Fast vertexer: just a smearing of the true primary vertex position

diff --git a/ITS/AliITSVertexerFast.cxx b/ITS/AliITSVertexerFast.cxx
new file mode 100644 (file)
index 0000000..1a0d214
--- /dev/null
+++ b/ITS/AliITSVertexerFast.cxx
@@ -0,0 +1,128 @@
+/**************************************************************************
+ * Copyright(c) 1998-2003, 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.                  *
+ **************************************************************************/
+#include <Riostream.h>
+#include <TArrayF.h>
+#include <TRandom.h>
+#include "AliITSVertex.h"
+#include <AliITSVertexerFast.h>
+#include "AliHeader.h"
+#include "AliGenEventHeader.h"
+#include "AliRun.h"
+#include "AliITSLoader.h"
+#include "AliRunLoader.h"
+
+/////////////////////////////////////////////////////////////////////////
+//                                                                     //
+// Fast vertexer - True (i.e. generated) vertex coordinates            //
+// are smeared with gaussians of given width                           //
+// Origin: masera@to.infn.it     25/09/2003                            //
+//                                                                     //
+/////////////////////////////////////////////////////////////////////////
+ClassImp(AliITSVertexerFast)
+
+
+
+//______________________________________________________________________
+AliITSVertexerFast::AliITSVertexerFast():AliITSVertexer() {
+  // Default Constructor
+  fSmear = 0;
+}
+
+//______________________________________________________________________
+AliITSVertexerFast::AliITSVertexerFast(Double_t *smear):AliITSVertexer() {
+  // Standard constructor
+  fSmear = new Double_t[3];
+  for(Int_t i=0;i<3;i++)fSmear[i]=smear[i];
+}
+
+//______________________________________________________________________
+AliITSVertexerFast::~AliITSVertexerFast(){
+  // Destructor
+  if(fSmear)delete [] fSmear;
+  fSmear = 0;
+}
+
+//______________________________________________________________________
+AliITSVertex* AliITSVertexerFast::FindVertexForCurrentEvent(Int_t evnumb){
+  // Defines the AliITSVertex for the current event
+  fCurrentVertex = 0;
+  AliRunLoader *rl =AliRunLoader::GetRunLoader();
+  rl->GetEvent(evnumb);
+  TArrayF primaryVertex(3);  // true vertex
+  AliHeader* header = gAlice->GetHeader();
+  AliGenEventHeader* genEventHeader = header->GenEventHeader();   
+  genEventHeader->PrimaryVertex(primaryVertex); 
+
+  // Smearing
+  Double_t vrttrue[3],vrtx[3];
+  for(Int_t k=0; k<3;k++){
+    vrttrue[k] = static_cast<Double_t>(primaryVertex[k]);
+    vrtx[k] = gRandom->Gaus(vrttrue[k],fSmear[k]);
+  }
+  char name[30];
+  sprintf(name,"Vertex_%d",evnumb);
+  fCurrentVertex = new AliITSVertex(vrtx,fSmear,name);
+  fCurrentVertex->SetTruePos(vrttrue);
+  return fCurrentVertex;
+}
+
+//______________________________________________________________________
+void AliITSVertexerFast::FindVertices(){
+  // computes the vertices of the events in the range FirstEvent - LastEvent
+
+  AliRunLoader *rl = AliRunLoader::GetRunLoader();
+  AliITSLoader* iTSloader =  (AliITSLoader*) rl->GetLoader("ITSLoader");
+  iTSloader->ReloadRecPoints();
+  for(Int_t i=fFirstEvent;i<=fLastEvent;i++){
+    rl->GetEvent(i);
+    FindVertexForCurrentEvent(i);   
+    if(fCurrentVertex) WriteCurrentVertex();
+    else {
+      cout<<"Vertex not found for event "<<i<<endl;
+
+    }
+
+  }
+
+}
+
+//________________________________________________________
+void AliITSVertexerFast::PrintStatus() const {
+  // Print current status
+  cout <<"=======================================================\n";
+
+  cout<<"First event to be processed "<<fFirstEvent;
+  cout<<"\n Last event to be processed "<<fLastEvent<<endl;
+  cout<<"RMS for gaussian smearing: ";
+  for(Int_t k=0;k<3;k++)cout<<" "<<fSmear[k];
+  cout<<endl;
+}
+
+//______________________________________________________________________
+AliITSVertexerFast::AliITSVertexerFast(const AliITSVertexerFast &vtxr) : 
+                    AliITSVertexer(vtxr) {
+  // Copy constructor
+  // Copies are not allowed. The method is protected to avoid misuse.
+  Error("AliITSVertexerFast","Copy constructor not allowed\n");
+}
+
+//______________________________________________________________________
+AliITSVertexerFast& AliITSVertexerFast::operator=(const 
+                    AliITSVertexerFast& /* vtxr */){
+  // Assignment operator
+  // Assignment is not allowed. The method is protected to avoid misuse.
+  Error("= operator","Assignment operator not allowed\n");
+  return *this;
+}

diff --git a/ITS/AliITSVertexerFast.h b/ITS/AliITSVertexerFast.h
new file mode 100644 (file)
index 0000000..0a675fa
--- /dev/null
+++ b/ITS/AliITSVertexerFast.h
@@ -0,0 +1,41 @@
+#ifndef ALIITSVERTEXERFAST_H
+#define ALIITSVERTEXERFAST_H
+/* Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
+ * See cxx source for full Copyright notice                               */
+
+
+#include <AliITSVertexer.h>
+
+/////////////////////////////////////////////////////////////////////
+//                                                                 //
+// Fast vertexer - True (i.e. generated) vertex coordinates        //
+// are smeared with gaussians of given width                       //
+//                                                                 //
+/////////////////////////////////////////////////////////////////////
+
+
+class AliITSVertexerFast : public AliITSVertexer {
+
+ public:
+  AliITSVertexerFast();
+  AliITSVertexerFast(Double_t *smear);
+  virtual ~AliITSVertexerFast(); 
+  virtual AliITSVertex* FindVertexForCurrentEvent(Int_t evnumb);
+  virtual void FindVertices();
+  virtual void PrintStatus() const;
+
+ protected:
+
+  // copy constructor (NO copy allowed: the constructor is protected
+  // to avoid misuse)
+  AliITSVertexerFast(const AliITSVertexerFast& vtxr);
+  // assignment operator (NO assignment allowed)
+  AliITSVertexerFast& operator=(const AliITSVertexerFast& /* vtxr */);
+
+  Double_t *fSmear;         // rms of gaussians used for smearing
+
+
+ClassDef(AliITSVertexerFast,1);
+};
+
+#endif