class RooHistError



RooHistError is a singleton class used to calculate the error bars for each bin of a RooHist object. Errors are calculated by integrating a specified area of a Poisson or Binomail error distribution.

Function Members (Methods)

public:
RooHistError(const RooHistError&)
virtual~RooHistError()
static TClass*Class()
static RooAbsFunc*createBinomialSum(Int_t n, Int_t m, Bool_t eff)
static RooAbsFunc*createPoissonSum(Int_t n)
Bool_tgetBinomialIntervalAsym(Int_t n, Int_t m, Double_t& a1, Double_t& a2, Double_t nSigma = 1) const
Bool_tgetBinomialIntervalEff(Int_t n, Int_t m, Double_t& a1, Double_t& a2, Double_t nSigma = 1) const
Bool_tgetInterval(const RooAbsFunc* Qu, const RooAbsFunc* Ql, Double_t pointEstimate, Double_t stepSize, Double_t& lo, Double_t& hi, Double_t nSigma) const
Bool_tgetPoissonInterval(Int_t n, Double_t& mu1, Double_t& mu2, Double_t nSigma = 1) const
static const RooHistError&instance()
virtual TClass*IsA() const
RooHistError&operator=(const RooHistError&)
virtual voidShowMembers(TMemberInspector& insp, char* parent)
virtual voidStreamer(TBuffer& b)
voidStreamerNVirtual(TBuffer& b)
private:
RooHistError()
Bool_tgetPoissonIntervalCalc(Int_t n, Double_t& mu1, Double_t& mu2, Double_t nSigma = 1) const
Double_tseek(const RooAbsFunc& f, Double_t startAt, Double_t step, Double_t value) const

Data Members

private:
Double_t_poissonHiLUT[1000]
Double_t_poissonLoLUT[1000]

Class Charts

Inheritance Inherited Members Includes Libraries
Class Charts

Function documentation

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(const RooHistError& )
 Construct our singleton 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. 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. This method uses a lookup table to return precalculated results
 for n<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) 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 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). The result is return in asym1 and asym2.
 If the return values is kFALSE and error occurred.
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). The result is return in asym1 and asym2.
 If the return values is kFALSE and error occurred.
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.
 The interval will be "central" when both cumulative 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.
RooAbsFunc * createPoissonSum(Int_t n)
 Create and return a PoissonSum function binding
RooAbsFunc * createBinomialSum(Int_t n, Int_t m, Bool_t eff)
 Create and return a BinomialSum function binding
virtual ~RooHistError()
{}
RooHistError(const RooHistError& )

Last change: Mon Aug 25 11:36:33 2008
Last generated: 2008-08-25 11:36
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