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RooHistError.h
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1/*****************************************************************************
2 * Project: RooFit *
3 * Package: RooFitCore *
4 * File: $Id: RooHistError.h,v 1.14 2007/05/11 09:11:30 verkerke Exp $
5 * Authors: *
6 * WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu *
7 * DK, David Kirkby, UC Irvine, dkirkby@uci.edu *
8 * *
9 * Copyright (c) 2000-2005, Regents of the University of California *
10 * and Stanford University. All rights reserved. *
11 * *
12 * Redistribution and use in source and binary forms, *
13 * with or without modification, are permitted according to the terms *
14 * listed in LICENSE (http://roofit.sourceforge.net/license.txt) *
15 *****************************************************************************/
16#ifndef ROO_HIST_ERROR
17#define ROO_HIST_ERROR
18
19#include "Rtypes.h"
20#include "RooNumber.h"
21#include "RooAbsFunc.h"
22#include <cmath>
23#include <iostream>
24
26public:
27 static const RooHistError &instance();
28 virtual ~RooHistError() {} ;
29
30 Bool_t getPoissonInterval(Int_t n, Double_t &mu1, Double_t &mu2, Double_t nSigma= 1) const;
33 Bool_t getInterval(const RooAbsFunc *Qu, const RooAbsFunc *Ql, Double_t pointEstimate, Double_t stepSize,
34 Double_t &lo, Double_t &hi, Double_t nSigma) const;
35
38
39private:
40
41
42 Bool_t getPoissonIntervalCalc(Int_t n, Double_t &mu1, Double_t &mu2, Double_t nSigma= 1) const;
45
47 Double_t seek(const RooAbsFunc &f, Double_t startAt, Double_t step, Double_t value) const;
48
49 // -----------------------------------------------------------
50 // Define a 1-dim RooAbsFunc of mu that evaluates the sum:
51 //
52 // Q(n|mu) = Sum_{k=0}^{n} P(k|mu)
53 //
54 // where P(n|mu) = exp(-mu) mu**n / n! is the Poisson PDF.
55 // -----------------------------------------------------------
56 class PoissonSum : public RooAbsFunc {
57 public:
58 inline PoissonSum(Int_t n) : RooAbsFunc(1), _n(n) { }
59 inline Double_t operator()(const Double_t xvec[]) const {
60 Double_t mu(xvec[0]),result(1),factorial(1);
61 for(Int_t k= 1; k <= _n; k++) {
62 factorial*= k;
63 result+= pow(mu,k)/factorial;
64 }
65 return exp(-mu)*result;
66 };
67 inline Double_t getMinLimit(UInt_t /*index*/) const { return 0; }
68 inline Double_t getMaxLimit(UInt_t /*index*/) const { return RooNumber::infinity() ; }
69 private:
71 };
72
73 // -----------------------------------------------------------
74 // Define a 1-dim RooAbsFunc of a that evaluates the sum:
75 //
76 // Q(n|n+m,a) = Sum_{k=0}^{n} B(k|n+m,a)
77 //
78 // where B(n|n+m,a) = (n+m)!/(n!m!) ((1+a)/2)**n ((1-a)/2)**m
79 // is the Binomial PDF.
80 // -----------------------------------------------------------
81 class BinomialSumAsym : public RooAbsFunc {
82 public:
84 }
85 inline Double_t operator()(const Double_t xvec[]) const
86 {
87 Double_t p1(0.5*(1+xvec[0])),p2(1-p1),result(0),fact1(1),fact2(1);
88 for(Int_t k= 0; k <= _n1; k++) {
89 if(k > 0) { fact2*= k; fact1*= _N1-k+1; }
90 result+= fact1/fact2*pow(p1,k)*pow(p2,_N1-k);
91 }
92 return result;
93 };
94
95 inline Double_t getMinLimit(UInt_t /*index*/) const { return -1; }
96 inline Double_t getMaxLimit(UInt_t /*index*/) const { return +1; }
97
98 private:
99 Int_t _n1 ; // WVE Solaris CC5 doesn't want _n or _N here (likely compiler bug)
101 } ;
102
103
104 // -----------------------------------------------------------
105 // Define a 1-dim RooAbsFunc of a that evaluates the sum:
106 //
107 // Q(n|n+m,a) = Sum_{k=0}^{n} B(k|n+m,a)
108 //
109 // where B(n|n+m,a) = (n+m)!/(n!m!) ((1+a)/2)**n ((1-a)/2)**m
110 // is the Binomial PDF.
111 // -----------------------------------------------------------
112 class BinomialSumEff : public RooAbsFunc {
113 public:
115 }
116 inline Double_t operator()(const Double_t xvec[]) const
117 {
118 Double_t p1(xvec[0]),p2(1-p1),result(0),fact1(1),fact2(1);
119 for(Int_t k= 0; k <= _n1; k++) {
120 if(k > 0) { fact2*= k; fact1*= _N1-k+1; }
121 result+= fact1/fact2*pow(p1,k)*pow(p2,_N1-k);
122 }
123 return result;
124 };
125
126 inline Double_t getMinLimit(UInt_t /*index*/) const { return 0; }
127 inline Double_t getMaxLimit(UInt_t /*index*/) const { return +1; }
128
129 private:
130 Int_t _n1 ; // WVE Solaris CC5 doesn't want _n or _N here (likely compiler bug)
132 } ;
133
134 ClassDef(RooHistError,1) // Utility class for calculating histogram errors
135};
136
137#endif
#define f(i)
Definition RSha256.hxx:104
int Int_t
Definition RtypesCore.h:45
bool Bool_t
Definition RtypesCore.h:63
double Double_t
Definition RtypesCore.h:59
#define ClassDef(name, id)
Definition Rtypes.h:325
#define hi
double pow(double, double)
double exp(double)
Abstract interface for evaluating a real-valued function of one real variable and performing numerica...
Definition RooAbsFunc.h:27
Double_t getMaxLimit(UInt_t) const
Double_t getMinLimit(UInt_t) const
Double_t operator()(const Double_t xvec[]) const
BinomialSumAsym(Int_t n, Int_t m)
BinomialSumEff(Int_t n, Int_t m)
Double_t getMaxLimit(UInt_t) const
Double_t getMinLimit(UInt_t) const
Double_t operator()(const Double_t xvec[]) const
Double_t getMinLimit(UInt_t) const
Double_t getMaxLimit(UInt_t) const
Double_t operator()(const Double_t xvec[]) const
RooHistError is a singleton class used to calculate the error bars for each bin of a RooHist object.
Bool_t getPoissonInterval(Int_t n, Double_t &mu1, Double_t &mu2, Double_t nSigma=1) const
Return a confidence interval for the expected number of events given n observed (unweighted) events.
Bool_t getBinomialIntervalEff(Int_t n, Int_t m, Double_t &a1, Double_t &a2, Double_t nSigma=1) const
Return 'nSigma' binomial confidence interval for (n,m).
static const RooHistError & instance()
Return a reference to a singleton object that is created the first time this method is called.
virtual ~RooHistError()
static RooAbsFunc * createBinomialSum(Int_t n, Int_t m, Bool_t eff)
Create and return a BinomialSum function binding.
Bool_t getBinomialIntervalAsym(Int_t n, Int_t m, Double_t &a1, Double_t &a2, Double_t nSigma=1) const
Return 'nSigma' binomial confidence interval for (n,m).
Double_t _poissonLoLUT[1000]
Double_t seek(const RooAbsFunc &f, Double_t startAt, Double_t step, Double_t value) const
Scan f(x)-value until it changes sign.
static RooAbsFunc * createPoissonSum(Int_t n)
Create and return a PoissonSum function binding.
Bool_t getInterval(const RooAbsFunc *Qu, const RooAbsFunc *Ql, Double_t pointEstimate, Double_t stepSize, Double_t &lo, Double_t &hi, Double_t nSigma) const
Calculate a confidence interval using the cumulative functions provided.
RooHistError()
Construct our singleton object.
Double_t _poissonHiLUT[1000]
Bool_t getPoissonIntervalCalc(Int_t n, Double_t &mu1, Double_t &mu2, Double_t nSigma=1) const
Calculate a confidence interval for the expected number of events given n observed (unweighted) event...
static Double_t infinity()
Return internal infinity representation.
Definition RooNumber.cxx:49
const Int_t n
Definition legend1.C:16
auto * m
Definition textangle.C:8