GammaLib

The GCTAMeanPsf class should implement the mean PSF in form of a histogram as function of Right Ascension or Galactic longitude, Declination or Galactic latitude and log10 energy (4D cube). The class may use the GSkymap class as storage container for the information. Log10 energy and offset angle can be implemented as nested array of the 3rd GSkymap dimension.

The mean PSF is an exposure weighted average of the PSF. The typical interface should look like this:

    // Constructors and destructors
    GCTAMeanPsf(void);
    GCTAMeanPsf(const GCTAMeanPsf& psf);
    GCTAMeanPsf(const GObservations& obs, const GSkymap& map, const double& min, const double& max, const int& nbins);
    virtual ~GCTAMeanPsf(void);

    // Operators
    GCTAMeanPsf& operator=(const GCTAMeanPsf& psf);

    // Methods
    void         clear(void);
    GCTAMeanPsf* clone(void) const;
    void         load(const std::string& filename);
    void         save(const std::string& filename);
    std::string  print(const GChatter& chatter = NORMAL) const;

protected:
    // Methods
    void init_members(void);
    void copy_members(const GCTAMeanPsf& psf);
    void free_members(void);

    // Data
    GSkymap m_cube; //!< Average PSF cube

The number of maps in a GSkymap object is nebin*nbins, idelta + ie * nbins can then be the access formula.