[ROOT] ROOT: Drawing histo saved in a file.root

From: Davide Gerbaudo (Davide.Gerbaudo@cern.ch)
Date: Tue Sep 17 2002 - 15:35:47 MEST 

Hi 
I'm having some troubles opening some TH1F I saved in a file .root .
If I try to list objects it seems that they're in gDirectory really, and
even when I create pointers to access them it does not give any error
message. 
But if I try to draw them it doesn't work and it says it's an illegal
pointer. I tought that I did it like in "A simple fitting example" but
maybe I'm  forgetting something. 
Thank you very much in advance

   Davide Gerbaudo
___________________________________________________
{
gROOT->Reset();

char name[50];
int i,j,k;
int NbApv = 4;

TH1F* ModRMS[4];

char *histosFileName;
histosFileName = "histoNOISE_090602_150833.root";

// Open the file containing histos

TFile *f = new TFile(histosFileName, "READ");

//cout<<f.GetNkeys();     // here it seems to see objects
//f.ls();
//gDirectory->ls();

//(h_ModMeanPed 0)->Draw();     // but I can't access directly to them
//TH1F *ModRMS = ((TH1F*)gROOT->FindObject("ModRMS 0"))->Draw();
//--------------------------
//  creating pointers to histos in the file
//-------------------------
for(i=0;i<4;i++)
  {
    sprintf(&name[i], "h_ModRMS%2d", i);
    TH1F* ModRMS[i] =   (TH1F*)gROOT->Get(name);    
  } 
//ModRMS[0]->Draw();
//  or
ModRMS[1]->Draw();
f.Close();
cout<<"\n";
}

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