| Geant4 Cross Reference |
1 // -*- C++ -*- 1
2 // -------------------------------------------
3 //
4 // This file is a part of the CLHEP - a Class
5 //
6 // This is the implementation of the subset of
7 // class which originated from the ZOOM SpaceV
8 // the esoteric concepts of polar/azimuthal an
9 //
10
11 #include "CLHEP/Vector/ThreeVector.h"
12
13 #include <cmath>
14
15 namespace CLHEP {
16
17 //-*******************************************
18 // - 6 -
19 // Decomposition of an angle between two vecto
20 //
21 //-*******************************************
22
23
24 double Hep3Vector::polarAngle (const Hep3Vecto
25 return std::fabs(v2.getTheta() - getTheta())
26 } /* polarAngle */
27
28 double Hep3Vector::polarAngle (const Hep3Vecto
29 const Hep3Vector & ref) const {
30 return std::fabs( v2.angle(ref) - angle(ref)
31 } /* polarAngle (v2, ref) */
32
33 // double Hep3Vector::azimAngle (const Hep3Vec
34 // is now in the .icc file as deltaPhi(v2)
35
36 double Hep3Vector::azimAngle (const Hep3Vecto
37 const Hep3Vector & ref) const {
38
39 Hep3Vector vperp ( perpPart(ref) );
40 if ( vperp.mag2() == 0 ) {
41 std::cerr << "Hep3Vector::azimAngle() - "
42 << "Cannot find azimuthal angle with ref
43 << "vector 1 -- will return zero" << std
44 return 0;
45 }
46
47 Hep3Vector v2perp ( v2.perpPart(ref) );
48 if ( v2perp.mag2() == 0 ) {
49 std::cerr << "Hep3Vector::azimAngle() - "
50 << "Cannot find azimuthal angle with ref
51 << "vector 2 -- will return zero" << std
52 return 0;
53 }
54
55 double ang = vperp.angle(v2perp);
56
57 // Now compute the sign of the answer: that
58 // the equivalent expression V*(V2xU).
59
60 if ( dot(v2.cross(ref)) >= 0 ) {
61 return ang;
62 } else {
63 return -ang;
64 }
65
66 //-| Note that if V*(V2xU) is zero, we want
67 //-| depending on whether vperp is aligned o
68 //-| The computed angle() expression does th
69
70 } /* azimAngle (v2, ref) */
71
72 } // namespace CLHEP
73