Re: [ROOT] HLABEL equivalent in ROOT (fwd)

From: Joanne Elise Cole (coleje@mail.desy.de)
Date: Wed Aug 28 2002 - 18:35:19 MEST 

Hi again,

Thank you to everyone for your suggestions - we have tried them
in a macro and they work.  However, if we try and do the following in a
C++ program, it does not work:

// this array gets filled with the names we want to use to label the axis
TString names[100];

// this is the histogram we want to label
funnel = new TH1D("funnel","funnel",14,0,14);

// labelling the axis
for (int i=0;i<20;i++){
    funnel->GetXaxis()->SetBinLabel(i+1,names[i+30]);
  }

when the code is compiled we see the following error:

passing `const char *' as argument 2 of `TAxis::SetBinLabel(int, char *)'
 discards qualifiers

Can anyone tell us what we are doing wrong ?

Thanks :)

All the best

Jo.

******************************************************************************

Jo Cole

ZEUS Collaboration                                 Dept. of Physics
DESY, Rm 1a/244                                    University of Bristol

email: coleje@mail.desy.de
Tel:   00 49 40 8998 2609
Fax:   00 49 40 8998 3092

******************************************************************************


---------- Forwarded message ----------
Date: Wed, 28 Aug 2002 16:18:48 +0200 (CEST)
From: Stanislav NESTEROV <Stanislav.Nesterov@cern.ch>
To: Joanne Elise Cole <coleje@mail.desy.de>
Subject: Re: [ROOT] HLABEL equivalent in ROOT

   Hi Joanne,

   I think there is no exact equivalent, but for any type of axis you can
assign to certain bin a character name:

     TAxis::SetBinLabel(Int_t nbin,char* label)

  Set label for a bin

and
     TAxis::LabelsOption(Option_t *option)

  Set option(s) to draw axis with labels
  option = "a" sort by alphabetic order
         = ">" sort by decreasing values
         = "<" sort by increasing values
         = "h" draw labels horizonthal
         = "v" draw labels vertical
         = "u" draw labels up (end of label right adjusted)
         = "d" draw labels down (start of label left adjusted)

   To use them for example with 1-d histogram you can do something like
this:
     TH1F ga("ga","Gauss",100,-3,3);  //create histo
     ga.FillRandom("gaus");           // and fill it
     for (Int_t i=1;i<ga.GetNbinsX()+1;i += 10) // Every 10th bin
       ga.GetXaxis()->SetBinLabel(i,Form("name%d",i)); //name as "name.."

		Best regards
				Stanislav.


On Wed, 28 Aug 2002, Joanne Elise Cole wrote:

> Hi,
>
> We are trying to change the axis labels of a histogram in ROOT to be
> names, rather than numbers.  If we were using HBOOK, the routine we
> would want to use would be HLABEL - what is the ROOT equivalent ?
>
> Thanks.
>
> All the best
>
> Jo.
>
> ******************************************************************************
>
> Jo Cole
>
> ZEUS Collaboration                                 Dept. of Physics
> DESY, Rm 1a/244                                    University of Bristol
>
> email: coleje@mail.desy.de
> Tel:   00 49 40 8998 2609
> Fax:   00 49 40 8998 3092
>
> ******************************************************************************
>
>
>

This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:51:06 MET