Fast event generation macro. First commit.

diff --git a/FASTSIM/fastGen.C b/FASTSIM/fastGen.C
new file mode 100644 (file)
index 0000000..35b1bb9
--- /dev/null
+++ b/FASTSIM/fastGen.C
@@ -0,0 +1,106 @@
+AliGenerator*  CreateGenerator();
+
+void fastGen(Int_t nev = 1, char* filename = "galice.root")
+{
+//
+//                        Construction
+//
+//  Output file
+    TFile*  file         = new TFile(filename, "recreate");
+//  Create stack
+    AliStack* stack      = new AliStack(10000);
+    stack->MakeTree(0, filename);
+
+//  Create Header
+    AliHeader* header    = new AliHeader();
+//  Create Header Tree
+    TTree* treeE         = new TTree("TE","Headers");
+    treeE->Branch("Header", "AliHeader", &header, 4000, 0);
+    treeE->Write();
+//
+//  Create and Initialize Generator
+    AliGenerator *gener = CreateGenerator();
+    gener->Init();
+    gener->SetStack(stack);
+    
+//
+//                        Event Loop
+//
+    Int_t iev;
+     
+    for (iev = 0; iev < nev; iev++) {
+
+       printf("\n \n Event number %d \n \n", iev);
+       
+//  Initialize event
+       header->Reset(0,iev);
+       stack->BeginEvent(iev);
+
+//  Generate event
+       gener->Generate();
+//  Analysis
+       Int_t npart = stack->GetNprimary();
+       printf("Analyse %d Particles\n", npart);
+       for (Int_t part=0; part<npart; part++) {
+           TParticle *MPart = stack->Particle(part);
+           Int_t mpart  = MPart->GetPdgCode();
+           printf("Particle %d\n", mpart);
+       }
+       
+//  Finish event
+       header->SetNprimary(stack->GetNprimary());
+       header->SetNtrack(stack->GetNtrack());  
+//      I/O
+//     
+//     stack->FinishEvent();
+//     header->SetStack(stack);
+//     treeE->Fill();
+//     Reset stack
+
+       stack->Reset();
+    } // event loop
+//
+//                         Termination
+//  Generator
+    gener->FinishRun();
+//  Header
+    treeE->Write(0,TObject::kOverwrite);
+    delete treeE;   treeE = 0;
+//  Stack
+    stack->FinishRun();
+//  Write file
+    gener->Write();
+    file->Write();
+}
+
+
+AliGenerator*  CreateGenerator()
+{
+    gener = new AliGenPythia(1);
+//
+//
+//   vertex position and smearing 
+    gener->SetVertexSmear(kPerEvent);
+//   structure function
+    gener->SetStrucFunc(kGRVHO);
+//   charm, beauty, charm_unforced, beauty_unforced, jpsi, jpsi_chi, mb
+    gener->SetProcess(kPyJets);
+//   Centre of mass energy 
+    gener->SetEnergyCMS(14000.);
+//   Pt transfer of the hard scattering
+    gener->SetPtHard(5.,5.1);
+//   Initialize generator    
+    return gener;
+}
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