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():
48 // default constructor
53 fDebugStream = new TTreeSRedirector("RiemanAlignDebug.root");
54 fRieman = new AliRieman(10000); // allocate rieman
58 AliTrackFitterRieman::AliTrackFitterRieman(AliTrackPointArray *array, Bool_t owner):
59 AliTrackFitter(array,owner)
67 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")) fDebugStream = new TTreeSRedirector("RiemanAlignDebug.root");
68 fRieman = new AliRieman(10000); //allocate rieman
71 AliTrackFitterRieman::AliTrackFitterRieman(const AliTrackFitterRieman &rieman):
72 AliTrackFitter(rieman)
77 fAlpha = rieman.fAlpha;
78 fNUsed = rieman.fNUsed;
80 fRieman = new AliRieman(*(rieman.fRieman));
83 //_____________________________________________________________________________
84 AliTrackFitterRieman &AliTrackFitterRieman::operator =(const AliTrackFitterRieman& rieman)
87 // Assignment operator
89 if(this==&rieman) return *this;
90 ((AliTrackFitter *)this)->operator=(rieman);
92 fAlpha = rieman.fAlpha;
93 fNUsed = rieman.fNUsed;
95 fRieman = new AliRieman(*(rieman.fRieman));
100 AliTrackFitterRieman::~AliTrackFitterRieman(){
108 void AliTrackFitterRieman::Reset()
110 // Reset the track parameters and
113 AliTrackFitter::Reset();
120 Bool_t AliTrackFitterRieman::Fit(const TArrayI *volIds,const TArrayI *volIdsFit,
121 AliAlignObj::ELayerID layerRangeMin,
122 AliAlignObj::ELayerID layerRangeMax)
124 // Fit the track points. The method takes as an input
125 // the set of id's (volids) of the volumes in which
126 // one wants to calculate the residuals.
127 // The following parameters are used to define the
128 // range of volumes to be used in the fitting
129 // As a result two AliTrackPointArray's obects are filled.
130 // The first one contains the space points with
131 // volume id's from volids list. The second array of points represents
132 // the track extrapolations corresponding to the space points
133 // in the first array. The two arrays can be used to find
134 // the residuals in the volids and consequently construct a
135 // chi2 function to be minimized during the alignment
136 // procedures. For the moment the track extrapolation is taken
137 // at the space-point reference plane. The reference plane is
138 // found using the covariance matrix of the point
139 // (assuming sigma(x)=0 at the reference coordinate system.
142 Int_t npoints = fPoints->GetNPoints();
143 if (fPoints && AliLog::GetDebugLevel("","AliTrackFitterRieman")>1){
144 Int_t nVol = volIds->GetSize();
145 Int_t nVolFit = volIdsFit->GetSize();
146 Int_t volId = volIds->At(0);
147 (*fDebugStream)<<"PInput"<<
148 "NPoints="<<npoints<< // number of points
149 "VolId="<<volId<< // first vol ID
150 "NVol="<<nVol<< // number of volumes
151 "NvolFit="<<nVolFit<< // number of volumes to fit
152 "fPoints.="<<fPoints<< // input points
155 if (npoints < 3) return kFALSE;
157 Bool_t isAlphaCalc = kFALSE;
158 AliTrackPoint p,plocal;
159 // fPoints->GetPoint(p,0);
160 // fAlpha = TMath::ATan2(p.GetY(),p.GetX());
164 Int_t *pindex = new Int_t[npoints];
165 for (Int_t ipoint = 0; ipoint < npoints; ipoint++)
167 fPoints->GetPoint(p,ipoint);
168 UShort_t iVolId = p.GetVolumeID();
169 if (FindVolId(volIds,iVolId)) {
170 pindex[npVolId] = ipoint;
173 if (volIdsFit != 0x0) {
174 if (!FindVolId(volIdsFit,iVolId)) continue;
177 if (iVolId < AliAlignObj::LayerToVolUID(layerRangeMin,0) ||
178 iVolId > AliAlignObj::LayerToVolUID(layerRangeMax,
179 AliAlignObj::LayerSize(layerRangeMax))) continue;
182 fAlpha = p.GetAngle();
185 plocal = p.Rotate(fAlpha);
186 if (TMath::Abs(plocal.GetX())>500 || TMath::Abs(plocal.GetX())<2){
187 printf("<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<</n");
190 printf("Problematic point\n");
191 printf("<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<</n");
193 AddPoint(plocal.GetX(),plocal.GetY(),plocal.GetZ(),
194 TMath::Sqrt(plocal.GetCov()[3]),TMath::Sqrt(plocal.GetCov()[5]));
195 // fNUsed++; AddPoint should be responsible
198 if (npVolId == 0 || fNUsed < fMinNPoints) {
210 if ((fParams[0] == 0) ||
211 ((-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1) <= 0)) {
217 if (fNUsed < fMinNPoints) {
222 fPVolId = new AliTrackPointArray(npVolId);
223 fPTrack = new AliTrackPointArray(npVolId);
225 for (Int_t ipoint = 0; ipoint < npVolId; ipoint++)
227 Int_t index = pindex[ipoint];
228 fPoints->GetPoint(p,index);
230 Float_t xyz[3],xyz2[3];
231 p.GetXYZ(xyz); p2.GetXYZ(xyz2);
232 // 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]);
233 fPVolId->AddPoint(ipoint,&p);
234 fPTrack->AddPoint(ipoint,&p2);
236 // what should be default bahavior -
246 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")>0){
250 AliTrackPointArray *lPVolId = new AliTrackPointArray(npVolId);
251 AliTrackPointArray *lPTrack = new AliTrackPointArray(npVolId);
252 AliRieman * residual = fRieman->MakeResiduals();
253 AliTrackPoint p2local;
254 for (Int_t ipoint = 0; ipoint < npVolId; ipoint++){
255 Int_t index = pindex[ipoint];
256 fPoints->GetPoint(p,index);
258 plocal = p.Rotate(fAlpha);
259 // plocal.Rotate(fAlpha);
260 Float_t xyz[3],xyz2[3];
264 xyz2[1] = GetYat(xyz[0]);
265 xyz2[2] = GetZat(xyz[0]);
266 p2local.SetXYZ(xyz2);
267 lPVolId->AddPoint(ipoint,&plocal);
268 lPTrack->AddPoint(ipoint,&p2local);
274 Int_t nVol = volIds->GetSize();
275 Int_t nVolFit = volIdsFit->GetSize();
276 Int_t volId = volIds->At(0);
278 Int_t layer = AliAlignObj::VolUIDToLayer(volId,modId);
280 (*fDebugStream)<<"Fit"<<
281 "VolId="<<volId<< // volume ID
282 "Layer="<<layer<< // layer ID
283 "Module="<<modId<< // module ID
284 "NVol="<<nVol<< // number of volumes
285 "NvolFit="<<nVolFit<< // number of volumes to fit
286 "Points0.="<<fPVolId<< // original points
287 "Points1.="<<fPTrack<< // fitted points
288 "LPoints0.="<<lPVolId<< // original points - local frame
289 "LPoints1.="<<lPTrack<< // fitted points - local frame
290 "Rieman.="<<this<< // original rieman fit
291 "Res.="<<residual<< // residuals of rieman fit
303 void AliTrackFitterRieman::AddPoint(Float_t x, Float_t y, Float_t z, Float_t sy, Float_t sz)
306 // add point to rieman fitter
308 fRieman->AddPoint(x,y,z,sy,sz);
309 fNUsed = fRieman->GetN();
314 void AliTrackFitterRieman::Update(){
320 if (fRieman->IsValid()){
321 for (Int_t ipar=0; ipar<6; ipar++){
322 fParams[ipar] = fRieman->GetParam()[ipar];
324 fChi2 = fRieman->GetChi2();
325 fNdf = fRieman->GetN()- 2;
326 fNUsed = fRieman->GetN();
331 //_____________________________________________________________________________
332 Bool_t AliTrackFitterRieman::GetPCA(const AliTrackPoint &p, AliTrackPoint &p2) const
335 // Get the closest to a given spacepoint track trajectory point
336 // Look for details in the description of the Fit() method
338 if (!fConv) return kFALSE;
340 // First X and Y coordinates
341 Double_t sin = TMath::Sin(fAlpha);
342 Double_t cos = TMath::Cos(fAlpha);
344 // fParam[1] = -x0/y0
345 // fParam[2] = - (R^2 - x0^2 - y0^2)/y0
346 if (fParams[0] == 0) return kFALSE;
347 // Track parameters in the global coordinate system
348 Double_t x0 = -fParams[1]/fParams[0]*cos - 1./fParams[0]*sin;
349 Double_t y0 = 1./fParams[0]*cos - fParams[1]/fParams[0]*sin;
350 if ((-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1) <= 0) return kFALSE;
351 Double_t r = TMath::Sqrt(-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1)/
354 // Define space-point refence plane
355 Double_t alphap = p.GetAngle();
356 Double_t sinp = TMath::Sin(alphap);
357 Double_t cosp = TMath::Cos(alphap);
358 Double_t x = p.GetX()*cosp + p.GetY()*sinp;
359 Double_t y = p.GetY()*cosp - p.GetX()*sinp;
360 Double_t x0p= x0*cosp + y0*sinp;
361 Double_t y0p= y0*cosp - x0*sinp;
362 if ((r*r - (x-x0p)*(x-x0p))<0) {
363 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));
366 Double_t temp = TMath::Sqrt(r*r - (x-x0p)*(x-x0p));
367 Double_t y1 = y0p + temp;
368 Double_t y2 = y0p - temp;
369 Double_t yprime = y1;
370 if(TMath::Abs(y2-y) < TMath::Abs(y1-y)) yprime = y2;
372 // Back to the global coordinate system
373 Double_t xsecond = x*cosp - yprime*sinp;
374 Double_t ysecond = yprime*cosp + x*sinp;
376 // Now Z coordinate and track angles
377 Double_t x2 = xsecond*cos + ysecond*sin;
378 Double_t zsecond = GetZat(x2);
379 Double_t dydx = GetDYat(x2);
380 Double_t dzdx = GetDZat(x2);
382 // Fill the cov matrix of the track extrapolation point
383 Double_t cov[6] = {0,0,0,0,0,0};
384 Double_t sigmax = 100*100.;
385 cov[0] = sigmax; cov[1] = sigmax*dydx; cov[2] = sigmax*dzdx;
386 cov[3] = sigmax*dydx*dydx; cov[4] = sigmax*dydx*dzdx;
387 cov[5] = sigmax*dzdx*dzdx;
390 newcov[0] = cov[0]*cos*cos-
393 newcov[1] = cov[1]*(cos*cos-sin*sin)-
394 (cov[3]-cov[0])*sin*cos;
395 newcov[2] = cov[2]*cos-
397 newcov[3] = cov[0]*sin*sin+
400 newcov[4] = cov[4]*cos+
404 p2.SetXYZ(xsecond,ysecond,zsecond,newcov);
405 if (AliLog::GetDebugLevel("","AliTrackFitterRieman")>1){
406 AliTrackPoint lp0(p);
407 AliTrackPoint lp2(p2);
408 if (0)(*fDebugStream)<<"PCA"<<