| Geant4 Cross Reference |
1 // -*- C++ -*-
2 //
3 // This file is a part of the CLHEP - a Class Library for High Energy Physics.
4 //
5 // This is the definition of the HepBoostX class for performing specialized
6 // Lorentz transformations which are pure boosts in the X direction, on
7 // objects of the HepLorentzVector class.
8 //
9 // HepLorentzRotation is a concrete implementation of Hep4RotationInterface.
10 //
11 // .SS See Also
12 // RotationInterfaces.h
13 // LorentzVector.h LorentzRotation.h
14 // Boost.h
15 //
16 // .SS Author
17 // Mark Fischler
18
19 #ifndef HEP_BOOSTX_H
20 #define HEP_BOOSTX_H
21
22 #include "CLHEP/Vector/RotationInterfaces.h"
23 #include "CLHEP/Vector/LorentzVector.h"
24
25 namespace CLHEP {
26
27 // Declarations of classes and global methods
28 class HepBoostX;
29 inline HepBoostX inverseOf ( const HepBoostX & b );
30 class HepBoost;
31 class HepRotation;
32
33 /**
34 * @author
35 * @ingroup vector
36 */
37 class HepBoostX {
38
39 public:
40
41 // ---------- Constructors and Assignment:
42
43 inline HepBoostX();
44 // Default constructor. Gives a boost of 0.
45
46 inline HepBoostX(const HepBoostX & b);
47 inline HepBoostX(HepBoostX && b) = default;
48 // Copy and move constructors.
49
50 inline HepBoostX & operator = (const HepBoostX & m);
51 inline HepBoostX & operator = (HepBoostX && m) = default;
52 // Copy and move assignment operators.
53
54 HepBoostX & set (double beta);
55 inline HepBoostX (double beta);
56 // Constructor from beta
57
58 // ---------- Accessors:
59
60 inline double beta() const;
61 inline double gamma() const;
62 inline Hep3Vector boostVector() const;
63 inline Hep3Vector getDirection() const;
64
65 inline double xx() const;
66 inline double xy() const;
67 inline double xz() const;
68 inline double xt() const;
69 inline double yx() const;
70 inline double yy() const;
71 inline double yz() const;
72 inline double yt() const;
73 inline double zx() const;
74 inline double zy() const;
75 inline double zz() const;
76 inline double zt() const;
77 inline double tx() const;
78 inline double ty() const;
79 inline double tz() const;
80 inline double tt() const;
81 // Elements of the matrix.
82
83 inline HepLorentzVector col1() const;
84 inline HepLorentzVector col2() const;
85 inline HepLorentzVector col3() const;
86 inline HepLorentzVector col4() const;
87 // orthosymplectic column vectors
88
89 inline HepLorentzVector row1() const;
90 inline HepLorentzVector row2() const;
91 inline HepLorentzVector row3() const;
92 inline HepLorentzVector row4() const;
93 // orthosymplectic row vectors
94
95 HepRep4x4 rep4x4() const;
96 // 4x4 representation:
97
98 HepRep4x4Symmetric rep4x4Symmetric() const;
99 // Symmetric 4x4 representation.
100
101 // ---------- Decomposition:
102
103 void decompose (HepRotation & rotation, HepBoost & boost) const;
104 void decompose (HepAxisAngle & rotation, Hep3Vector & boost) const;
105 // Find R and B such that L = R*B -- trivial, since R is identity
106
107 void decompose ( HepBoost & boost, HepRotation & rotation) const;
108 void decompose (Hep3Vector & boost, HepAxisAngle & rotation) const;
109 // Find R and B such that L = B*R -- trivial, since R is identity
110
111 // ---------- Comparisons:
112
113 inline int compare( const HepBoostX & b ) const;
114 // Dictionary-order comparison, in order of beta.
115 // Used in operator<, >, <=, >=
116
117 inline bool operator == (const HepBoostX & b) const;
118 inline bool operator != (const HepBoostX & b) const;
119 inline bool operator <= (const HepBoostX & b) const;
120 inline bool operator >= (const HepBoostX & b) const;
121 inline bool operator < (const HepBoostX & b) const;
122 inline bool operator > (const HepBoostX & b) const;
123 // Comparisons.
124
125 inline bool isIdentity() const;
126 // Returns true if a null boost.
127
128 inline double distance2( const HepBoostX & b ) const;
129 double distance2( const HepBoost & b ) const;
130 // Defined as the distance2 between the vectors (gamma*betaVector)
131
132 double distance2( const HepRotation & r ) const;
133 double distance2( const HepLorentzRotation & lt ) const;
134 // Decompose lt = B*R; add norm2 to distance2 to between boosts.
135
136 inline double howNear( const HepBoostX & b ) const;
137 inline double howNear( const HepBoost & b ) const;
138 inline double howNear( const HepRotation & r ) const;
139 inline double howNear( const HepLorentzRotation & lt ) const;
140
141 inline bool isNear( const HepBoostX & b,
142 double epsilon=Hep4RotationInterface::tolerance) const;
143 inline bool isNear( const HepBoost & b,
144 double epsilon=Hep4RotationInterface::tolerance) const;
145 bool isNear( const HepRotation & r,
146 double epsilon=Hep4RotationInterface::tolerance) const;
147 bool isNear( const HepLorentzRotation & lt,
148 double epsilon=Hep4RotationInterface::tolerance) const;
149
150 // ---------- Properties:
151
152 inline double norm2() const;
153 // distance2 (IDENTITY), which is beta^2 * gamma^2
154
155 void rectify();
156 // sets according to the stored beta
157
158 // ---------- Application:
159
160 inline HepLorentzVector operator()( const HepLorentzVector & w ) const;
161 // Transform a Lorentz Vector.
162
163 inline HepLorentzVector operator* ( const HepLorentzVector & w ) const;
164 // Multiplication with a Lorentz Vector.
165
166 // ---------- Operations in the group of 4-Rotations
167
168 HepBoostX operator * (const HepBoostX & b) const;
169 HepLorentzRotation operator * (const HepBoost & b) const;
170 HepLorentzRotation operator * (const HepRotation & r) const;
171 HepLorentzRotation operator * (const HepLorentzRotation & lt) const;
172 // Product of two Lorentz Rotations (this) * lt - matrix multiplication
173 // Notice that the product of two pure boosts in different directions
174 // is no longer a pure boost.
175
176 inline HepBoostX inverse() const;
177 // Return the inverse.
178
179 inline friend HepBoostX inverseOf ( const HepBoostX & b );
180 // global methods to invert.
181
182 inline HepBoostX & invert();
183 // Inverts the Boost matrix.
184
185 // ---------- I/O:
186
187 std::ostream & print( std::ostream & os ) const;
188 // Output form is BOOSTX (beta=..., gamma=...);
189
190 // ---------- Tolerance
191
192 static inline double getTolerance();
193 static inline double setTolerance(double tol);
194
195 protected:
196
197 inline HepLorentzVector vectorMultiplication
198 ( const HepLorentzVector & w ) const;
199 // Multiplication with a Lorentz Vector.
200
201 HepLorentzRotation matrixMultiplication (const HepRep4x4 & m) const;
202 HepLorentzRotation matrixMultiplication (const HepRep4x4Symmetric & m) const;
203
204 inline HepBoostX (double beta, double gamma);
205
206 double beta_;
207 double gamma_;
208
209 }; // HepBoostX
210
211 inline
212 std::ostream & operator <<
213 ( std::ostream & os, const HepBoostX& b ) {return b.print(os);}
214
215 } // namespace CLHEP
216
217 #include "CLHEP/Vector/BoostX.icc"
218
219 #endif /* HEP_BOOSTX_H */
220