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 ///////////////////////////////////////////////////////////////////////////////
20 // Class to the track points on the Riemann sphere. Inputs are
21 // the set of id's (volids) of the volumes in which residuals are
22 // calculated to construct a chi2 function to be minimized during
23 // the alignment procedures. For the moment the track extrapolation is
24 // taken at the space-point reference plane. The reference plane is
25 // found using the covariance matrix of the point
26 // (assuming sigma(x)=0 at the reference coordinate system.
28 // Internal usage of AliRieman class for minimization
30 //////////////////////////////////////////////////////////////////////////////
32 #include "TMatrixDSym.h"
35 #include "AliTrackFitterRieman.h"
37 #include "TTreeStream.h"
38 #include "AliRieman.h"
41 ClassImp(AliTrackFitterRieman)
44 AliTrackFitterRieman::AliTrackFitterRieman():
50 fRieman(new AliRieman(10000)), // allocate rieman
51 fDebugStream(new TTreeSRedirector("RiemanAlignDebug.root"))
54 // default constructor
59 AliTrackFitterRieman::AliTrackFitterRieman(AliTrackPointArray *array, Bool_t owner):
60 AliTrackFitter(array,owner),
65 fRieman(new AliRieman(10000)), //allocate rieman
71 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")) fDebugStream = new TTreeSRedirector("RiemanAlignDebug.root");
74 AliTrackFitterRieman::AliTrackFitterRieman(const AliTrackFitterRieman &rieman):
75 AliTrackFitter(rieman),
76 fAlpha(rieman.fAlpha),
77 fNUsed(rieman.fNUsed),
79 fMaxDelta(rieman.fMaxDelta),
80 fRieman(new AliRieman(*(rieman.fRieman))),
86 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")) fDebugStream = new TTreeSRedirector("RiemanAlignDebug.root");
89 //_____________________________________________________________________________
90 AliTrackFitterRieman &AliTrackFitterRieman::operator =(const AliTrackFitterRieman& rieman)
93 // Assignment operator
95 if(this==&rieman) return *this;
96 ((AliTrackFitter *)this)->operator=(rieman);
98 fAlpha = rieman.fAlpha;
99 fNUsed = rieman.fNUsed;
100 fConv = rieman.fConv;
101 fMaxDelta = rieman.fMaxDelta;
102 fRieman = new AliRieman(*(rieman.fRieman));
104 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")) fDebugStream = new TTreeSRedirector("RiemanAlignDebug.root");
109 AliTrackFitterRieman::~AliTrackFitterRieman(){
117 void AliTrackFitterRieman::Reset()
119 // Reset the track parameters and
122 AliTrackFitter::Reset();
129 Bool_t AliTrackFitterRieman::Fit(const TArrayI *volIds,const TArrayI *volIdsFit,
130 AliAlignObj::ELayerID layerRangeMin,
131 AliAlignObj::ELayerID layerRangeMax)
133 // Fit the track points. The method takes as an input
134 // the set of id's (volids) of the volumes in which
135 // one wants to calculate the residuals.
136 // The following parameters are used to define the
137 // range of volumes to be used in the fitting
138 // As a result two AliTrackPointArray's obects are filled.
139 // The first one contains the space points with
140 // volume id's from volids list. The second array of points represents
141 // the track extrapolations corresponding to the space points
142 // in the first array. The two arrays can be used to find
143 // the residuals in the volids and consequently construct a
144 // chi2 function to be minimized during the alignment
145 // procedures. For the moment the track extrapolation is taken
146 // at the space-point reference plane. The reference plane is
147 // found using the covariance matrix of the point
148 // (assuming sigma(x)=0 at the reference coordinate system.
151 Int_t npoints = fPoints->GetNPoints();
152 if (fPoints && AliLog::GetDebugLevel("","AliTrackFitterRieman")>1){
153 Int_t nVol = volIds->GetSize();
154 Int_t nVolFit = volIdsFit->GetSize();
155 Int_t volId = volIds->At(0);
156 (*fDebugStream)<<"PInput"<<
157 "NPoints="<<npoints<< // number of points
158 "VolId="<<volId<< // first vol ID
159 "NVol="<<nVol<< // number of volumes
160 "NvolFit="<<nVolFit<< // number of volumes to fit
161 "fPoints.="<<fPoints<< // input points
164 if (npoints < 3) return kFALSE;
166 Bool_t isAlphaCalc = kFALSE;
167 AliTrackPoint p,plocal;
168 // fPoints->GetPoint(p,0);
169 // fAlpha = TMath::ATan2(p.GetY(),p.GetX());
173 Int_t *pindex = new Int_t[npoints];
174 for (Int_t ipoint = 0; ipoint < npoints; ipoint++)
176 fPoints->GetPoint(p,ipoint);
177 UShort_t iVolId = p.GetVolumeID();
178 if (FindVolId(volIds,iVolId)) {
179 pindex[npVolId] = ipoint;
182 if (volIdsFit != 0x0) {
183 if (!FindVolId(volIdsFit,iVolId)) continue;
186 if (iVolId < AliAlignObj::LayerToVolUID(layerRangeMin,0) ||
187 iVolId > AliAlignObj::LayerToVolUID(layerRangeMax,
188 AliAlignObj::LayerSize(layerRangeMax))) continue;
191 fAlpha = p.GetAngle();
194 plocal = p.Rotate(fAlpha);
195 if (TMath::Abs(plocal.GetX())>500 || TMath::Abs(plocal.GetX())<2 || plocal.GetCov()[3]<=0 ||plocal.GetCov()[5]<=0 ){
196 printf("<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<</n");
199 printf("Problematic point\n");
200 printf("<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<</n");
202 AddPoint(plocal.GetX(),plocal.GetY(),plocal.GetZ(),
203 TMath::Sqrt(plocal.GetCov()[3]),TMath::Sqrt(plocal.GetCov()[5]));
205 // fNUsed++; AddPoint should be responsible
208 if (npVolId == 0 || fNUsed < fMinNPoints) {
220 if ((fParams[0] == 0) ||
221 ((-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1) <= 0)) {
227 if (fNUsed < fMinNPoints) {
232 fPVolId = new AliTrackPointArray(npVolId);
233 fPTrack = new AliTrackPointArray(npVolId);
235 for (Int_t ipoint = 0; ipoint < npVolId; ipoint++)
237 Int_t index = pindex[ipoint];
238 fPoints->GetPoint(p,index);
239 if (GetPCA(p,p2) && (
240 TMath::Abs(p.GetX()-p2.GetX())<fMaxDelta &&
241 TMath::Abs(p.GetY()-p2.GetY())<fMaxDelta &&
242 TMath::Abs(p.GetZ()-p2.GetZ())<fMaxDelta
244 Float_t xyz[3],xyz2[3];
245 p.GetXYZ(xyz); p2.GetXYZ(xyz2);
246 // printf("residuals %f %d %d %f %f %f %f %f %f\n",fChi2,fNUsed,fConv,xyz[0],xyz[1],xyz[2],xyz2[0]-xyz[0],xyz2[1]-xyz[1],xyz2[2]-xyz[2]);
247 fPVolId->AddPoint(ipoint,&p);
248 fPTrack->AddPoint(ipoint,&p2);
250 // what should be default bahavior -
260 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")>0){
264 AliTrackPointArray *lPVolId = new AliTrackPointArray(npVolId);
265 AliTrackPointArray *lPTrack = new AliTrackPointArray(npVolId);
266 AliRieman * residual = fRieman->MakeResiduals();
267 AliTrackPoint p2local;
268 for (Int_t ipoint = 0; ipoint < npVolId; ipoint++){
269 Int_t index = pindex[ipoint];
270 fPoints->GetPoint(p,index);
272 plocal = p.Rotate(fAlpha);
273 // plocal.Rotate(fAlpha);
274 Float_t xyz[3],xyz2[3];
278 xyz2[1] = GetYat(xyz[0]);
279 xyz2[2] = GetZat(xyz[0]);
280 p2local.SetXYZ(xyz2);
281 lPVolId->AddPoint(ipoint,&plocal);
282 lPTrack->AddPoint(ipoint,&p2local);
288 Int_t nVol = volIds->GetSize();
289 Int_t nVolFit = volIdsFit->GetSize();
290 Int_t volId = volIds->At(0);
292 Int_t layer = AliAlignObj::VolUIDToLayer(volId,modId);
294 (*fDebugStream)<<"Fit"<<
295 "VolId="<<volId<< // volume ID
296 "Layer="<<layer<< // layer ID
297 "Module="<<modId<< // module ID
298 "NVol="<<nVol<< // number of volumes
299 "NvolFit="<<nVolFit<< // number of volumes to fit
300 "Points0.="<<fPVolId<< // original points
301 "Points1.="<<fPTrack<< // fitted points
302 "LPoints0.="<<lPVolId<< // original points - local frame
303 "LPoints1.="<<lPTrack<< // fitted points - local frame
304 "Rieman.="<<this<< // original rieman fit
305 "Res.="<<residual<< // residuals of rieman fit
317 void AliTrackFitterRieman::AddPoint(Float_t x, Float_t y, Float_t z, Float_t sy, Float_t sz)
320 // add point to rieman fitter
322 fRieman->AddPoint(x,y,z,sy,sz);
323 fNUsed = fRieman->GetN();
328 void AliTrackFitterRieman::Update(){
334 if (fRieman->IsValid()){
335 for (Int_t ipar=0; ipar<6; ipar++){
336 fParams[ipar] = fRieman->GetParam()[ipar];
338 fChi2 = fRieman->GetChi2();
339 fNdf = fRieman->GetN()- 2;
340 fNUsed = fRieman->GetN();
345 //_____________________________________________________________________________
346 Bool_t AliTrackFitterRieman::GetPCA(const AliTrackPoint &p, AliTrackPoint &p2) const
349 // Get the closest to a given spacepoint track trajectory point
350 // Look for details in the description of the Fit() method
352 if (!fConv) return kFALSE;
354 // First X and Y coordinates
355 Double_t sin = TMath::Sin(fAlpha);
356 Double_t cos = TMath::Cos(fAlpha);
358 // fParam[1] = -x0/y0
359 // fParam[2] = - (R^2 - x0^2 - y0^2)/y0
360 if (fParams[0] == 0) return kFALSE;
361 // Track parameters in the global coordinate system
362 Double_t x0 = -fParams[1]/fParams[0]*cos - 1./fParams[0]*sin;
363 Double_t y0 = 1./fParams[0]*cos - fParams[1]/fParams[0]*sin;
364 if ((-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1) <= 0) return kFALSE;
365 Double_t r = TMath::Sqrt(-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1)/
368 // Define space-point refence plane
369 Double_t alphap = p.GetAngle();
370 Double_t sinp = TMath::Sin(alphap);
371 Double_t cosp = TMath::Cos(alphap);
372 Double_t x = p.GetX()*cosp + p.GetY()*sinp;
373 Double_t y = p.GetY()*cosp - p.GetX()*sinp;
374 Double_t x0p= x0*cosp + y0*sinp;
375 Double_t y0p= y0*cosp - x0*sinp;
376 if ((r*r - (x-x0p)*(x-x0p))<0) {
377 AliWarning(Form("Track extrapolation failed ! (Track radius = %f, track circle x = %f, space-point x = %f, reference plane angle = %f\n",r,x0p,x,alphap));
380 Double_t temp = TMath::Sqrt(r*r - (x-x0p)*(x-x0p));
381 Double_t y1 = y0p + temp;
382 Double_t y2 = y0p - temp;
383 Double_t yprime = y1;
384 if(TMath::Abs(y2-y) < TMath::Abs(y1-y)) yprime = y2;
386 // Back to the global coordinate system
387 Double_t xsecond = x*cosp - yprime*sinp;
388 Double_t ysecond = yprime*cosp + x*sinp;
390 // Now Z coordinate and track angles
391 Double_t x2 = xsecond*cos + ysecond*sin;
392 Double_t zsecond = GetZat(x2);
393 Double_t dydx = GetDYat(x2);
394 Double_t dzdx = GetDZat(x2);
396 // Fill the cov matrix of the track extrapolation point
397 Double_t cov[6] = {0,0,0,0,0,0};
398 Double_t sigmax = 100*100.;
399 cov[0] = sigmax; cov[1] = sigmax*dydx; cov[2] = sigmax*dzdx;
400 cov[3] = sigmax*dydx*dydx; cov[4] = sigmax*dydx*dzdx;
401 cov[5] = sigmax*dzdx*dzdx;
404 newcov[0] = cov[0]*cos*cos-
407 newcov[1] = cov[1]*(cos*cos-sin*sin)-
408 (cov[3]-cov[0])*sin*cos;
409 newcov[2] = cov[2]*cos-
411 newcov[3] = cov[0]*sin*sin+
414 newcov[4] = cov[4]*cos+
418 p2.SetXYZ(xsecond,ysecond,zsecond,newcov);
419 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")>1){
420 AliTrackPoint lp0(p);
421 AliTrackPoint lp2(p2);
422 if (0)(*fDebugStream)<<"PCA"<<