proj ntuple into predefined histogram

Stephen Bailey (bailey@physics.harvard.edu)
Tue, 18 Aug 1998 16:16:54 -0400 (EDT)


Hi.

I'm trying to project an ntuple into a histogram which I
defined so that I can control the number of bins used.
e.g.

TH1F h1 = new TH1F("blat", "quat", 20, 4.5, 6);
ntuple->Draw("m>>+h1", "(4.5<m)&&(m<6.0)");
h1->Draw();

I also tryed m>>h1, but the ntuple->Draw command always
picks its own choice for number of bins and h1 always
seems to remain empty. If I don't predefine h1 then it
gets created and properly filled but I don't have control
over the number of bins.

Is there a way to do this easily (i.e. without looping
trough the ntuple and filling the histogram event by event)?

Thanks.

Stephen Bailey