CLHEP/Random/RandStudentT.h

0001 // $Id: RandStudentT.h,v 1.5 2010/06/16 17:24:53 garren Exp $
0002 // -*- C++ -*-
0003 //
0004 // -----------------------------------------------------------------------
0005 //                             HEP Random
0006 //                         --- RandStudentT ---
0007 //                          class header file
0008 // -----------------------------------------------------------------------
0009
0010 // Class defining methods for shooting Student's t- distributed random
0011 // values, given a number of degrees of freedom a (default=1.0).
0012 // Default values are used for operator()().
0013
0014 // Valid input values are a > 0.  When invalid values are presented, the
0015 // code silently returns DBL_MAX from <float.h> which is the same as
0016 // MAXDOUBLE in <values.h> on systems where the latter exists.
0017
0018 // =======================================================================
0019 // John Marraffino - Created: Based on the C-Rand package
0020 //                   by Ernst Stadlober and Franz Niederl of the Technical
0021 //                   University of Graz, Austria : 12th May 1998
0022 //                 - Removed <values.h> because that won't work
0023 //                   on NT : 26th Jun 1998
0024 // Gabriele Cosmo  - Fixed minor bug on inline definition for shoot()
0025 //                   methods. Created .icc file : 20th Aug 1998
0026 //                 - Removed useless methods and data: 5th Jan 1999
0027 // M Fischler      - put and get to/from streams 12/10/04
0028 // =======================================================================
0029
0030 #ifndef RandStudentT_h
0031 #define RandStudentT_h 1
0032
0033 #include "CLHEP/Random/defs.h"
0034 #include "CLHEP/Random/Random.h"
0035 #include "CLHEP/Utility/memory.h"
0036
0037 namespace CLHEP {
0038
0039 /**
0040  * @author
0041  * @ingroup random
0042  */
0043 class RandStudentT : public HepRandom {
0044
0045 public:
0046
0047   inline RandStudentT ( HepRandomEngine& anEngine, double a=1.0 );
0048   inline RandStudentT ( HepRandomEngine* anEngine, double a=1.0 );
0049   // These constructors should be used to instantiate a RandStudentT
0050   // distribution object defining a local engine for it.
0051   // The static generator will be skipped using the non-static methods
0052   // defined below.
0053   // If the engine is passed by pointer the corresponding engine object
0054   // will be deleted by the RandStudentT destructor.
0055   // If the engine is passed by reference the corresponding engine object
0056   // will not be deleted by the RandStudentT destructor.
0057
0058   virtual ~RandStudentT();
0059   // Destructor
0060
0061   // Save and restore to/from streams
0062
0063   std::ostream & put ( std::ostream & os ) const;
0064   std::istream & get ( std::istream & is );
0065
0066   // Static methods to shoot random values using the static generator
0067
0068   static  inline double shoot();
0069
0070   static  double shoot( double a );
0071
0072   static  void shootArray ( const int size, double* vect,
0073                             double a=1.0 );
0074
0075   //  Static methods to shoot random values using a given engine
0076   //  by-passing the static generator.
0077
0078   static  inline double shoot( HepRandomEngine* anEngine );
0079
0080   static  double shoot( HepRandomEngine* anEngine,
0081                            double a );
0082
0083   static  void shootArray ( HepRandomEngine* anEngine, const int size,
0084                             double* vect, double a=1.0 );
0085
0086   //  Methods using the localEngine to shoot random values, by-passing
0087   //  the static generator.
0088
0089   inline double fire();
0090
0091   double fire( double a );
0092
0093   void fireArray ( const int size, double* vect );
0094   void fireArray ( const int size, double* vect, double a );
0095   double operator()();
0096   double operator()( double a );
0097
0098   std::string name() const;
0099   HepRandomEngine & engine();
0100
0101   static std::string distributionName() {return "RandStudentT";}
0102   // Provides the name of this distribution class
0103
0104
0105 private:
0106
0107   std::shared_ptr<HepRandomEngine> localEngine;
0108   double defaultA;
0109
0110 };
0111
0112 }  // namespace CLHEP
0113
0114 #ifdef ENABLE_BACKWARDS_COMPATIBILITY
0115 //  backwards compatibility will be enabled ONLY in CLHEP 1.9
0116 using namespace CLHEP;
0117 #endif
0118
0119 #include "CLHEP/Random/RandStudentT.icc"
0120
0121 #endif