Geant4  10.02.p01
RandExponential.cc
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1 // $Id:$
2 // -*- C++ -*-
3 //
4 // -----------------------------------------------------------------------
5 // HEP Random
6 // --- RandExponential ---
7 // class implementation file
8 // -----------------------------------------------------------------------
9 // This file is part of Geant4 (simulation toolkit for HEP).
10 
11 // =======================================================================
12 // Gabriele Cosmo - Created: 17th May 1996
13 // - Added methods to shoot arrays: 28th July 1997
14 // J.Marraffino - Added default mean as attribute and
15 // operator() with mean: 16th Feb 1998
16 // M Fischler - put and get to/from streams 12/15/04
17 // M Fischler - put/get to/from streams uses pairs of ulongs when
18 // + storing doubles avoid problems with precision
19 // 4/14/05
20 // =======================================================================
21 
22 #include "CLHEP/Random/RandExponential.h"
23 #include "CLHEP/Random/DoubConv.h"
24 
25 namespace CLHEP {
26 
27 std::string RandExponential::name() const {return "RandExponential";}
28 HepRandomEngine & RandExponential::engine() {return *localEngine;}
29 
30 RandExponential::~RandExponential() {
31 }
32 
33 double RandExponential::operator()() {
34  return fire( defaultMean );
35 }
36 
37 double RandExponential::operator()( double mean ) {
38  return fire( mean );
39 }
40 
41 double RandExponential::shoot() {
42  return -std::log(HepRandom::getTheEngine()->flat());
43 }
44 
45 double RandExponential::shoot(double mean) {
46  return -std::log(HepRandom::getTheEngine()->flat())*mean;
47 }
48 
49 void RandExponential::shootArray( const int size, double* vect,
50  double mean )
51 {
52  for( double* v = vect; v != vect+size; ++v )
53  *v = shoot(mean);
54 }
55 
56 void RandExponential::shootArray(HepRandomEngine* anEngine, const int size,
57  double* vect, double mean )
58 {
59  for( double* v = vect; v != vect+size; ++v )
60  *v = shoot(anEngine, mean);
61 }
62 
63 void RandExponential::fireArray( const int size, double* vect)
64 {
65  for( double* v = vect; v != vect+size; ++v )
66  *v = fire( defaultMean );
67 }
68 
69 void RandExponential::fireArray( const int size, double* vect,
70  double mean )
71 {
72  for( double* v = vect; v != vect+size; ++v )
73  *v = fire( mean );
74 }
75 
76 std::ostream & RandExponential::put ( std::ostream & os ) const {
77  int pr=os.precision(20);
78  std::vector<unsigned long> t(2);
79  os << " " << name() << "\n";
80  os << "Uvec" << "\n";
81  t = DoubConv::dto2longs(defaultMean);
82  os << defaultMean << " " << t[0] << " " << t[1] << "\n";
83  os.precision(pr);
84  return os;
85 }
86 
87 std::istream & RandExponential::get ( std::istream & is ) {
88  std::string inName;
89  is >> inName;
90  if (inName != name()) {
91  is.clear(std::ios::badbit | is.rdstate());
92  std::cerr << "Mismatch when expecting to read state of a "
93  << name() << " distribution\n"
94  << "Name found was " << inName
95  << "\nistream is left in the badbit state\n";
96  return is;
97  }
98  if (possibleKeywordInput(is, "Uvec", defaultMean)) {
99  std::vector<unsigned long> t(2);
100  is >> defaultMean >> t[0] >> t[1]; defaultMean = DoubConv::longs2double(t);
101  return is;
102  }
103  // is >> defaultMean encompassed by possibleKeywordInput
104  return is;
105 }
106 
107 
108 } // namespace CLHEP
ThreeVector shoot(const G4int Ap, const G4int Af)
G4String name
Definition: TRTMaterials.hh:40
static int engine(pchar, pchar, double &, pchar &, const dic_type &)
Definition: Evaluator.cc:358
double flat()
Definition: G4AblaRandom.cc:47