Hi Andreas,
you can use TTree::Project() for this purpose (note that TNtuple
is a TTree by inheritance):
TH2F* xy = new TH2F("xy_histo","density",nBinsX,xmin,xmax,nBinsY,ymin,ymax);
ntuple->Project("xy_histo","y:x");
This asumes that yo have declared and intialised nBinsX etc.
to sensible values.
cheers,
Kurt
On Wed, Jul 02, 2003 at 04:34:21PM +0200, Andreas Adelmann wrote:
> Hi rooter suppose I have data filled in an
> ntuple of the following form:
>
> TNtuple* ntuple = new
> TNtuple("ntuple","NTUPLE","x:px:y:py:z:pz:id:node");
>
> and I would like to make a density plot in the x and y
> plane.
>
> How do I fill a histogram from the ntuple?
>
> Thanks, Andreas
>
> --
> Andreas (Andy) Adelmann
> Paul Scherrer Institut
> CH-5232 Villigen PSI
> Phone Office: xx41 56 310 42 33 Fax: xx41 56 310 31 91
> Phone Home: xx41 62 891 91 44
--
Kurt Rinnert, University of Karlsruhe (TH) - Faculty for Physics
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