ROOT   Reference Guide
RatioOfProfiledLikelihoodsTestStat.cxx
Go to the documentation of this file.
1// @(#)root/roostats:$Id$
2// Author: Kyle Cranmer, Lorenzo Moneta, Gregory Schott, Wouter Verkerke
3/*************************************************************************
6 * *
7 * For the licensing terms see $ROOTSYS/LICENSE. * 8 * For the list of contributors see$ROOTSYS/README/CREDITS. *
9 *************************************************************************/
10
11/** \class RooStats::RatioOfProfiledLikelihoodsTestStat
12 \ingroup Roostats
13
14TestStatistic that returns the ratio of profiled likelihoods.
15
16By default the calculation is:
17
18\f[
19 \log{ \frac{ \lambda(\mu_{alt} , {conditional \: MLE \: for \: alt \: nuisance}) }
20 { \lambda(\mu_{null} , {conditional \: MLE \: for \: null \: nuisance}) } }
21\f]
22
23where \f$\lambda \f$ is the profile likelihood ratio, so the
24MLE for the null and alternate are subtracted off.
25
26If SetSubtractMLE(false) then it calculates:
27
28\f[
29 \log{ \frac{ L(\mu_{alt} , {conditional \: MLE \: for \: alt \: nuisance}) }
30 { L(\mu_{null} , {conditional \: MLE \: for \: null \: nuisance}) } }
31\f]
32
33where \f$L \f$ is the Likelihood function.
34
35The values of the parameters of interest for the alternative
36hypothesis are taken at the time of the construction.
37If empty, it treats all free parameters as nuisance parameters.
38
39The value of the parameters of interest for the null hypotheses
40are given at each call of Evaluate.
41
42This test statistic is often called the Tevatron test statistic, because it has
43been used by the Tevatron experiments.
44*/
45
46
47
49
50#include "RooArgSet.h"
51#include "RooAbsData.h"
52#include "TMath.h"
53#include "RooMsgService.h"
54#include "RooGlobalFunc.h"
55
56
58
60
61////////////////////////////////////////////////////////////////////////////////
62/// returns -logL(poi, conditional MLE of nuisance params)
63/// subtract off the global MLE or not depending on the option
64/// It is the numerator or the denominator of the ratio (depending on the pdf)
65///
66/// L.M. : not sure why this method is needed now
67
69 int type = (fSubtractMLE) ? 0 : 2;
70
71 // null
72 if ( &pdf == fNullProfile.GetPdf() )
73 return fNullProfile.EvaluateProfileLikelihood(type, data, poi);
74 else if (&pdf == fAltProfile.GetPdf() )
75 return fAltProfile.EvaluateProfileLikelihood(type, data, poi);
76
77 oocoutE(nullptr,InputArguments) << "RatioOfProfiledLikelihoods::ProfileLikelihood - invalid pdf used for computing the profiled likelihood - return NaN"
78 << std::endl;
79
80 return TMath::QuietNaN();
81
82}
83
84////////////////////////////////////////////////////////////////////////////////
85/// evaluate the ratio of profile likelihood
86
88
89 int type = (fSubtractMLE) ? 0 : 2;
90
91 // null
92 double nullNLL = fNullProfile.EvaluateProfileLikelihood(type, data, nullParamsOfInterest);
93 const RooArgSet *nullset = fNullProfile.GetDetailedOutput();
94
95 // alt
96 double altNLL = fAltProfile.EvaluateProfileLikelihood(type, data, *fAltPOI);
97 const RooArgSet *altset = fAltProfile.GetDetailedOutput();
98
99 if (fDetailedOutput != nullptr) {
100 delete fDetailedOutput;
101 fDetailedOutput = nullptr;
102 }
103 if (fDetailedOutputEnabled) {
104 fDetailedOutput = new RooArgSet();
105 for (auto const *var : static_range_cast<RooRealVar *>(*nullset)) {
106 RooRealVar* cloneVar = new RooRealVar(TString::Format("nullprof_%s", var->GetName()),
107 TString::Format("%s for null", var->GetTitle()), var->getVal());
109 }
110 for (auto const *var : static_range_cast<RooRealVar *>(*altset)) {
111 RooRealVar* cloneVar = new RooRealVar(TString::Format("altprof_%s", var->GetName()),
112 TString::Format("%s for null", var->GetTitle()), var->getVal());
114 }
115 }
116
117/*
118// set variables back to where they were
119nullParamsOfInterest = *saveNullPOI;
120*allVars = *saveAll;
121delete saveAll;
122delete allVars;
123*/
124
125 return nullNLL -altNLL;
126}
#define oocoutE(o, a)
Definition: RooMsgService.h:52
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void data
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t Float_t Float_t Int_t Int_t UInt_t UInt_t Rectangle_t Int_t Int_t Window_t TString Int_t GCValues_t GetPrimarySelectionOwner GetDisplay GetScreen GetColormap GetNativeEvent const char const char dpyName wid window const char font_name cursor keysym reg const char only_if_exist regb h Point_t winding char text const char depth char const char Int_t count const char ColorStruct_t color const char Pixmap_t Pixmap_t PictureAttributes_t attr const char char ret_data h unsigned char height h Atom_t Int_t ULong_t ULong_t unsigned char prop_list Atom_t Atom_t Atom_t Time_t type
RooAbsData is the common abstract base class for binned and unbinned datasets.
Definition: RooAbsData.h:61
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgSet.h:56
RooRealVar represents a variable that can be changed from the outside.
Definition: RooRealVar.h:40
double Evaluate(RooAbsData &data, RooArgSet &nullParamsOfInterest) override
evaluate the ratio of profile likelihood
double ProfiledLikelihood(RooAbsData &data, RooArgSet &poi, RooAbsPdf &pdf)
returns -logL(poi, conditional MLE of nuisance params) it does not subtract off the global MLE becaus...
static TString Format(const char *fmt,...)
Static method which formats a string using a printf style format descriptor and return a TString.
Definition: TString.cxx:2357
@ InputArguments
Definition: RooGlobalFunc.h:63
Double_t QuietNaN()
Returns a quiet NaN as defined by IEEE 754.
Definition: TMath.h:900