Obsolete file (Ivana)

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

diff --git a/STEER/AliHelix.cxx b/STEER/AliHelix.cxx
index 670d0c74666b0752ba8d3030518f04e2b269c5cc..1810a0f68f3b412210a284bc4d7e5df39fee44c5 100644 (file)
--- a/STEER/AliHelix.cxx
+++ b/STEER/AliHelix.cxx
@@ -156,7 +156,7 @@ AliHelix::AliHelix(Double_t x[3], Double_t p[3], Double_t charge, Double_t conve
 
 }
 
-void  AliHelix::GetMomentum(Double_t phase, Double_t p[4],Double_t conversion)
+void  AliHelix::GetMomentum(Double_t phase, Double_t p[4],Double_t conversion, Double_t *xr)
 {
   // return  momentum at given phase
   Double_t x[3],g[3],gg[3];
@@ -166,6 +166,9 @@ void  AliHelix::GetMomentum(Double_t phase, Double_t p[4],Double_t conversion)
   p[0] = fHelix[8]*g[0]/(mt*conversion);
   p[1] = fHelix[8]*g[1]/(mt*conversion);
   p[2] = fHelix[8]*g[2]/(mt*conversion);
+  if (xr){
+    xr[0] = x[0]; xr[1] = x[1]; xr[2] = x[2];
+  }
 }
 
 void   AliHelix::GetAngle(Double_t t1, AliHelix &h, Double_t t2, Double_t angle[3])
@@ -267,6 +270,26 @@ Int_t     AliHelix::GetClosestPhases(AliHelix &h, Double_t phase[2][2])
   return 1;
 }
 
+Double_t  AliHelix::GetPointAngle(AliHelix &h, Double_t phase[2], const Float_t * vertex)
+{
+  //
+  // get point angle bettwen two helixes
+  // 
+  Double_t r0[3],p0[4];
+  Double_t r1[3],p1[4];
+  GetMomentum(phase[0],p0,1,r0);
+  h.GetMomentum(phase[1],p1,1,r1);
+  //
+  Double_t r[3] = {(r0[0]+r1[0])*0.5-vertex[0],(r0[1]+r1[1])*0.5-vertex[1],(r0[2]+r1[2])*0.5-vertex[2]};
+  //intersection point - relative to the prim vertex
+  Double_t p[3] = { p0[0]+p1[0], p0[1]+p1[1],p0[2]+p1[2]};
+  // derivation vector
+  Double_t normr = TMath::Sqrt(r[0]*r[0]+r[1]*r[1]+r[2]*r[2]);
+  Double_t normp = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]+p[2]*p[2]);   
+  Double_t pointAngle = (r[0]*p[0]+r[1]*p[1]+r[2]*p[2])/(normr*normp);
+  return pointAngle;
+}
+
 Double_t  AliHelix::GetPhase(Double_t x, Double_t y )
                        
 {