Set different colors for Bars in TGraph object

[amvargash]

Hi everyone,

Is there a way to set different colors for each bar when using the “AB” draw option in TGraph?

Int_t y[4] = {5,9,8,10}
Int_t x[4] = {1,2,3,4}

TGraph *gr = new TGraph(4,x,y)
gr->Draw("AB");

[couet]

you need one TGraph for each bar. You can group them in a multigraph

[amvargash]

Hi @couet, I found a glitch when using "AB" Option and SetRangeUser, look:

Int_t y[4] = {5,9,8,10};
Int_t x[4] = {1,2,3,4};

TCanvas *c1 = new TCanvas();

TGraph *gr = new TGraph(4,x,y);
gr->GetXaxis()->SetRangeUser(2.,4.);
gr->Draw("AB");
c1->Print("me.png");

Which yields to:

ROOT 6.13/01

[couet]

I see it too. I tried to find a work around without success.
As you need bar chart why don’t you use an histogram instead of a graph ?
with histogram you control the bin width … not with graphs (there is no bin).
This option B for graphs is rarely used because of that. But I agree it should be fixed.

[amvargash]

Thank you @couet I’ll use histograms instead. I also opened a JIRA ticket for this issue:

https://sft.its.cern.ch/jira/browse/ROOT-9144

[couet]

@amvargash

I also opened a JIRA ticket for this issue:

I saw that, Thanks !

[couet]

Now fixed in master.