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Reference Guide
TStatistic.h
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1 // @(#)root/mathcore:$Id$
2 // Author: G. Ganis 2012
3 
4 /*************************************************************************
5  * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *
6  * All rights reserved. *
7  * *
8  * For the licensing terms see $ROOTSYS/LICENSE. *
9  * For the list of contributors see $ROOTSYS/README/CREDITS. *
10  *************************************************************************/
11 
12 #ifndef ROOT_TStatistic
13 #define ROOT_TStatistic
14 
15 
16 //////////////////////////////////////////////////////////////////////////
17 // //
18 // TStatistic //
19 // //
20 // Statistical variable, defined by its mean, RMS and related errors. //
21 // Named, streamable, storable and mergeable. //
22 // //
23 //////////////////////////////////////////////////////////////////////////
24 
25 #include "TObject.h"
26 
27 #include "TCollection.h"
28 
29 #include "TMath.h"
30 
31 #include "TString.h"
32 
33 #include "TROOT.h"
34 
35 class TStatistic : public TObject {
36 
37 private:
39  Long64_t fN; // Number of fills
40  Double_t fW; // Sum of weights
41  Double_t fW2; // Sum of weights**2
42  Double_t fM; // Sum of elements ( i.e. mean * sum_of_weights)
43  Double_t fM2; // Second order momentum
44 
45 public:
46 
47  TStatistic(const char *name = "") : fName(name), fN(0), fW(0.), fW2(0.), fM(0.), fM2(0.) { }
48  TStatistic(const char *name, Int_t n, const Double_t *val, const Double_t *w = 0);
50 
51  // Getters
52  const char *GetName() const { return fName; }
53  ULong_t Hash() const { return fName.Hash(); }
54 
55  inline Long64_t GetN() const { return fN; }
56  inline Long64_t GetNeff() const { return fW*fW/fW2; }
57  inline Double_t GetM2() const { return fM2; }
58  inline Double_t GetMean() const { return (fW > 0) ? fM/fW : 0; }
59  inline Double_t GetMeanErr() const { return (fW > 0.) ? TMath::Sqrt( GetVar()/ GetNeff() ) : 0; }
60  inline Double_t GetRMS() const { double var = GetVar(); return (var>0) ? TMath::Sqrt(var) : -1; }
61  inline Double_t GetVar() const { return (fW>0) ? ( (fN>1) ? (fM2 / fW)*(fN / (fN-1.)) : 0 ) : -1; }
62  inline Double_t GetW() const { return fW; }
63  inline Double_t GetW2() const { return fW2; }
64 
65  // Merging
66  Int_t Merge(TCollection *in);
67 
68  // Fill
69  void Fill(Double_t val, Double_t w = 1.);
70 
71  // Print
72  void Print(Option_t * = "") const;
73  void ls(Option_t *opt = "") const { Print(opt); }
74 
75  ClassDef(TStatistic,2) //Named statistical variable
76 };
77 
78 #endif
const char * GetName() const
Returns name of object.
Definition: TStatistic.h:52
Double_t GetRMS() const
Definition: TStatistic.h:60
Double_t GetMean() const
Definition: TStatistic.h:58
Double_t GetMeanErr() const
Definition: TStatistic.h:59
long long Long64_t
Definition: RtypesCore.h:69
Double_t fM2
Definition: TStatistic.h:43
const char Option_t
Definition: RtypesCore.h:62
Double_t fM
Definition: TStatistic.h:42
ULong_t Hash() const
Return hash value for this object.
Definition: TStatistic.h:53
Double_t GetW() const
Definition: TStatistic.h:62
Basic string class.
Definition: TString.h:129
int Int_t
Definition: RtypesCore.h:41
void Print(Option_t *="") const
This method must be overridden when a class wants to print itself.
Definition: TStatistic.cxx:76
UInt_t Hash(ECaseCompare cmp=kExact) const
Return hash value.
Definition: TString.cxx:616
Double_t fW
Definition: TStatistic.h:40
TStatistic(const char *name="")
Definition: TStatistic.h:47
#define ClassDef(name, id)
Definition: Rtypes.h:297
TString fName
Definition: TStatistic.h:38
Statistical variable, defined by its mean and variance (RMS).
Definition: TStatistic.h:35
Long64_t fN
Definition: TStatistic.h:39
Double_t GetM2() const
Definition: TStatistic.h:57
Collection abstract base class.
Definition: TCollection.h:42
Long64_t GetNeff() const
Definition: TStatistic.h:56
double Double_t
Definition: RtypesCore.h:55
Double_t fW2
Definition: TStatistic.h:41
unsigned long ULong_t
Definition: RtypesCore.h:51
void ls(Option_t *opt="") const
The ls function lists the contents of a class on stdout.
Definition: TStatistic.h:73
void Fill(Double_t val, Double_t w=1.)
Definition: TStatistic.cxx:48
Double_t GetW2() const
Definition: TStatistic.h:63
Mother of all ROOT objects.
Definition: TObject.h:37
Double_t GetVar() const
Definition: TStatistic.h:61
Int_t Merge(TCollection *in)
Definition: TStatistic.cxx:85
Double_t Sqrt(Double_t x)
Definition: TMath.h:591
Long64_t GetN() const
Definition: TStatistic.h:55
const Int_t n
Definition: legend1.C:16