library: libRooFit #include "RooHistError.h"

# RooHistError

class description - source file - inheritance tree (.pdf)

## class RooHistError

| Inheritance Chart:
`RooHistError` |

        private:

                       RooHistError()
                Bool_t getPoissonIntervalCalc(Int_t n, Double_t& mu1, Double_t& mu2, Double_t nSigma = 1) const
              Double_t seek(const RooAbsFunc& f, Double_t startAt, Double_t step, Double_t value) const

        public:

                                     RooHistError(const RooHistError&)
                             virtual ~RooHistError()
                      static TClass* Class()
                  static RooAbsFunc* createBinomialSum(Int_t n, Int_t m)
                  static RooAbsFunc* createPoissonSum(Int_t n)
                              Bool_t getBinomialInterval(Int_t n, Int_t m, Double_t& a1, Double_t& a2, Double_t nSigma = 1) const
                              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
                              Bool_t getPoissonInterval(Int_t n, Double_t& mu1, Double_t& mu2, Double_t nSigma = 1) const
          static const RooHistError& instance() const
                     virtual TClass* IsA() const
                       RooHistError& operator=(const RooHistError&)
                        virtual void ShowMembers(TMemberInspector& insp, char* parent)
                        virtual void Streamer(TBuffer& b)
                                void StreamerNVirtual(TBuffer& b)

### Data Members

        private:

          Double_t _poissonLoLUT[1000]
          Double_t _poissonHiLUT[1000]

## Class Description

const RooHistError& instance()

     Return a reference to a singleton object that is created the
     first time this method is called. Only one object will be
     constructed per ROOT session.

RooHistError()

     Construct our singleton object.

Bool_t getPoissonInterval(Int_t n, Double_t &mu1, Double_t &mu2, Double_t nSigma) const

     Use lookup table for most common cases

Bool_t getPoissonIntervalCalc(Int_t n, Double_t &mu1, Double_t &mu2, Double_t nSigma) const

     Calculate a confidence interval for the expected number of events given n
     observed (unweighted) events. The interval will contain the same probability
     as nSigma of a Gaussian. Uses a central interval unless this does not enclose
     the point estimate n (ie, for small n) in which case the interval is adjusted
     to start at n.

Bool_t getBinomialInterval(Int_t n, Int_t m, Double_t &asym1, Double_t &asym2, Double_t nSigma) const

     sanity checks

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 cummulative functions provided.
     The interval will be "central" when both cummulative functions are provided,
     unless this would exclude the pointEstimate, in which case a one-sided interval
     pinned at the point estimate is returned instead.

Double_t seek(const RooAbsFunc &f, Double_t startAt, Double_t step, Double_t value) const

     Scan f(x)-value until it changes sign. Start at the specified point and take constant
     steps of the specified size. Give up after 1000 steps.

### Inline Functions

                     void ~RooHistError()
              RooAbsFunc* createPoissonSum(Int_t n)
              RooAbsFunc* createBinomialSum(Int_t n, Int_t m)
                  TClass* Class()
                  TClass* IsA() const
                     void ShowMembers(TMemberInspector& insp, char* parent)
                     void Streamer(TBuffer& b)
                     void StreamerNVirtual(TBuffer& b)
             RooHistError RooHistError(const RooHistError&)
            RooHistError& operator=(const RooHistError&)

Last update: Tue Jun 28 18:13:06 2005
Copyright (c) 2000-2005, Regents of the University of California *