CLHEP/Random/RandStudentT.h

00001 // $Id: RandStudentT.h,v 1.10 2002/05/25 08:36:11 evc Exp $
00002 // -*- C++ -*-
00003 //
00004 // -----------------------------------------------------------------------
00005 //                             HEP Random
00006 //                         --- RandStudentT ---
00007 //                          class header file
00008 // -----------------------------------------------------------------------
00009 
00010 // Class defining methods for shooting Student's t- distributed random 
00011 // values, given a number of degrees of freedom a (default=1.0).
00012 // Default values are used for operator()().
00013 
00014 // Valid input values are a > 0.  When invalid values are presented, the
00015 // code silently returns DBL_MAX from <float.h> which is the same as
00016 // MAXDOUBLE in <values.h> on systems where the latter exists.
00017 
00018 // =======================================================================
00019 // John Marraffino - Created: Based on the C-Rand package
00020 //                   by Ernst Stadlober and Franz Niederl of the Technical
00021 //                   University of Graz, Austria : 12th May 1998
00022 //                 - Removed <values.h> because that won't work
00023 //                   on NT : 26th Jun 1998
00024 // Gabriele Cosmo  - Fixed minor bug on inline definition for shoot()
00025 //                   methods. Created .icc file : 20th Aug 1998
00026 //                 - Removed useless methods and data: 5th Jan 1999
00027 // =======================================================================
00028 
00029 #ifndef RandStudentT_h
00030 #define RandStudentT_h 1
00031 
00032 #include "CLHEP/Random/Random.h"
00033 
00038 class RandStudentT : public HepRandom {
00039 
00040 public:
00041 
00042   inline RandStudentT ( HepRandomEngine& anEngine, double a=1.0 );
00043   inline RandStudentT ( HepRandomEngine* anEngine, double a=1.0 );
00044   // These constructors should be used to instantiate a RandStudentT
00045   // distribution object defining a local engine for it.
00046   // The static generator will be skipped using the non-static methods
00047   // defined below.
00048   // If the engine is passed by pointer the corresponding engine object
00049   // will be deleted by the RandStudentT destructor.
00050   // If the engine is passed by reference the corresponding engine object
00051   // will not be deleted by the RandStudentT destructor.
00052 
00053   virtual ~RandStudentT();
00054   // Destructor
00055 
00056   // Static methods to shoot random values using the static generator
00057 
00058   static  inline double shoot();
00059 
00060   static  double shoot( double a );
00061 
00062   static  void shootArray ( const int size, double* vect,
00063                             double a=1.0 );
00064 
00065   //  Static methods to shoot random values using a given engine
00066   //  by-passing the static generator.
00067 
00068   static  inline double shoot( HepRandomEngine* anEngine );
00069 
00070   static  double shoot( HepRandomEngine* anEngine, 
00071                            double a );
00072 
00073   static  void shootArray ( HepRandomEngine* anEngine, const int size,
00074                             double* vect, double a=1.0 );
00075 
00076   //  Methods using the localEngine to shoot random values, by-passing
00077   //  the static generator.
00078 
00079   inline double fire();
00080 
00081   double fire( double a );
00082   
00083   void fireArray ( const int size, double* vect );
00084   void fireArray ( const int size, double* vect, double a );
00085   double operator()();
00086   double operator()( double a );
00087 
00088 private:
00089 
00090   // Private copy constructor. Defining it here disallows use.
00091   RandStudentT(const RandStudentT& d);
00092 
00093   HepRandomEngine* localEngine;
00094   bool deleteEngine;
00095   const double defaultA;
00096 
00097 };
00098 
00099 #include "CLHEP/Random/RandStudentT.icc"
00100 
00101 #endif

Class Library for High Energy Physics (version 1.8)