Re: [ROOT] bug in TLine drawing at log scales

From: Rene Brun (Rene.Brun@cern.ch)
Date: Mon Sep 24 2001 - 08:59:54 MEST


Hi Miro,

In ROOT, only high level objects, such as TH1xx and TGraph understand log
scales. You can use a TGraph instead of a TLine or give the log(x) as argument.

Rene Brun

Miroslav Helbich wrote:
> 
>  Hi rooters,
> 
>   I think this is a bug. When drawing lines on log scale, the lines are
> displaced.
> 
> I'm using version 3.01/05 for SuSE Linux 6.3 (i386) - Kernel 2.2.16
> (pts/1).
> 
>                                         Miro
> 
> {
> 
> TH1F *hh = new TH1F("hh","test",100,-10.,10.);
> TF1 *ff = new TF1("ff","2.",-10.,10.); // constant function
> 
> hh->FillRandom("ff",1000.);
> 
> Float_t ymax=hh->GetMaximum();
> 
> TLine *l1 = new TLine(0.,0.,0.,ymax);
> 
> TCanvas *c1 = new TCanvas("c1");
> c1->Divide(1,2);
> 
> c1->cd(1);
> 
> hh->Draw();
> l1->Draw();
> 
> c1->cd(2);
> gPad->SetLogy();
> 
> hh->Draw();
> l1->Draw();
> 
> }



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