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2018-12-07 15:15:39 +01:00

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// -*- C++ -*-
//
// -----------------------------------------------------------------------
// HEP Random
// --- RandChiSquare ---
// class header file
// -----------------------------------------------------------------------
// Class defining methods for shooting Chi^2 distributed random values,
// given a number of degrees of freedom a (default=1.0).
// Default values are used for operator()().
// Valid values of a satisfy a > 1. When invalid values are presented,
// the code silently returns -1.0.
// =======================================================================
// John Marraffino - Created: 12th May 1998 Based on the C-Rand package
// by Ernst Stadlober and Franz Niederl of the Technical
// University of Graz, Austria.
// Gabriele Cosmo - Removed useless methods and data: 5th Jan 1999
// M Fischler - put and get to/from streams 12/10/04
// =======================================================================
#ifndef RandChiSquare_h
#define RandChiSquare_h 1
#include "CLHEP/Random/Random.h"
#include "CLHEP/Utility/memory.h"
namespace CLHEP {
/**
* @author
* @ingroup random
*/
class RandChiSquare : public HepRandom {
public:
inline RandChiSquare ( HepRandomEngine& anEngine, double a=1 );
inline RandChiSquare ( HepRandomEngine* anEngine, double a=1 );
// These constructors should be used to instantiate a RandChiSquare
// distribution object defining a local engine for it.
// The static generator will be skipped using the non-static methods
// defined below.
// If the engine is passed by pointer the corresponding engine object
// will be deleted by the RandChiSquare destructor.
// If the engine is passed by reference the corresponding engine object
// will not be deleted by the RandChiSquare destructor.
virtual ~RandChiSquare();
// Destructor
// Static methods to shoot random values using the static generator
static inline double shoot();
static double shoot( double a );
static void shootArray ( const int size, double* vect,
double a=1.0 );
// Static methods to shoot random values using a given engine
// by-passing the static generator.
static inline double shoot( HepRandomEngine* anEngine );
static double shoot( HepRandomEngine* anEngine,
double a );
static void shootArray ( HepRandomEngine* anEngine, const int size,
double* vect, double a=1.0 );
// Methods using the localEngine to shoot random values, by-passing
// the static generator.
inline double fire();
double fire( double a );
void fireArray ( const int size, double* vect);
void fireArray ( const int size, double* vect,
double a );
inline double operator()();
inline double operator()( double a );
// Save and restore to/from streams
std::ostream & put ( std::ostream & os ) const;
std::istream & get ( std::istream & is );
std::string name() const;
HepRandomEngine & engine();
static std::string distributionName() {return "RandChiSquare";}
// Provides the name of this distribution class
private:
static double genChiSquare( HepRandomEngine *anEngine, double a );
std::shared_ptr<HepRandomEngine> localEngine;
double defaultA;
};
} // namespace CLHEP
#include "CLHEP/Random/RandChiSquare.icc"
#endif