re: Saving histograms in a file AFTER book+fill

From: Mark Pollack (markp@bnl.gov)
Date: Wed Jul 15 1998 - 04:52:38 MEST 

Dear Roottalk,

I am running into some difficulty trying to
book/fill histograms inside a *directory structure* 
and save them to a file AFTER the mkdirs/books/fills.

Following the advice from this previous thread, I can
easily save histograms which are not inside any directories.
However, if I make some directories and put histograms
inside them, the statement

gROOT->GetList()->Write() 

does not write out the directories and the histos contained inside 
of them.

Here is an example macro.  I tried to save the directories
explicitly at the end put I feel I did not make a "correct" root 
file since

.ls and myfile->ls() show different results...


{

  gROOT->Reset();

  gROOT->cd();
  TH1F *hpx   = new TH1F("hpx","This is the px distribution",100,-4,4);

  gROOT->mkdir("1DS");
  gROOT->cd("1DS");
  TH1F *hpy   = new TH1F("hpy","This is the py distribution",100,-4,4);

  gROOT->cd();
  gROOT->mkdir("2DS");
  gROOT->cd("2DS");
  TH2F *hpxpy = new TH2F("hpxpy","py ps px",40,-4,4,40,-4,4);


  gROOT->cd("1DS");
  for (int i=1; i<100; i++) {
    hpx->Fill(i,i);
  }

  gROOT->cd("2DS");
  for (int i=1; i<100; i++) {
    hpxpy->Fill(i,i,i);
  }


  TDirectory *fdir;
  TDirectory *mdir;
  TFile *hfile = new TFile("file.root","RECREATE");
  if (hfile->IsOpen()) {
    hfile->pwd();    //file.root
    gROOT->pwd();    //Rint:

    //gROOT->GetList()->Write();  //does not work on directories

    
    TList *l = gROOT->GetList();
    TIter next(l);
    l->ls();
    TObject *obj;
    while((obj = (TObject*) next())) {
      if (obj->IsA() == TDirectory::Class()) {
        mdir = (TDirectory*)obj;
	hfile->cd();
	fdir = hfile->mkdir(mdir->GetName());
	fdir->cd();
	if (fdir->IsWritable()) {
	  printf("directory contents..");
	  mdir->GetList()->Print();
	  mdir->GetList()->Write();
	  fdir->Write();
	}
      } else {
	obj->Write();
      }
    }
  }

root [0] .x rootdirs.cc
file.root:/
Rint:/
OBJ: TH1F       hpx     This is the px distribution : 0
TDirectory*             1DS     1DS
 OBJ: TH1F      hpy     This is the py distribution : 0
TDirectory*             2DS     2DS
 OBJ: TH2F      hpxpy   py ps px : 0
directory contents..TH1.Print Name= hpy, Total sum= 0
directory contents..TH1.Print Name= hpxpy, Total sum= 6
root [1] .q


root [0] TFile tf = new TFile("file.root");
root [1] .ls
TFile**         file.root
 TFile*         file.root
  KEY: TH1F     hpx;1   This is the px distribution
  KEY: TDirectory       1DS;1   1DS
  KEY: TDirectory       2DS;1   2DS
root [2] tf->ls();
TFile**         file.root
 TFile*         file.root
root [3] tf->cd();
root [4] tf->ls();
TFile**         file.root
 TFile*         file.root
root [5] tf->ls("1DS");
TFile**         file.root
 TFile*         file.root
root [6] tf->cd("1DS");

 *** Break *** segmentation violation



This is different behavior than in the provided dirs.C sample


root [0] TFile *top = new TFile("top.root");
root [1] .ls
TFile**         top.root
 TFile*         top.root
  KEY: TDirectory       tof;1   tof
root [2] top->ls();                         
TFile**         top.root
 TFile*         top.root
  KEY: TDirectory       tof;1   tof


Any ideas how to easily save the whole thing to a file after the
creating the directory structure + book/filling?

Thanks,
Mark

This archive was generated by hypermail 2b29 : Tue Jan 04 2000 - 00:34:35 MET