Re: gcut/projections inconsistancy

From: Rene Brun <brun_at_pcroot.cern.ch>
Date: Wed, 20 Apr 2005 23:29:46 +0200 (MEST)


Boris,

Today we made a few changes with [cutg] in TH2::ProjectionX, etc. Coul you try your problem with this version (CVS head). If the problem is not fixed, please send a script.

Rene Brun

On Wed,
20 Apr 2005, Boris Skorodumov wrote:

> dear rooters,
>
> imagine, i have tree with var de and e.
> i am making 2d histogram t->Draw("de:de+e >>hh") hh.
> hh has 422928 Entries.
>
> now i am creating two graphical cuts: cut1 and cut2 which do not have
> any common points.
>
> later, i am making two 1d histograms with cut1 and cut2
>
> hh->ProjectionX("a",-1,-1,"[cut1]"); a->Integral() gives 6070
> hh->ProjectionX("b",-1,-1,"[cut2]"); b->Integral() gives 1967
>
> later i am making other two 1d histograms:
>
> t->Draw("de:de+e >> h1","cut1");
> t->Draw("de:de+e >> h2","cut2");
>
> h1->Integral() gives me 5934
> h2->Integral() gives me 1936
>
> why that numbers are different from the a and b ?
>
> why the number of entries for a and b which is plotted in the canvas are
> 422928 but not 6070 and 1967 while for h1 and h2 the number of entries
> are 5934 and 1936 which is consistent with h1->Integral() and
> h2->Integral() ?
>
> i was not able to combine cut1 and cut2:
>
> t->Draw("de:de+e >> h3","cut2 || cut1");
> h3->Integral() gives me 7870(5934+1936) which is correct.
>
> hh->ProjectionX("rr",-1,-1,"[cut1, cut2]") ignores second cut (cut2).
> according to http://root.cern.ch/root/html/TH2.html#TH2:ProjectionX that
> should work.
>
>
> thank you,
> boris.
>
>
Received on Wed Apr 20 2005 - 23:30:03 MEST

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