Re: [ROOT] log bar charts/kumacs

From: Rene Brun (Rene.Brun@cern.ch)
Date: Tue Dec 03 2002 - 11:35:00 MET


Hi Daniel,


On Tue, 3 Dec 2002, Daniel Holmes wrote:

> Hello RootFans,
> 
> anyone any ideas.??:...
> 
> 1/i have a bar chart which upon which i would like to set the y axis as a
> log axis:  i rt click on the axis and select "selectLogY". ..i then get
> the error message: 
> 
> Error in <THistPainter::PaintInit>: log scale requested with zero or
> negative argument (0.000000)
> 
> ..i think this is not true, in fact i am reading out the (5) values as i
> fill my bar chart and they are all well above 0. ,my number of bins is 5
> so there are no non filled bins.  ..any thoughts anyone??

Somewhere you must have set the minimum to 0 or a negative value

> 
> 
> 2/ I use some standard commands everytime i use root but some don't seem
> to work from within a kumac.
> 
> examples are in:
> /afs/cern.ch/user/d/dholmes/public/
> 
> any ideas on either of these problems are much appreciated..

the commands like .L file.C can only be typed at the command line.
Within a macro, do, eg:
  gROOT->ProcessLine(".L h3003.C");

Rene Brun

> 
> cheers,
> 
> Dan.
> 
> 
> 
>  
> 
> 
> 
> CMS-Bristol
> http://cern.ch/dan.holmes
> 



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