it)
36// M. Vala (martin.vala@cern.ch)
37//
38////////////////////////////////////////////////////////////////////////////////
39
40#include "Riostream.h"
41#include "AliVVertex.h"
42#include "AliMultiplicity.h"
43#include "AliESDtrackCuts.h"
44#include "AliESDpid.h"
45#include "AliAODPid.h"
46#include "AliCentrality.h"
47#include "AliESDUtils.h"
48
49#include "AliRsnEvent.h"
50#include "AliRsnDaughter.h"
51#include "AliRsnMother.h"
52#include "AliRsnPairDef.h"
53#include "AliRsnDaughterDef.h"
54
55#include "AliRsnValuePair.h"
56
57ClassImp(AliRsnValuePair)
58
59//_____________________________________________________________________________
60AliRsnValuePair::AliRsnValuePair(const char *name, EType type) :
61 AliRsnValue(name, AliRsnTarget::kMother),
62 fType(type)
63{
64//
65// Constructor
66//
67}
68
69//_____________________________________________________________________________
70AliRsnValuePair::AliRsnValuePair(const AliRsnValuePair& copy) :
71 AliRsnValue(copy),
72 fType(copy.fType)
73{
74//
75// Copy constructor
76//
77}
78
79//_____________________________________________________________________________
80AliRsnValuePair& AliRsnValuePair::operator=(const AliRsnValuePair& copy)
81{
82//
83// Assignment operator.
84// Works like copy constructor.
85//
86
87 AliRsnValue::operator=(copy);
e6f3a909 88 if (this == &copy)
89 return *this;
2895972e 90 fType = copy.fType;
91
92 return (*this);
93}
94
95//_____________________________________________________________________________
96const char* AliRsnValuePair::GetTypeName() const
97{
98//
99// This method returns a string to give a name to each possible
100// computation value.
101//
102
103 switch (fType) {
104 case kPt: return "PairPt";
105 case kPz: return "PairPz";
106 case kInvMass: return "PairInvMass";
107 case kInvMassRes: return "PairInvMassResolution";
108 case kEta: return "PairEta";
109 case kMt: return "PairMt";
110 case kY: return "PairY";
111 case kPtRatio: return "PairPtRatio";
112 case kDipAngle: return "PairDipAngle";
113 case kCosThetaStar: return "PairCosThetaStar";
b63357a0 114 case kAngleLeading: return "PairAngleToLeading";
2895972e 115 default: return "Undefined";
116 }
117}
118
119//_____________________________________________________________________________
120Bool_t AliRsnValuePair::Eval(TObject *object)
121{
122//
123// Evaluation of the required value.
124// In this implementation, fills the member 4-vectors with data
125// coming from the object passed as argument, and then returns the value
126//
127
128 // coherence check, which also casts object
129 // to AliRsnTarget data members and returns kFALSE
130 // in case the object is NULL
131 if (!TargetOK(object)) return kFALSE;
132
133 // set a reference to the mother momentum
134 TLorentzVector &sum = fMother->Sum(fUseMCInfo);
135 TLorentzVector &ref = fMother->Ref(fUseMCInfo);
136 TLorentzVector &p1 = fMother->GetDaughter(0)->P(fUseMCInfo);
137 TLorentzVector &p2 = fMother->GetDaughter(1)->P(fUseMCInfo);
138
b63357a0 139 // utility variables
140 Bool_t success;
141
2895972e 142 // compute value depending on types in the enumeration
143 // if the type does not match any available choice, or if
144 // the computation is not doable due to any problem
145 // (not initialized support object, wrong values, risk of floating point errors)
146 // the method returng kFALSE and sets the computed value to a meaningless number
147 switch (fType) {
148 case kPt:
149 fComputedValue = sum.Perp();
150 return kTRUE;
151 case kInvMass:
152 fComputedValue = sum.M();
153 return kTRUE;
154 case kEta:
155 fComputedValue = sum.Eta();
156 return kTRUE;
157 case kInvMassRes:
158 fComputedValue = fMother->Sum(kFALSE).M() - fMother->Sum(kTRUE).M();
159 fComputedValue /= fMother->Sum(kTRUE).M();
160 return kTRUE;
161 case kMt:
162 fComputedValue = ref.Mt();
163 return kTRUE;
164 case kY:
165 fComputedValue = ref.Rapidity();
166 return kTRUE;
167 case kPtRatio:
168 fComputedValue = TMath::Abs(p1.Perp() - p2.Perp());
169 fComputedValue /= TMath::Abs(p1.Perp() + p2.Perp());
170 return kTRUE;
171 case kDipAngle:
172 fComputedValue = p1.Perp() * p2.Perp() + p1.Z() * p2.Z();
173 fComputedValue /= p1.Mag() * p2.Mag();
174 return kTRUE;
175 case kCosThetaStar:
176 fComputedValue = fMother->CosThetaStar();
177 return kTRUE;
b63357a0 178 case kAngleLeading:
179 fComputedValue = fMother->AngleToLeading(success);
180 return success;
2895972e 181 default:
182 AliError(Form("[%s] Invalid value type for this computation", GetName()));
183 return kFALSE;
184 }
185}