| Geant4 Cross Reference |
1 // -*- C++ -*-
2 //
3 // -----------------------------------------------------------------------
4 // HEP Random
5 // --- RandExponential ---
6 // class implementation file
7 // -----------------------------------------------------------------------
8 // This file is part of Geant4 (simulation toolkit for HEP).
9
10 // =======================================================================
11 // Gabriele Cosmo - Created: 17th May 1996
12 // - Added methods to shoot arrays: 28th July 1997
13 // J.Marraffino - Added default mean as attribute and
14 // operator() with mean: 16th Feb 1998
15 // M Fischler - put and get to/from streams 12/15/04
16 // M Fischler - put/get to/from streams uses pairs of ulongs when
17 // + storing doubles avoid problems with precision
18 // 4/14/05
19 // =======================================================================
20
21 #include "CLHEP/Random/RandExponential.h"
22 #include "CLHEP/Random/DoubConv.h"
23 #include <cmath>
24 #include <iostream>
25 #include <string>
26 #include <vector>
27
28 namespace CLHEP {
29
30 std::string RandExponential::name() const {return "RandExponential";}
31 HepRandomEngine & RandExponential::engine() {return *localEngine;}
32
33 RandExponential::~RandExponential() {
34 }
35
36 double RandExponential::operator()() {
37 return fire( defaultMean );
38 }
39
40 double RandExponential::operator()( double mean ) {
41 return fire( mean );
42 }
43
44 double RandExponential::shoot() {
45 return -std::log(HepRandom::getTheEngine()->flat());
46 }
47
48 double RandExponential::shoot(double mean) {
49 return -std::log(HepRandom::getTheEngine()->flat())*mean;
50 }
51
52 void RandExponential::shootArray( const int size, double* vect,
53 double mean )
54 {
55 for( double* v = vect; v != vect+size; ++v )
56 *v = shoot(mean);
57 }
58
59 void RandExponential::shootArray(HepRandomEngine* anEngine, const int size,
60 double* vect, double mean )
61 {
62 for( double* v = vect; v != vect+size; ++v )
63 *v = shoot(anEngine, mean);
64 }
65
66 void RandExponential::fireArray( const int size, double* vect)
67 {
68 for( double* v = vect; v != vect+size; ++v )
69 *v = fire( defaultMean );
70 }
71
72 void RandExponential::fireArray( const int size, double* vect,
73 double mean )
74 {
75 for( double* v = vect; v != vect+size; ++v )
76 *v = fire( mean );
77 }
78
79 std::ostream & RandExponential::put ( std::ostream & os ) const {
80 long pr=os.precision(20);
81 std::vector<unsigned long> t(2);
82 os << " " << name() << "\n";
83 os << "Uvec" << "\n";
84 t = DoubConv::dto2longs(defaultMean);
85 os << defaultMean << " " << t[0] << " " << t[1] << "\n";
86 os.precision(pr);
87 return os;
88 }
89
90 std::istream & RandExponential::get ( std::istream & is ) {
91 std::string inName;
92 is >> inName;
93 if (inName != name()) {
94 is.clear(std::ios::badbit | is.rdstate());
95 std::cerr << "Mismatch when expecting to read state of a "
96 << name() << " distribution\n"
97 << "Name found was " << inName
98 << "\nistream is left in the badbit state\n";
99 return is;
100 }
101 if (possibleKeywordInput(is, "Uvec", defaultMean)) {
102 std::vector<unsigned long> t(2);
103 is >> defaultMean >> t[0] >> t[1]; defaultMean = DoubConv::longs2double(t);
104 return is;
105 }
106 // is >> defaultMean encompassed by possibleKeywordInput
107 return is;
108 }
109
110
111 } // namespace CLHEP
112