GammaLib

/***************************************************************************

 *        GOnOffFitterSpectrum.hpp - ON-OFF spectral analysis class        *

 * ----------------------------------------------------------------------- *

 *  copyright (C) 2009-2013 by Juergen Knoedlseder                         *

 * ----------------------------------------------------------------------- *

 *                                                                         *

 *  This program is free software: you can redistribute it and/or modify   *

 *  it under the terms of the GNU General Public License as published by   *

 *  the Free Software Foundation, either version 3 of the License, or      *

 *  (at your option) any later version.                                    *

 *                                                                         *

 *  This program is distributed in the hope that it will be useful,        *

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of         *

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *

 *  GNU General Public License for more details.                           *

 *                                                                         *

 *  You should have received a copy of the GNU General Public License      *

 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.  *

 *                                                                         *

 ***************************************************************************/

/**

 * @file GOnOffFitterSpectrum.hpp

 * @brief ON-OFF spectral analysis class

 * @author Pierrick Martin

 */

#ifndef GONOFFFITTERSPECTRUM_HPP

#define GONOFFFITTERSPECTRUM_HPP

/* __ Includes ___________________________________________________________ */

#include <string>

#include <vector>

#include "GObservations.hpp"

#include "GEbounds.hpp"

#include "GEnergy.hpp"

#include "GOnOffMaker.hpp"

#include "GModelSpectral.hpp"

/***********************************************************************//**

* @class GOnOffFitterSpectrum

*

* @brief ON-OFF spectral analysis class

*

* This class implements the spectral analysis of data with an ON-OFF

* approach for the evaluation of the instrumental background.

*

* Two kinds of analyses can be considered: either the global fit of 

* given spectral shape over the entire energy grid, or the determination

* of flux points for all energy bins. The selection of one or the other

* option is done from whether or not a GModelSpectral object is passed on

* instantiation. In the case of flux points computation, an instance of 

* GModelSpectralFunc is created internally and filled with the results.

*

* The method convolve_spectrum() performs the convolution of the spectral 

* model with the instrument response and fills the m_expcts variable.

* Note that the convolution is done for each observation run and we store

* here only the summed counts.

*

* The method compute_energy() computes the average true energy and its 

* variance for each reconstructed energy bin and fills the m_truemean 

* and m_truevar variables. Both cannot be accessed at the moment.

* 

* The method compute_significance() evaluates the significance of the 

* source signal in each energy bin from the Li&Ma-1983 prescription.

* The result can be accessed through the significance() method.

*

* The method sum_data() sets the m_sum flag to indicate if the analysis

* is performed on summed ON and OFF data or keeping the ON and OFF

* information of each run independent. This implies a separate 

* optimization function for each case.

*

* The results, either best-fit spectral parameters or best-fit flux points,

* are written to an XML file through the methods of the GModelSpectral 

* object.

*

* To be decided:

* - Output format for the significance ? Just in log file ?

* - Do we store expected/observed counts per run in GOnOffBin ?

* - Do we want npred/eval/gradient methods as in GModel 

*   (working on GonOffBin instead of GEvent) ?

*

***************************************************************************/

class GOnOffFitterSpectrum : public GOnOffFitter {

public:

    // Constructors and destructors

    GOnOffFitterSpectrum(void);

    GOnOffFitterSpectrum(const GOnOffFitterSpectrum& onoff);

        explicit GOnOffFitterSpectrum(const std::string& filename, const GOnOffMaker& maker);

        explicit GOnOffFitterSpectrum(const GObservations& obs, const GOnOffMaker& maker);

        explicit GOnOffFitterSpectrum(const std::string& filename, const GOnOffMaker& maker, const GModelSpectral& spectral);

        explicit GOnOffFitterSpectrum(const GObservations& obs, const GOnOffMaker& maker, const GModelSpectral& spectral);

        explicit GOnOffFitterSpectrum(const std::string& filename, const GOnOffMaker& maker, const std::string& spec);

        explicit GOnOffFitterSpectrum(const GObservations& obs, const GOnOffMaker& maker, const std::string& spec);

    virtual ~GOnOffFitterSpectrum(void);

    // Operators

    virtual GOnOffFitterSpectrum&    operator=(const GOnOffFitterSpectrum& onoff);

    // Implemented pure virtual base class methods

    virtual void                     clear(void);

    virtual GOnOffFitterSpectrum*    clone(void) const;

    virtual int                      size(void) const;

        virtual std::string              type(void) const;

    virtual std::string              print(const GChatter& chatter = NORMAL) const;

        virtual void                     optimize(GOptimizer& opt);

        // Methods specific to the derived class

        void                             spectral(const GModelSpectral& spectral);

    void                             spectral(const std::string& filename);

    const GModelSpectral*            spectral(void) const;

        void                             sum_data(void);

        const std::vector<double>        significance(void) const;

        const std::vector<GEnergy>       true_energy(void) const;

        const std::vector<GEnergy>       true_variance(void) const;

    void                             convolve_spectrum(); 

        void                             compute_energy();

        void                             compute_significance();

protected:

    // Protected methods

    void init_members(void);

    void copy_members(const GOnOffFitterSpectrum& obs);

    void free_members(void);

    // Protected members

        GModelSpectral*              m_spectral;   //!< Spectral model

        std::vector<double>          m_expcts;     //!< Array of expected counts in all reconstructed energy bins (summed over all runs)

        std::vector<double>          m_obscts;     //!< Array of observed counts in all reconstructed energy bins (summed over all runs)        

    std::vector<GEnergy>         m_truemean;   //!< Array of average true energy for all reconstructed energy bins

    std::vector<GEnergy>         m_truevar;    //!< Array of true energy variance for all reconstructed energy bins

        std::vector<double>          m_sig;        //!< Array of significances of each flux point

        bool                         m_sum         //!< Flag to tell if analysis to be done on summed ON/OFF data

};

#endif /* GONOFFFITTERSPECTRUM_HPP */