118 lines
3.7 KiB
C++
118 lines
3.7 KiB
C++
// -*- C++ -*-
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//
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// -----------------------------------------------------------------------
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// HEP Random
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// --- RandGamma ---
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// class header file
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// -----------------------------------------------------------------------
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// Class defining methods for shooting gamma distributed random values,
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// given a k (default=1) and specifying also a lambda (default=1).
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// Default values are used for operator()().
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// Valid input values are k > 0 and lambda > 0. When invalid values are
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// presented, the code silently returns -1.0.
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// =======================================================================
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// John Marraffino - Created: 12th May 1998 Based on the C-Rand package
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// by Ernst Stadlober and Franz Niederl of the Technical
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// University of Graz, Austria.
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// Gabriele Cosmo - Removed useless methods and data: 5th Jan 1999
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// M Fischler - put and get to/from streams 12/10/04
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// =======================================================================
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#ifndef RandGamma_h
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#define RandGamma_h 1
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#include "CLHEP/Random/Random.h"
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#include "CLHEP/Utility/memory.h"
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namespace CLHEP {
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/**
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* @author
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* @ingroup random
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*/
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class RandGamma : public HepRandom {
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public:
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inline RandGamma ( HepRandomEngine& anEngine, double k=1.0,
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double lambda=1.0 );
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inline RandGamma ( HepRandomEngine* anEngine, double k=1.0,
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double lambda=1.0 );
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// These constructors should be used to instantiate a RandGamma
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// distribution object defining a local engine for it.
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// The static generator will be skipped using the non-static methods
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// defined below.
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// If the engine is passed by pointer the corresponding engine object
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// will be deleted by the RandGamma destructor.
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// If the engine is passed by reference the corresponding engine object
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// will not be deleted by the RandGamma destructor.
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virtual ~RandGamma();
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// Destructor
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// Static methods to shoot random values using the static generator
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static inline double shoot();
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static double shoot( double k, double lambda );
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static void shootArray ( const int size, double* vect,
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double k=1.0, double lambda=1.0 );
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// Static methods to shoot random values using a given engine
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// by-passing the static generator.
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static inline double shoot( HepRandomEngine* anEngine );
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static double shoot( HepRandomEngine* anEngine,
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double k, double lambda );
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static void shootArray ( HepRandomEngine* anEngine, const int size,
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double* vect, double k=1.0,
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double lambda=1.0 );
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// Methods using the localEngine to shoot random values, by-passing
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// the static generator.
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inline double fire();
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double fire( double k, double lambda );
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void fireArray ( const int size, double* vect);
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void fireArray ( const int size, double* vect,
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double k, double lambda );
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inline double operator()();
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inline double operator()( double k, double lambda );
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// Save and restore to/from streams
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std::ostream & put ( std::ostream & os ) const;
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std::istream & get ( std::istream & is );
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std::string name() const;
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HepRandomEngine & engine();
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static std::string distributionName() {return "RandGamma";}
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// Provides the name of this distribution class
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private:
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static double genGamma( HepRandomEngine *anEngine, double k,
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double lambda );
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std::shared_ptr<HepRandomEngine> localEngine;
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double defaultK;
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double defaultLambda;
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};
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} // namespace CLHEP
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#include "CLHEP/Random/RandGamma.icc"
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#endif
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