Hi Natalia,
instead of
TH1F* hist = new TH1F("hist","", 7, Lower);
do
TH1F* hist = new TH1F("hist","", 6, Lower);
see comments in TH1 constructor. In case of variable bins histogram,
you must specify an array with N+1 bin values.
Rene Brun
On Sun, 8 Sep 2002, Natalia Kuznetsova wrote:
> Dear ROOTers,
>
> I would like to create a variable bin histogram with the following array
> of low edges:
>
> Float_t Lower[8];
>
> Lower[0] = 2;
> Lower[1] = 3;
> Lower[2] = 4;
> Lower[3] = 5;
> Lower[4] = 6;
> Lower[5] = 8;
> Lower[6] = 10;
> Lower[7] = 14;
>
> I used TH1F* hist = new TH1F("hist","", 7, Lower);
>
> The resulting histogram appears to be skewed by 1 bin. When I print out
> the bin content, it says:
>
> bin 0 = 0.005
> bin 1 = 0.013
>
> but the actual histogram's first point sits at 2.5 (the histogram
> starts at 2), and it is the entry corresponding to bin 1 (0.013).
>
> How do I make sure that bin 0 is plotted, and plotted exactly at 2?
>
> Thanks for your help,
>
> Natalia
>
> ______________________
> Natalia Kuznetsova
> Fermilab/CDF
> P.O. Box 500, MS 318
> Batavia, IL 60510
> (630) 840-5115
> ______________________
>
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