TRD/AliTRDseedV1.cxx

   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   *
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  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 /* $Id$ */
  17
  18 ////////////////////////////////////////////////////////////////////////////
  19 //                                                                        //
  20 //  The TRD track seed                                                    //
  21 //                                                                        //
  22 //  Authors:                                                              //
  23 //    Alex Bercuci <A.Bercuci@gsi.de>                                     //
  24 //    Markus Fasel <M.Fasel@gsi.de>                                       //
  25 //                                                                        //
  26 ////////////////////////////////////////////////////////////////////////////
  27
  28 #include "TMath.h"
  29 #include "TLinearFitter.h"
  30
  31 #include "AliLog.h"
  32 #include "AliMathBase.h"
  33
  34 #include "AliTRDseedV1.h"
  35 #include "AliTRDcluster.h"
  36 #include "AliTRDtrack.h"
  37 #include "AliTRDcalibDB.h"
  38 #include "AliTRDstackLayer.h"
  39 #include "AliTRDrecoParam.h"
  40
  41 #define SEED_DEBUG
  42
  43 ClassImp(AliTRDseedV1)
  44
  45 //____________________________________________________________________
  46 AliTRDseedV1::AliTRDseedV1(Int_t layer, AliTRDrecoParam *p)
  47   :AliTRDseed()
  48   ,fPlane(layer)
  49   ,fOwner(kFALSE)
  50   ,fRecoParam(p)
  51 {
  52   //
  53   // Constructor
  54   //
  55 }
  56
  57 //____________________________________________________________________
  58 AliTRDseedV1::AliTRDseedV1(const AliTRDseedV1 &ref)
  59   :AliTRDseed((AliTRDseed&)ref)
  60   ,fPlane(ref.fPlane)
  61   ,fOwner(kFALSE)
  62   ,fRecoParam(ref.fRecoParam)
  63 {
  64   //
  65   // Copy Constructor performing a deep copy
  66   //
  67
  68         //AliInfo("");
  69         if(ref.fOwner) SetOwner();
  70 }
  71
  72
  73 //____________________________________________________________________
  74 AliTRDseedV1& AliTRDseedV1::operator=(const AliTRDseedV1 &ref)
  75 {
  76   //
  77   // Assignment Operator using the copy function
  78   //
  79
  80         //AliInfo("");
  81         if(this != &ref){
  82                 ref.Copy(*this);
  83         }
  84         return *this;
  85
  86 }
  87
  88 //____________________________________________________________________
  89 AliTRDseedV1::~AliTRDseedV1()
  90 {
  91   //
  92   // Destructor. The RecoParam object belongs to the underlying tracker.
  93   //
  94
  95         //AliInfo(Form("fOwner[%s]", fOwner?"YES":"NO"));
  96
  97         if(fOwner) delete [] fClusters;
  98 }
  99
 100 //____________________________________________________________________
 101 void AliTRDseedV1::Copy(TObject &ref) const
 102 {
 103   //
 104   // Copy function
 105   //
 106
 107         //AliInfo("");
 108         AliTRDseedV1 &target = (AliTRDseedV1 &)ref;
 109
 110         target.fPlane         = fPlane;
 111         target.fRecoParam     = fRecoParam;
 112         AliTRDseed::Copy(target);
 113 }
 114
 115
 116 //____________________________________________________________
 117 void AliTRDseedV1::Init(AliTRDtrack *track)
 118 {
 119 // Initialize this tracklet using the track information
 120 //
 121 // Parameters:
 122 //   track - the TRD track used to initialize the tracklet
 123 //
 124 // Detailed description
 125 // The function sets the starting point and direction of the
 126 // tracklet according to the information from the TRD track.
 127 //
 128 // Caution
 129 // The TRD track has to be propagated to the beginning of the
 130 // chamber where the tracklet will be constructed
 131 //
 132
 133         Double_t y, z;
 134         track->GetProlongation(fX0, y, z);
 135         fYref[0] = y;
 136         fYref[1] = track->GetSnp() < 0. ? track->GetTgl() : -track->GetTgl();
 137         fZref[0] = z;
 138         // TO DO
 139         // tilting pad correction !!
 140         fZref[1] = 0.; // TMath::Tan(track->Theta());
 141
 142         //printf("Tracklet ref x[%7.3f] y[%7.3f] z[%7.3f], snp[%f] tgl[%f]\n", fX0, fYref[0], fZref[0], track->GetSnp(), track->GetTgl());
 143 }
 144
 145 //____________________________________________________________________
 146 Float_t AliTRDseedV1::GetQuality(Bool_t kZcorr) const
 147 {
 148   //
 149   // Returns a quality measurement of the current seed
 150   //
 151
 152         Float_t zcorr = kZcorr ? fTilt * (fZProb - fZref[0]) : 0.;
 153         return .5 * (18.0 - fN2)
 154                 + 10.* TMath::Abs(fYfit[1] - fYref[1])
 155                 + 5.* TMath::Abs(fYfit[0] - fYref[0] + zcorr)
 156                 + 2. * TMath::Abs(fMeanz - fZref[0]) / fPadLength;
 157 }
 158
 159 //____________________________________________________________________
 160 void AliTRDseedV1::GetCovAt(Double_t /*x*/, Double_t *cov) const
 161 {
 162 // Computes covariance in the y-z plane at radial point x
 163
 164         const Float_t k0= .2; // to be checked in FindClusters
 165         Double_t sy20   = k0*TMath::Tan(fYfit[1]); sy20 *= sy20;
 166
 167         Double_t sy2    = fSigmaY2*fSigmaY2 + sy20;
 168         Double_t sz2    = fPadLength/12.;
 169
 170         //printf("Yfit[1] %f sy20 %f SigmaY2 %f\n", fYfit[1], sy20, fSigmaY2);
 171
 172         cov[0] = sy2;
 173         cov[1] = fTilt*(sy2-sz2);
 174         cov[2] = sz2;
 175 }
 176
 177 //____________________________________________________________________
 178 void AliTRDseedV1::SetOwner(Bool_t own)
 179 {
 180   //
 181   // Handles the ownership of the clusters
 182   //
 183         if(own){
 184                 for(int ic=0; ic<fgTimeBins; ic++){
 185                         if(!fClusters[ic]) continue;
 186                         fClusters[ic] = new AliTRDcluster(*fClusters[ic]);
 187                 }
 188                 fOwner = kTRUE;
 189         } else {
 190                 if(fOwner){
 191                         for(int ic=0; ic<fgTimeBins; ic++){
 192                                 if(!fClusters[ic]) continue;
 193                                 delete fClusters[ic];
 194                         }
 195                 }
 196                 fOwner = kFALSE;
 197         }
 198 }
 199
 200 //____________________________________________________________________
 201 Bool_t  AliTRDseedV1::AttachClustersIter(AliTRDstackLayer *layer
 202                                        , Float_t quality
 203                                        , Bool_t kZcorr
 204                                        , AliTRDcluster *c)
 205 {
 206   //
 207   // Iterative process to register clusters to the seed.
 208   // In iteration 0 we try only one pad-row and if quality not
 209   // sufficient we try 2 pad-rows (about 5% of tracks cross 2 pad-rows)
 210   //
 211
 212         if(!fRecoParam){
 213                 AliError("Seed can not be used without a valid RecoParam.");
 214                 return kFALSE;
 215         }
 216
 217         //AliInfo(Form("TimeBins = %d TimeBinsRange = %d", fgTimeBins, fTimeBinsRange));
 218
 219         Float_t  tquality;
 220         Double_t kroady = fRecoParam->GetRoad1y();
 221         Double_t kroadz = fPadLength * .5 + 1.;
 222
 223         // initialize configuration parameters
 224         Float_t zcorr = kZcorr ? fTilt * (fZProb - fZref[0]) : 0.;
 225         Int_t   niter = kZcorr ? 1 : 2;
 226
 227         Double_t yexp, zexp;
 228         Int_t ncl = 0;
 229         // start seed update
 230         for (Int_t iter = 0; iter < niter; iter++) {
 231         //AliInfo(Form("iter = %i", iter));
 232                 ncl = 0;
 233                 for (Int_t iTime = 0; iTime < fgTimeBins; iTime++) {
 234                         // define searching configuration
 235                         Double_t dxlayer = layer[iTime].GetX() - fX0;
 236                         if(c){
 237                                 zexp = c->GetZ();
 238                                 //Try 2 pad-rows in second iteration
 239                                 if (iter > 0) {
 240                                         zexp = fZref[0] + fZref[1] * dxlayer - zcorr;
 241                                         if (zexp > c->GetZ()) zexp = c->GetZ() + fPadLength*0.5;
 242                                         if (zexp < c->GetZ()) zexp = c->GetZ() - fPadLength*0.5;
 243                                 }
 244                         } else zexp = fZref[0];
 245                         yexp  = fYref[0] + fYref[1] * dxlayer - zcorr;
 246                         // get  cluster
 247 //                      printf("xexp = %3.3f ,yexp = %3.3f, zexp = %3.3f\n",layer[iTime].GetX(),yexp,zexp);
 248 //                      printf("layer[%i].GetNClusters() = %i\n", iTime, layer[iTime].GetNClusters());
 249                         Int_t    index = layer[iTime].SearchNearestCluster(yexp, zexp, kroady, kroadz);
 250
 251 //                      printf("%d[%d] x[%7.3f | %7.3f] y[%7.3f] z[%7.3f]\n", iTime, layer[iTime].GetNClusters(), dxlayer, layer[iTime].GetX(), yexp, zexp);
 252 //                      for(Int_t iclk = 0; iclk < layer[iTime].GetNClusters(); iclk++){
 253 //                              AliTRDcluster *testcl = layer[iTime].GetCluster(iclk);
 254 //                              printf("Cluster %i: %d x = %7.3f, y = %7.3f, z = %7.3f\n", iclk, testcl->GetLocalTimeBin(), testcl->GetX(), testcl->GetY(), testcl->GetZ());
 255 //                      }
 256 //                      printf("Index = %i\n",index);
 257
 258                         if (index < 0) continue;
 259
 260                         // Register cluster
 261                         AliTRDcluster *cl = (AliTRDcluster*) layer[iTime].GetCluster(index);
 262
 263                         //printf("Cluster %i(0x%x): x = %3.3f, y = %3.3f, z = %3.3f\n", index, cl, cl->GetX(), cl->GetY(), cl->GetZ());
 264
 265                         Int_t globalIndex = layer[iTime].GetGlobalIndex(index);
 266                         fIndexes[iTime]  = globalIndex;
 267                         fClusters[iTime] = cl;
 268                         fX[iTime]        = dxlayer;
 269                         fY[iTime]        = cl->GetY();
 270                         fZ[iTime]        = cl->GetZ();
 271
 272                         // Debugging
 273                         ncl++;
 274                 }
 275
 276 #ifdef SEED_DEBUG
 277 //              Int_t nclusters = 0;
 278 //              Float_t fD[iter] = 0.;
 279 //              for(int ic=0; ic<fgTimeBins+1; ic++){
 280 //                      AliTRDcluster *ci = fClusters[ic];
 281 //                      if(!ci) continue;
 282 //                      for(int jc=ic+1; jc<fgTimeBins+1; jc++){
 283 //                              AliTRDcluster *cj = fClusters[jc];
 284 //                              if(!cj) continue;
 285 //                              fD[iter] += TMath::Sqrt((ci->GetY()-cj->GetY())*(ci->GetY()-cj->GetY())+
 286 //                              (ci->GetZ()-cj->GetZ())*(ci->GetZ()-cj->GetZ()));
 287 //                              nclusters++;
 288 //                      }
 289 //              }
 290 //              if(nclusters) fD[iter] /= float(nclusters);
 291 #endif
 292
 293                 AliTRDseed::Update();
 294
 295                 if(IsOK()){
 296                         tquality = GetQuality(kZcorr);
 297                         if(tquality < quality) break;
 298                         else quality = tquality;
 299                 }
 300                 kroadz *= 2.;
 301         } // Loop: iter
 302         if (!IsOK()) return kFALSE;
 303
 304         CookLabels();
 305         UpdateUsed();
 306         return kTRUE;
 307 }
 308
 309 //____________________________________________________________________
 310 Bool_t  AliTRDseedV1::AttachClusters(AliTRDstackLayer *layer
 311                                        ,Bool_t kZcorr)
 312 {
 313   //
 314   // Projective algorithm to attach clusters to seeding tracklets
 315   //
 316   // Parameters
 317   //
 318   // Output
 319   //
 320   // Detailed description
 321   // 1. Collapse x coordinate for the full detector plane
 322   // 2. truncated mean on y (r-phi) direction
 323   // 3. purge clusters
 324   // 4. truncated mean on z direction
 325   // 5. purge clusters
 326   // 6. fit tracklet
 327   //
 328
 329         if(!fRecoParam){
 330                 AliError("Seed can not be used without a valid RecoParam.");
 331                 return kFALSE;
 332         }
 333
 334         const Int_t kClusterCandidates = 2 * knTimebins;
 335
 336         //define roads
 337         Double_t kroady = fRecoParam->GetRoad1y();
 338         Double_t kroadz = fPadLength * 1.5 + 1.;
 339         // correction to y for the tilting angle
 340         Float_t zcorr = kZcorr ? fTilt * (fZProb - fZref[0]) : 0.;
 341
 342         // working variables
 343         AliTRDcluster *clusters[kClusterCandidates];
 344         Double_t cond[4], yexp[knTimebins], zexp[knTimebins],
 345                 yres[kClusterCandidates], zres[kClusterCandidates];
 346         Int_t ncl, *index = 0x0, tboundary[knTimebins];
 347
 348         // Do cluster projection
 349         Int_t nYclusters = 0; Bool_t kEXIT = kFALSE;
 350         for (Int_t iTime = 0; iTime < fgTimeBins; iTime++) {
 351                 fX[iTime] = layer[iTime].GetX() - fX0;
 352                 zexp[iTime] = fZref[0] + fZref[1] * fX[iTime];
 353                 yexp[iTime] = fYref[0] + fYref[1] * fX[iTime] - zcorr;
 354
 355                 // build condition and process clusters
 356                 cond[0] = yexp[iTime] - kroady; cond[1] = yexp[iTime] + kroady;
 357                 cond[2] = zexp[iTime] - kroadz; cond[3] = zexp[iTime] + kroadz;
 358                 layer[iTime].GetClusters(cond, index, ncl);
 359                 for(Int_t ic = 0; ic<ncl; ic++){
 360                         AliTRDcluster *c = layer[iTime].GetCluster(index[ic]);
 361                         clusters[nYclusters] = c;
 362                         yres[nYclusters++] = c->GetY() - yexp[iTime];
 363                         if(nYclusters >= kClusterCandidates) {
 364                                 AliWarning(Form("Cluster candidates reached limit %d. Some may be lost.", kClusterCandidates));
 365                                 kEXIT = kTRUE;
 366                                 break;
 367                         }
 368                 }
 369                 tboundary[iTime] = nYclusters;
 370                 if(kEXIT) break;
 371         }
 372
 373         // Evaluate truncated mean on the y direction
 374         Double_t mean, sigma;
 375         AliMathBase::EvaluateUni(nYclusters, yres, mean, sigma, Int_t(nYclusters*.8)-2);
 376         //purge cluster candidates
 377         Int_t nZclusters = 0;
 378         for(Int_t ic = 0; ic<nYclusters; ic++){
 379                 if(yres[ic] - mean > 4. * sigma){
 380                         clusters[ic] = 0x0;
 381                         continue;
 382                 }
 383                 zres[nZclusters++] = clusters[ic]->GetZ() - zexp[clusters[ic]->GetLocalTimeBin()];
 384         }
 385
 386         // Evaluate truncated mean on the z direction
 387         AliMathBase::EvaluateUni(nZclusters, zres, mean, sigma, Int_t(nZclusters*.8)-2);
 388         //purge cluster candidates
 389         for(Int_t ic = 0; ic<nZclusters; ic++){
 390                 if(zres[ic] - mean > 4. * sigma){
 391                         clusters[ic] = 0x0;
 392                         continue;
 393                 }
 394         }
 395
 396
 397         // Select only one cluster/TimeBin
 398         Int_t lastCluster = 0;
 399         fN2 = 0;
 400         for (Int_t iTime = 0; iTime < fgTimeBins; iTime++) {
 401                 ncl = tboundary[iTime] - lastCluster;
 402                 if(!ncl) continue;
 403                 AliTRDcluster *c = 0x0;
 404                 if(ncl == 1){
 405                         c = clusters[lastCluster];
 406                 } else if(ncl > 1){
 407                         Float_t dold = 9999.; Int_t iptr = lastCluster;
 408                         for(int ic=lastCluster; ic<tboundary[iTime]; ic++){
 409                                 if(!clusters[ic]) continue;
 410                                 Float_t y = yexp[iTime] - clusters[ic]->GetY();
 411                                 Float_t z = zexp[iTime] - clusters[ic]->GetZ();
 412                                 Float_t d = y * y + z * z;
 413                                 if(d > dold) continue;
 414                                 dold = d;
 415                                 iptr = ic;
 416                         }
 417                         c = clusters[iptr];
 418                 }
 419                 //Int_t GlobalIndex = layer[iTime].GetGlobalIndex(index);
 420                 //fIndexes[iTime]  = GlobalIndex;
 421                 fClusters[iTime] = c;
 422                 fY[iTime]        = c->GetY();
 423                 fZ[iTime]        = c->GetZ();
 424                 lastCluster = tboundary[iTime];
 425                 fN2++;
 426         }
 427
 428         // number of minimum numbers of clusters expected for the tracklet
 429         Int_t kClmin = Int_t(fRecoParam->GetFindableClusters()*fgTimeBins);
 430   if (fN2 < kClmin){
 431                 AliWarning(Form("Not enough clusters to fit the tracklet %d [%d].", fN2, kClmin));
 432     fN2 = 0;
 433     return kFALSE;
 434   }
 435
 436         // update used clusters
 437         fNUsed = 0;
 438         for (Int_t iTime = 0; iTime < fgTimeBins; iTime++) {
 439                 if(!fClusters[iTime]) continue;
 440                 if((fClusters[iTime]->IsUsed())) fNUsed++;
 441         }
 442
 443   if (fN2-fNUsed < kClmin){
 444                 AliWarning(Form("Too many clusters already in use %d (from %d).", fNUsed, fN2));
 445     fN2 = 0;
 446     return kFALSE;
 447   }
 448
 449         return kTRUE;
 450 }
 451
 452 //____________________________________________________________________
 453 Bool_t AliTRDseedV1::Fit()
 454 {
 455   //
 456   // Linear fit of the tracklet
 457   //
 458   // Parameters :
 459   //
 460   // Output :
 461   //  True if successful
 462   //
 463   // Detailed description
 464   // 2. Check if tracklet crosses pad row boundary
 465   // 1. Calculate residuals in the y (r-phi) direction
 466   // 3. Do a Least Square Fit to the data
 467   //
 468
 469         //Float_t  sigmaexp  = 0.05 + TMath::Abs(fYref[1] * 0.25); // Expected r.m.s in y direction
 470   Float_t  ycrosscor = fPadLength * fTilt * 0.5; // Y correction for crossing
 471   Float_t  anglecor = fTilt * fZref[1];  // Correction to the angle
 472
 473         // calculate residuals
 474         Float_t yres[knTimebins]; // y (r-phi) residuals
 475         Int_t zint[knTimebins],   // Histograming of the z coordinate
 476               zout[2*knTimebins];//
 477
 478         fN = 0;
 479         for (Int_t iTime = 0; iTime < fTimeBinsRange; iTime++) {
 480     if (!fClusters[iTime]) continue;
 481     yres[iTime] = fY[iTime] - fYref[0] - (fYref[1] + anglecor) * fX[iTime];
 482                 zint[fN] = Int_t(fZ[iTime]);
 483                 fN++;
 484         }
 485
 486         // calculate pad row boundary crosses
 487         Int_t kClmin = Int_t(fRecoParam->GetFindableClusters()*fTimeBinsRange);
 488         Int_t nz = AliMathBase::Freq(fN, zint, zout, kFALSE);
 489   fZProb   = zout[0];
 490   if(nz <= 1) zout[3] = 0;
 491   if(zout[1] + zout[3] < kClmin) {
 492                 AliWarning(Form("Not enough clusters to fit the cross boundary tracklet %d [%d].", zout[1]+zout[3], kClmin));
 493                 return kFALSE;
 494         }
 495   // Z distance bigger than pad - length
 496   if (TMath::Abs(zout[0]-zout[2]) > fPadLength) zout[3]=0;
 497
 498
 499   Double_t sumw   = 0.,
 500                 sumwx  = 0.,
 501                 sumwx2 = 0.,
 502                 sumwy  = 0.,
 503                 sumwxy = 0.,
 504                 sumwz  = 0.,
 505                 sumwxz = 0.;
 506         Int_t npads;
 507   fMPads = 0;
 508         fMeanz = 0.;
 509         // we will use only the clusters which are in the detector range
 510         for(int iTime=0; iTime<fTimeBinsRange; iTime++){
 511     fUsable[iTime] = kFALSE;
 512     if (!fClusters[iTime]) continue;
 513                 npads = fClusters[iTime]->GetNPads();
 514
 515                 fUsable[iTime] = kTRUE;
 516     fN2++;
 517     fMPads += npads;
 518     Float_t weight = 1.0;
 519     if(npads > 5) weight = 0.2;
 520     else if(npads > 4) weight = 0.5;
 521     sumw   += weight;
 522     sumwx  += fX[iTime] * weight;
 523     sumwx2 += fX[iTime] * fX[iTime] * weight;
 524     sumwy  += weight * yres[iTime];
 525     sumwxy += weight * yres[iTime] * fX[iTime];
 526     sumwz  += weight * fZ[iTime];
 527     sumwxz += weight * fZ[iTime] * fX[iTime];
 528         }
 529   if (fN2 < kClmin){
 530                 AliWarning(Form("Not enough clusters to fit the tracklet %d [%d].", fN2, kClmin));
 531     fN2 = 0;
 532     return kFALSE;
 533   }
 534   fMeanz = sumwz / sumw;
 535         fNChange = 0;
 536
 537         // Tracklet on boundary
 538   Float_t correction = 0;
 539   if (fNChange > 0) {
 540     if (fMeanz < fZProb) correction =  ycrosscor;
 541     if (fMeanz > fZProb) correction = -ycrosscor;
 542   }
 543
 544   Double_t det = sumw * sumwx2 - sumwx * sumwx;
 545   fYfitR[0]    = (sumwx2 * sumwy  - sumwx * sumwxy) / det;
 546   fYfitR[1]    = (sumw   * sumwxy - sumwx * sumwy)  / det;
 547
 548   fSigmaY2 = 0;
 549   for (Int_t i = 0; i < fTimeBinsRange+1; i++) {
 550     if (!fUsable[i]) continue;
 551     Float_t delta = yres[i] - fYfitR[0] - fYfitR[1] * fX[i];
 552     fSigmaY2 += delta*delta;
 553   }
 554   fSigmaY2 = TMath::Sqrt(fSigmaY2 / Float_t(fN2-2));
 555
 556   fZfitR[0]  = (sumwx2 * sumwz  - sumwx * sumwxz) / det;
 557   fZfitR[1]  = (sumw   * sumwxz - sumwx * sumwz)  / det;
 558   fZfit[0]   = (sumwx2 * sumwz  - sumwx * sumwxz) / det;
 559   fZfit[1]   = (sumw   * sumwxz - sumwx * sumwz)  / det;
 560   fYfitR[0] += fYref[0] + correction;
 561   fYfitR[1] += fYref[1];
 562   fYfit[0]   = fYfitR[0];
 563   fYfit[1]   = fYfitR[1];
 564
 565         return kTRUE;
 566 }
 567
 568 //_____________________________________________________________________________
 569 Float_t AliTRDseedV1::FitRiemanTilt(AliTRDseedV1 *cseed, Bool_t terror)
 570 {
 571   //
 572   // Fit the Rieman tilt
 573   //
 574
 575   // Fitting with tilting pads - kz not fixed
 576         AliTRDcalibDB *cal = AliTRDcalibDB::Instance();
 577         Int_t nTimeBins = cal->GetNumberOfTimeBins();
 578   TLinearFitter fitterT2(4,"hyp4");
 579   fitterT2.StoreData(kTRUE);
 580   Float_t xref2 = (cseed[2].fX0 + cseed[3].fX0) * 0.5; // Reference x0 for z
 581
 582   Int_t npointsT = 0;
 583   fitterT2.ClearPoints();
 584
 585   for (Int_t iLayer = 0; iLayer < 6; iLayer++) {
 586 //              printf("\nLayer %d\n", iLayer);
 587 //     cseed[iLayer].Print();
 588                 if (!cseed[iLayer].IsOK()) continue;
 589     Double_t tilt = cseed[iLayer].fTilt;
 590
 591     for (Int_t itime = 0; itime < nTimeBins+1; itime++) {
 592 //                      printf("\ttime %d\n", itime);
 593       if (!cseed[iLayer].fUsable[itime]) continue;
 594       // x relative to the midle chamber
 595       Double_t x = cseed[iLayer].fX[itime] + cseed[iLayer].fX0 - xref2;
 596       Double_t y = cseed[iLayer].fY[itime];
 597       Double_t z = cseed[iLayer].fZ[itime];
 598
 599       //
 600       // Tilted rieman
 601       //
 602       Double_t uvt[6];
 603       Double_t x2 = cseed[iLayer].fX[itime] + cseed[iLayer].fX0;      // Global x
 604       Double_t t  = 1.0 / (x2*x2 + y*y);
 605       uvt[1]  = t;
 606       uvt[0]  = 2.0 * x2   * uvt[1];
 607       uvt[2]  = 2.0 * tilt * uvt[1];
 608       uvt[3]  = 2.0 * tilt *uvt[1] * x;
 609       uvt[4]  = 2.0 * (y + tilt * z) * uvt[1];
 610
 611       Double_t error = 2.0 * uvt[1];
 612       if (terror) {
 613         error *= cseed[iLayer].fSigmaY;
 614       }
 615       else {
 616         error *= 0.2; //Default error
 617       }
 618 //                      printf("\tadd point :\n");
 619 //                      for(int i=0; i<5; i++) printf("%f ", uvt[i]);
 620 //                      printf("\n");
 621       fitterT2.AddPoint(uvt,uvt[4],error);
 622       npointsT++;
 623
 624     }
 625
 626   }
 627   fitterT2.Eval();
 628   Double_t rpolz0 = fitterT2.GetParameter(3);
 629   Double_t rpolz1 = fitterT2.GetParameter(4);
 630
 631   //
 632   // Linear fitter  - not possible to make boundaries
 633   // non accept non possible z and dzdx combination
 634   //
 635   Bool_t acceptablez = kTRUE;
 636   for (Int_t iLayer = 0; iLayer < 6; iLayer++) {
 637     if (cseed[iLayer].IsOK()) {
 638       Double_t zT2 = rpolz0 + rpolz1 * (cseed[iLayer].fX0 - xref2);
 639       if (TMath::Abs(cseed[iLayer].fZProb - zT2) > cseed[iLayer].fPadLength * 0.5 + 1.0) {
 640         acceptablez = kFALSE;
 641       }
 642     }
 643   }
 644   if (!acceptablez) {
 645     Double_t zmf  = cseed[2].fZref[0] + cseed[2].fZref[1] * (xref2 - cseed[2].fX0);
 646     Double_t dzmf = (cseed[2].fZref[1] + cseed[3].fZref[1]) * 0.5;
 647     fitterT2.FixParameter(3,zmf);
 648     fitterT2.FixParameter(4,dzmf);
 649     fitterT2.Eval();
 650     fitterT2.ReleaseParameter(3);
 651     fitterT2.ReleaseParameter(4);
 652     rpolz0 = fitterT2.GetParameter(3);
 653     rpolz1 = fitterT2.GetParameter(4);
 654   }
 655
 656   Double_t chi2TR = fitterT2.GetChisquare() / Float_t(npointsT);
 657   Double_t params[3];
 658   params[0] =  fitterT2.GetParameter(0);
 659   params[1] =  fitterT2.GetParameter(1);
 660   params[2] =  fitterT2.GetParameter(2);
 661   Double_t curvature =  1.0 + params[1] * params[1] - params[2] * params[0];
 662
 663   for (Int_t iLayer = 0; iLayer < 6; iLayer++) {
 664
 665     Double_t  x  = cseed[iLayer].fX0;
 666     Double_t  y  = 0;
 667     Double_t  dy = 0;
 668     Double_t  z  = 0;
 669     Double_t  dz = 0;
 670
 671     // y
 672     Double_t res2 = (x * params[0] + params[1]);
 673     res2 *= res2;
 674     res2  = 1.0 - params[2]*params[0] + params[1]*params[1] - res2;
 675     if (res2 >= 0) {
 676       res2 = TMath::Sqrt(res2);
 677       y    = (1.0 - res2) / params[0];
 678     }
 679
 680     //dy
 681     Double_t x0 = -params[1] / params[0];
 682     if (-params[2]*params[0] + params[1]*params[1] + 1 > 0) {
 683       Double_t rm1 = params[0] / TMath::Sqrt(-params[2]*params[0] + params[1]*params[1] + 1);
 684       if (1.0/(rm1*rm1) - (x-x0) * (x-x0) > 0.0) {
 685         Double_t res = (x - x0) / TMath::Sqrt(1.0 / (rm1*rm1) - (x-x0)*(x-x0));
 686         if (params[0] < 0) res *= -1.0;
 687         dy = res;
 688       }
 689     }
 690     z  = rpolz0 + rpolz1 * (x - xref2);
 691     dz = rpolz1;
 692     cseed[iLayer].fYref[0] = y;
 693     cseed[iLayer].fYref[1] = dy;
 694     cseed[iLayer].fZref[0] = z;
 695     cseed[iLayer].fZref[1] = dz;
 696     cseed[iLayer].fC       = curvature;
 697
 698   }
 699
 700   return chi2TR;
 701
 702 }
 703
 704 //___________________________________________________________________
 705 void AliTRDseedV1::Print()
 706 {
 707   //
 708   // Printing the seedstatus
 709   //
 710
 711         AliTRDcalibDB *cal = AliTRDcalibDB::Instance();
 712         Int_t nTimeBins = cal->GetNumberOfTimeBins();
 713
 714         printf("Seed status :\n");
 715         printf("  fTilt      = %f\n", fTilt);
 716         printf("  fPadLength = %f\n", fPadLength);
 717         printf("  fX0        = %f\n", fX0);
 718         for(int ic=0; ic<nTimeBins; ic++) {
 719           const Char_t *isUsable = fUsable[ic]?"Yes":"No";
 720           printf("  %d X[%f] Y[%f] Z[%f] Indexes[%d] clusters[%p] usable[%s]\n"
 721                 , ic
 722                 , fX[ic]
 723                 , fY[ic]
 724                 , fZ[ic]
 725                 , fIndexes[ic]
 726                 , ((void*) fClusters[ic])
 727                 , isUsable);
 728         }
 729
 730         printf("  fYref[0] =%f fYref[1] =%f\n", fYref[0], fYref[1]);
 731         printf("  fZref[0] =%f fZref[1] =%f\n", fZref[0], fZref[1]);
 732         printf("  fYfit[0] =%f fYfit[1] =%f\n", fYfit[0], fYfit[1]);
 733         printf("  fYfitR[0]=%f fYfitR[1]=%f\n", fYfitR[0], fYfitR[1]);
 734         printf("  fZfit[0] =%f fZfit[1] =%f\n", fZfit[0], fZfit[1]);
 735         printf("  fZfitR[0]=%f fZfitR[1]=%f\n", fZfitR[0], fZfitR[1]);
 736         printf("  fSigmaY =%f\n", fSigmaY);
 737         printf("  fSigmaY2=%f\n", fSigmaY2);
 738         printf("  fMeanz  =%f\n", fMeanz);
 739         printf("  fZProb  =%f\n", fZProb);
 740         printf("  fLabels[0]=%d fLabels[1]=%d\n", fLabels[0], fLabels[1]);
 741         printf("  fN      =%d\n", fN);
 742         printf("  fN2     =%d (>8 isOK)\n",fN2);
 743         printf("  fNUsed  =%d\n", fNUsed);
 744         printf("  fFreq   =%d\n", fFreq);
 745         printf("  fNChange=%d\n",  fNChange);
 746         printf("  fMPads  =%f\n", fMPads);
 747
 748         printf("  fC      =%f\n", fC);
 749         printf("  fCC     =%f\n",fCC);
 750         printf("  fChi2   =%f\n", fChi2);
 751         printf("  fChi2Z  =%f\n", fChi2Z);
 752
 753 }