Common track parametrization in the barrel detectors (Yu.Belikov)

[u/mrichter/AliRoot.git] / STEER / AliKink.cxx

diff --git a/STEER/AliKink.cxx b/STEER/AliKink.cxx
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+/**************************************************************************
+ * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
+ *                                                                        *
+ * Author: The ALICE Off-line Project.                                    *
+ * Contributors are mentioned in the code where appropriate.              *
+ *                                                                        *
+ * Permission to use, copy, modify and distribute this software and its   *
+ * documentation strictly for non-commercial purposes is hereby granted   *
+ * without fee, provided that the above copyright notice appears in all   *
+ * copies and that both the copyright notice and this permission notice   *
+ * appear in the supporting documentation. The authors make no claims     *
+ * about the suitability of this software for any purpose. It is          *
+ * provided "as is" without express or implied warranty.                  *
+ **************************************************************************/
+
+//-------------------------------------------------------------------------
+//    Origin: Marian Ivanov marian.ivanov@cern.ch
+//-------------------------------------------------------------------------
+
+#include <TMath.h>
+#include "AliKink.h"
+#include "AliHelix.h"
+
+
+ClassImp(AliKink)
+
+void  AliKink::Update()
+{
+  //
+  // updates Kink Info
+  //
+  Float_t distance2=1000;
+  //
+  AliHelix dhelix1(fParamDaughter);
+  AliHelix mhelix(fParamMother);    
+  //
+  //find intersection linear
+  //
+  Double_t phase[2][2],radius[2];
+  Double_t delta1=10000,delta2=10000;  
+  Int_t points=0;
+  /*
+    Float_t distance1=0;
+  Int_t  points = dhelix1.GetRPHIintersections(mhelix, phase, radius,200);
+  
+  if (points>0){
+    dhelix1.LinearDCA(mhelix,phase[0][0],phase[0][1],radius[0],delta1);
+  }
+  if (points==2){    
+    dhelix1.LinearDCA(mhelix,phase[1][0],phase[1][1],radius[1],delta2);
+  }
+  distance1 = TMath::Min(delta1,delta2);
+  */
+  //
+  //find intersection parabolic
+  //
+  points = dhelix1.GetRPHIintersections(mhelix, phase, radius,7);
+
+  delta1=10000,delta2=10000;  
+  Double_t d1=1000.,d2=10000.;
+  if (points>0){
+    dhelix1.ParabolicDCA(mhelix,phase[0][0],phase[0][1],radius[0],delta1,6);
+    //    dhelix1.ParabolicDCA(mhelix,phase[0][0],phase[0][1],radius[0],delta1);
+    Double_t xd[3],xm[3];
+    dhelix1.Evaluate(phase[0][0],xd);
+    mhelix.Evaluate(phase[0][1],xm);
+    d1 = (xd[0]-xm[0])*(xd[0]-xm[0])+(xd[1]-xm[1])*(xd[1]-xm[1])+(xd[2]-xm[2])*(xd[2]-xm[2]);
+  }
+  if (points==2){    
+    dhelix1.ParabolicDCA(mhelix,phase[1][0],phase[1][1],radius[1],delta2,6);
+    //dhelix1.ParabolicDCA(mhelix,phase[1][0],phase[1][1],radius[1],delta2);
+    Double_t xd[3],xm[3];
+    dhelix1.Evaluate(phase[1][0],xd);
+    mhelix.Evaluate(phase[1][1],xm);
+    d2 = (xd[0]-xm[0])*(xd[0]-xm[0])+(xd[1]-xm[1])*(xd[1]-xm[1])+(xd[2]-xm[2])*(xd[2]-xm[2]);
+  }
+  //
+  distance2 = TMath::Min(delta1,delta2);
+  if (delta1<delta2){
+    //get V0 info
+    //    dhelix1.Evaluate(phase[0][0],fXr);
+    Double_t xd[3],xm[3];
+    dhelix1.Evaluate(phase[0][0],xd);
+    mhelix.Evaluate(phase[0][1], xm);
+    fXr[0] = 0.5*(xd[0]+xm[0]);
+    fXr[1] = 0.5*(xd[1]+xm[1]);
+    fXr[2] = 0.5*(xd[2]+xm[2]);
+    //
+    dhelix1.GetMomentum(phase[0][0],fPdr);
+    mhelix.GetMomentum(phase[0][1],fPm);
+    dhelix1.GetAngle(phase[0][0],mhelix,phase[0][1],fAngle);
+    //fRr = TMath::Sqrt(radius[0]);
+    fRr = TMath::Sqrt(fXr[0]*fXr[0]+fXr[1]*fXr[1]);
+  }
+  else{
+    //dhelix1.Evaluate(phase[1][0],fXr);
+    Double_t xd[3],xm[3];
+    dhelix1.Evaluate(phase[1][0],xd);
+    mhelix.Evaluate(phase[1][1], xm);
+    fXr[0] = 0.5*(xd[0]+xm[0]);
+    fXr[1] = 0.5*(xd[1]+xm[1]);
+    fXr[2] = 0.5*(xd[2]+xm[2]);
+    //
+    dhelix1.GetMomentum(phase[1][0], fPdr);
+    mhelix.GetMomentum(phase[1][1], fPm);
+    dhelix1.GetAngle(phase[1][0],mhelix,phase[1][1],fAngle);
+    //    fRr = TMath::Sqrt(radius[1]); 
+    fRr = TMath::Sqrt(fXr[0]*fXr[0]+fXr[1]*fXr[1]);
+  }
+  fDist1 = TMath::Sqrt(TMath::Min(d1,d2));
+  fDist2 = TMath::Sqrt(distance2);      
+  //            
+  //
+
+}
+