// $Id$
//-----------------------------------------------------------------------
//       The GSI Online Offline Object Oriented (Go4) Project
//         Experiment Data Processing at EE department, GSI
//-----------------------------------------------------------------------
// Copyright (C) 2000- GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
//                     Planckstr. 1, 64291 Darmstadt, Germany
// Contact:            http://go4.gsi.de
//-----------------------------------------------------------------------
// This software can be used under the license agreements as stated
// in Go4License.txt file which is part of the distribution.
//-----------------------------------------------------------------------

#ifndef TGO4FITMODELGAUSS2_H
#define TGO4FITMODELGAUSS2_H

#include "TGo4FitModel.h"

/**
 * @brief Two dimensional gaussian peak.
 *
 * @details Has following parameters:
 *   - "Ampl" - amplitude;
 *   - "Pos0" - line position on first coordinate;
 *   - "Pos1" - line position on second coordinate;
 *   - "Width0" - line width on first coordinate;
 *   - "Width1" - line width on second coordinate;
 *   - "Cov0_1" - covariation between first and second coordinate.
 *
 * By default, first coordinate associated with x axis, second - with y axis. To create instance of this model:
 * ~~~{cpp}
 * *   TGo4FitModelGauss2 *g = new TGo4FitModelGauss2("Gauss", 5., 5., 1., 1., 0.5);
 * ~~~
 * where first parameter - name of model component, then initial value for positions, widths and covariation parameters are defined. To assigned coordinates to another axis, two more parameters should be used in the constructor:
 * ~~~{cpp}
 *   TGo4FitModelGauss2 *g = new TGo4FitModelGauss2("Gauss", 5., 5., 1., 1., 0.5, 1, 2);
 * ~~~
 * where 1 - assignment of first coordinate to y axis, 2 - assignment of second coordinate to z axis.
 *
 * @ingroup go4_fit
 */
class TGo4FitModelGauss2 : public TGo4FitModel {
   public:

      /**
       * Default constructor.
       */
      TGo4FitModelGauss2();

      /**
       * Creates TGo4FitModelGauss2 with specified name.
       * Initial value for positions, widths and covariation parameters can be specified.
       * Also number of selected axis, where 2-dim gaussian will be build, can be specified (default 0 and 1).
       */
      TGo4FitModelGauss2(const char *iName, Double_t iPos1 = 1., Double_t iPos2 = 1.,
                                       Double_t iWidth1 = 1., Double_t iWidth2 = 1., Double_t iCov12 = 0.,
                                       Int_t iNaxis1 = 0, Int_t iNaxis2 = 1);

      /**
       * Destroys TGo4FitModelGauss2 object.
       */
      virtual ~TGo4FitModelGauss2();

      /**
       * Return number of first selected axis.
       */
      Int_t GetNumAxis1() const { return fiNaxis1; }

      /**
       * Return number of second selected axis.
       */
      Int_t GetNumAxis2() const { return fiNaxis2; }

      /**
       * Sets number of first selected axis.
       */
      Int_t SetNumAxis1(Int_t n) { return fiNaxis1 = n; }

      /**
       * Sets number of second selected axis.
       */
      Int_t SetNumAxis2(Int_t n) { return fiNaxis2 = n; }

      /**
       * Prints information to standard output.
       */
      void Print(Option_t *option = "") const override;

      Bool_t BeforeEval(Int_t ndim) override;
      Double_t EvalN(const Double_t *v) override;

   protected:
      Int_t GetPosParIndex(Int_t naxis) override { return (naxis == fiNaxis1) ? 1 : (naxis == fiNaxis2) ? 2 : -1; }
      Int_t GetWidthParIndex(Int_t naxis) override { return (naxis == fiNaxis1) ? 3 : (naxis == fiNaxis2) ? 4 : -1; }

      /**
       * Number of first selected axis.
       */
      Int_t fiNaxis1{0};

      /**
       * Number of second selected axis.
       */
      Int_t fiNaxis2{0};

   private:

      /**
       * Temporary variable for EvalN() function.
       */
      Double_t Par_mu1{0};                //!

      /**
       * Temporary variable for EvalN() function.
       */
      Double_t Par_mu2{0};                //!

      /**
       * Temporary variable for EvalN() function.
       */
      Double_t Par_sig1{0};               //!

      /**
       * Temporary variable for EvalN() function.
       */
      Double_t Par_sig2{0};               //!

      /**
       * Temporary variable for EvalN() function.
       */
      Double_t Par_ro{0};                 //!

      /**
       * Temporary variable for EvalN() function.
       */
      Double_t Par_mult{0};               //!

   ClassDefOverride(TGo4FitModelGauss2,1)
};
#endif // TGO4FITMODELGAUSS2_H