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25 //
26 ///////////////////////////////////////////////////////////////////////////////
27 // File: CCalMagneticField.cc
28 // Description: User Field class implementation.
29 ///////////////////////////////////////////////////////////////////////////////
30 #include <fstream>
31
32 #include "CCalMagneticField.hh"
33 #include "CCalutils.hh"
34 #include "G4SystemOfUnits.hh"
35 #include "G4FieldManager.hh"
36
37 //#define ddebug
38 //#define debug
39
40 //Constructor and destructor:
41
42 CCalMagneticField::CCalMagneticField(const G4String &filename) :
43 fval(0), pos(0), slope(0), intercept(0)
44 {
45 #ifdef debug
46 fVerbosity = 1;
47 #else
48 fVerbosity = 0;
49 #endif
50
51 //Let's open the file
52 G4cout << " ==> Opening file " << filename << " to read magnetic field..."
53 << G4endl;
54 G4String pathName = std::getenv("CCAL_GLOBALPATH");
55 std::ifstream is;
56 G4bool ok = openGeomFile(is, pathName, filename);
57
58 if (ok) {
59 findDO(is, G4String("FLDM"));
60 is >> fval >> npts >> xoff;
61
62 if (fVerbosity)
63 G4cout << "Field value " << fval << " # points " << npts <<
64 " offset in x "
65 << xoff*mm << G4endl;
66
67 if (npts > 0) {
68 pos = new G4double[npts];
69 slope = new G4double[npts];
70 intercept = new G4double[npts];
71
72 for (G4int i = 0; i < npts; i++) {
73 is >> pos[i] >> slope[i] >> intercept[i];
74 if (fVerbosity)
75 G4cout << tab << "Position " << i << " " << pos[i] << " Slope "
76 << slope[i] << " Intercept " << intercept[i] << G4endl;
77 }
78 }
79
80 ///////////////////////////////////////////////////////////////
81 // Close the file
82 G4cout << " ==> Closing file " << filename << G4endl;
83 is.close();
84 }
85 }
86
87
88 CCalMagneticField::~CCalMagneticField() {
89 if (pos)
90 delete[] pos;
91 if (slope)
92 delete[] slope;
93 if (intercept)
94 delete[] intercept;
95 }
96
97
98 // Member functions
99
100 void CCalMagneticField::MagneticField(const G4double x[3], G4double B[3]) const
101 {
102 G4int i=0;
103 for (i=0; i<2; i++) {
104 B[i] = 0*kilogauss;
105 }
106
107 G4double m1=0;
108 G4double c1=0;
109 G4double xnew = x[0]/mm + xoff;
110 if (npts > 0) {
111 for (i=0; i<npts; i++) {
112 if (xnew > pos[i]*mm) {
113 m1 = slope[i];
114 c1 = intercept[i];
115 }
116 }
117 }
118 G4double scor = c1 + m*xnew;
119 if (scor < 0.) scor = 0.;
120 if (scor > 1.) scor = 1.0;
121
122 B[2] = scor*fval*kilogauss;
123 if (fVerbosity)
124 {
125
126 G4cout << "Field at x: " << x[0]/mm << "mm (" << xnew << ") = " <<
127 B[2]/tesla
128 << "T (m = " << m1 << ", c = " <<
129 c1 << ", scale = " << scor << ")"
130 << G4endl;
131 }
132 }
133
134
135 CLHEP::Hep3Vector CCalMagneticField::
136 MagneticField(const CLHEP::Hep3Vector point) const {
137
138 G4double x[3],B[3];
139 CLHEP::Hep3Vector v;
140
141 x[0] = point.x();
142 x[1] = point.y();
143 x[2] = point.z();
144 CCalMagneticField::MagneticField(x, B);
145 v.setX(B[0]);
146 v.setY(B[1]);
147 v.setZ(B[2]);
148 return v;
149 }
150
151
152 void CCalMagneticField::GetFieldValue(const G4double x[3], G4double* B) const {
153 CCalMagneticField::MagneticField(x, B);
154 }
155
156