Re: root : strange behaviour of AddBinContent()

Hi Marc,

An alternative to Lorenzo's reply is to use TParameter<int>::GetVal(): simple int with a name, wrapped as TObject.

Cheers, Axel.

Marc Escalier wrote on 09/02/2011 04:24 PM:
> Hello,
>
> it seems that there is a strange behaviour of TH1::AddBinContent()
>
> intuitively, i would think that adding a content to a bin would mean
> that the number of entries should increase,
> as it is when one does TH1::Fill(1) (apart that this last comment is
> very slow)
>
> but :
>
> root [0] TH1F *hist_initial_events=new
> TH1F("hist_initial_events","hist_initial_events",20,0.5,20.5);
> root [1] hist_initial_events.GetEntries()
> (const Double_t)0.00000000000000000e+00
> root [3] hist_initial_events->AddBinContent(1)
> root [4] hist_initial_events.GetEntries()
> (const Double_t)0.00000000000000000e+00
>
> root [5] hist_initial_events.GetBinContent(1)
> (const Double_t)1.00000000000000000e+00
>
> -->
> *is the fact that AddBinContent() does not increase the number of
> entries expected ?
>
> *On other subject, is there a way to find a much faster command that
> TH1::Fill to add 1 to an histogram ?
>
> (i see that a simple counter "int" is much more faster, but i need a TH1
> for proof, because TH1 derivates from a TObject and the fOutput needs
> derivatives from TObject : it can not deal with common counters ; and
> recreating a class derivated from TObject with an integer is rather
> painful for a clean implementation)
>
> thanks for your help
>
>
Received on Fri Sep 02 2011 - 18:03:31 CEST