Some of the coding violations corrected
[u/mrichter/AliRoot.git] / TPC / AliTPCExBEffective.cxx
CommitLineData
ae425f91 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
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 **************************************************************************/
15
16////////////////////////////////////////////////////////////////////////////
17// //
18// AliTPCExBEffective class //
19// Correct for the rest of ExB effect which are not covered by physical models
20//
21// Motivation:
22// ExB correction:
602803b6 23// dr = c0* integral(Er/Ez) + c1* integral(Erphi/Ez)
24// drphi = -c1* integral(Er/Ez) + c0* integral(Erphi/Ez)
ae425f91 25// Where:
26// wt = Bz*(k*vdrift/E) ~ 0.3 at B=0.5 T
27// c0 = 1/(1+T2*T2*wt*wt)
28// c1 = T1*wt/(1+T1*T1*wt*wt)
29//
602803b6 30// Residual integral(Er/Ez,Erphi/Ez) obtained comparing the B field 0 and B field +-0.5 T setting
ae425f91 31// minimizing track matching residuals
602803b6 32// delta(Er/Ez) ~ sum[ poln(r) * polm(z) * cos(n,phi)]
ae425f91 33//
34////////////////////////////////////////////////////////////////////////////
35#include "AliMagF.h"
36#include "TGeoGlobalMagField.h"
37#include "AliTPCcalibDB.h"
38#include "AliTPCParam.h"
39#include "AliLog.h"
40
41#include "TMath.h"
42#include "AliTPCROC.h"
43#include "AliTPCExBEffective.h"
44ClassImp(AliTPCExBEffective)
45
46AliTPCExBEffective::AliTPCExBEffective()
47 : AliTPCCorrection("ExB_effective","ExB effective"),
48 fC0(1.),fC1(0.),
49 fPolynomA(0),
50 fPolynomC(0),
51 fPolynomValA(0),
52 fPolynomValC(0)
53{
54 //
55 // default constructor
56 //
57}
58
59AliTPCExBEffective::~AliTPCExBEffective() {
60 //
61 // default destructor
62 //
63}
64
65
66
67void AliTPCExBEffective::Init() {
68 //
69 // Initialization funtion
70 //
71
72 AliMagF* magF= (AliMagF*)TGeoGlobalMagField::Instance()->GetField();
73 if (!magF) AliError("Magneticd field - not initialized");
74 Double_t bzField = magF->SolenoidField()/10.; //field in T
75 AliTPCParam *param= AliTPCcalibDB::Instance()->GetParameters();
76 if (!param) AliError("Parameters - not initialized");
77 Double_t vdrift = param->GetDriftV()/1000000.; // [cm/us] // From dataBase: to be updated: per second (ideally)
78 Double_t ezField = 400; // [V/cm] // to be updated: never (hopefully)
79 Double_t wt = -10.0 * (bzField*10) * vdrift / ezField ;
80 // Correction Terms for effective omegaTau; obtained by a laser calibration run
81 SetOmegaTauT1T2(wt,fT1,fT2);
82
83
84}
85
86void AliTPCExBEffective::Update(const TTimeStamp &/*timeStamp*/) {
87 //
88 // Update function
89 //
90 AliMagF* magF= (AliMagF*)TGeoGlobalMagField::Instance()->GetField();
91 if (!magF) AliError("Magneticd field - not initialized");
92 Double_t bzField = magF->SolenoidField()/10.; //field in T
93 AliTPCParam *param= AliTPCcalibDB::Instance()->GetParameters();
94 if (!param) AliError("Parameters - not initialized");
95 Double_t vdrift = param->GetDriftV()/1000000.; // [cm/us] // From dataBase: to be updated: per second (ideally)
96 Double_t ezField = 400; // [V/cm] // to be updated: never (hopefully)
97 Double_t wt = -10.0 * (bzField*10) * vdrift / ezField ;
98 // Correction Terms for effective omegaTau; obtained by a laser calibration run
99 SetOmegaTauT1T2(wt,fT1,fT2);
100
101
102}
103
104
105
106void AliTPCExBEffective::GetCorrection(const Float_t x[],const Short_t roc,Float_t dx[]) {
107 //
108 // Calculates the correction due conical shape
109 //
110 if (!fPolynomA) return;
111 AliTPCROC * calROC = AliTPCROC::Instance();
112 const Double_t kRTPC0 =calROC->GetPadRowRadii(0,0);
113 const Double_t kRTPC1 =calROC->GetPadRowRadii(36,calROC->GetNRows(36)-1);
114 Float_t rmiddle=(kRTPC0+kRTPC1)/2.;
115 //
116 Double_t phi = TMath::ATan2(x[1],x[0]);
117 Double_t r = TMath::Sqrt(x[1]*x[1]+x[0]*x[0]);
118 Double_t driftN = 1.-TMath::Abs(x[2])/calROC->GetZLength(0); // drift from 0 to 1
119 Double_t localxN = 2*(r-rmiddle)/(kRTPC1-kRTPC0); // normalize local x position
120 //
602803b6 121 Double_t erez = 0;
122 Double_t erphiez = 0;
123 if (roc%36<18) erez= GetSum(*fPolynomA, *fPolynomValA, localxN, driftN, phi,0);
124 if (roc%36>=18) erez= GetSum(*fPolynomC, *fPolynomValC, localxN, driftN, phi,0);
125 if (roc%36<18) erphiez= GetSum(*fPolynomA, *fPolynomValA, localxN, driftN, phi,1);
126 if (roc%36>=18) erphiez= GetSum(*fPolynomC, *fPolynomValC, localxN, driftN, phi,1);
127
128 Double_t dr = fC0 * erez + fC1 * erphiez;
129 Double_t drphi = -fC1 * erez + fC0 * erphiez;
d2faad4f 130
131 // Calculate distorted position
132 if ( r > 0.0 ) {
133 r = r + dr;
134 phi = phi + drphi/r;
135 }
136 // Calculate correction in cartesian coordinates
137 dx[0] = r * TMath::Cos(phi) - x[0];
138 dx[1] = r * TMath::Sin(phi) - x[1];
139 dx[2] = 0.; // z distortion not implemented (1st order distortions)
ae425f91 140
141}
142
143
144
145Double_t AliTPCExBEffective::GetSum(const TMatrixD& mpol, const TMatrixD&mcoef, Double_t r, Double_t drift, Double_t phi, Int_t coord) const {
146 //
d2faad4f 147 // Summation of the polynomials
ae425f91 148 //
149 Int_t npols=mpol.GetNrows();
150 Double_t sum=0;
151 for (Int_t ipol=0;ipol<npols; ipol++){
152 Double_t pR = 1, pD=1, pPhi=1;
153 Int_t icoord = TMath::Nint(mpol(ipol,0));
154 if (icoord!=coord) continue;
155 Int_t npolR = TMath::Nint(mpol(ipol,1));
156 Int_t npolD = TMath::Nint(mpol(ipol,2));
157 Int_t npolPhi = TMath::Nint(mpol(ipol,3));
158 Double_t coef=mcoef(ipol,0);
159 //
160 for (Int_t ipolR=1; ipolR<=npolR; ipolR++) pR*=r; // use simple polynoms
161 for (Int_t ipolD=1; ipolD<=npolD; ipolD++) pD*=drift; // use simple polynoms
162 pPhi=TMath::Cos(npolPhi*phi);
163 sum+= pR*pD*pPhi*coef;
164 }
165 return sum;
166}
167
168
169void AliTPCExBEffective::SetPolynoms(const TMatrixD *polA,const TMatrixD *polC){
170 //
171 // Set correction polynom - coefficients
172 //
173 fPolynomA = new TMatrixD(*polA);
174 fPolynomC = new TMatrixD(*polC);
175}
176
177void AliTPCExBEffective::SetCoeficients(const TMatrixD *valA,const TMatrixD *valC){
178 //
179 // Set correction polynom - coefficients
180 //
181 fPolynomValA = new TMatrixD(*valA);
182 fPolynomValC = new TMatrixD(*valC);
183}
184
f1fd5b3f 185
186
187
188void AliTPCExBEffective::Print(const Option_t* option) const {
189 //
190 // Print function to check the settings (e.g. the twist in the X direction)
191 // option=="a" prints the C0 and C1 coefficents for calibration purposes
192 //
193
194 TString opt = option; opt.ToLower();
195 printf("%s\t%s\n",GetName(),GetTitle());
196
197 if (opt.Contains("a")) { // Print all details
198 printf(" - T1: %1.4f, T2: %1.4f \n",fT1,fT2);
199 printf(" - C0: %1.4f, C1: %1.4f \n",fC0,fC1);
200 fPolynomValA->Print();
201 fPolynomValC->Print();
202 }
203
204
205}