Re: Access to TGraph from Tree->Draw 2D

From: Jean-Eric Campagne <campagne_at_lal.in2p3.fr>
Date: Mon, 23 May 2005 16:07:52 +0200

Sorry Olivier I was a little bit too short.

1. When I do only T1.Draw("numum:log10enm","log10enm>-1 && log10enm<2","LSAME"); The drawing is Ok but the color of the line is red and I do not manage to change it.
2. When I am trying to access the TGraph T1.Draw("numum:log10enm","log10enm>-1 && log10enm<2"); TGraph *graph = (TGraph*)gPad->GetPrimitive("graph"); Then graph=0. I was looking for this data access to change color of the line...

At the end of the day I would like to superpose other graphs on top of each other.

Best
J.E

--On lundi 23 mai 2005 16:01 +0200 Olivier Couet <couet_at_mail.cern.ch> wrote:

>
> Hello,
>
> I am a bit confused with your email. You 1st said:
>
> "graph seems to be 0."
>
> But nevertheless it seems you get the graph because later on you said:
>
> "when I only Draw with LSAME option it is Ok"
>
> So where is the problem ? you can draw the graph, don't you ? is your
> problem "only" with the graph color definition ?
>
> Cheers, O.Couet
>
> On Mon, 23 May 2005, Jean-Eric Campagne wrote:
>
>> Hello,
>> I would like to access the TGraph created by a TTree->Draw(x1:x2) as in
>> the folowing:
>>
>> T1.Draw("numum:log10enm","log10enm>-1 && log10enm<2");
>> TGraph *graph = (TGraph*)gPad->GetPrimitive("graph");
>>
>> But graph seems to be 0. My complete C macro is:
>>
>> {
>> TGaxis::SetMaxDigits(2);
>> //gStyle->SetOptStat(1); //stat
>> TCanvas* c1 = new TCanvas("c1","SPL Flux",100,100,600,600);
>> c1->SetGridx();
>> c1->SetGridy();
>> c1->SetLogx();
>>
>> //draw a dummy frame
>> TH2D* hdum = new TH2D("hdum","Lipari Xcc",10,1e-1,1e2,10,0,1.6);
>> hdum->SetXTitle("E_{#nu} (GeV)");
>> hdum->SetYTitle("#sigma/E (10^{-38}cm^{2})/GeV");
>> hdum->Draw();
>>
>> TPad *overlay = new TPad("overlay","",
>> gStyle->GetPadLeftMargin(),
>> gStyle->GetPadBottomMargin(),
>> 1-gStyle->GetPadRightMargin(),
>> 1-gStyle->GetPadTopMargin());
>> overlay->SetFillStyle(4000);
>> overlay->Draw();
>> overlay->Range(-1.,0.,2.,1.6); //set the range in linear scale
>>
>>
>> TTree T1("t1","Xsection CC");
>> //Globes x-section
>>
>> T1.ReadFile("./LipSezUrtoMauro.txt","log10enm/F:nuem/F:numum/F:nutaum/F:
>> anuem/F: anumum/F:anutaum/F");
>> overlay->cd();
>> T1.Draw("numum:log10enm","log10enm>-1 && log10enm<2");
>> TGraph *graph = (TGraph*)gPad->GetPrimitive("graph");
>> graph->SetLineColor(4);
>> graph->Draw("LSAME");
>> }
>>
>> Of course when I only Draw with LSAME option it is Ok, but I do not
>> manage to change the color of the line...
>>
>> An idea?
>> J.E
>>
>> ........................................................................
>> ... .LAL - IN2P3 - CNRS
>> .LAL - B.P 34 - 91898 Orsay Cedex - France
>> .Piece 108
>> .Tel +33 (0)1 64 46 84 29
>> .Fax +33 (0)1 64 46 83 97
>> ........................................................................
>> ...
>>
>>
>>
>
> --
> Org: CERN - European Laboratory for Particle Physics.
> Mail: 1211 Geneve 23 - Switzerland Mailbox: J25910
> E-Mail: Olivier.Couet_at_cern.ch Phone: +41 22
> 7676522 WWW: http://cern.ch/Olivier.Couet/ Fax:
> +41 22 7670300

...........................................................................
.LAL - IN2P3 - CNRS
.LAL - B.P 34 - 91898 Orsay Cedex - France
.Piece 108
.Tel +33 (0)1 64 46 84 29

.Fax +33 (0)1 64 46 83 97

...........................................................................

Received on Mon May 23 2005 - 16:08:03 MEST