New fitter for millipede2 + updates to AliITSAlignMille2 (Ruben)
[u/mrichter/AliRoot.git] / ITS / AliITSTPArrayFit.cxx
CommitLineData
6be22b3f 1/**************************************************************************
2 * Copyright(c) 2009-2011, 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/* $Id$ */
16///////////////////////////////////////////////////////////////////////////////////////////////
17// //
18// The line is defined by equations (1) //
19// a0*z+a1*x-a0*a1=0 and //
20// b0*z+b1*y-b0*b1=0 //
21// where x,y,z are NOT the lab axes but z is the lab axis along which the track //
22// has the largest lever arm and x,y are the remaining 2 axis in //
23// the order of fgkAxisID[z][0], fgkAxisID[z][1] //
24// The parameters are fParams[kA0,kB0,kA1,kB1] and the axis chosen as the independent //
25// var. is fParAxis (i.e. if fParAxis==kZ, then a0=ax,b0=bx, a1=ay,b1=by) //
26// //
27// //
28// The helix is defined by the equations (2) //
29// X(t) = (dr+R)*cos(phi0) - (R+sum{dRi})*cos(t+phi0) + sum{dRi*cos(phi0+ti)} //
30// Y(t) = (dr+R)*sin(phi0) - (R+sum{dRi})*sin(t+phi0) + sum{dRi*sin(phi0+ti)} //
31// Z(t) = dz - (R+sum{dRi})*t*tg(dip) + sum{dRi*ti}*tg(dip) //
32// where dRi is the change of the radius due to the ELoss at parameter ti //
33// //
34// Author: ruben.shahoyan@cern.ch //
35// //
36///////////////////////////////////////////////////////////////////////////////////////////////
37
38#include "AliITSTPArrayFit.h"
39#include "AliExternalTrackParam.h"
40#include "AliSymMatrix.h"
41#include "AliLog.h"
42#include "AliParamSolver.h"
43#include "AliGeomManager.h"
44#include "AliITSgeomTGeo.h"
45#include "AliTracker.h"
46#include <TRandom.h>
47
48ClassImp(AliITSTPArrayFit)
49
50const Int_t AliITSTPArrayFit::fgkAxisID[3][3] = {
51 {AliITSTPArrayFit::kY,AliITSTPArrayFit::kZ,AliITSTPArrayFit::kX},
52 {AliITSTPArrayFit::kZ,AliITSTPArrayFit::kX,AliITSTPArrayFit::kY},
53 {AliITSTPArrayFit::kX,AliITSTPArrayFit::kY,AliITSTPArrayFit::kZ} };
54
55const Int_t AliITSTPArrayFit::fgkAxisCID[3][6] = {
56 {AliITSTPArrayFit::kYY,AliITSTPArrayFit::kYZ,AliITSTPArrayFit::kXY,
57 AliITSTPArrayFit::kZZ,AliITSTPArrayFit::kXZ,AliITSTPArrayFit::kXX},
58 //
59 {AliITSTPArrayFit::kZZ,AliITSTPArrayFit::kXZ,AliITSTPArrayFit::kYZ,
60 AliITSTPArrayFit::kXX,AliITSTPArrayFit::kYX,AliITSTPArrayFit::kYY},
61 //
62 {AliITSTPArrayFit::kXX,AliITSTPArrayFit::kXY,AliITSTPArrayFit::kXZ,
63 AliITSTPArrayFit::kYY,AliITSTPArrayFit::kYZ,AliITSTPArrayFit::kZZ}
64};
65//
66
67const Double_t AliITSTPArrayFit::fgkAlmostZero = 1E-55;
68const Double_t AliITSTPArrayFit::fgkCQConv = 0.299792458e-3;// R = PT/Bz/fgkCQConv with GeV,kGauss,cm
69const Double_t AliITSTPArrayFit::fgkZSpanITS[AliITSTPArrayFit::kMaxLrITS] = {
70 36. ,14.1,14.1, 38., 22.2,29.7, 51. ,43.1,48.9};
71
72const Double_t AliITSTPArrayFit::fgkRLayITS[AliITSTPArrayFit::kMaxLrITS] = {
73 2.94, 3.9,7.6, 11.04, 15.0,23.9, 29.44 ,38.0,43.0};
74
75const Int_t AliITSTPArrayFit::fgkPassivLrITS[3] =
76 {AliITSTPArrayFit::kLrBeamPime,AliITSTPArrayFit::kLrShield1,AliITSTPArrayFit::kLrShield2};
77
78const Int_t AliITSTPArrayFit::fgkActiveLrITS[6] =
79 {AliITSTPArrayFit::kLrSPD1,AliITSTPArrayFit::kLrSPD2,
80 AliITSTPArrayFit::kLrSDD1,AliITSTPArrayFit::kLrSDD2,
81 AliITSTPArrayFit::kLrSSD1,AliITSTPArrayFit::kLrSSD2};
82
83Double_t AliITSTPArrayFit::fgRhoLITS[AliITSTPArrayFit::kMaxLrITS] = {
84 1.48e-01, 2.48e-01,2.57e-01, 1.34e-01, 3.34e-01,3.50e-01, 2.22e-01, 2.38e-01,2.25e-01};
85
86//____________________________________________________
87AliITSTPArrayFit::AliITSTPArrayFit() :
88 fPoints(0),fParSol(0),fBz(0),fCharge(0),fPntFirst(-1),
89 fPntLast(-1),fNPBooked(0),fParAxis(-1),fCovI(0),fChi2NDF(0),
90 fMaxIter(20),fIter(0),fEps(1e-6),fMass(0),fkAxID(0),fkAxCID(0),fCurT(0),
91 fFirstPosT(0),fNElsPnt(0),fElsId(0),fElsDR(0)
92{
93 // default constructor
94 for (int i=kMaxParam;i--;) fParams[i] = 0;
95 for (int i=kMaxParamSq;i--;) fParamsCov[i] = 0;
96 SetMass();
97}
98
99//____________________________________________________
100AliITSTPArrayFit::AliITSTPArrayFit(Int_t np) :
101 fPoints(0),fParSol(0),fBz(0),fCharge(0),fPntFirst(-1),
102 fPntLast(-1),fNPBooked(np),fParAxis(-1),fCovI(0),fChi2NDF(0),
103 fMaxIter(20),fIter(0),fEps(1e-6),fMass(0),fkAxID(0),fkAxCID(0),fCurT(0),
104 fFirstPosT(0),fNElsPnt(0),fElsId(0),fElsDR(0)
105{
106 // constructor with booking of np points
107 for (int i=kMaxParam;i--;) fParams[i] = 0;
108 for (int i=kMaxParamSq;i--;) fParamsCov[i] = 0;
109 InitAux();
110 SetEps();
111 SetMass();
112 SetMaxIterations();
113}
114
115//____________________________________________________
116AliITSTPArrayFit::AliITSTPArrayFit(const AliITSTPArrayFit &src) :
117 TObject(src),fPoints(src.fPoints),fParSol(0),fBz(src.fBz),
118 fCharge(src.fCharge),fPntFirst(src.fPntFirst),fPntLast(src.fPntLast),fNPBooked(src.fNPBooked),
119 fParAxis(src.fParAxis),fCovI(0),fChi2NDF(0),fMaxIter(20),fIter(0),fEps(0),fMass(src.fMass),
120 fkAxID(0),fkAxCID(0),fCurT(0),fFirstPosT(0),fNElsPnt(0),fElsId(0),fElsDR(0)
121{
122 // copy constructor
123 InitAux();
124 memcpy(fCovI,src.fCovI,fNPBooked*6*sizeof(Double_t));
125 for (int i=kMaxParam;i--;) fParams[i] = src.fParams[i];
126 for (int i=kMaxParamSq;i--;) fParamsCov[i] = src.fParamsCov[i];
127 memcpy(fCurT,src.fCurT,fNPBooked*sizeof(Double_t));
128 SetEps(src.fEps);
129 SetMaxIterations(src.fMaxIter);
130 //
131}
132
133//____________________________________________________
134AliITSTPArrayFit &AliITSTPArrayFit::operator =(const AliITSTPArrayFit& src)
135{
136 // assignment operator
137 if (this==&src) return *this;
138 ((TObject*)this)->operator=(src);
139 fPoints = src.fPoints;
140 if (!fParSol) fParSol = new AliParamSolver(*src.fParSol);
141 else *fParSol = *src.fParSol;
142 fBz = src.fBz;
143 fCharge = src.fCharge;
144 fNPBooked = src.fNPBooked;
145 fPntFirst = src.fPntFirst;
146 fPntLast = src.fPntLast;
147 InitAux();
148 memcpy(fCovI,src.fCovI,fNPBooked*6*sizeof(Double_t));
149 for (int i=kMaxParam;i--;) fParams[i] = src.fParams[i];
150 for (int i=kMaxParamSq;i--;) fParamsCov[i] = src.fParamsCov[i];
151 SetParAxis(src.fParAxis);
152 fNElsPnt = src.fNElsPnt;
153 fFirstPosT = src.fFirstPosT;
154 memcpy(fCurT ,src.fCurT ,fNPBooked*sizeof(Double_t));
155 memcpy(fElsId ,src.fElsId ,fNPBooked*sizeof(Int_t));
156 memcpy(fElsDR ,src.fElsDR ,fNPBooked*sizeof(Double_t));
157 memcpy(fCurT ,src.fCurT ,fNPBooked*sizeof(Double_t));
158 SetEps(src.fEps);
159 SetMaxIterations(src.fMaxIter);
160 //
161 return *this;
162 //
163}
164
165//____________________________________________________
166AliITSTPArrayFit::~AliITSTPArrayFit()
167{
168 // destructor
169 delete fParSol;
170 delete[] fCovI;
171 delete[] fCurT;
172 delete[] fElsId;
173 delete[] fElsDR;
174}
175
176//____________________________________________________
177void AliITSTPArrayFit::Reset()
178{
179 // reset to process new track
180 if (fParSol) fParSol->Clear();
181 fPoints=0;
182 fNElsPnt = 0;
183 fFirstPosT = 0;
184 // fBz = 0;
185 fCharge = 0;
186 fIter = 0;
187 fPntFirst=fPntLast=-1;
188 SetParAxis(-1);
189 ResetBit(kFitDoneBit|kCovInvBit);
190}
191
192//____________________________________________________
193void AliITSTPArrayFit::AttachPoints(const AliTrackPointArray* points, Int_t pfirst,Int_t plast)
194{
195 // create from piece of AliTrackPointArray
196 Reset();
197 fPoints = points;
198 int np = points->GetNPoints();
199 if (fNPBooked<np) {
200 fNPBooked = np;
201 InitAux();
202 }
203 fPntFirst = pfirst<0 ? 0 : pfirst;
204 fPntLast = plast<fPntFirst ? np-1 : plast;
205 //
206 for (int i=kMaxParam;i--;) fParams[i] = 0;
207 for (int i=kMaxParamSq;i--;) fParamsCov[i] = 0;
208 //
209 InvertPointsCovMat();
210 //
211}
212
213//____________________________________________________
214Bool_t AliITSTPArrayFit::SetFirstLast(Int_t pfirst,Int_t plast)
215{
216 // set first and last point to fit
217 const AliTrackPointArray* pnts = fPoints;
218 if (!pnts) {AliError("TrackPointArray is not attached yet"); return kFALSE;}
219 AttachPoints(pnts,pfirst,plast);
220 return kTRUE;
221 //
222}
223
224//____________________________________________________
225Bool_t AliITSTPArrayFit::InvertPointsCovMat()
226{
227 // invert the cov.matrices of the points
228 for (int i=fPntFirst;i<=fPntLast;i++) {
229 //
230 const float *cov = fPoints->GetCov() + i*6; // pointer on cov.matrix
231 //
232 Double_t t0 = cov[kYY]*cov[kZZ] - cov[kYZ]*cov[kYZ];
233 Double_t t1 = cov[kXY]*cov[kZZ] - cov[kXZ]*cov[kYZ];
234 Double_t t2 = cov[kXY]*cov[kYZ] - cov[kXZ]*cov[kYY];
235 Double_t det = cov[kXX]*t0 - cov[kXY]*t1 + cov[kXZ]*t2;
236 if (TMath::Abs(det)<fgkAlmostZero) {
237 AliInfo(Form("Cov.Matrix for point %d is singular",i));
238 return kFALSE;
239 }
240 //
241 Double_t *covI = GetCovI(i);
242 covI[kXX] = t0/det;
243 covI[kXY] = -t1/det;
244 covI[kXZ] = t2/det;
245 covI[kYY] = (cov[kXX]*cov[kZZ] - cov[kXZ]*cov[kXZ])/det;
246 covI[kYZ] = (cov[kXY]*cov[kXZ] - cov[kXX]*cov[kYZ])/det;
247 covI[kZZ] = (cov[kXX]*cov[kYY] - cov[kXY]*cov[kXY])/det;
248 //
249 }
250 SetCovInv();
251 return kTRUE;
252}
253
254//____________________________________________________
255void AliITSTPArrayFit::InitAux()
256{
257 // init auxiliary space
258 if (fCovI) delete[] fCovI;
259 if (fCurT) delete[] fCurT;
260 //
261 fCovI = new Double_t[6*fNPBooked];
262 fCurT = new Double_t[fNPBooked+kMaxLrITS];
263 fElsId = new Int_t[fNPBooked+kMaxLrITS];
264 fElsDR = new Double_t[fNPBooked+kMaxLrITS];
265 memset(fElsDR,0,(fNPBooked+kMaxLrITS)*sizeof(Double_t));
266 memset(fCovI,0,fNPBooked*6*sizeof(Double_t));
267 //
268}
269
270//____________________________________________________
271Bool_t AliITSTPArrayFit::FitLineCrude()
272{
273 // perform linear fit w/o accounting the errors
274 // fit is done in the parameterization
275 // x = res[0] + res[1]*z
276 // y = res[2] + res[3]*z
277 // where x,y,z are NOT the lab axes but z is the lab axis along which the track
278 // has the largest lever arm and x,y are the remaining 2 axis in
279 // the order of fgkAxisID[z][0], fgkAxisID[z][1]
280 //
281 int np = fPntLast - fPntFirst + 1;
282 if (np<2) {
283 AliError("At least 2 points are needed for straight line fit");
284 return kFALSE;
285 }
286 //
287 if (fParAxis<0) SetParAxis(ChoseParAxis());
288 Double_t sZ=0,sZZ=0,sY=0,sYZ=0,sX=0,sXZ=0,det=0;
289 //
290 const float *coord[3] = {fPoints->GetX(),fPoints->GetY(),fPoints->GetZ()};
291 const Float_t *varZ = coord[ fParAxis ];
292 const Float_t *varX = coord[ fkAxID[kX] ];
293 const Float_t *varY = coord[ fkAxID[kY] ];
294 //
295 for (int i=fPntFirst;i<=fPntLast;i++) {
296 sZ += varZ[i];
297 sZZ += varZ[i]*varZ[i];
298 //
299 sX += varX[i];
300 sXZ += varX[i]*varZ[i];
301 //
302 sY += varY[i];
303 sYZ += varY[i]*varZ[i];
304 }
305 det = sZZ*np-sZ*sZ;
306 if (TMath::Abs(det)<fgkAlmostZero) return kFALSE;
307 fParams[0] = (sX*sZZ-sZ*sXZ)/det;
308 fParams[1] = (sXZ*np-sZ*sX)/det;
309 //
310 fParams[2] = (sY*sZZ-sZ*sYZ)/det;
311 fParams[3] = (sYZ*np-sZ*sY)/det;
312 //
313 return kTRUE;
314 //
315}
316
317//____________________________________________________
318void AliITSTPArrayFit::SetParAxis(Int_t ax)
319{
320 // select the axis which will be used as a parameter for the line: longest baseline
321 if (ax>kZ) {
322 AliInfo(Form("Wrong axis choice: %d",ax));
323 fParAxis = -1;
324 }
325 fParAxis = ax;
326 if (ax>=0) {
327 fkAxID = fgkAxisID[ax];
328 fkAxCID = fgkAxisCID[ax];
329 }
330 else {
331 fkAxID = fkAxCID = 0;
332 }
333 //
334}
335
336//____________________________________________________
337Int_t AliITSTPArrayFit::ChoseParAxis() const
338{
339 // select the variable with largest base as a parameter
340 Double_t cmn[3]={1.e9,1.e9,1.e9},cmx[3]={-1.e9,-1.e9,-1.e9};
341 //
342 const float *coord[3] = {fPoints->GetX(),fPoints->GetY(),fPoints->GetZ()};
343 for (int i=fPntFirst;i<=fPntLast;i++) {
344 for (int j=3;j--;) {
345 Double_t val = coord[j][i];
346 if (cmn[j]>val) cmn[j] = val;
347 if (cmx[j]<val) cmx[j] = val;
348 }
349 }
350 //
351 int axis = kZ;
352 if (cmx[axis]-cmn[axis] < cmx[kX]-cmn[kX]) axis = kX;
353 if (cmx[axis]-cmn[axis] < cmx[kY]-cmn[kY]) axis = kY;
354 return axis;
355 //
356}
357
358//____________________________________________________
359Double_t AliITSTPArrayFit::GetPosition(Double_t *xyzPCA, const Double_t *xyz, const Double_t *covI) const
360{
361 // calculate the position of the track at PCA to xyz
362 Double_t t = GetParPCA(xyz,covI);
363 GetPosition(xyzPCA,t);
364 return t;
365}
366
367//____________________________________________________
368Double_t AliITSTPArrayFit::GetPosition(Double_t *xyzPCA, const AliTrackPoint *pntCovInv) const
369{
370 // calculate the position of the track at PCA to pntCovInv
371 // NOTE: the covariance matrix of the point must be inverted
372 Double_t covI[6],xyz[3] = {pntCovInv->GetX(),pntCovInv->GetY(),pntCovInv->GetZ()};
373 for (int i=6;i--;) covI[i] = pntCovInv->GetCov()[i];
374 Double_t t = GetParPCA(xyz,covI);
375 GetPosition(xyzPCA,t);
376 return t;
377}
378
379//____________________________________________________
380void AliITSTPArrayFit::GetResiduals(Double_t *resPCA, const AliTrackPoint *pntCovInv) const
381{
382 // calculate the residuals of the track at PCA to pntCovInv
383 // NOTE: the covariance matrix of the point must be inverted
384 GetPosition(resPCA,pntCovInv);
385 resPCA[0] -= pntCovInv->GetX();
386 resPCA[1] -= pntCovInv->GetY();
387 resPCA[2] -= pntCovInv->GetZ();
388}
389
390//____________________________________________________
391void AliITSTPArrayFit::GetResiduals(Double_t *resPCA, const Double_t *xyz, const Double_t *covI) const
392{
393 // calculate the residuals of the track at PCA to xyz
394 GetPosition(resPCA,xyz,covI);
395 resPCA[kX] -= xyz[kX];
396 resPCA[kY] -= xyz[kY];
397 resPCA[kZ] -= xyz[kZ];
398}
399
400//____________________________________________________
401Double_t AliITSTPArrayFit::GetParPCALine(const Double_t *xyz, const Double_t *covI) const
402{
403 // get parameter for the point with least weighted distance to the point
404 //
405 Double_t rhs,denom;
406 Double_t dx = fParams[kA0]-xyz[ fkAxID[kX] ];
407 Double_t dy = fParams[kA1]-xyz[ fkAxID[kY] ];
408 Double_t dz = -xyz[ fkAxID[kZ] ];
409 //
410 if (covI) {
411 Double_t tx = fParams[kB0]*covI[ fkAxCID[kXX] ] + fParams[kB1]*covI[ fkAxCID[kXY] ] + covI[ fkAxCID[kXZ] ];
412 Double_t ty = fParams[kB0]*covI[ fkAxCID[kXY] ] + fParams[kB1]*covI[ fkAxCID[kYY] ] + covI[ fkAxCID[kYZ] ];
413 Double_t tz = fParams[kB0]*covI[ fkAxCID[kXZ] ] + fParams[kB1]*covI[ fkAxCID[kYZ] ] + covI[ fkAxCID[kZZ] ];
414 rhs = tx*dx + ty*dy + tz*dz;
415 denom = -(fParams[kB0]*(covI[ fkAxCID[kXZ] ] + tx) + fParams[kB1]*(covI[ fkAxCID[kYZ] ] + ty) + covI[ fkAxCID[kZZ] ]);
416 }
417 else {
418 rhs = fParams[kB0]*dx + fParams[kB1]*dy + dz;
419 denom = -(fParams[kB0]*fParams[kB0] + fParams[kB1]*fParams[kB1] + 1);
420 }
421 //
422 return rhs/denom;
423 //
424}
425
426//____________________________________________________
427void AliITSTPArrayFit::GetDResDPosLine(Double_t *dXYZdP, /*const Double_t *xyz,*/ const Double_t *covI) const
428{
429 // calculate detivative of the PCA residuals vs point position and fill in user provide
430 // array in the format {dXdXp,dY/dXp,dZdXp, ... dXdZp,dYdZp,dZdZp}
431 //
432 Double_t dTdP[3];
433 GetDtDPosLine(dTdP, /*xyz,*/ covI); // derivative of the t-param over point position
434 //
435 for (int i=3;i--;) {
436 int var = fkAxID[i];
437 Double_t *curd = dXYZdP + var*3; // d/dCoord_i
438 curd[ fkAxID[kX] ] = fParams[kB0]*dTdP[var];
439 curd[ fkAxID[kY] ] = fParams[kB1]*dTdP[var];
440 curd[ fkAxID[kZ] ] = dTdP[var];
441 curd[ var ]-= 1.;
442 }
443 //
444}
445
446//____________________________________________________
447void AliITSTPArrayFit::GetDResDParamsLine(Double_t *dXYZdP, const Double_t *xyz, const Double_t *covI) const
448{
449 // calculate detivative of the PCA residuals vs line parameters and fill in user provide
450 // array in the format {dXdP0,dYdP0,dZdP0, ... dXdPn,dYdPn,dZdPn}
451 //
452 Double_t dTdP[4];
453 Double_t t = GetDtDParamsLine(dTdP, xyz, covI); // derivative of the t-param over line params
454 //
455 Double_t *curd = dXYZdP + kA0*3; // d/dA0
456 curd[ fkAxID[kX] ] = fParams[kB0]*dTdP[kA0] + 1.;
457 curd[ fkAxID[kY] ] = fParams[kB1]*dTdP[kA0];
458 curd[ fkAxID[kZ] ] = dTdP[kA0];
459 //
460 curd = dXYZdP + kB0*3; // d/dB0
461 curd[ fkAxID[kX] ] = fParams[kB0]*dTdP[kB0] + t;
462 curd[ fkAxID[kY] ] = fParams[kB1]*dTdP[kB0];
463 curd[ fkAxID[kZ] ] = dTdP[kB0];
464 //
465 curd = dXYZdP + kA1*3; // d/dA1
466 curd[ fkAxID[kX] ] = fParams[kB0]*dTdP[kA1];
467 curd[ fkAxID[kY] ] = fParams[kB1]*dTdP[kA1] + 1.;
468 curd[ fkAxID[kZ] ] = dTdP[kA1];
469 //
470 curd = dXYZdP + kB1*3; // d/dB1
471 curd[ fkAxID[kX] ] = fParams[kB0]*dTdP[kB1];
472 curd[ fkAxID[kY] ] = fParams[kB1]*dTdP[kB1] + t;
473 curd[ fkAxID[kZ] ] = dTdP[kB1];
474 //
475}
476
477//____________________________________________________
478Double_t AliITSTPArrayFit::GetDtDParamsLine(Double_t *dtparam,const Double_t *xyz, const Double_t *covI) const
479{
480 // get t-param detivative over the parameters for the point with least weighted distance to the point
481 //
482 Double_t rhs,denom;
483 Double_t dx = fParams[kA0]-xyz[ fkAxID[kX] ];
484 Double_t dy = fParams[kA1]-xyz[ fkAxID[kY] ];
485 Double_t dz = -xyz[ fkAxID[kZ] ];
486 Double_t rhsDA0,rhsDA1,rhsDB0,rhsDB1,denDB0,denDB1;
487 //
488 if (covI) {
489 Double_t tx = fParams[kB0]*covI[ fkAxCID[kXX] ] + fParams[kB1]*covI[ fkAxCID[kXY] ] + covI[ fkAxCID[kXZ] ];
490 Double_t ty = fParams[kB0]*covI[ fkAxCID[kXY] ] + fParams[kB1]*covI[ fkAxCID[kYY] ] + covI[ fkAxCID[kYZ] ];
491 Double_t tz = fParams[kB0]*covI[ fkAxCID[kXZ] ] + fParams[kB1]*covI[ fkAxCID[kYZ] ] + covI[ fkAxCID[kZZ] ];
492 rhs = tx*dx + ty*dy + tz*dz;
493 denom = -(fParams[kB0]*(covI[ fkAxCID[kXZ] ] + tx) + fParams[kB1]*(covI[ fkAxCID[kYZ] ] + ty) + covI[ fkAxCID[kZZ] ]);
494 //
495 rhsDA0 = tx;
496 rhsDA1 = ty;
497 rhsDB0 = covI[ fkAxCID[kXX] ]*dx + covI[ fkAxCID[kXY] ]*dy + covI[ fkAxCID[kXZ] ]*dz;
498 rhsDB1 = covI[ fkAxCID[kXY] ]*dx + covI[ fkAxCID[kYY] ]*dy + covI[ fkAxCID[kYZ] ]*dz;
499 //
500 denDB0 = -(tx + tx);
501 denDB1 = -(ty + ty);
502 }
503 else {
504 rhs = fParams[kB0]*dx + fParams[kB1]*dy + dz;
505 denom = -(fParams[kB0]*fParams[kB0] + fParams[kB1]*fParams[kB1] + 1);
506 //
507 rhsDA0 = fParams[kB0];
508 rhsDB0 = dx;
509 rhsDA1 = fParams[kB1];
510 rhsDB1 = dy;
511 //
512 denDB0 = -(fParams[kB0]+fParams[kB0]);
513 denDB1 = -(fParams[kB1]+fParams[kB1]);
514 //
515 }
516 //
517 Double_t denom2 = denom*denom;
518 dtparam[kA0] = rhsDA0/denom; // denom does not depend on A0,A1
519 dtparam[kA1] = rhsDA1/denom;
520 dtparam[kB0] = rhsDB0/denom - rhs/denom2 * denDB0;
521 dtparam[kB1] = rhsDB1/denom - rhs/denom2 * denDB1;
522 //
523 return rhs/denom;
524}
525
526//____________________________________________________
527void AliITSTPArrayFit::GetDtDPosLine(Double_t *dtpos,/*const Double_t *xyz,*/ const Double_t *covI) const
528{
529 // get t-param detivative over the parameters for the point with least weighted distance to the point
530 //
531 // Double_t rhs;
532 // Double_t dx = fParams[kA0]-xyz[ fkAxID[kX] ];
533 // Double_t dy = fParams[kA1]-xyz[ fkAxID[kY] ];
534 // Double_t dz = -xyz[ fkAxID[kZ] ];
535 Double_t denom;
536 Double_t rhsDX,rhsDY,rhsDZ;
537 //
538 if (covI) {
539 Double_t tx = fParams[kB0]*covI[ fkAxCID[kXX] ] + fParams[kB1]*covI[ fkAxCID[kXY] ] + covI[ fkAxCID[kXZ] ];
540 Double_t ty = fParams[kB0]*covI[ fkAxCID[kXY] ] + fParams[kB1]*covI[ fkAxCID[kYY] ] + covI[ fkAxCID[kYZ] ];
541 Double_t tz = fParams[kB0]*covI[ fkAxCID[kXZ] ] + fParams[kB1]*covI[ fkAxCID[kYZ] ] + covI[ fkAxCID[kZZ] ];
542 // rhs = tx*dx + ty*dy + tz*dz;
543 denom = -(fParams[kB0]*(covI[ fkAxCID[kXZ] ] + tx) + fParams[kB1]*(covI[ fkAxCID[kYZ] ] + ty) + covI[ fkAxCID[kZZ] ]);
544 //
545 rhsDX = -tx;
546 rhsDY = -ty;
547 rhsDZ = -tz;
548 }
549 else {
550 // rhs = fParams[kB0]*dx + fParams[kB1]*dy + dz;
551 denom = -(fParams[kB0]*fParams[kB0] + fParams[kB1]*fParams[kB1] + 1);
552 //
553 rhsDX = -fParams[kB0];
554 rhsDY = -fParams[kB1];
555 rhsDZ = -1;
556 //
557 }
558 //
559 dtpos[ fkAxID[kX] ] = rhsDX/denom;
560 dtpos[ fkAxID[kY] ] = rhsDY/denom;
561 dtpos[ fkAxID[kZ] ] = rhsDZ/denom;
562 //
563 // return rhs/denom;
564}
565
566//____________________________________________________
567void AliITSTPArrayFit::GetDResDParamsLine(Double_t *dXYZdP, Int_t ipnt) const
568{
569 // calculate detivative of the PCA residuals vs line parameters and fill in user provide
570 // array in the format {dXdP0,dYdP0,dZdP0, ... dXdPn,dYdPn,dZdPn}
571 //
572 if (ipnt<fPntFirst || ipnt>fPntLast) {
573 AliError(Form("Attempt to access the point %d not in the fitted points [%d:%d]",ipnt,fPntFirst,fPntLast));
574 return;
575 }
576 GetDResDParamsLine(dXYZdP, GetPoint(ipnt) , IsCovIgnored() ? 0 : GetCovI(ipnt));
577}
578
579//____________________________________________________
580void AliITSTPArrayFit::GetDResDPosLine(Double_t *dXYZdP, Int_t ipnt) const
581{
582 // calculate detivative of the PCA residuals vs point position and fill in user provide
583 // array in the format {dXdXp,dY/dXp,dZdXp, ... dXdZp,dYdZp,dZdZp}
584 //
585 if (ipnt<fPntFirst || ipnt>fPntLast) {
586 AliError(Form("Attempt to access the point %d not in the fitted points [%d:%d]",ipnt,fPntFirst,fPntLast));
587 return;
588 }
589 GetDResDPosLine(dXYZdP,IsCovIgnored() ? 0 : GetCovI(ipnt));
590}
591
592//____________________________________________________
593void AliITSTPArrayFit::GetDResDParams(Double_t *dXYZdP, Int_t ipnt)
594{
595 // calculate detivative of the PCA residuals vs track parameters and fill in user provide
596 // array in the format {dXdP0,dYdP0,dZdP0, ... dXdPn,dYdPn,dZdPn}
597 //
598 if (ipnt<fPntFirst || ipnt>fPntLast) {
599 AliError(Form("Attempt to access the point %d not in the fitted points [%d:%d]",ipnt,fPntFirst,fPntLast));
600 return;
601 }
602 GetDResDParams(dXYZdP, GetPoint(ipnt) , IsCovIgnored() ? 0 : GetCovI(ipnt));
603}
604
605//____________________________________________________
606void AliITSTPArrayFit::GetDResDPos(Double_t *dXYZdP, Int_t ipnt)
607{
608 // calculate detivative of the PCA residuals vs point position and fill in user provide
609 // array in the format {dXdXp,dY/dXp,dZdXp, ... dXdZp,dYdZp,dZdZp}
610 //
611 if (ipnt<fPntFirst || ipnt>fPntLast) {
612 AliError(Form("Attempt to access the point %d not in the fitted points [%d:%d]",ipnt,fPntFirst,fPntLast));
613 return;
614 }
615 GetDResDPos(dXYZdP, GetPoint(ipnt), IsCovIgnored() ? 0 : GetCovI(ipnt));
616}
617
618//____________________________________________________
619void AliITSTPArrayFit::GetDResDParams(Double_t *dXYZdP, const Double_t *xyz, const Double_t *covI)
620{
621 // get residual detivatives over the track parameters for the point with least weighted distance to the point
622 //
623 if (!IsFieldON()) { // for the straight line calculate analytically
624 GetDResDParamsLine(dXYZdP, xyz, covI);
625 return;
626 }
627 //
628 // calculate derivative numerically
629 const Double_t delta = 0.01;
630 Double_t xyzVar[4][3];
631 //
632 for (int ipar = 5;ipar--;) {
633 double sav = fParams[ipar];
634 fParams[ipar] -= delta;
635 GetPosition(xyzVar[0],xyz,covI);
636 fParams[ipar] += delta/2;
637 GetPosition(xyzVar[1],xyz,covI);
638 fParams[ipar] += delta;
639 GetPosition(xyzVar[2],xyz,covI);
640 fParams[ipar] += delta/2;
641 GetPosition(xyzVar[3],xyz,covI);
642 fParams[ipar] = sav; // restore
643 //
644 double *curd = dXYZdP + 3*ipar;
645 for (int i=3;i--;) curd[i] = (8.*(xyzVar[2][i]-xyzVar[1][i]) - (xyzVar[3][i]-xyzVar[0][i]))/6./delta;
646 }
647 //
648}
649
650
651//____________________________________________________
652void AliITSTPArrayFit::GetDResDPos(Double_t *dXYZdP, const Double_t *xyz, const Double_t *covI)
653{
654 // get residuals detivative over the point position for the point with least weighted distance to the point
655 //
656
657 if (!IsFieldON()) { // for the straight line calculate analytically
658 GetDResDPosLine(dXYZdP, /*xyz,*/ covI);
659 return;
660 }
661 //
662 // calculate derivative numerically
663 const Double_t delta = 0.005;
664 Double_t xyzVar[4][3];
665 Double_t xyzv[3] = {xyz[0],xyz[1],xyz[2]};
666 //
667 for (int ipar = 3;ipar--;) {
668 double sav = xyzv[ipar];
669 xyzv[ipar] -= delta;
670 GetPosition(xyzVar[0],xyzv,covI);
671 xyzv[ipar] += delta/2;
672 GetPosition(xyzVar[1],xyzv,covI);
673 xyzv[ipar] += delta;
674 GetPosition(xyzVar[2],xyzv,covI);
675 xyzv[ipar] += delta/2;
676 GetPosition(xyzVar[3],xyzv,covI);
677 xyzv[ipar] = sav; // restore
678 //
679 double *curd = dXYZdP + 3*ipar;
680 for (int i=3;i--;) curd[i] = (8.*(xyzVar[2][i]-xyzVar[1][i]) - (xyzVar[3][i]-xyzVar[0][i]))/6./delta;
681 curd[ipar] -= 1.;
682 }
683 //
684}
685
686//________________________________________________________________________________________________________
687Double_t AliITSTPArrayFit::GetParPCAHelix(const Double_t* xyz, const Double_t* covI) const
688{
689 // find track parameter t (eq.2) corresponding to point of closest approach to xyz
690 //
691 Double_t phi = GetParPCACircle(xyz[kX],xyz[kY]);
692 Double_t cs = TMath::Cos(fParams[kPhi0]);
693 Double_t sn = TMath::Sin(fParams[kPhi0]);
694 Double_t xc = (fParams[kD0]+fParams[kR0])*cs;
695 Double_t yc = (fParams[kD0]+fParams[kR0])*sn;
696 Double_t dchi2,ddchi2;
697 //
698 Double_t dzD = -fParams[kR0]*fParams[kDip];
699 Double_t dphi = 0;
700 //
701 int it=0;
702 do {
703 cs = TMath::Cos(phi + fParams[kPhi0]);
704 sn = TMath::Sin(phi + fParams[kPhi0]);
705 //
706 Double_t dxD = fParams[kR0]*sn;
707 Double_t dyD = -fParams[kR0]*cs;
708 Double_t dxDD = -dyD;
709 Double_t dyDD = dxD;
710 //
711 Double_t dx = xc - fParams[kR0]*cs - xyz[kX];
712 Double_t dy = yc - fParams[kR0]*sn - xyz[kY];
713 Double_t dz = fParams[kDZ] + dzD*phi- xyz[kZ];
714 //
715 if (covI) {
716 Double_t tx = dx*covI[kXX] + dy*covI[kXY] + dz*covI[kXZ];
717 Double_t ty = dx*covI[kXY] + dy*covI[kYY] + dz*covI[kYZ];
718 Double_t tz = dx*covI[kXZ] + dy*covI[kYZ] + dz*covI[kZZ];
719 //
720 Double_t ttx = dxD*covI[kXX] + dyD*covI[kXY] + dzD*covI[kXZ];
721 Double_t tty = dxD*covI[kXY] + dyD*covI[kYY] + dzD*covI[kYZ];
722 Double_t ttz = dxD*covI[kXZ] + dyD*covI[kYZ] + dzD*covI[kZZ];
723 //
724 // chi2 = dx*tx + dy*ty + dz*tz;
725 dchi2 = dxD*tx + dyD*ty + dzD*tz;
726 ddchi2 = dxDD*tx + dyDD*ty + dxD *ttx + dyD *tty + dzD *ttz;
727 //
728 }
729 else {
730 // chi2 = dx*dx + dy*dy + dz*dz;
731 dchi2 = dxD*dx + dyD*dy + dzD*dz;
732 ddchi2 = dxDD*dx + dyDD*dy + + dxD*dxD + dyD*dyD + dzD*dzD;
733 }
734 //
735 if (TMath::Abs(ddchi2)<fgkAlmostZero || TMath::Abs(dphi=dchi2/ddchi2)<fEps) break;
736 phi -= dphi;
737 } while(++it<fMaxIter);
738 //
739 return phi;
740}
741
742//________________________________________________________________________________________________________
743Double_t AliITSTPArrayFit::GetParPCACircle(Double_t x,Double_t y) const
744{
745 // find track parameter t (eq.2) corresponding to point on the circle with closest approach to x,y
746 //
747 Double_t r = fParams[kD0]+fParams[kR0];
748 Double_t t = TMath::ATan2( r*TMath::Sin(fParams[kPhi0])-y, r*TMath::Cos(fParams[kPhi0])-x ) - fParams[kPhi0];
749 if (fParams[kR0] < 0) t += TMath::Pi();
750 if (t > TMath::Pi()) t -= TMath::Pi()*2;
751 if (t <-TMath::Pi()) t += TMath::Pi()*2;
752 return t;
753}
754
755//________________________________________________________________________________________________________
756Double_t AliITSTPArrayFit::GetHelixParAtR(Double_t r) const
757{
758 // find helix parameter t (eq.2) corresponding to point on the circle of radius t
759 //
760 double gam = 1. - (r-fParams[kD0])*(r+fParams[kD0])/fParams[kR0]/(fParams[kD0]+fParams[kR0])/2.;
761 return (TMath::Abs(gam)>1) ? -1e9 : TMath::ACos(gam);
762}
763
764//________________________________________________________________________________________________________
765Double_t AliITSTPArrayFit::CalcChi2NDF() const
766{
767 // calculate fit chi2/ndf
768 Double_t chi2 = 0;
769 Double_t dr[3]; // residuals
770 //if (!IsFitDone()) return -1;
771 for (int ipnt=fPntFirst;ipnt<=fPntLast;ipnt++) {
772 GetResiduals(dr,ipnt);
773 Double_t* covI = GetCovI(ipnt);
774 chi2 += dr[kX]*(dr[kX]*covI[ kXX ]+dr[kY]*covI[ kXY ]+dr[kZ]*covI[ kXZ ])
775 + dr[kY]*(dr[kX]*covI[ kXY ]+dr[kY]*covI[ kYY ]+dr[kZ]*covI[ kYZ ])
776 + dr[kZ]*(dr[kX]*covI[ kXZ ]+dr[kY]*covI[ kYZ ]+dr[kZ]*covI[ kZZ ]);
777 }
778 int ndf = (fPntLast-fPntFirst+1)*3 - GetNParams();
779 chi2 /= ndf;
780 return chi2;
781}
782
783//________________________________________________________________________________________________________
784void AliITSTPArrayFit::GetResiduals(Double_t *res,Int_t ipnt) const
785{
786 // calculate residuals at point
787 if (ipnt<fPntFirst || ipnt>fPntLast) {
788 AliError(Form("Attempt to access the point %d not in the fitted points [%d:%d]",ipnt,fPntFirst,fPntLast));
789 return;
790 }
791 GetPosition(res,fCurT[ipnt]);
792 res[kX] -= fPoints->GetX()[ipnt];
793 res[kY] -= fPoints->GetY()[ipnt];
794 res[kZ] -= fPoints->GetZ()[ipnt];
795}
796
797//________________________________________________________________________________________________________
798void AliITSTPArrayFit::GetPosition(Double_t *xyz, Double_t t) const
799{
800 // calculate track position for parameter value t
801 if (IsFieldON()) {
802 //
803 Double_t rrho = fParams[kD0]+fParams[kR0];
804 Double_t xc = rrho*TMath::Cos(fParams[kPhi0]);
805 Double_t yc = rrho*TMath::Sin(fParams[kPhi0]);
806 Double_t r = fParams[kR0];
807 Double_t ze = 0;
808 //
809 if (IsELossON()) {
810 if (t>0) {
811 for (int i=fFirstPosT;i<fNElsPnt;i++) { // along the track direction
812 int indE = fElsId[i];
813 if ( t<fCurT[indE] ) break; // does not reach this layer on its way to t
814 xc += fElsDR[indE] * TMath::Cos(fParams[kPhi0] + fCurT[indE]);
815 yc += fElsDR[indE] * TMath::Sin(fParams[kPhi0] + fCurT[indE]);
816 ze += fElsDR[indE] * fCurT[indE];
817 r += fElsDR[indE];
818 //printf("ELoss@ %+.2e r:%+.3e got %+.3e\n",fCurT[indE],r,fElsDR[indE]);
819 }
820 } else {
821 for (int i=fFirstPosT;i--;) { // against the track direction
822 int indE = fElsId[i];
823 if ( t>=fCurT[indE] ) break; // does not reach this layer on its way to t
824 xc += fElsDR[indE] * TMath::Cos(fParams[kPhi0] + fCurT[indE]);
825 yc += fElsDR[indE] * TMath::Sin(fParams[kPhi0] + fCurT[indE]);
826 ze += fElsDR[indE] * fCurT[indE];
827 r += fElsDR[indE];
828 //printf("ELoss@ %+.2e r:%+.3e got %+.3e\n",fCurT[indE],r,fElsDR[indE]);
829 }
830 }
831 }
832 //
833 xyz[kZ] = fParams[kDZ] - fParams[kDip]*(t*r - ze);
834 //
835 t += fParams[kPhi0];
836 xyz[kX] = xc - r*TMath::Cos(t);
837 xyz[kY] = yc - r*TMath::Sin(t);
838 // printf("t: %+.3e xyz:%+.2e %+.2e %+.2e | R %+.6e -> %+.6e | sign %d\n",t-fParams[kPhi0],xyz[0],xyz[1],xyz[2],fParams[kR0],r,GetSignQB());
839 }
840 else {
841 xyz[ fkAxID[kX] ] = fParams[kA0] + fParams[kB0]*t;
842 xyz[ fkAxID[kY] ] = fParams[kA1] + fParams[kB1]*t;
843 xyz[ fParAxis ] = t;
844 }
845}
846
847//________________________________________________________________________________________________________
848void AliITSTPArrayFit::GetDirCos(Double_t *dircos, Double_t t) const
849{
850 // calculate track direction cosines for parameter value t
851 if (IsFieldON()) {
852 dircos[kZ] = -fParams[kDip];
853 t += fParams[kPhi0];
854 dircos[kX] = TMath::Sin(t);
855 dircos[kY] =-TMath::Cos(t);
856 double gam = TMath::Sign(1/TMath::Sqrt(dircos[kZ]*dircos[kZ]+dircos[kY]*dircos[kY]+dircos[kX]*dircos[kX]),fParams[kR0]);
857 for (int i=3;i--;) dircos[i] *= gam;
858 }
859 else {
860 double gam = 1/TMath::Sqrt( fParams[kB0]*fParams[kB0] + fParams[kB1]*fParams[kB1] + 1.);
861 dircos[ fkAxID[kX] ] = fParams[kB0]*gam;
862 dircos[ fkAxID[kY] ] = fParams[kB1]*gam;
863 dircos[ fParAxis ] = gam;
864 }
865}
866
867//________________________________________________________________________________________________________
868Double_t AliITSTPArrayFit::GetMachinePrec()
869{
870 // estimate machine precision
871 Double_t eps=1.0,a;
872 do { a = 1. + (eps=eps/2.0); } while(a>1.);
873 return TMath::Abs(2.*eps);
874}
875
876//________________________________________________________________________________________________________
877Bool_t AliITSTPArrayFit::FitHelixCrude(Int_t extQ)
878{
879 // crude estimate of helix parameters, w/o errors and Eloss.
880 // 1st fit the circle (R,xc,yc) by minimizing
881 // chi2 = sum{ (bx*xi + by*yi + xi^2+yi^2 + rho)^2 } vs bx,by,rho
882 // with bx = -2*xc, by = -2*yc , rho = xc^2+yc^2 - R2
883 //
884 // if charge is not imposed (extQ==0) then it will be determined from the collision type
885 //
886 Bool_t eloss = IsELossON();
887 //
888 int np = fPntLast - fPntFirst + 1;
889 if (np<2) { AliError("At least 3 points are needed for helix fit"); return kFALSE; }
890 //
891 const float *x=fPoints->GetX(),*y=fPoints->GetY(),*z=fPoints->GetZ(),*cov=fPoints->GetCov();
892 //
893 // linear circle fit --------------------------------------------------- >>>
894 Double_t sxx=0,sxy=0,syy=0,sx=0,sy=0,rhs0=0,rhs1=0,rhs2=0,minR=1E9;
895 int minRId = 0;
896 for (int i=fPntFirst;i<=fPntLast;i++) {
897 Double_t xx = x[i]*x[i];
898 Double_t yy = y[i]*y[i];
899 Double_t xy = x[i]*y[i];
900 Double_t xxyy = xx + yy;
901 //
902 sxx += xx;
903 sxy += xy;
904 syy += yy;
905 sx += x[i];
906 sy += y[i];
907 //
908 rhs0 -= xxyy*x[i];
909 rhs1 -= xxyy*y[i];
910 rhs2 -= xxyy;
911 //
912 // remember Id of the point closest to origin, to determine the charge
913 if (xxyy<minR) { minR = xxyy; minRId = i; }
914 //
915 if (eloss) { // find layer id
916 int lrid,volid = fPoints->GetVolumeID()[i];
917 if (volid>0) lrid = fgkActiveLrITS[AliGeomManager::VolUIDToLayer(fPoints->GetVolumeID()[i])-1];
918 else { // missing layer info, find from radius
919 double r = TMath::Sqrt(xxyy);
920 for (lrid=kMaxLrITS;lrid--;) if ( IsZero(r-fgkRLayITS[ lrid ],1.) ) break;
921 }
922 fElsDR[i] = (lrid>=0 && lrid<kMaxLrITS) ? fgRhoLITS[ lrid ] : 0; // eloss for normal track
923 }
924 //
925 }
926 //
927 Double_t mn00 = syy*np-sy*sy;
928 Double_t mn01 = sxy*np-sy*sx;
929 Double_t mn02 = sxy*sy-syy*sx;
930 Double_t det = sxx*mn00 - sxy*mn01 + sx*mn02;
931 if (TMath::Abs(det)<fgkAlmostZero) return kFALSE;
932 //
933 Double_t mn11 = sxx*np-sx*sx;
934 Double_t mn12 = sxx*sy-sxy*sx;
935 Double_t mn22 = sxx*syy-sxy*sxy;
936 //
937 Double_t mi00 = mn00/det;
938 Double_t mi01 = -mn01/det;
939 Double_t mi02 = mn02/det;
940 Double_t mi11 = mn11/det;
941 Double_t mi12 = -mn12/det;
942 Double_t mi22 = mn22/det;
943 //
944 Double_t xc = -(rhs0*mi00 + rhs1*mi01 + rhs2*mi02)/2;
945 Double_t yc = -(rhs0*mi01 + rhs1*mi11 + rhs2*mi12)/2;
946 Double_t rho2 = (rhs0*mi02 + rhs1*mi12 + rhs2*mi22);
947 //
948 Double_t dcen = xc*xc + yc*yc;
949 Double_t rad = dcen - rho2;
950 rad = (rad>fgkAlmostZero) ? (TMath::Sqrt(rad)):fgkAlmostZero;
951 //
952 // printf("Rad: %+e xc: %+e yc: %+e\n",rad,xc,yc);
953 // linear circle fit --------------------------------------------------- <<<
954 //
955 // decide sign(Q*B) and fill cicrle parameters ------------------------- >>>
956 int sqb;
957 if (extQ) {
958 SetCharge(extQ);
959 sqb = fBz<0 ? -GetCharge():GetCharge();
960 }
961 else {
962 // determine the charge from the collision type and field sign
963 // the negative Q*B will have positive Vc x V0 product Z component
964 // with Vc={-xc,-yc} : vector from circle center to the origin
965 // and V0 - track direction vector (take {0,-1,1} for cosmics)
966 // If Bz is not provided, assume positive Bz
967 sqb = ( IsTypeCosmics() ? xc:(yc*x[minRId]-xc*y[minRId]) ) > 0 ? -1:1;
968 SetCharge( fBz<0 ? -sqb : sqb);
969 }
970 //
971 dcen = TMath::Sqrt(dcen);
972 fParams[kD0] = dcen-rad;
973 Double_t phi = TMath::ATan2(yc,xc);
974 if (sqb<0) phi += TMath::Pi();
975 if (phi > TMath::Pi()) phi -= 2.*TMath::Pi();
976 else if (phi <-TMath::Pi()) phi += 2.*TMath::Pi();
977 fParams[kPhi0] = phi;
978 fParams[kR0] = sqb<0 ? -rad:rad;
979 //
980 // decide sign(Q*B) and fill cicrle parameters ------------------------- <<<
981 //
982 // find z-offset and dip + the parameter t of closest approach to hits - >>>
983 //
984 UInt_t hitLrPos=0; // pattern of hit layers at pos
985 UInt_t hitLrNeg=0; // and negative t's
986
987 Double_t ss=0,st=0,sz=0,stt=0,szt=0;
988 for (int i=fPntFirst;i<=fPntLast;i++) {
989 //
990 Double_t ze2 = cov[i*6 + kZZ];
991 Double_t t = TMath::ATan2(yc-y[i],xc-x[i]) - fParams[kPhi0]; // angle at measured z
992 if (fParams[kR0]<0) t += TMath::Pi();
993 if (t > TMath::Pi()) t -= TMath::Pi()*2;
994 else if (t <-TMath::Pi()) t += TMath::Pi()*2;
995 if (ze2<fgkAlmostZero) ze2 = 1E-8;
996 ze2 = 1./ze2;
997 ss += ze2;
998 st += t*ze2;
999 stt+= t*t*ze2;
1000 sz += z[i]*ze2;
1001 szt+= z[i]*t*ze2;
1002 //
1003 fCurT[i] = t; // parameter of the closest approach to the point
1004 // printf("%d %+e %+e %+e %+e\n",i,x[i],y[i],z[i],t);
1005 if (eloss) {
1006 double r = TMath::Sqrt(x[i]*x[i]+y[i]*y[i]);
1007 int lr;
1008 for (lr=kMaxLrITS;lr--;) if ( IsZero(r-fgkRLayITS[ lr ],1.) ) break;
1009 if (lr<kMaxLrITS) {
1010 if (t>0) hitLrPos |= (1<<lr); // set bit of the layer
1011 else hitLrNeg |= (1<<lr); // set bit of the layer
1012 }
1013 }
1014 }
1015 det = ss*stt - st*st;
1016 if (TMath::Abs(det)<fgkAlmostZero) { // no Z dependence
1017 fParams[kDZ] = sz/ss;
1018 fParams[kDip] = 0;
1019 }
1020 else {
1021 fParams[kDZ] = (sz*stt-st*szt)/det;
1022 fParams[kDip] = -(ss*szt-st*sz)/det/fParams[kR0];
1023 }
1024 //
1025 // find z-offset and dip + the parameter t of closest approach to hits - <<<
1026 //
1027 // fill info needed to account for ELoss ------------------------------- >>>
1028 if (eloss) {
1029 fNElsPnt = fPntLast - fPntFirst + 1;
1030 //
1031 // to account for the energy loss in the passive volumes, calculate the relevant t-parameters
1032 double* tcur = fCurT + fPntFirst;
1033 double* ecur = fElsDR+ fPntFirst;
1034 //
1035 for (int ilp=3;ilp--;) {
1036 int id = fgkPassivLrITS[ilp];
1037 double tp = GetHelixParAtR( fgkRLayITS[ id ] );
1038 if (tp<0) continue; // does not hit this radius
1039 //
1040 tcur[fNElsPnt] = GetSignQB()>0 ? -tp : tp;
1041 ecur[fNElsPnt] = fgRhoLITS[ id ];
1042 fNElsPnt++;
1043 // printf("Passive on lr %d %+e\n",ilp,tcur[fNElsPnt-1]);
1044 //
1045 if (IsTypeCosmics() && !IsZero(tp)) { // 2 crossings for cosmics
1046 tcur[fNElsPnt] = -tcur[fNElsPnt-1];
1047 ecur[fNElsPnt] = ecur[fNElsPnt-1];
1048 fNElsPnt++;
1049 //printf("Passive* on lr %d %+e\n",ilp,-tcur[fNElsPnt-1]);
1050 }
1051 //
1052 }
1053 // check if some active layers did not miss the hit, treat them as passive
1054 for (int ilp=6;ilp--;) {
1055 int id = fgkActiveLrITS[ilp];
1056 double tp = GetHelixParAtR( fgkRLayITS[ id ] );
1057 if (tp<0) continue; // does not hit this radius
1058 //
1059 if ( (GetSignQB()>0||IsTypeCosmics()) && !(hitLrNeg & (1<<id)) ) {
1060 tcur[fNElsPnt] = -tp;
1061 ecur[fNElsPnt] = fgRhoLITS[ id ];
1062 fNElsPnt++;
1063 //printf("Missed on lr %d %+e\n",ilp,-tp);
1064 }
1065 //
1066 if ( (GetSignQB()<0||IsTypeCosmics()) && !(hitLrPos & (1<<id)) ) {
1067 tcur[fNElsPnt] = tp;
1068 ecur[fNElsPnt] = fgRhoLITS[ id ];
1069 fNElsPnt++;
1070 //printf("Missed* on lr %d %e\n",ilp,tp);
1071 }
1072 }
1073 //
1074 TMath::Sort(fNElsPnt,fCurT+fPntFirst,fElsId,kFALSE); // index e-loss points in increasing order
1075 // find the position of smallest positive t-param
1076 for (fFirstPosT=0;fFirstPosT<fNElsPnt;fFirstPosT++) if (fCurT[ fElsId[ fFirstPosT ] ]>0) break;
1077 //
1078 Double_t cdip = 1./TMath::Sqrt(1.+fParams[kDip]*fParams[kDip]);
1079 Double_t ptot = TMath::Abs(fParams[kR0]*fgkCQConv*fBz/cdip); // momentum and energy
1080 Double_t etot = TMath::Sqrt(ptot*ptot + fMass*fMass); // in the point of closest approach to beam
1081 Double_t normS[3];
1082 //
1083 // Positive t-params: along the track direction for negative track, against for positive
1084 Double_t pcur = ptot, ecurr = etot;
1085 for (int ip=fFirstPosT;ip<fNElsPnt;ip++) {
1086 int tID = fElsId[ip];
1087 Double_t t = fCurT[ tID ];
1088 //
1089 if (tID>fPntLast) { // this is not a hit layer but passive layer
1090 double php = TMath::ATan2(yc-fParams[kR0]*TMath::Cos(fParams[kPhi0]+t),
1091 xc-fParams[kR0]*TMath::Cos(fParams[kPhi0]+t));
1092 normS[0] = -TMath::Cos(php); // normal to the cylinder at intersection point
1093 normS[1] = -TMath::Sin(php);
1094 normS[2] = 0;
1095 }
1096 else GetNormal(normS,fPoints->GetCov()+tID*6); // vector normal to hit module
1097 fElsDR[tID] = GetDRofELoss(t,cdip,fElsDR[tID],normS,ptot,etot);
1098 }
1099 //
1100 // negaive t-params: against the track direction for negative track, along for positive
1101 pcur = ptot;
1102 ecurr = etot;
1103 for (int ip=fFirstPosT;ip--;) {
1104 int tID = fElsId[ip];
1105 Double_t t = fCurT[ tID ];
1106 //
1107 if (tID>fPntLast) { // this is not a hit layer but passive layer
1108 double php = TMath::ATan2(yc-fParams[kR0]*TMath::Cos(fParams[kPhi0]+t),
1109 xc-fParams[kR0]*TMath::Cos(fParams[kPhi0]+t));
1110 normS[0] = -TMath::Cos(php); // normal to the cylinder at intersection point
1111 normS[1] = -TMath::Sin(php);
1112 normS[2] = 0;
1113 }
1114 else GetNormal(normS,fPoints->GetCov()+tID*6); // vector normal to hit module
1115 //
1116 fElsDR[tID] = GetDRofELoss(t,cdip,fElsDR[tID],normS,ptot,etot);
1117 }
1118 }
1119 // fill info needed to account for ELoss ------------------------------- <<<
1120 //
1121 return kTRUE;
1122}
1123
1124//____________________________________________________
1125Double_t AliITSTPArrayFit::FitHelix(Int_t extQ, Double_t extPT,Double_t extPTerr)
1126{
1127 // fit by helix accounting for the errors of all coordinates (and energy loss if requested)
1128 //
1129 // If extQ is non-0, its sign is imposed as a charge of the track
1130 // If extPT>0 and extPTerr>=0, constrain to measured tr.momentum PT
1131 // with corresponding error (err=0 -> rel.err=1e-6)
1132 //
1133 double chiprev=1e99;
1134 //const Double_t kMaxTEffect = 1E-6;
1135 Double_t dXYZdGlo[3*5],dXYZdLoc[3],xyzRes[3];
1136 //
1137 SetFitDone(kFALSE);
1138 fChi2NDF = -1;
1139 //
1140 if (!FitHelixCrude(extQ)) return -1; // get initial estimate, ignoring the errors
1141 //
1142 if (!IsCovInv()) InvertPointsCovMat(); // prepare inverted errors
1143 if (!fParSol) fParSol = new AliParamSolver(5);
1144 fParSol->SetNGlobal(5);
1145 //
1146 // printf("-1 | %+.2e %+.2e %+.2e %+.2e %+.2e | chi2: %+.4e\n",fParams[0],fParams[1],fParams[2],fParams[3],fParams[4],CalcChi2NDF());
1147 int iter = 0;
1148 fChi2NDF = 1e99;
1149 Bool_t converged = kFALSE;
1150 while(iter<fMaxIter) {
1151 chiprev = fChi2NDF;
1152 fParSol->Clear();
1153 for (int ip=fPntFirst;ip<=fPntLast;ip++) {
1154 //
1155 GetResiduals(xyzRes, ip); // current residuals at point ip
1156 Double_t rrho = fParams[kR0]+fParams[kD0];
1157 Double_t cs0 = TMath::Cos(fParams[kPhi0]);
1158 Double_t sn0 = TMath::Sin(fParams[kPhi0]);
1159 Double_t cst = TMath::Cos(fCurT[ip]+fParams[kPhi0]);
1160 Double_t snt = TMath::Sin(fCurT[ip]+fParams[kPhi0]);
1161 //
1162 int offs = kD0; // dXYZ/dD0
1163 dXYZdGlo[offs + kX] = cs0;
1164 dXYZdGlo[offs + kY] = sn0;
1165 dXYZdGlo[offs + kZ] = 0;
1166 //
1167 offs = kPhi0*3; // dXYZ/dPhi0
1168 dXYZdGlo[offs + kX] = -rrho*sn0;
1169 dXYZdGlo[offs + kY] = rrho*cs0;
1170 dXYZdGlo[offs + kZ] = 0;
1171 //
1172 offs = kR0*3; // dXYZ/dR0
1173 dXYZdGlo[offs + kX] = cs0 - cst;
1174 dXYZdGlo[offs + kY] = sn0 - snt;
1175 dXYZdGlo[offs + kZ] = -fParams[kDip]*fCurT[ip];
1176 //
1177 offs = kDZ*3; // dXYZ/dDZ
1178 dXYZdGlo[offs + kX] = 0;
1179 dXYZdGlo[offs + kY] = 0;
1180 dXYZdGlo[offs + kZ] = 1.;
1181 //
1182 offs = kDip*3; // dXYZ/dDip
1183 dXYZdGlo[offs + kX] = 0;
1184 dXYZdGlo[offs + kY] = 0;
1185 dXYZdGlo[offs + kZ] = -fParams[kR0]*fCurT[ip];
1186 //
1187 dXYZdLoc[kX] = fParams[kR0]*snt;
1188 dXYZdLoc[kY] = -fParams[kR0]*cst;
1189 dXYZdLoc[kZ] = -fParams[kR0]*fParams[kDip];
1190 //
1191 fParSol->AddEquation(dXYZdGlo,dXYZdLoc,xyzRes,GetCovI(ip));
1192 }
1193 //
1194 if (extPT>0) { // add constraint on pt
1195 if (extPTerr<fgkAlmostZero) extPTerr = 1e-6*extPT;
1196 Double_t cf = fBz*GetCharge()*fgkCQConv;
1197 Double_t err2i = extPTerr/cf;
1198 err2i = 1./err2i/err2i;
1199 // printf("Constrain R to %+e\n",extPT/cf);
1200 fParSol->AddConstraint(kR0,-extPT/cf+fParams[kR0],err2i);
1201 }
1202 if (!fParSol->Solve()) { AliError("Failed to fit helix"); return -1; }
1203 Double_t *deltaG = fParSol->GetGlobals();
1204 Double_t *deltaT = fParSol->GetLocals();
1205 for (int ipar=5;ipar--;) fParams[ipar] -= deltaG[ipar];
1206 for (int ip=fPntFirst;ip<=fPntLast;ip++) fCurT[ip] -= deltaT[ip-fPntFirst];
1207 iter++;
1208 //
1209 fChi2NDF = CalcChi2NDF();
1210 // printf("%d | %+.2e %+.2e %+.2e %+.2e %+.2e | chi2: %+.4e %+.4e\n",iter,deltaG[0],deltaG[1],deltaG[2],deltaG[3],deltaG[4],fChi2NDF,fChi2NDF-chiprev);
1211 // printf("->> %+.2e %+.2e %+.2e %+.2e %+.2e | Chi2: %+.6e %+.6e\n",fParams[0],fParams[1],fParams[2],fParams[3],fParams[4],fChi2NDF,fChi2NDF-chiprev);
1212 double difchi2 = chiprev - fChi2NDF;
1213 if ( difchi2<fEps && TMath::Abs(difchi2)<1e-4) {converged = kTRUE; break;}
1214 // if (errT*TMath::Abs(fParams[kR0])<kMaxTEffect && errP<fEps) {converged = kTRUE; break;}
1215 }
1216 //
1217 if (!converged) {
1218 AliDebug(2,Form("Max number of %d iteration reached, Current chi2:%.3e, chi2 change %+.3e",iter,
1219 fChi2NDF,chiprev-fChi2NDF));
1220 for (int ip=fPntFirst;ip<=fPntLast;ip++)
1221 AliDebug(2,Form("P%2d| %+.3e %+.3e %+.3e\n",ip,fPoints->GetX()[ip],fPoints->GetY()[ip],fPoints->GetZ()[ip]));
1222
1223 }
1224 fIter = iter;
1225 SetCharge( fParams[kR0]>0 ? (fBz<0?-1:1):(fBz>0?-1:1) );
1226 SetFitDone();
1227 // printf("F1>> %+.7e %+.7e %+.7e %+.7e %.7e\n",fParams[0],fParams[1],fParams[2],fParams[3],fParams[4]);
1228 //
1229 return fChi2NDF;
1230}
1231
1232//____________________________________________________
1233Double_t AliITSTPArrayFit::FitLine()
1234{
1235 // fit by helix accounting for the errors of all coordinates (and energy loss if requested)
1236 //
1237 double chiprev=1e99;
1238 // const Double_t kMaxTEffect = 1.e-6;
1239 Double_t dXYZdGlo[3*4],dXYZdLoc[3],xyzRes[3];
1240 SetFitDone(kFALSE);
1241 fChi2NDF = -1;
1242 //
1243 if (fParAxis<0) SetParAxis(ChoseParAxis());
1244 //
1245 const float *xyzp[3]={fPoints->GetX(),fPoints->GetY(),fPoints->GetZ()};
1246 if (!IsCovInv()) InvertPointsCovMat();
1247 if (!FitLineCrude()) return -1; // get initial estimate, ignoring the errors
1248 //
1249 if (!fParSol) fParSol = new AliParamSolver(5);
1250 fParSol->SetNGlobal(4);
1251 // initial set of parameters
1252 for (int ip=fPntFirst;ip<=fPntLast;ip++) fCurT[ip] = xyzp[fParAxis][ip]; // use measured param-coordinate
1253 //
1254 int iter = 0;
1255 Bool_t converged = kFALSE;
1256 fChi2NDF = 1e99;
1257 while(iter<fMaxIter) {
1258 chiprev = fChi2NDF;
1259 fParSol->Clear();
1260 for (int ip=fPntFirst;ip<=fPntLast;ip++) {
1261 //
1262 int offs;
1263 GetResiduals(xyzRes, ip); // current residuals at point ip
1264 //
1265 offs = kA0*3; // dXYZ/dA0
1266 dXYZdGlo[offs + fkAxID[kX]] = 1;
1267 dXYZdGlo[offs + fkAxID[kY]] = 0;
1268 dXYZdGlo[offs + fParAxis ] = 0;
1269 //
1270 offs = kB0*3; // dXYZ/dB0
1271 dXYZdGlo[offs + fkAxID[kX]] = fCurT[ip];
1272 dXYZdGlo[offs + fkAxID[kY]] = 0;
1273 dXYZdGlo[offs + fParAxis ] = 0;
1274 //
1275 offs = kA1*3; // dXYZ/dA1
1276 dXYZdGlo[offs + fkAxID[kX]] = 0;
1277 dXYZdGlo[offs + fkAxID[kY]] = 1;
1278 dXYZdGlo[offs + fParAxis ] = 0;
1279 //
1280 offs = kB1*3; // dXYZ/dB1
1281 dXYZdGlo[offs + fkAxID[kX]] = 0;
1282 dXYZdGlo[offs + fkAxID[kY]] = fCurT[ip];
1283 dXYZdGlo[offs + fParAxis ] = 0;
1284 //
1285 dXYZdLoc[ fkAxID[kX] ] = fParams[kB0]; // dX/dt
1286 dXYZdLoc[ fkAxID[kY] ] = fParams[kB1]; // dY/dt
1287 dXYZdLoc[ fParAxis ] = 1;
1288 //
1289 fParSol->AddEquation(dXYZdGlo,dXYZdLoc,xyzRes,GetCovI(ip));
1290 }
1291 //
1292 if (!fParSol->Solve()) { AliError("Failed to fit line"); return -1; }
1293 Double_t *deltaG = fParSol->GetGlobals();
1294 Double_t *deltaT = fParSol->GetLocals();
1295 for (int ipar=4;ipar--;) fParams[ipar] -= deltaG[ipar];
1296 for (int ip=fPntFirst;ip<=fPntLast;ip++) fCurT[ip] -= deltaT[ip-fPntFirst];
1297 iter++;
1298 fChi2NDF = CalcChi2NDF();
1299 // printf("%d %+e %+e | %+.2e %+.2e %+.2e %+.2e | chi2: %+.4e %+.4e\n",iter,errP,errT, deltaG[0],deltaG[1],deltaG[2],deltaG[3],fChi2NDF,fChi2NDF-chiprev);
1300 // printf("->> %+.2e %+.2e %+.2e %+.2e %+.2e | Chi2: %+.6e %+.6e\n",fParams[0],fParams[1],fParams[2],fParams[3],fParams[4],fChi2NDF,fChi2NDF-chiprev);
1301 double difchi2 = chiprev - fChi2NDF;
1302 if ( difchi2<fEps && TMath::Abs(difchi2)<1e-4) {converged = kTRUE; break;}
1303 chiprev = fChi2NDF;
1304 // if (errT<kMaxTEffect && errP<fEps) {converged = kTRUE; break;}
1305 }
1306 //
1307 if (!converged) {
1308 AliDebug(2,Form("Max number of %d iteration reached, Current chi2:%.3e, chi2 change %+.3e",iter,
1309 fChi2NDF,chiprev-fChi2NDF));
1310 for (int ip=fPntFirst;ip<=fPntLast;ip++)
1311 AliDebug(2,Form("P%2d| %+.3e %+.3e %+.3e\n",ip,fPoints->GetX()[ip],fPoints->GetY()[ip],fPoints->GetZ()[ip]));
1312 }
1313 fIter = iter;
1314 SetFitDone();
1315 //printf("F1>> %+.2e %+.2e %+.2e %+.2e\n",fParams[0],fParams[1],fParams[2],fParams[3]);
1316 return fChi2NDF;
1317 //
1318}
1319
1320//____________________________________________________
1321void AliITSTPArrayFit::GetNormal(Double_t *norm, const Float_t *covMat)
1322{
1323 // obtain the lab normal vector to the sensor from the covariance matrix
1324 // in such a way that when the local frame of the sensor coincides with
1325 // the lab frame, the vector {0,1,0} is obtained
1326 Double_t tgxy = TMath::Tan(0.5*TMath::ATan2(2.*covMat[kXY],covMat[kYY]-covMat[kXX]));
1327 Double_t tgyz = TMath::Tan(0.5*TMath::ATan2(2.*covMat[kYZ],covMat[kZZ]-covMat[kYY]));
1328 norm[kY] = 1./TMath::Sqrt(1 + tgxy*tgxy + tgyz*tgyz);
1329 norm[kX] = norm[kY]*tgxy;
1330 norm[kZ] = norm[kY]*tgyz;
1331 //
1332}
1333
1334//____________________________________________________
1335Double_t AliITSTPArrayFit::GetDRofELoss(Double_t t,Double_t cdip,Double_t rhoL,const Double_t *normS,
1336 Double_t &p,Double_t &e) const
1337{
1338 // Calculate energy loss of the particle at given t-param on the layer with rhoL (thickness*density) with
1339 // normal vector normS in the lab. The particle before eloss has energy "e" and momentum "p"
1340 // cdip = cosine of the dip angle = 1/sqrt(1+tgL^2)
1341 // Return the change DR of the radius due to the ELoss
1342 //
1343 // NOTE: with B>0 the negative particles propagate along increasing t-param and positive
1344 // particles - against.
1345 // t-param = 0 corresponds to the point of closest approach of the track to the beam.
1346 // Since the fitted helix parameters of the track are defined in this PCA point, when the correction
1347 // is applied upstream of the PCS, the energy must be increased (DR>0) rather than decreased (DR<0)
1348 //
1349 Double_t dirTr[3];
1350 dirTr[0] = -TMath::Sin(fParams[kPhi0]+t);
1351 dirTr[1] = TMath::Cos(fParams[kPhi0]+t);
1352 dirTr[2] = fParams[kDip];
1353 // cosine of the impact angle
1354 Double_t cosImp = cdip*TMath::Abs(dirTr[0]*normS[0]+dirTr[1]*normS[1]+dirTr[2]*normS[2]);
1355 //
1356 if (cosImp<0.3) cosImp = 0.3; //?
1357 Double_t dE = AliExternalTrackParam::BetheBlochSolid(p/fMass)*rhoL/cosImp;
1358 Double_t dP = e/p*dE;
1359 //
1360 if (t*GetSignQB() < 0) {
1361 dP = -dP;
1362 dE = -dE;
1363 }
1364 //
1365 if (p+dP<0) {
1366 AliInfo(Form("Estimated PLoss %.3f is larger than particle momentum %.3f. Skipping",dP,p));
1367 return 0;
1368 }
1369 //
1370 p += dP;
1371 e += dE;
1372 //
1373 return fCharge*dP*cdip/fBz/fgkCQConv;
1374}
1375
1376//_____________________________________________________________
1377Double_t AliITSTPArrayFit::GetLineOffset(Int_t axis) const
1378{
1379 // return intercept of the parameterization coord = intercept + slope*t for given axis
1380 if (fParAxis<0) return -1E6; // no line fit
1381 if (axis==fParAxis) return 0;
1382 if (fParAxis==kX) return fParams[axis==kY ? kA0 : kA1 ];
1383 if (fParAxis==kY) return fParams[axis==kZ ? kA0 : kA1 ];
1384 return fParams[axis==kX ? kA0 : kA1 ];
1385}
1386
1387//_____________________________________________________________
1388Double_t AliITSTPArrayFit::GetLineSlope(Int_t axis) const
1389{
1390 // return intercept of the parameterization coord = intercept + slope*t for given axis
1391 if (fParAxis<0) return -1E6; // no line fit
1392 if (axis==fParAxis) return 1.;
1393 if (fParAxis==kX) return fParams[axis==kY ? kB0 : kB1 ];
1394 if (fParAxis==kY) return fParams[axis==kZ ? kB0 : kB1 ];
1395 return fParams[axis==kX ? kB0 : kB1 ];
1396}
1397
1398//_____________________________________________________________
1399void AliITSTPArrayFit::Print(Option_t *) const
1400{
1401 const char kCxyz[] = "XYZ";
1402 if (!fPoints) return;
1403 //
1404 printf("Track of %3d points in Bz=%+.1f |Fit ",fPntLast-fPntFirst+1,fBz);
1405 if ( IsFitDone() ) {
1406 if (IsFieldON())
1407 printf("Helix: Chi2: %5.1f | %+.2e %+.2e %+.2e %+.2e %+.2e\n",
1408 fChi2NDF,fParams[kD0],fParams[kPhi0],fParams[kR0],fParams[kDZ],fParams[kDip]);
1409 else
1410 printf("Line%c: Chi2: %5.1f | %+.2e %+.2e %+.2e %+.2e\n",
1411 kCxyz[fParAxis],fChi2NDF,fParams[kA0],fParams[kB0],fParams[kA1],fParams[kB1]);
1412 }
1413 else printf("N/A\n");
1414}
1415
1416
1417
1418
1419//____________________________________________________
1420void AliITSTPArrayFit::BuildMaterialLUT(Int_t ntri)
1421{
1422 // Fill a look-up table with mean material a la AliITSTrackerMI
1423 //
1424 if (!AliGeomManager::GetGeometry()) AliFatal("Geometry is not loaded");
1425 //
1426 // detector layer to check: dX,dZ,Ymin,Ymax
1427 const double kLayr[9][4] = {{0. ,60. , 2.80,3.00}, // beam pipe
1428 {1.28,7.07,-0.20,0.22}, // SPD1
1429 {1.28,7.07,-0.20,0.22}, // SPD2
1430 {0. ,76.0, 10.4,11.8}, // Shield1
1431 {7.02,7.53,-1.00,4.50}, // SDD1
1432 {7.02,7.53,-1.00,4.50}, // SDD2
1433 {0. ,102., 29.0,30.0}, // Shield2
1434 {7.50,4.20,-0.15,4.50}, // SSD1
1435 {7.50,4.20,-0.15,4.50}}; // SSD2
1436 //
1437 //
1438 // build <dens*L> for detectors (track hitting the sensor in normal direction)
1439 double pg1[3],pg2[3],res[7];
1440 //
1441 int sID = 0;
1442 int actLrID = 0;
1443 for (int lr=0;lr<9;lr++) {
1444 //
1445 Bool_t active = kFALSE;
1446 const double* tpars = kLayr[lr];
1447 //
1448 if (IsZero(tpars[0])) { // passive layer
1449 active = kFALSE;
1450 AliInfo(Form("Probing passive layer (total layer #%d)",lr));
1451 }
1452 else {
1453 active = kTRUE;
1454 sID += AliGeomManager::LayerSize(++actLrID);
1455 AliInfo(Form("Probing sensors of active layer #%d (total layers #%d)",actLrID,lr));
1456 }
1457 double shift = TMath::Abs(tpars[2]-tpars[3])*1E-4;
1458 double rhol = 0;
1459 for (int i=ntri;i--;) {
1460 //
1461 if (active) {
1462 int ssID = sID -1 - AliGeomManager::LayerSize(actLrID)*gRandom->Rndm();
1463 pg1[0] = pg2[0] = (gRandom->Rndm()-0.5)*tpars[0] + shift; // local X
1464 pg2[0] -= 2*shift;
1465 pg1[1] = tpars[2];
1466 pg2[1] = tpars[3];
1467 pg1[2] = pg2[2] = (gRandom->Rndm()-0.5)*tpars[1] + shift; // local Z
1468 pg2[2] -= 2*shift;
1469 AliITSgeomTGeo::LocalToGlobal(ssID,pg1,pg1);
1470 AliITSgeomTGeo::LocalToGlobal(ssID,pg2,pg2);
1471 }
1472 else {
1473 double ang = gRandom->Rndm()*TMath::Pi()*2;
1474 pg1[0] = tpars[2]*TMath::Cos(ang)+shift;
1475 pg2[0] = tpars[3]*TMath::Cos(ang)-shift;
1476 pg1[1] = tpars[2]*TMath::Sin(ang);
1477 pg2[1] = tpars[3]*TMath::Sin(ang);
1478 pg1[2] = pg2[2] = (gRandom->Rndm()-0.5)*tpars[1]+shift; // local Z
1479 pg2[2] -= 2*shift;
1480 }
1481
1482 //
1483 AliTracker::MeanMaterialBudget(pg1,pg2,res);
1484 rhol += res[0]*res[4]; // rho*L
1485 }
1486 fgRhoLITS[lr] = rhol/ntri;
1487 AliInfo(Form("Obtained <rho*L> = %e\n",fgRhoLITS[lr]));
1488 }
1489 //
1490 return;
1491}
1492
1493
1494//____________________________________________________
1495Double_t AliITSTPArrayFit::GetPCA2PlaneInfo(Double_t *xyz, Double_t *dir, Int_t axis, Double_t axval) const
1496{
1497 // calculate the PCA to plane normal ti axis and crossing it at axval
1498 // fill the position and direction cosines at this point
1499 //
1500 double xyzp[3] = {0,0,0}; // create fake point
1501 xyzp[axis] = axval;
1502 double covI[6] = {1e-4,0,0,1e-4,0,1e-4}; // fake cov.matrix loose in all directions
1503 covI[4*axis - axis*(axis+1)/2] = 1e8; // except axis
1504 //
1505 double t = GetPosition(xyz, xyzp, covI); // got pca
1506 //
1507 if (dir) GetDirCos(dir,t);
1508 return t;
1509}
1510