RooMCIntegrator.h

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/*****************************************************************************
 * Project: RooFit                                                           *
 * Package: RooFitCore                                                       *
 *    File: $Id: RooMCIntegrator.h,v 1.15 2007/05/11 09:11:30 verkerke Exp $
 * Authors:                                                                  *
 *   WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu       *
 *   DK, David Kirkby,    UC Irvine,         dkirkby@uci.edu                 *
 *                                                                           *
 * Copyright (c) 2000-2005, Regents of the University of California          *
 *                          and Stanford University. All rights reserved.    *
 *                                                                           *
 * Redistribution and use in source and binary forms,                        *
 * with or without modification, are permitted according to the terms        *
 * listed in LICENSE (http://roofit.sourceforge.net/license.txt)             *
 *****************************************************************************/
#ifndef ROO_MC_INTEGRATOR
#define ROO_MC_INTEGRATOR
 
#include "RooAbsIntegrator.h"
#include "RooGrid.h"
#include "RooNumIntConfig.h"
#include "TStopwatch.h"
 
class RooMCIntegrator : public RooAbsIntegrator {
public:
   // Constructors, assignment etc
   enum SamplingMode { Importance, ImportanceOnly, Stratified };
   enum GeneratorType { QuasiRandom, PseudoRandom };
   RooMCIntegrator(const RooAbsFunc &function, SamplingMode mode = Importance, GeneratorType genType = QuasiRandom,
                   bool verbose = false);
   RooMCIntegrator(const RooAbsFunc &function, const RooNumIntConfig &config);
 
   bool checkLimits() const override;
   double integral(const double *yvec = nullptr) override;
 
   enum Stage { AllStages, ReuseGrid, RefineGrid };
   double vegas(Stage stage, UInt_t calls, UInt_t iterations, double *absError = nullptr);
 
   double getAlpha() const { return _alpha; }
   void setAlpha(double alpha) { _alpha = alpha; }
 
   GeneratorType getGenType() const { return _genType; }
   void setGenType(GeneratorType type) { _genType = type; }
 
   const RooGrid &grid() const { return _grid; }
 
protected:
   friend class RooNumIntFactory;
   static void registerIntegrator(RooNumIntFactory &fact);
 
   mutable RooGrid _grid; // Sampling grid definition
 
   // control variables
   bool _verbose;           ///< Verbosity control
   double _alpha;           ///< Grid stiffness parameter
   Int_t _mode;             ///< Sampling mode
   GeneratorType _genType;  ///< Generator type
   Int_t _nRefineIter;      ///< Number of refinement iterations
   Int_t _nRefinePerDim;    ///< Number of refinement samplings (per dim)
   Int_t _nIntegratePerDim; ///< Number of integration samplings (per dim)
 
   TStopwatch _timer; ///< Timer
 
   double _jac, _wtd_int_sum, _sum_wgts, _chi_sum, _chisq, _result,
      _sigma;                                           ///< Scratch variables preserved between calls to vegas1/2/2
   UInt_t _it_start, _it_num, _samples, _calls_per_box; ///< Scratch variables preserved between calls to vegas1/2/2
};
 
#endif