Color of errorbars

ROOT
1

hay
I would like to set the color of errorbars in a TGraphErrors. Does anybody know how to do this? SetMarkerColor sets only the marker color not the errorbars…
thanks
florian

2

It is SetFillColor() because the Line Color is for the graph line and also errors can be drawn as boxes so the fill color makes some sense some how.

3

thanks for the quick answer
but

tf->SetFillColor(4);

does not work… I googled it and I found this command only for histograms…?
or is my syntax wrong?
regards
florian

4

For me it works with the following little example:

{
   TCanvas *c1 = new TCanvas("c1", "c1",15,48,700,502);

   TGraphErrors *gre = new TGraphErrors(3);
   gre->SetName("Graph");
   gre->SetTitle("Graph");
   gre->SetFillColor(2);
   gre->SetLineColor(3);
   gre->SetLineWidth(3);
   gre->SetMarkerStyle(25);
   gre->SetPoint(0,1,1);
   gre->SetPointError(0,0,5);
   gre->SetPoint(1,2,4);
   gre->SetPointError(1,0,5);
   gre->SetPoint(2,3,9);
   gre->SetPointError(2,0,5);

   gre->Draw("AP2L");

}
5

if I use P2 in the draw command I get boxes instead of errorbars. These boxes have indeed the color which I specified with the SetFillColor command but actually I would like to have normal errorbars
I attached a plot, the blue boxed are the errorbars…
thanks
and regards
florian
ctf.pdf (16.4 KB)
ctf.pdf (16.4 KB)

6

Oh yes indeed you are right !! it was because there was no error along x in my case…
Here is the modified macro. It gives the attached plot.

{
   TCanvas *c1 = new TCanvas("c1", "c1",15,48,700,502);
   TGraphErrors *gre = new TGraphErrors(3);
   gre->SetName("Graph");
   gre->SetTitle("Graph");
   gre->SetLineColor(3);
   gre->SetMarkerStyle(24);
   gre->SetMarkerColor(2);
   gre->SetPoint(0,1,1); gre->SetPointError(0,0,5);
   gre->SetPoint(1,2,4); gre->SetPointError(1,0,5);
   gre->SetPoint(2,3,9); gre->SetPointError(2,0,5);
   gre->Draw("AP");
}

c1.gif696×474 4.02 KB

7

it works! thank you very much…