| 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 HepRotation class which
7 // were introduced when ZOOM PhysicsVectors was merged in, which might cause
8 // pulling in of LorentzTransformation related code units.
9 //
10
11 #include "CLHEP/Vector/Rotation.h"
12 #include "CLHEP/Vector/LorentzRotation.h"
13
14 #include <cmath>
15
16 namespace CLHEP {
17
18 // ---------- distance2 and related member functions:
19 //
20 // WHy do we have forms for HepLorentzRotation and HepBoost but not for
21 // HepBoostX, HepBoostY, HepBoostZ? Because the latter can be gotten by
22 // implicit conversion to HepBoost; but if we just had HepLorentzRotation
23 // then this would involve double conversion when HepBoostX was used.
24
25 double HepRotation::distance2( const HepLorentzRotation & lt ) const {
26 HepAxisAngle a;
27 Hep3Vector b;
28 lt.decompose(b, a);
29 double bet = b.beta();
30 double bet2 = bet*bet;
31 HepRotation r(a);
32 return bet2/(1-bet2) + distance2(r);
33 }
34
35 double HepRotation::distance2( const HepBoost & lt ) const {
36 return distance2( HepLorentzRotation(lt));
37 }
38
39 double HepRotation::howNear( const HepLorentzRotation & lt ) const {
40 return std::sqrt( distance2( lt ) );
41 }
42
43 double HepRotation::howNear( const HepBoost & lt ) const {
44 return std::sqrt( distance2( lt ) );
45 }
46
47 bool HepRotation::isNear( const HepLorentzRotation & lt,
48 double epsilon) const {
49 return distance2( lt ) <= epsilon*epsilon;
50 }
51
52 bool HepRotation::isNear( const HepBoost & lt,
53 double epsilon) const {
54 return distance2( lt ) <= epsilon*epsilon;
55 }
56
57 } // namespace CLHEP
58
59