Re: Crash:illegal pointer to class object (not happened before!)

Hi Deepak,

sorry, I meant

TFile *f= new TFile("gen.root");
f->cd("Ana/dyjet/Hist");
f->ls()

But anyway - I believe you have given me the answer nevertheless :-) There seems to be no directory "Ana" in your file gen.root. The TProfile seems not to be in a subdirectory, so you should call gDirectory->Get("dyjet_Pnchg5pairpt2"); - and maybe the same for the other TProfile.

Cheers, Axel.

Deepak Kar wrote on 04/21/2009 10:43 AM:
> Hi Axel,
>
> Thanks for your comment.
> Here is what I get:
>
> root [0] TFile *f= new TFile("gen.root");
> root [1] f->cd("Ana/dyjet/Hist/dyjet_Pnchg5pairpt2");
> Error in <TFile::cd>: Object Ana is not a directory (I am not sure if
> this was an error before or a warning)
> root [2] f->ls()
> OBJ: TProfile dyjet_Pnchg5pairpt2 dyjet: TRV - <No of Charged> vs
> Lepton Pair PT (Z Range) : 0 at: 0x8cf7270
> (...and my other histograms with similar lines)
>
> Regards,
> Deepak
>
> On Tue, Apr 21, 2009 at 8:54 AM, Axel Naumann <Axel.Naumann_at_cern.ch> wrote:

>> Hi Deepak,
>>
>> CINT claims hist2 is NULL, which means that gen.root does not contain
>> Ana/dyjet/Hist/dyjet_Pnchg5pairpt2. Could you send the output of
>>
>> TFile *f= new TFile("gen.root");
>> f->cd("Ana/dyjet/Hist/dyjet_Pnchg5pairpt2");
>> f->ls()
>>
>> Cheers, Axel.
>>
>> Deepak Kar wrote on 04/21/2009 01:22 AM:
>>> Hello folks!
>>>
>>> I am sure I am missing something trivial here. I had a bunch of codes
>>> before, and they ran fine. After a while I am trying to run them,
>>> without changing anything to my knowledge. They are all crashing with
>>> the same error, and this just a simple example.
>>>
>>> {
>>>  gROOT->Reset();
>>>
>>>  TFile *f= new TFile("gen.root");
>>>  TProfile *hist2=(TProfile*)
>>> gDirectory->Get("Ana/dyjet/Hist/dyjet_Pnchg5pairpt2");
>>>
>>>  TFile *f=new TFile("ze_tlt.root");
>>>  TProfile *hist3=(TProfile*)
>>> gDirectory->Get("Ana/dyjet/Hist/dyjet_Pnchg5pairpt2");
>>>
>>>
>>>  for(i=1;i<=31;i++){
>>>    xbin1= hist2->GetBinCenter(i);
>>>    gen = hist2->GetBinContent(i);
>>>    sim = hist3->GetBinContent(i);
>>>  printf("MC bin, Gen/SIM  = %f, %f,\n",gen/sim);
>>>  }
>>> }
>>>
>>> It crashes with:
>>>
>>> Warning: Automatic variable i is allocated draw_ratio.C:19:
>>> Error: illegal pointer to class object hist2 0x0 1046  draw_ratio.C:20:
>>> Warning: Automatic variable xbin1 is allocated draw_ratio.C:20:
>>> Error: Undeclared variable xbin1 draw_ratio.C:20:
>>> *** Interpreter error recovered ***
>>>
>>> The .root files are all there, so are the histograms in that path.
>>>
>>> Thanks a lot for any input.
>>>
>>> Deepak
>>>
>>>