//
// This tutorials demonstrate how to store and restore simple vectors
// in a TTree
//

#include <vector>
#include <iostream>

#include "TFile.h"
#include "TTree.h"
#include "TH1F.h"
#include "TPad.h"
#include "TRandom.h"

#ifdef __MAKECINT__
#pragma link C++ class vector<float>+;
#endif

void write() 
{
   TFile *f = TFile::Open("hvector3.root","RECREATE");
   if (!f) { return; }

   TH1F hf("hf","This is the px distribution",100,-4,4);
   vector<float> v;

   TTree *t = new TTree("tvec","Tree with vectors");
   t->Branch("hf",&hf);
   t->Branch("v",&v);

   gRandom->SetSeed();
   for (Int_t i = 0; i < 500; i++) {
      hf.Reset();
      v.clear();

      Int_t npx = (Int_t)(gRandom->Rndm(1)*150);
      for (Int_t j = 0; j < npx; ++j){
	Float_t px,py;
	gRandom->Rannor(px,py);
 
	hf.Fill(px);
	v.push_back(py);
      }
      t->Fill();
   }
   f->Write();
   
   delete f;
}


void read() 
{
   TFile *f = TFile::Open("hvector3.root","READ");
   if (!f) { return; }

   TTree *t;
   f->GetObject("tvec",t);

   TH1F *hf = 0;
   TBranch *bhf = 0;
   t->SetBranchAddress("hf",&hf,&bhf);

   vector<float> *v = 0;
   TBranch *bv = 0;
   t->SetBranchAddress("v",&v,&bv);

   TH1F *h = new TH1F("h","This is the py distribution",100,-4,4);

   const Int_t kUPDATE = 100;
   for (Int_t i = 0; i < 500; i++){
     h->Reset();

     Long64_t tentry = t->LoadTree(i);

     bhf->GetEntry(tentry);
     bv->GetEntry(tentry);
     for (UInt_t j = 0; j < v->size(); ++j){
       h->Fill(v->at(j));          
     }

     if (i && (i%kUPDATE) == 0){
       hf->Draw();
       gPad->Update();
       h->Draw();
       gPad->Update();
     }
   }
   t->ResetBranchAddresses();
}

void hvector3() 
{
   write();
   read();
}