| Geant4 Cross Reference |
1 // -*- C++ -*-
2 // ---------------------------------------------------------------------------
3 //
4 // This file is a part of the CLHEP - a Class Library for High Energy Physics.
5 //
6 // This is the implementation of methods of the HepRotationZ class which
7 // were introduced when ZOOM PhysicsVectors was merged in.
8 //
9
10 #include "CLHEP/Vector/RotationZ.h"
11 #include "CLHEP/Vector/AxisAngle.h"
12 #include "CLHEP/Vector/EulerAngles.h"
13 #include "CLHEP/Vector/LorentzRotation.h"
14 #include "CLHEP/Units/PhysicalConstants.h"
15
16 #include <cmath>
17 #include <stdlib.h>
18 #include <iostream>
19
20 namespace CLHEP {
21
22 static inline double safe_acos (double x) {
23 if (std::abs(x) <= 1.0) return std::acos(x);
24 return ( (x>0) ? 0 : CLHEP::pi );
25 }
26
27 HepRotationZ::HepRotationZ(double ddelta) :
28 its_d(proper(ddelta)), its_s(std::sin(ddelta)), its_c(std::cos(ddelta))
29 {}
30
31 HepRotationZ & HepRotationZ::set ( double ddelta ) {
32 its_d = proper(ddelta);
33 its_s = std::sin(its_d);
34 its_c = std::cos(its_d);
35 return *this;
36 }
37
38 double HepRotationZ::phi() const {
39 return - its_d/2.0;
40 } // HepRotationZ::phi()
41
42 double HepRotationZ::theta() const {
43 return 0.0 ;
44 } // HepRotationZ::theta()
45
46 double HepRotationZ::psi() const {
47 return - its_d/2.0;
48 } // HepRotationZ::psi()
49
50 HepEulerAngles HepRotationZ::eulerAngles() const {
51 return HepEulerAngles( phi(), theta(), psi() );
52 } // HepRotationZ::eulerAngles()
53
54
55 // From the defining code in the implementation of CLHEP (in Rotation.cc)
56 // it is clear that thetaX, phiX form the polar angles in the original
57 // coordinate system of the new X axis (and similarly for phiY and phiZ).
58 //
59 // This code is take directly from CLHEP original. However, there are as
60 // shown opportunities for significant speed improvement.
61
62 double HepRotationZ::phiX() const {
63 return (yx() == 0.0 && xx() == 0.0) ? 0.0 : std::atan2(yx(),xx());
64 // or ---- return d;
65 }
66
67 double HepRotationZ::phiY() const {
68 return (yy() == 0.0 && xy() == 0.0) ? 0.0 : std::atan2(yy(),xy());
69 }
70
71 double HepRotationZ::phiZ() const {
72 return (yz() == 0.0 && xz() == 0.0) ? 0.0 : std::atan2(yz(),xz());
73 // or ---- return 0.0;
74 }
75
76 double HepRotationZ::thetaX() const {
77 return safe_acos(zx());
78 // or ---- return CLHEP::halfpi;
79 }
80
81 double HepRotationZ::thetaY() const {
82 return safe_acos(zy());
83 // or ---- return CLHEP::halfpi;
84 }
85
86 double HepRotationZ::thetaZ() const {
87 return safe_acos(zz());
88 // or ---- return 0.0;
89 }
90
91 void HepRotationZ::setDelta ( double ddelta ) {
92 set(ddelta);
93 }
94
95 void HepRotationZ::decompose
96 (HepAxisAngle & rotation, Hep3Vector & boost) const {
97 boost.set(0,0,0);
98 rotation = axisAngle();
99 }
100
101 void HepRotationZ::decompose
102 (Hep3Vector & boost, HepAxisAngle & rotation) const {
103 boost.set(0,0,0);
104 rotation = axisAngle();
105 }
106
107 void HepRotationZ::decompose
108 (HepRotation & rotation, HepBoost & boost) const {
109 boost.set(0,0,0);
110 rotation = HepRotation(*this);
111 }
112
113 void HepRotationZ::decompose
114 (HepBoost & boost, HepRotation & rotation) const {
115 boost.set(0,0,0);
116 rotation = HepRotation(*this);
117 }
118
119 double HepRotationZ::distance2( const HepRotationZ & r ) const {
120 double answer = 2.0 * ( 1.0 - ( its_s * r.its_s + its_c * r.its_c ) ) ;
121 return (answer >= 0) ? answer : 0;
122 }
123
124 double HepRotationZ::distance2( const HepRotation & r ) const {
125 double sum = xx() * r.xx() + xy() * r.xy()
126 + yx() * r.yx() + yy() * r.yy()
127 + r.zz();
128 double answer = 3.0 - sum;
129 return (answer >= 0 ) ? answer : 0;
130 }
131
132 double HepRotationZ::distance2( const HepLorentzRotation & lt ) const {
133 HepAxisAngle a;
134 Hep3Vector b;
135 lt.decompose(b, a);
136 double bet = b.beta();
137 double bet2 = bet*bet;
138 HepRotation r(a);
139 return bet2/(1-bet2) + distance2(r);
140 }
141
142 double HepRotationZ::distance2( const HepBoost & lt ) const {
143 return distance2( HepLorentzRotation(lt));
144 }
145
146 double HepRotationZ::howNear( const HepRotationZ & r ) const {
147 return std::sqrt(distance2(r));
148 }
149 double HepRotationZ::howNear( const HepRotation & r ) const {
150 return std::sqrt(distance2(r));
151 }
152 double HepRotationZ::howNear( const HepBoost & lt ) const {
153 return std::sqrt(distance2(lt));
154 }
155 double HepRotationZ::howNear( const HepLorentzRotation & lt ) const {
156 return std::sqrt(distance2(lt));
157 }
158 bool HepRotationZ::isNear(const HepRotationZ & r,double epsilon)const {
159 return (distance2(r) <= epsilon*epsilon);
160 }
161 bool HepRotationZ::isNear(const HepRotation & r,double epsilon)const {
162 return (distance2(r) <= epsilon*epsilon);
163 }
164 bool HepRotationZ::isNear( const HepBoost & lt,double epsilon) const {
165 return (distance2(lt) <= epsilon*epsilon);
166 }
167 bool HepRotationZ::isNear( const HepLorentzRotation & lt,
168 double epsilon) const {
169 return (distance2(lt) <= epsilon*epsilon);
170 }
171
172 double HepRotationZ::norm2() const {
173 return 2.0 - 2.0 * its_c;
174 }
175
176 std::ostream & HepRotationZ::print( std::ostream & os ) const {
177 os << "\nRotation about Z (" << its_d <<
178 ") [cos d = " << its_c << " sin d = " << its_s << "]\n";
179 return os;
180 }
181
182 } // namespace CLHEP
183
184