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25 //
26 // Code developed by:
27 // S.Larsson and J. Generowicz.
28 //
29 // *************************************
30 // * *
31 // * PurgMagTabulatedField3D.cc *
32 // * *
33 // *************************************
34 //
35 //
36
37 #include "PurgMagTabulatedField3D.hh"
38 #include "G4SystemOfUnits.hh"
39 #include "G4AutoLock.hh"
40
41 namespace{
42 G4Mutex myPurgMagTabulatedField3DLock = G4MUTEX_INITIALIZER;
43 }
44
45 using namespace std;
46
47 PurgMagTabulatedField3D::PurgMagTabulatedField3D(const char* filename,
48 double zOffset )
49 :fZoffset(zOffset),invertX(false),invertY(false),invertZ(false)
50 {
51
52 double lenUnit= meter;
53 double fieldUnit= tesla;
54 G4cout << "\n-----------------------------------------------------------"
55 << "\n Magnetic field"
56 << "\n-----------------------------------------------------------";
57
58 G4cout << "\n ---> " "Reading the field grid from " << filename << " ... " << G4endl;
59
60 //
61 //This is a thread-local class and we have to avoid that all workers open the
62 //file at the same time
63 G4AutoLock lock(&myPurgMagTabulatedField3DLock);
64
65 ifstream file( filename ); // Open the file for reading.
66
67 if (!file.is_open())
68 {
69 G4ExceptionDescription ed;
70 ed << "Could not open input file " << filename << std::endl;
71 G4Exception("PurgMagTabulatedField3D::PurgMagTabulatedField3D",
72 "pugmag001",FatalException,ed);
73 }
74
75 // Ignore first blank line
76 char buffer[256];
77 file.getline(buffer,256);
78
79 // Read table dimensions
80 file >> nx >> ny >> nz; // Note dodgy order
81
82 G4cout << " [ Number of values x,y,z: "
83 << nx << " " << ny << " " << nz << " ] "
84 << G4endl;
85
86 // Set up storage space for table
87 xField.resize( nx );
88 yField.resize( nx );
89 zField.resize( nx );
90 int ix, iy, iz;
91 for (ix=0; ix<nx; ix++) {
92 xField[ix].resize(ny);
93 yField[ix].resize(ny);
94 zField[ix].resize(ny);
95 for (iy=0; iy<ny; iy++) {
96 xField[ix][iy].resize(nz);
97 yField[ix][iy].resize(nz);
98 zField[ix][iy].resize(nz);
99 }
100 }
101
102 // Ignore other header information
103 // The first line whose second character is '0' is considered to
104 // be the last line of the header.
105 do {
106 file.getline(buffer,256);
107 } while ( buffer[1]!='0');
108
109 // Read in the data
110 double xval,yval,zval,bx,by,bz;
111 double permeability; // Not used in this example.
112 for (ix=0; ix<nx; ix++) {
113 for (iy=0; iy<ny; iy++) {
114 for (iz=0; iz<nz; iz++) {
115 file >> xval >> yval >> zval >> bx >> by >> bz >> permeability;
116 if ( ix==0 && iy==0 && iz==0 ) {
117 minx = xval * lenUnit;
118 miny = yval * lenUnit;
119 minz = zval * lenUnit;
120 }
121 xField[ix][iy][iz] = bx * fieldUnit;
122 yField[ix][iy][iz] = by * fieldUnit;
123 zField[ix][iy][iz] = bz * fieldUnit;
124 }
125 }
126 }
127 file.close();
128
129 lock.unlock();
130
131 maxx = xval * lenUnit;
132 maxy = yval * lenUnit;
133 maxz = zval * lenUnit;
134
135 G4cout << "\n ---> ... done reading " << G4endl;
136
137 // G4cout << " Read values of field from file " << filename << G4endl;
138 G4cout << " ---> assumed the order: x, y, z, Bx, By, Bz "
139 << "\n ---> Min values x,y,z: "
140 << minx/cm << " " << miny/cm << " " << minz/cm << " cm "
141 << "\n ---> Max values x,y,z: "
142 << maxx/cm << " " << maxy/cm << " " << maxz/cm << " cm "
143 << "\n ---> The field will be offset by " << zOffset/cm << " cm " << G4endl;
144
145 // Should really check that the limits are not the wrong way around.
146 if (maxx < minx) {swap(maxx,minx); invertX = true;}
147 if (maxy < miny) {swap(maxy,miny); invertY = true;}
148 if (maxz < minz) {swap(maxz,minz); invertZ = true;}
149 G4cout << "\nAfter reordering if neccesary"
150 << "\n ---> Min values x,y,z: "
151 << minx/cm << " " << miny/cm << " " << minz/cm << " cm "
152 << " \n ---> Max values x,y,z: "
153 << maxx/cm << " " << maxy/cm << " " << maxz/cm << " cm ";
154
155 dx = maxx - minx;
156 dy = maxy - miny;
157 dz = maxz - minz;
158 G4cout << "\n ---> Dif values x,y,z (range): "
159 << dx/cm << " " << dy/cm << " " << dz/cm << " cm in z "
160 << "\n-----------------------------------------------------------" << G4endl;
161 }
162
163 void PurgMagTabulatedField3D::GetFieldValue(const double point[4],
164 double *Bfield ) const
165 {
166
167 double x = point[0];
168 double y = point[1];
169 double z = point[2] + fZoffset;
170
171 // Check that the point is within the defined region
172 if ( x>=minx && x<=maxx &&
173 y>=miny && y<=maxy &&
174 z>=minz && z<=maxz ) {
175
176 // Position of given point within region, normalized to the range
177 // [0,1]
178 double xfraction = (x - minx) / dx;
179 double yfraction = (y - miny) / dy;
180 double zfraction = (z - minz) / dz;
181
182 if (invertX) { xfraction = 1 - xfraction;}
183 if (invertY) { yfraction = 1 - yfraction;}
184 if (invertZ) { zfraction = 1 - zfraction;}
185
186 // Need addresses of these to pass to modf below.
187 // modf uses its second argument as an OUTPUT argument.
188 double xdindex, ydindex, zdindex;
189
190 // Position of the point within the cuboid defined by the
191 // nearest surrounding tabulated points
192 double xlocal = ( std::modf(xfraction*(nx-1), &xdindex));
193 double ylocal = ( std::modf(yfraction*(ny-1), &ydindex));
194 double zlocal = ( std::modf(zfraction*(nz-1), &zdindex));
195
196 // The indices of the nearest tabulated point whose coordinates
197 // are all less than those of the given point
198 int xindex = static_cast<int>(xdindex);
199 int yindex = static_cast<int>(ydindex);
200 int zindex = static_cast<int>(zdindex);
201
202
203 #ifdef DEBUG_INTERPOLATING_FIELD
204 G4cout << "Local x,y,z: " << xlocal << " " << ylocal << " " << zlocal << G4endl;
205 G4cout << "Index x,y,z: " << xindex << " " << yindex << " " << zindex << G4endl;
206 double valx0z0, mulx0z0, valx1z0, mulx1z0;
207 double valx0z1, mulx0z1, valx1z1, mulx1z1;
208 valx0z0= table[xindex ][0][zindex]; mulx0z0= (1-xlocal) * (1-zlocal);
209 valx1z0= table[xindex+1][0][zindex]; mulx1z0= xlocal * (1-zlocal);
210 valx0z1= table[xindex ][0][zindex+1]; mulx0z1= (1-xlocal) * zlocal;
211 valx1z1= table[xindex+1][0][zindex+1]; mulx1z1= xlocal * zlocal;
212 #endif
213
214 // Full 3-dimensional version
215 Bfield[0] =
216 xField[xindex ][yindex ][zindex ] * (1-xlocal) * (1-ylocal) * (1-zlocal) +
217 xField[xindex ][yindex ][zindex+1] * (1-xlocal) * (1-ylocal) * zlocal +
218 xField[xindex ][yindex+1][zindex ] * (1-xlocal) * ylocal * (1-zlocal) +
219 xField[xindex ][yindex+1][zindex+1] * (1-xlocal) * ylocal * zlocal +
220 xField[xindex+1][yindex ][zindex ] * xlocal * (1-ylocal) * (1-zlocal) +
221 xField[xindex+1][yindex ][zindex+1] * xlocal * (1-ylocal) * zlocal +
222 xField[xindex+1][yindex+1][zindex ] * xlocal * ylocal * (1-zlocal) +
223 xField[xindex+1][yindex+1][zindex+1] * xlocal * ylocal * zlocal ;
224 Bfield[1] =
225 yField[xindex ][yindex ][zindex ] * (1-xlocal) * (1-ylocal) * (1-zlocal) +
226 yField[xindex ][yindex ][zindex+1] * (1-xlocal) * (1-ylocal) * zlocal +
227 yField[xindex ][yindex+1][zindex ] * (1-xlocal) * ylocal * (1-zlocal) +
228 yField[xindex ][yindex+1][zindex+1] * (1-xlocal) * ylocal * zlocal +
229 yField[xindex+1][yindex ][zindex ] * xlocal * (1-ylocal) * (1-zlocal) +
230 yField[xindex+1][yindex ][zindex+1] * xlocal * (1-ylocal) * zlocal +
231 yField[xindex+1][yindex+1][zindex ] * xlocal * ylocal * (1-zlocal) +
232 yField[xindex+1][yindex+1][zindex+1] * xlocal * ylocal * zlocal ;
233 Bfield[2] =
234 zField[xindex ][yindex ][zindex ] * (1-xlocal) * (1-ylocal) * (1-zlocal) +
235 zField[xindex ][yindex ][zindex+1] * (1-xlocal) * (1-ylocal) * zlocal +
236 zField[xindex ][yindex+1][zindex ] * (1-xlocal) * ylocal * (1-zlocal) +
237 zField[xindex ][yindex+1][zindex+1] * (1-xlocal) * ylocal * zlocal +
238 zField[xindex+1][yindex ][zindex ] * xlocal * (1-ylocal) * (1-zlocal) +
239 zField[xindex+1][yindex ][zindex+1] * xlocal * (1-ylocal) * zlocal +
240 zField[xindex+1][yindex+1][zindex ] * xlocal * ylocal * (1-zlocal) +
241 zField[xindex+1][yindex+1][zindex+1] * xlocal * ylocal * zlocal ;
242
243 } else {
244 Bfield[0] = 0.0;
245 Bfield[1] = 0.0;
246 Bfield[2] = 0.0;
247 }
248 }
249
250