GammaLib

#ifndef FLUX_SPECTRUMSTATS_HH

#define FLUX_SPECTRUMSTATS_HH

#include "SpectrumConstants.hh"

namespace Flux {

  /**

   * \brief Container for counts and exposure information in an energy / time bin.

   *

   * \author Heidelberg team

   *

   * \todo SpectrumStats should be a subclass of Tools::EventStats,

   * instead of copy & pasting code.

   * There is some subtle error handling in methods like SignificanceUnchecked

   * or Excess and copying will eventually lead to different behavior of

   * calling this method on a SpectrumStats and an EventStats, which is bad.

   *

   */

  class SpectrumStats {

  public: 

    SpectrumStats();

    inline virtual ~SpectrumStats() {}

    virtual void Clear();

    virtual double GetField(std::string field) const;

    virtual void SetField(std::string field, double value);

    bool Compare(const SpectrumStats& rhs) const;

    bool operator==(const SpectrumStats& rhs) const;

    bool operator!=(const SpectrumStats& rhs) const;

    void Add(const SpectrumStats& rhs);

    SpectrumStats& operator+=(const SpectrumStats& rhs);

    SpectrumStats operator+(const SpectrumStats& rhs) const;

    double Alpha() const;

    double AlphaUnchecked() const;

    double Significance() const; 

    double SignificanceUnchecked() const;

    double Excess() const;

    double ExcessError() const;

    double ExcessErrorUp() const;

    double ExcessErrorDown() const;

    double FracError() const;

    double FracErrorUp() const;

    double FracErrorDown() const;

    double ExcessSensitivity(double cl=DEFAULT_CL) const;

    void ExcessLimits(double& excess_down, double& excess_up, double cl=DEFAULT_CL) const;

    void ZeroExcessLimits(double& excess_down, double& excess_up, double cl=DEFAULT_CL) const;

    double Background() const;

    void SetPrintPrefix(std::string prefix){ fPrintPrefix = prefix; }

    virtual void print(std::ostream& os) const;

  public:

    // Counts

    int     nOn;                ///< On region event count

    int     nOff;                ///< Off region event count

    // Relative background exposure

    double  exposureOn;                ///< On region hadron exposure

    double  exposureOff;        ///< Off region hadron exposure

    // Gamma exposure

    double trueAreaTimeOn;        ///< On region gamma true exposure

    double trueAreaTimeOff;        ///< Off region gamma true exposure

    double recoAreaTimeOn;        ///< On region gamma reco exposure

    double recoAreaTimeOff;        ///< Off region gamma reco exposure

    // For EventWeighted flux point computation

    double liveTime;            ///< Livetime

    double offLiveTime;         ///< offLiveTime

    // The following two numbers are sums of inverse effective

    // areas of events collected in the given livetime.

    double invRecoAreaOn;        ///< On region Sum(1/A_i)

    double invRecoAreaOff;        ///< Off region Sum(1/A_i)

  protected:

    mutable std::string fPrintPrefix; //! not streamed, just for pretty printing

  private:

    ClassDef(Flux::SpectrumStats,2)

  };

}

std::ostream& operator<<( std::ostream& stream, const Flux::SpectrumStats&);

#endif