Event blending implemented

[u/mrichter/AliRoot.git] / HBTAN / AliHBTReader.cxx

diff --git a/HBTAN/AliHBTReader.cxx b/HBTAN/AliHBTReader.cxx
index 1cecb7e47d4ca497f1ab43204991d1101103a2df..fd4d25d213df324df7ca22f7258b070039f8a0d7 100644 (file)
--- a/HBTAN/AliHBTReader.cxx
+++ b/HBTAN/AliHBTReader.cxx
@@ -4,6 +4,7 @@
 #include <TObjString.h>
 #include <TObjArray.h>
 #include <TClass.h>
+#include <TRandom.h>
 
 #include "AliHBTParticleCut.h"
 #include "AliHBTEvent.h"
@@ -67,6 +68,8 @@ Int_t AliHBTReader::Next()
   if ( ReadNext() == kTRUE)
      return kTRUE;
   
+  if (fBlend) Blend();
+  
   if (fBufferEvents)
    {
      if ( ReadsTracks() && fTracksEvent) 
@@ -303,4 +306,17 @@ TString& AliHBTReader::GetDirName(Int_t entry)
   if (gDebug > 0) Info("GetDirName","Returned ok %s",dir->String().Data());
   return dir->String();
 }
+/*************************************************************************************/
 
+void AliHBTReader::Blend()
+{
+  //randomly change positions of the particles after reading
+  //is used to check if some distr depends on order of particles
+  //(tracking gives particles Pt sorted)
+  for (Int_t i = 2; i < fParticlesEvent->GetNumberOfParticles(); i++)
+   {
+     Int_t with = gRandom->Integer(i);
+     fParticlesEvent->SwapParticles(i,with);
+     if (fTracksEvent) fTracksEvent->SwapParticles(i,with);
+   }
+}