Writing Histograms to Trees

ROOT
#1

Hi all,

I have a

stl::vector<TH1D*> h(3);
stl::vector<TH1D*> haux1(100);
stl::vector<TH1D*> haux2(100);
stl::vector<TH1D*> haux3(100);

and create TTree branches from it using

t->Branch("h0", "TH1D", &h[0]);
t->Branch("h1", "TH1D", &h[1]);
t->Branch("h2", "TH1D", &h[2]);

with i going from 0 to 2 inclusive.
Histograms haux1, haux2 and haux3 are all created, filled and fitted first, then I do a cycle with:

h[0] = haux1[j];
h[1] = haux2[j];
h[2] = haux3[j];
t->Fill();

with j from 0 to 99.

an error comes out every time I call t->Fill() (twice: one for TBranchElement::Fill, one for TTree::Fill):

… Failed filling branch … nbytes=-1

Further more, I’m writing to a file and ROOT crashed when closing it.
Is there anything obvious I shouldn’t be doing?
While debugging I tried:

TH1D* htry = new TH1D("h1","h1",10,0,10);
t->SetBranchAddress("h0", &htry);
t->SetBranchAddress("h1", &htry);
t->SetBranchAddress("h2", &htry);
t->Fill();

and it worked fine, though ROOT still crashes on exit.

I’m really stucked and hope someone can help.

Best regards,

  Rui
#2

Hi,

There is nothing obviously wrong in your code snippets and many things could lead to the error you see (double delete, writing in a read-only file, etc.).

The best way to submit your problem is to provide the following:

  • ROOT version number
  • OS and compiler version number
  • complete example reproducing the problem with instruction on how to run it.

Cheers,
Philippe.