TH1

Jacek M. Holeczek (holeczek@clri6f.gsi.de)
Thu, 20 Feb 1997 12:59:21 +0100 (CET)

Hi,
Could you, please, tell me how can I Draw part of a histogram ( NOT FIT,
JUST DRAW ). I would like to do this from a root c-source code line
( something like EventLength.Zoom(10.,20.) which should draw the
part of the EventLength histogram in x-axis-subrange from 10. to 20. ),
and graphically - assume I have drawn the whole histogram using
EventLength.Draw(), and then I would like to see a part of it, so I would
like to "klick" at the left-edge-of-required-zoom, then "klick" at the
right-edge-of-required-zoom and ... that should be all.
Some time ago I was adviced to use :
if (hist=(TH1F*)gDirectory->GetList()->FindObject("EventLength"))
{ ... }
as a replacement for
if ( hexist(9999) ) ...
Now I tried to use it ... having some 100 histograms in directory ... .
Seems that the root FindObject is order(s) of magnitude slower then paw's
hexist ( used with the same amount of histograms ).
Jacek.