Re: Reusing the automatic histogram

From: Rene Brun (Rene.Brun@cern.ch)
Date: Mon Apr 19 1999 - 16:23:28 MEST


Hi Bill,
I cannot reproduce your problem. Send me your file giving this problem.
I will investigate. Also, don't forget to specify the version number
and machine type.
However, I strongly suggest that you replace the statement:
   h1->Delete();
by
   delete h1;

Rene Brun


William Love wrote:
> 
>    Rooters
> 
>     I am trying to use in a loop the automatic binning feature of
>   ntuple->Draw("x>>h1","selection")
> 
>    If I try to reuse h1 without deleting it the contents are replaced
>  but the bins and limits are not recalculated which is no use.  If
>  I delete h1 before replacing it, new limits are computed but I get a
>  segmentation violation.
> 
>  root [0] TFile f("straight3rd.root");
> root [1]  stks->Draw("z>>h1","z>28 && z<32");
> Warning in <MakeDefCanvas>: creating a default canvas with name c1
> root [2]  h1->Print();
> TH1.Print Name= h1, Total sum= 18409
> root [3]  h1->Delete();
> root [4]  stks->Draw("z>>h1","z>55 && z<60");
> root [5] h1->Print();
> 
>  *** Break *** segmentation violation
> 
>    Help?
> 
>                                  Bill Love



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