+//_____________________________________________________________________________
+Int_t AliTRDtrack::UpdateMI(const AliTRDcluster *c, Double_t chisq, UInt_t index, Double_t h01,
+ Int_t plane)
+{
+ // Assignes found cluster to the track and updates track information
+
+ Bool_t fNoTilt = kTRUE;
+ if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
+ // add angular effect to the error contribution and make correction - MI
+ AliTRDclusterCorrection *corrector = AliTRDclusterCorrection::GetCorrection();
+ //
+ Double_t tangent2 = (fC*fX-fE)*(fC*fX-fE);
+ if (tangent2 < 0.90000){
+ tangent2 = tangent2/(1.-tangent2);
+ }
+ Double_t tangent = TMath::Sqrt(tangent2);
+ if ((fC*fX-fE)<0) tangent*=-1;
+ Double_t correction = 0;
+ Double_t errang = tangent2*0.04; //
+ if (corrector!=0){
+ //if (0){
+ correction = corrector->GetCorrection(plane,c->GetLocalTimeBin(),tangent);
+ if (TMath::Abs(correction)>0){
+ //if we have info
+ errang = corrector->GetSigma(plane,c->GetLocalTimeBin(),tangent);
+ errang *= errang;
+ errang += tangent2*0.04;
+ }
+ }
+
+ //
+ Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12.);
+
+ Double_t r00=c->GetSigmaY2() +errang, r01=0., r11=c->GetSigmaZ2()*10000.;
+ r00+=fCyy; r01+=fCzy; r11+=fCzz;
+ Double_t det=r00*r11 - r01*r01;
+ Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
+
+ Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
+ Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
+ Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
+ Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
+ Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
+
+ Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
+ Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
+
+
+ if(fNoTilt) {
+ if (TMath::Abs(cur*fX-eta) >= 0.90000) {
+ // Int_t n=GetNumberOfClusters();
+ //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
+ return 0;
+ }
+ fY += k00*dy + k01*dz;
+ fZ += k10*dy + k11*dz;
+ fE = eta;
+ //fT += k30*dy + k31*dz;
+ fC = cur;
+ }
+ else {
+ Double_t xu_factor = 1000.; // empirical factor set by C.Xu
+ // in the first tilt version
+ dy=c->GetY() - fY; dz=c->GetZ() - fZ;
+ dy=dy+h01*dz+correction;
+ Double_t add=0;
+ if (TMath::Abs(dz)>padlength/2.){
+ //Double_t dy2 = c->GetY() - fY;
+ //Double_t sign = (dz>0) ? -1.: 1.;
+ //dy2-=h01*sign*padlength/2.;
+ //dy = dy2;
+ add =1.;
+ }
+ Double_t s00 = c->GetSigmaY2()+errang+add; // error pad
+ Double_t s11 = c->GetSigmaZ2()*xu_factor; // error pad-row
+ //
+ r00 = fCyy + 2*fCzy*h01 + fCzz*h01*h01+s00;
+ r01 = fCzy + fCzz*h01;
+ r11 = fCzz + s11;
+ det = r00*r11 - r01*r01;
+ // inverse matrix
+ tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
+
+ // K matrix
+ k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
+ k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
+ k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
+ k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
+ k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
+ //
+ //Update measurement
+ cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
+ if (TMath::Abs(cur*fX-eta) >= 0.90000) {
+ //Int_t n=GetNumberOfClusters();
+ // if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
+ return 0;
+ }
+ fY += k00*dy + k01*dz;
+ fZ += k10*dy + k11*dz;
+ fE = eta;
+ fT += k30*dy + k31*dz;
+ fC = cur;
+
+ k01+=h01*k00;
+ k11+=h01*k10;
+ k21+=h01*k20;
+ k31+=h01*k30;
+ k41+=h01*k40;
+
+ }
+ //Update covariance
+ //
+ //
+ Double_t oldyy = fCyy, oldzz = fCzz; //, oldee=fCee, oldcc =fCcc;
+ Double_t oldzy = fCzy, oldey = fCey, oldty=fCty, oldcy =fCcy;
+ Double_t oldez = fCez, oldtz = fCtz, oldcz=fCcz;
+ //Double_t oldte = fCte, oldce = fCce;
+ //Double_t oldct = fCct;
+
+ fCyy-=k00*oldyy+k01*oldzy;
+ fCzy-=k10*oldyy+k11*oldzy;
+ fCey-=k20*oldyy+k21*oldzy;
+ fCty-=k30*oldyy+k31*oldzy;
+ fCcy-=k40*oldyy+k41*oldzy;
+ //
+ fCzz-=k10*oldzy+k11*oldzz;
+ fCez-=k20*oldzy+k21*oldzz;
+ fCtz-=k30*oldzy+k31*oldzz;
+ fCcz-=k40*oldzy+k41*oldzz;
+ //
+ fCee-=k20*oldey+k21*oldez;
+ fCte-=k30*oldey+k31*oldez;
+ fCce-=k40*oldey+k41*oldez;
+ //
+ fCtt-=k30*oldty+k31*oldtz;
+ fCct-=k40*oldty+k41*oldtz;
+ //
+ fCcc-=k40*oldcy+k41*oldcz;
+ //
+
+ Int_t n=GetNumberOfClusters();
+ fIndex[n]=index;
+ SetNumberOfClusters(n+1);
+
+ SetChi2(GetChi2()+chisq);
+ // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
+
+ return 1;
+}