Logo ROOT  
Reference Guide
Go to the documentation of this file.
1// @(#)root/roostats:$Id$
2// Author: Kyle Cranmer, Lorenzo Moneta, Gregory Schott, Wouter Verkerke
4 * Copyright (C) 1995-2008, Rene Brun and Fons Rademakers. *
5 * All rights reserved. *
6 * *
7 * For the licensing terms see $ROOTSYS/LICENSE. *
8 * For the list of contributors see $ROOTSYS/README/CREDITS. *
9 *************************************************************************/
11#ifndef ROOSTATS_BayesianCalculator
12#define ROOSTATS_BayesianCalculator
14#include "TNamed.h"
16#include "Math/IFunctionfwd.h"
18#include "RooArgSet.h"
24class RooAbsData;
25class RooAbsPdf;
26class RooPlot;
27class RooAbsReal;
28class TF1;
29class TH1;
32namespace RooStats {
34 class ModelConfig;
35 class SimpleInterval;
39 public:
41 // constructor
45 RooAbsPdf& pdf,
46 const RooArgSet& POI,
47 RooAbsPdf& priorPdf,
48 const RooArgSet* nuisanceParameters = 0 );
53 // destructor
54 virtual ~BayesianCalculator();
56 // get the plot with option to get it normalized
57 RooPlot* GetPosteriorPlot(bool norm = false, double precision = 0.01) const;
59 // return posterior pdf (object is managed by the user)
61 // return posterior function (object is managed by the BayesianCalculator class)
64 // return the approximate posterior as histogram (TH1 object). Note the object is managed by the BayesianCalculator class
65 TH1 * GetPosteriorHistogram() const;
67 // compute the interval. By Default a central interval is computed
68 // By using SetLeftTileFraction can control if central/ upper/lower interval
69 // For shortest interval use SetShortestInterval(true)
70 virtual SimpleInterval* GetInterval() const ;
72 virtual void SetData( RooAbsData & data ) {
73 fData = &data;
74 ClearAll();
75 }
78 // set the model via the ModelConfig
79 virtual void SetModel( const ModelConfig& model );
81 // specify the parameters of interest in the interval
82 virtual void SetParameters(const RooArgSet& set) { fPOI.removeAll(); fPOI.add(set); }
84 // specify the nuisance parameters (eg. the rest of the parameters)
87 // Set only the Prior Pdf
88 virtual void SetPriorPdf(RooAbsPdf& pdf) { fPriorPdf = &pdf; }
90 // set the conditional observables which will be used when creating the NLL
91 // so the pdf's will not be normalized on the conditional observables when computing the NLL
94 // set the global observables which will be used when creating the NLL
95 // so the constraint pdf's will be normalized correctly on the global observables when computing the NLL
98 // set the size of the test (rate of Type I error) ( Eg. 0.05 for a 95% Confidence Interval)
99 virtual void SetTestSize( Double_t size ) {
100 fSize = size;
101 fValidInterval = false;
102 }
103 // set the confidence level for the interval (eg. 0.95 for a 95% Confidence Interval)
104 virtual void SetConfidenceLevel( Double_t cl ) { SetTestSize(1.-cl); }
105 // Get the size of the test (eg. rate of Type I error)
106 virtual Double_t Size() const { return fSize; }
107 // Get the Confidence level for the test
108 virtual Double_t ConfidenceLevel() const { return 1.-fSize; }
110 // set the fraction of probability content on the left tail
111 // Central limits use 0.5 (default case)
112 // for upper limits it is 0 and 1 for lower limit
113 // For shortest intervals a negative value (i.e. -1) must be given
114 void SetLeftSideTailFraction(Double_t leftSideFraction ) {fLeftSideFraction = leftSideFraction;}
116 // set the Bayesian calculator to compute the shortest interval (default is central interval)
117 // to switch off SetLeftSideTailFraction to the right value
120 // set the precision of the Root Finder
121 void SetBrfPrecision( double precision ) { fBrfPrecision = precision; }
123 // use directly the approximate posterior function obtained by binning it in nbins
124 // by default the cdf is used by integrating the posterior
125 // if a value of nbin <= 0 the cdf function will be used
126 void SetScanOfPosterior(int nbin = 100) { fNScanBins = nbin; }
128 // set the number of iterations when running a MC integration algorithm
129 // If not set use default algorithmic values
130 // In case of ToyMC sampling of the nuisance the value is 100
131 // In case of using the GSL MCintegrations types the default value is
132 // defined in ROOT::Math::IntegratorMultiDimOptions::DefaultNCalls()
133 virtual void SetNumIters(Int_t numIters) { fNumIterations = numIters; }
135 // set the integration type (possible type are) :
136 void SetIntegrationType(const char * type);
138 // return the mode (most probable value of the posterior function)
139 double GetMode() const;
141 // force the nuisance pdf when using the toy mc sampling
144 protected:
146 void ClearAll() const;
148 void ApproximatePosterior() const;
150 void ComputeIntervalFromApproxPosterior(double c1, double c2) const;
152 void ComputeIntervalFromCdf(double c1, double c2) const;
154 void ComputeIntervalUsingRooFit(double c1, double c2) const;
156 void ComputeShortestInterval() const;
158 private:
160 // plan to replace the above: return a SimpleInterval integrating
161 // over all other parameters except the one specified as argument
162 // virtual SimpleInterval* GetInterval( RooRealVar* parameter ) const { return 0; }
164 RooAbsData* fData; // data set
165 RooAbsPdf* fPdf; // model pdf (could contain the nuisance pdf as constraint term)
167 RooAbsPdf* fPriorPdf; // prior pdf (typically for the POI)
168 RooAbsPdf* fNuisancePdf; // nuisance pdf (needed when using nuisance sampling technique)
169 RooArgSet fNuisanceParameters; // nuisance parameters
170 RooArgSet fConditionalObs ; // conditional observables
171 RooArgSet fGlobalObs; // global observables
173 mutable RooAbsPdf* fProductPdf; // internal pointer to model * prior
174 mutable RooAbsReal* fLogLike; // internal pointer to log likelihood function
175 mutable RooAbsReal* fLikelihood; // internal pointer to likelihood function
176 mutable RooAbsReal* fIntegratedLikelihood; // integrated likelihood function, i.e - unnormalized posterior function
177 mutable RooAbsPdf* fPosteriorPdf; // normalized (on the poi) posterior pdf
178 mutable ROOT::Math::IGenFunction * fPosteriorFunction; // function representing the posterior
179 mutable TF1 * fApproxPosterior; // TF1 representing the scanned posterior function
180 mutable Double_t fLower; // computer lower interval bound
181 mutable Double_t fUpper; // upper interval bound
182 mutable Double_t fNLLMin; // minimum value of Nll
183 double fSize; // size used for getting the interval
184 double fLeftSideFraction; // fraction of probability content on left side of interval
185 double fBrfPrecision; // root finder precision
186 mutable int fNScanBins; // number of bins to scan, if = -1 no scan is done (default)
187 int fNumIterations; // number of iterations (when using ToyMC)
192 protected:
194 ClassDef(BayesianCalculator,2) // BayesianCalculator class
196 };
int Int_t
Definition: RtypesCore.h:43
bool Bool_t
Definition: RtypesCore.h:61
double Double_t
Definition: RtypesCore.h:57
#define ClassDef(name, id)
Definition: Rtypes.h:322
int type
Definition: TGX11.cxx:120
Interface (abstract class) for generic functions objects of one-dimension Provides a method to evalua...
Definition: IFunction.h:135
virtual void removeAll()
Remove all arguments from our set, deleting them if we own them.
RooAbsData is the common abstract base class for binned and unbinned datasets.
Definition: RooAbsData.h:44
RooAbsReal is the common abstract base class for objects that represent a real value and implements f...
Definition: RooAbsReal.h:60
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgSet.h:28
virtual Bool_t add(const RooAbsCollection &col, Bool_t silent=kFALSE)
Add a collection of arguments to this collection by calling add() for each element in the source coll...
Definition: RooArgSet.h:88
A RooPlot is a plot frame and a container for graphics objects within that frame.
Definition: RooPlot.h:44
BayesianCalculator is a concrete implementation of IntervalCalculator, providing the computation of a...
void SetBrfPrecision(double precision)
void ForceNuisancePdf(RooAbsPdf &pdf)
ROOT::Math::IGenFunction * fPosteriorFunction
virtual void SetConditionalObservables(const RooArgSet &set)
virtual void SetData(RooAbsData &data)
Set the DataSet ( add to the the workspace if not already there ?)
RooAbsPdf * GetPosteriorPdf() const
Build and return the posterior pdf (i.e posterior function normalized to all range of poi) Note that ...
virtual SimpleInterval * GetInterval() const
Compute the interval.
RooPlot * GetPosteriorPlot(bool norm=false, double precision=0.01) const
return a RooPlot with the posterior and the credibility region NOTE: User takes ownership of the retu...
void ClearAll() const
clear all cached pdf objects
virtual Double_t ConfidenceLevel() const
Get the Confidence level for the test.
void SetScanOfPosterior(int nbin=100)
void ComputeShortestInterval() const
compute the shortest interval from the histogram representing the posterior
virtual Double_t Size() const
Get the size of the test (eg. rate of Type I error)
virtual void SetTestSize(Double_t size)
set the size of the test (rate of Type I error) ( e.g. 0.05 for a 95% Confidence Interval)
void ApproximatePosterior() const
approximate posterior in nbins using a TF1 scan the poi values and evaluate the posterior at each poi...
virtual void SetModel(const ModelConfig &model)
set the model to use The model pdf, prior pdf, parameter of interest and nuisances will be taken acco...
virtual void SetConfidenceLevel(Double_t cl)
set the confidence level for the interval (e.g. 0.95 for a 95% Confidence Interval)
virtual void SetNuisanceParameters(const RooArgSet &set)
double GetMode() const
Returns the value of the parameter for the point in parameter-space that is the most likely.
virtual void SetGlobalObservables(const RooArgSet &set)
virtual void SetNumIters(Int_t numIters)
virtual void SetPriorPdf(RooAbsPdf &pdf)
RooAbsReal * GetPosteriorFunction() const
Build and return the posterior function (not normalized) as a RooAbsReal the posterior is obtained fr...
virtual void SetParameters(const RooArgSet &set)
void SetIntegrationType(const char *type)
set the integration type (possible type are) :
TH1 * GetPosteriorHistogram() const
When am approximate posterior is computed binninig the parameter of interest (poi) range (see SetScan...
void SetLeftSideTailFraction(Double_t leftSideFraction)
void ComputeIntervalFromApproxPosterior(double c1, double c2) const
compute the interval using the approximate posterior function
default constructor
void ComputeIntervalUsingRooFit(double c1, double c2) const
internal function compute the interval using RooFit
void ComputeIntervalFromCdf(double c1, double c2) const
internal function compute the interval using Cdf integration
IntervalCalculator is an interface class for a tools which produce RooStats ConfIntervals.
ModelConfig is a simple class that holds configuration information specifying how a model should be u...
Definition: ModelConfig.h:30
SimpleInterval is a concrete implementation of the ConfInterval interface.
1-Dim function class
Definition: TF1.h:210
The TH1 histogram class.
Definition: TH1.h:56
The TNamed class is the base class for all named ROOT classes.
Definition: TNamed.h:29
Basic string class.
Definition: TString.h:131
return c1
Definition: legend1.C:41
return c2
Definition: legend2.C:14
Namespace for the RooStats classes.
Definition: Asimov.h:19