1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 //-----------------------------------------------------------------------
19 // Class for Alice magnetic field with constant mesh
20 // Used in the configuration macros (macros/Config.C, etc.)
22 //-----------------------------------------------------------------------
28 #include "AliMagFCM.h"
32 //_______________________________________________________________________
33 AliMagFCM::AliMagFCM():
50 // Standard constructor
57 //_______________________________________________________________________
58 AliMagFCM::AliMagFCM(const char *name, const char *title, Int_t integ,
59 Float_t factor, Float_t fmax):
60 AliMagFC(name,title,integ,factor,fmax),
77 // Standard constructor
83 if(fDebug>-1) Info("ctor",
84 "%s: Constant Mesh Field %s created: map= %d, factor= %f, file= %s\n",
85 ClassName(),fName.Data(), fMap, factor,fTitle.Data());
88 //_______________________________________________________________________
89 AliMagFCM::AliMagFCM(const AliMagFCM &magf):
112 //_______________________________________________________________________
113 void AliMagFCM::Field(Float_t *x, Float_t *b) const
116 // Method to calculate the magnetic field
118 Double_t ratx, raty, ratz, hix, hiy, hiz, ratx1, raty1, ratz1,
119 bhyhz, bhylz, blyhz, blylz, bhz, blz, xl[3];
120 const Double_t kone=1;
123 // --- find the position in the grid ---
128 if(-700 < -x[2] && -x[2] < fZbeg && x[0] * x[0] +(x[1]+30)*(x[1]+30) < 560*560) {
131 // The field map used here was calculated in a coordinate system where the muon arm is at z > 0
132 // Transfom x -> -x and z -> -z
137 Bool_t infield=(fZbeg <= zm && zm < fZbeg+fZdel*(fZn-1)
138 && ( fXbeg <= TMath::Abs(xm) && TMath::Abs(xm) < fXbeg+fXdel*(fXn-1) )
139 && ( fYbeg <= TMath::Abs(ym) && TMath::Abs(ym) < fYbeg+fYdel*(fYn-1) ));
141 xl[0]=TMath::Abs(xm)-fXbeg;
142 xl[1]=TMath::Abs(ym)-fYbeg;
160 // ... simple interpolation
164 bhyhz = Bx(ix ,iy+1,iz+1)*ratx1+Bx(ix+1,iy+1,iz+1)*ratx;
165 bhylz = Bx(ix ,iy+1,iz )*ratx1+Bx(ix+1,iy+1,iz )*ratx;
166 blyhz = Bx(ix ,iy ,iz+1)*ratx1+Bx(ix+1,iy ,iz+1)*ratx;
167 blylz = Bx(ix ,iy ,iz )*ratx1+Bx(ix+1,iy ,iz )*ratx;
168 bhz = blyhz *raty1+bhyhz *raty;
169 blz = blylz *raty1+bhylz *raty;
170 b[0] = blz *ratz1+bhz *ratz;
172 bhyhz = By(ix ,iy+1,iz+1)*ratx1+By(ix+1,iy+1,iz+1)*ratx;
173 bhylz = By(ix ,iy+1,iz )*ratx1+By(ix+1,iy+1,iz )*ratx;
174 blyhz = By(ix ,iy ,iz+1)*ratx1+By(ix+1,iy ,iz+1)*ratx;
175 blylz = By(ix ,iy ,iz )*ratx1+By(ix+1,iy ,iz )*ratx;
176 bhz = blyhz *raty1+bhyhz *raty;
177 blz = blylz *raty1+bhylz *raty;
178 b[1] = blz *ratz1+bhz *ratz;
180 bhyhz = Bz(ix ,iy+1,iz+1)*ratx1+Bz(ix+1,iy+1,iz+1)*ratx;
181 bhylz = Bz(ix ,iy+1,iz )*ratx1+Bz(ix+1,iy+1,iz )*ratx;
182 blyhz = Bz(ix ,iy ,iz+1)*ratx1+Bz(ix+1,iy ,iz+1)*ratx;
183 blylz = Bz(ix ,iy ,iz )*ratx1+Bz(ix+1,iy ,iz )*ratx;
184 bhz = blyhz *raty1+bhyhz *raty;
185 blz = blylz *raty1+bhylz *raty;
186 b[2] = blz *ratz1+bhz *ratz;
187 //printf("ratx,raty,ratz,b[0],b[1],b[2] %f %f %f %f %f %f\n",
188 //ratx,raty,ratz,b[0],b[1],b[2]);
190 // ... use the dipole symmetry
191 if (xm*ym < 0) b[1]=-b[1];
192 if (xm<0) b[2]=-b[2];
197 printf("Invalid field map for constant mesh %d\n",fMap);
200 //This is the ZDC part
212 //_______________________________________________________________________
213 void AliMagFCM::ReadField()
216 // Method to read the magnetic field map from file
219 Int_t ix, iy, iz, ipx, ipy, ipz;
222 if(fDebug) printf("%s: Reading Magnetic Field %s from file %s\n",ClassName(),fName.Data(),fTitle.Data());
223 fname = gSystem->ExpandPathName(fTitle.Data());
224 magfile=fopen(fname,"r");
227 fscanf(magfile,"%d %d %d %f %f %f %f %f %f",
228 &fXn, &fYn, &fZn, &fXdel, &fYdel, &fZdel, &fXbeg, &fYbeg, &fZbeg);
229 if(fDebug>1) printf("%s: fXn %d, fYn %d, fZn %d, fXdel %f, fYdel %f, fZdel %f, fXbeg %f, fYbeg %f, fZbeg %f\n",
230 ClassName(),fXn, fYn, fZn, fXdel, fYdel, fZdel, fXbeg, fYbeg, fZbeg);
234 fB = new TVector(3*fXn*fYn*fZn);
235 for (iz=0; iz<fZn; iz++) {
237 for (iy=0; iy<fYn; iy++) {
239 for (ix=0; ix<fXn; ix++) {
241 fscanf(magfile,"%f %f %f",&bz,&by,&bx);
249 printf("%s: File %s not found !\n",ClassName(),fTitle.Data());
254 //_______________________________________________________________________
255 void AliMagFCM::Copy(TObject & /* magf */) const
258 // Copy *this onto magf -- Not implemented
260 Fatal("Copy","Not implemented!\n");