| Geant4 Cross Reference |
1 // -*- C++ -*- 1 // -*- C++ -*-
2 // ------------------------------------------- 2 // ---------------------------------------------------------------------------
3 // 3 //
4 // This file is a part of the CLHEP - a Class 4 // This file is a part of the CLHEP - a Class Library for High Energy Physics.
5 // 5 //
6 // This is the implementation of the HepBoostX 6 // This is the implementation of the HepBoostX class.
7 // 7 //
8 8
>> 9 #ifdef GNUPRAGMA
>> 10 #pragma implementation
>> 11 #endif
>> 12
9 #include "CLHEP/Vector/BoostX.h" 13 #include "CLHEP/Vector/BoostX.h"
10 #include "CLHEP/Vector/Boost.h" 14 #include "CLHEP/Vector/Boost.h"
11 #include "CLHEP/Vector/Rotation.h" 15 #include "CLHEP/Vector/Rotation.h"
12 #include "CLHEP/Vector/LorentzRotation.h" 16 #include "CLHEP/Vector/LorentzRotation.h"
13 <<
14 #include <cmath> <<
15 #include <iostream> <<
16 17
17 namespace CLHEP { 18 namespace CLHEP {
18 19
19 20
20 // ---------- Constructors and Assignment: 21 // ---------- Constructors and Assignment:
21 22
22 HepBoostX & HepBoostX::set (double bbeta) { 23 HepBoostX & HepBoostX::set (double bbeta) {
23 double b2 = bbeta*bbeta; 24 double b2 = bbeta*bbeta;
24 if (b2 >= 1) { 25 if (b2 >= 1) {
25 std::cerr << "HepBoostX::set() - " 26 std::cerr << "HepBoostX::set() - "
26 << "Beta supplied to set HepBoostX repre 27 << "Beta supplied to set HepBoostX represents speed >= c." << std::endl;
27 beta_ = 1.0 - 1.0E-8; // NaN-proofing 28 beta_ = 1.0 - 1.0E-8; // NaN-proofing
28 gamma_ = 1.0 / std::sqrt(1.0 - b2); 29 gamma_ = 1.0 / std::sqrt(1.0 - b2);
29 return *this; 30 return *this;
30 } 31 }
31 beta_ = bbeta; 32 beta_ = bbeta;
32 gamma_ = 1.0 / std::sqrt(1.0 - b2); 33 gamma_ = 1.0 / std::sqrt(1.0 - b2);
33 return *this; 34 return *this;
34 } 35 }
35 36
36 // ---------- Accessors: 37 // ---------- Accessors:
37 38
38 HepRep4x4 HepBoostX::rep4x4() const { 39 HepRep4x4 HepBoostX::rep4x4() const {
39 double bg = beta_*gamma_; 40 double bg = beta_*gamma_;
40 return HepRep4x4( gamma_, 0, 0, bg, 41 return HepRep4x4( gamma_, 0, 0, bg,
41 0, 1, 0, 0, 42 0, 1, 0, 0,
42 0, 0, 1, 0, 43 0, 0, 1, 0,
43 bg, 0, 0, gamma_ 44 bg, 0, 0, gamma_ );
44 } 45 }
45 46
46 HepRep4x4Symmetric HepBoostX::rep4x4Symmetric( 47 HepRep4x4Symmetric HepBoostX::rep4x4Symmetric() const {
47 double bg = beta_*gamma_; 48 double bg = beta_*gamma_;
48 return HepRep4x4Symmetric( gamma_, 0, 0 49 return HepRep4x4Symmetric( gamma_, 0, 0, bg,
49 1, 0, 50 1, 0, 0,
50 1, 51 1, 0,
51 gam 52 gamma_ );
52 } 53 }
53 54
54 // ---------- Decomposition: 55 // ---------- Decomposition:
55 56
56 void HepBoostX::decompose (HepRotation & rotat 57 void HepBoostX::decompose (HepRotation & rotation, HepBoost & boost) const {
57 HepAxisAngle vdelta = HepAxisAngle(); 58 HepAxisAngle vdelta = HepAxisAngle();
58 rotation = HepRotation(vdelta); 59 rotation = HepRotation(vdelta);
59 Hep3Vector bbeta = boostVector(); 60 Hep3Vector bbeta = boostVector();
60 boost = HepBoost(bbeta); 61 boost = HepBoost(bbeta);
61 } 62 }
62 63
63 void HepBoostX::decompose (HepAxisAngle & rota 64 void HepBoostX::decompose (HepAxisAngle & rotation, Hep3Vector & boost) const {
64 rotation = HepAxisAngle(); 65 rotation = HepAxisAngle();
65 boost = boostVector(); 66 boost = boostVector();
66 } 67 }
67 68
68 void HepBoostX::decompose (HepBoost & boost, H 69 void HepBoostX::decompose (HepBoost & boost, HepRotation & rotation) const {
69 HepAxisAngle vdelta = HepAxisAngle(); 70 HepAxisAngle vdelta = HepAxisAngle();
70 rotation = HepRotation(vdelta); 71 rotation = HepRotation(vdelta);
71 Hep3Vector bbeta = boostVector(); 72 Hep3Vector bbeta = boostVector();
72 boost = HepBoost(bbeta); 73 boost = HepBoost(bbeta);
73 } 74 }
74 75
75 void HepBoostX::decompose (Hep3Vector & boost, 76 void HepBoostX::decompose (Hep3Vector & boost, HepAxisAngle & rotation) const {
76 rotation = HepAxisAngle(); 77 rotation = HepAxisAngle();
77 boost = boostVector(); 78 boost = boostVector();
78 } 79 }
79 80
80 // ---------- Comparisons: 81 // ---------- Comparisons:
81 82
82 double HepBoostX::distance2( const HepBoost & 83 double HepBoostX::distance2( const HepBoost & b ) const {
83 return b.distance2(*this); 84 return b.distance2(*this);
84 } 85 }
85 86
86 double HepBoostX::distance2( const HepRotation 87 double HepBoostX::distance2( const HepRotation & r ) const {
87 double db2 = norm2(); 88 double db2 = norm2();
88 double dr2 = r.norm2(); 89 double dr2 = r.norm2();
89 return (db2 + dr2); 90 return (db2 + dr2);
90 } 91 }
91 92
92 double HepBoostX::distance2( const HepLorentzR 93 double HepBoostX::distance2( const HepLorentzRotation & lt ) const {
93 HepBoost b1; 94 HepBoost b1;
94 HepRotation r1; 95 HepRotation r1;
95 lt.decompose(b1,r1); 96 lt.decompose(b1,r1);
96 double db2 = distance2(b1); 97 double db2 = distance2(b1);
97 double dr2 = r1.norm2(); 98 double dr2 = r1.norm2();
98 return (db2 + dr2); 99 return (db2 + dr2);
99 } 100 }
100 101
101 bool HepBoostX::isNear (const HepRotation & r, 102 bool HepBoostX::isNear (const HepRotation & r, double epsilon) const {
102 double db2 = norm2(); 103 double db2 = norm2();
103 if (db2 > epsilon*epsilon) return false; 104 if (db2 > epsilon*epsilon) return false;
104 double dr2 = r.norm2(); 105 double dr2 = r.norm2();
105 return (db2+dr2 <= epsilon*epsilon); 106 return (db2+dr2 <= epsilon*epsilon);
106 } 107 }
107 108
108 bool HepBoostX::isNear ( const HepLorentzRotat 109 bool HepBoostX::isNear ( const HepLorentzRotation & lt,
109 double epsilon) const { 110 double epsilon) const {
110 HepBoost b1; 111 HepBoost b1;
111 HepRotation r1; 112 HepRotation r1;
112 double db2 = distance2(b1); 113 double db2 = distance2(b1);
113 lt.decompose(b1,r1); 114 lt.decompose(b1,r1);
114 if (db2 > epsilon*epsilon) return false; 115 if (db2 > epsilon*epsilon) return false;
115 double dr2 = r1.norm2(); 116 double dr2 = r1.norm2();
116 return (db2 + dr2); 117 return (db2 + dr2);
117 } 118 }
118 119
119 // ---------- Properties: 120 // ---------- Properties:
120 121
121 void HepBoostX::rectify() { 122 void HepBoostX::rectify() {
122 // Assuming the representation of this is cl 123 // Assuming the representation of this is close to a true pure boost,
123 // but may have drifted due to round-off err 124 // but may have drifted due to round-off error from many operations,
124 // this forms an "exact" pure boostX matrix 125 // this forms an "exact" pure boostX matrix for again.
125 126
126 double b2 = beta_*beta_; 127 double b2 = beta_*beta_;
127 if (b2 >= 1) { 128 if (b2 >= 1) {
128 beta_ = 1.0 - 1.0e-8; // NaN-proofing 129 beta_ = 1.0 - 1.0e-8; // NaN-proofing
129 b2 = beta_*beta_; 130 b2 = beta_*beta_;
130 } 131 }
131 gamma_ = 1.0 / std::sqrt(1.0 - b2); 132 gamma_ = 1.0 / std::sqrt(1.0 - b2);
132 } 133 }
133 134
134 // ---------- Application: 135 // ---------- Application:
135 136
136 // ---------- Operations in the group of 4-Rot 137 // ---------- Operations in the group of 4-Rotations
137 138
138 HepBoostX HepBoostX::operator * (const HepBoos 139 HepBoostX HepBoostX::operator * (const HepBoostX & b) const {
139 return HepBoostX ( (beta()+b.beta()) / (1+be 140 return HepBoostX ( (beta()+b.beta()) / (1+beta()*b.beta()) );
140 } 141 }
141 HepLorentzRotation HepBoostX::operator * (cons 142 HepLorentzRotation HepBoostX::operator * (const HepBoost & b) const {
142 HepLorentzRotation me (*this); 143 HepLorentzRotation me (*this);
143 return me*b; 144 return me*b;
144 } 145 }
145 HepLorentzRotation HepBoostX::operator * (cons 146 HepLorentzRotation HepBoostX::operator * (const HepRotation & r) const {
146 HepLorentzRotation me (*this); 147 HepLorentzRotation me (*this);
147 return me*r; 148 return me*r;
148 } 149 }
149 HepLorentzRotation HepBoostX::operator * (cons 150 HepLorentzRotation HepBoostX::operator * (const HepLorentzRotation & lt) const {
150 HepLorentzRotation me (*this); 151 HepLorentzRotation me (*this);
151 return me*lt; 152 return me*lt;
152 } 153 }
153 154
154 // ---------- I/O: 155 // ---------- I/O:
155 156
156 std::ostream & HepBoostX::print( std::ostream 157 std::ostream & HepBoostX::print( std::ostream & os ) const {
157 os << "Boost in X direction (beta = " << bet 158 os << "Boost in X direction (beta = " << beta_
158 << ", gamma = " << gamma_ << ") "; 159 << ", gamma = " << gamma_ << ") ";
159 return os; 160 return os;
160 } 161 }
161 162
162 } // namespace CLHEP 163 } // namespace CLHEP
163 164