make jet event background tnamed, add reset

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

diff --git a/STEER/AliRieman.cxx b/STEER/AliRieman.cxx
index fc9feacc0ec5132fdbba69d77e3d4e2c5aa42965..11994ecd1254f58d9669fde0c31aec1a16410094 100755 (executable)
--- a/STEER/AliRieman.cxx
+++ b/STEER/AliRieman.cxx
@@ -41,9 +41,10 @@
 // neglecting error of xi, and supposing  xi>>yi    sigmai ~ sigmaVi ~ 2*sigmay*t  
 
 
-#include "TMatrixDSym.h"
-//#include "TDecompChol.h"
-#include "TMatrixD.h"
+#include <TMatrixDSym.h>
+#include <TMath.h>
+#include <TMatrixD.h>
+
 #include "AliRieman.h"
 
 ClassImp(AliRieman)
@@ -576,8 +577,9 @@ Double_t AliRieman::GetDYat(Double_t x) const {
   Double_t x0 = -fParams[1]/fParams[0];
   if (-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1<0) return 0;
   Double_t rm1  = fParams[0]/TMath::Sqrt(-fParams[2]*fParams[0]+fParams[1]*fParams[1]+1); 
-  if ( 1./(rm1*rm1)-(x-x0)*(x-x0)<=0) return 0;
-  Double_t res = (x-x0)/TMath::Sqrt(1./(rm1*rm1)-(x-x0)*(x-x0));
+  Double_t arg = (1./rm1-(x-x0))*(1./rm1+(x-x0));
+  if ( arg <= 0) return 0;
+  Double_t res = (x-x0)/TMath::Sqrt(arg);
   if (fParams[0]<0) res*=-1.;
   return res;
 }