SetTitle TGraph

ROOT
1

Hi everybody :slight_smile:

I have need your help, I have already read the ROOT guide, but I’m a beginner with root.
I have set the Graph’s title:

gr->SetTitle(“title”) ;

Then I would like set the position of the Graph’s title,nut not only top, center, left,ecc but for all coordinate in the canvas, how can i do this?

Another question is, how I can insert the tex when I have a canvas divide in 3?
Because when the canvas is only 1, I have not problem with these comand:

{
TText *t = new TText(.5,.5,“Hello World !”);
t->SetTextAlign(22);
t->SetTextColor(kRed+2);
t->SetTextFont(43);
t->SetTextSize(40);
t->SetTextAngle(45);
t->Draw();
}

But when the canvas is divided I don’t see the text.

Thank you very much in advance :wink:

2

  1. you cannot set the position of the title relatively to the pad coordinates. If you want to do that you need to use TText of TLatex.

  2. Before drawing in a sub-pad you have to do cd() on it. If “c” is your canvas you need to do c->cd(3) before drawing the text in pad #3.

3

Thank you very much for the answer!!! :wink:

before drawing I move in c->cd(3) where i want the tex, I draw the Graph and finally insert the tex, but i don’t see it. I have tried to insert the txt befor to draw the graph but the result it is same. how can I do?

thanks a lot :wink:

4

Post here a small macro reproducing your problem.

5

It’ only one piece of the macro, the one that contains the text:

{
TCanvas *canvas = new TCanvas("canvas","canvas");		
canvas->Divide(3,1);						
canvas->cd(3);

TText *t = new TText(.5,.9,"CHAMBER");
t->SetTextAlign(22);
t->SetTextFont(43);
t->SetTextSize(20);
t->Draw();

gPad->SetGrid();

gPad->SetBottomMargin(0.07); gPad->SetTopMargin(0.18);			

TGraph *c1 = new TGraph ("1tw"); 
c1->SetLineStyle(1); c1->SetLineColor(kBlue);  c1->SetLineWidth(2); c1->SetMarkerStyle(20); c1->SetMarkerSize(0.9); c1->SetMarkerColor(kBlue);
TGraph *c2 = new TGraph ("2tw"); 
c2->SetLineStyle(1); c2->SetLineColor(kRed);  c2->SetLineWidth(2); c2->SetMarkerStyle(21); c2->SetMarkerSize(0.9); c2->SetMarkerColor(kRed);
TGraph *c3 = new TGraph ("3tw");
c3->SetLineStyle(1); c3->SetLineColor(kGreen);  c3->SetLineWidth(2); c3->SetMarkerStyle(22); c3->SetMarkerSize(0.9); c3->SetMarkerColor(kGreen); 

TMultiGraph * c = new TMultiGraph();

c->Add(c1);
c->Add(c2);
c->Add(c3);

c->Draw("apl"); 

c->SetTitle("TW");
c->GetXaxis()->SetLimits(8600,10000.0); 
c->SetMinimum(0.); c->SetMaximum(2.);
c->GetXaxis()->SetLabelSize(0.03); c->GetYaxis()->SetLabelSize(0.03);		
c->GetXaxis()->SetLabelOffset(0.0); c->GetYaxis()->SetLabelOffset(.015);
c->GetXaxis()->SetTickLength(0.015); c->GetYaxis()->SetTickLength(0.02);
c->GetXaxis()->SetNdivisions(20,5,0); c->GetYaxis()->SetNdivisions(20,5,0);


canvas->SaveAs("plot1.png");
}

Thank you very much :wink:

6

Try this:

{
   TCanvas *canvas = new TCanvas("canvas","canvas");
   canvas->Divide(3,1);

   canvas->cd(1);
   TGraph *g[3];
   Double_t x[10] = {0,1,2,3,4,5,6,7,8,9};
   Double_t y[10] = {1,2,3,4,5,5,4,3,2,1};
   TMultiGraph *mg = new TMultiGraph();

   for (int i=0; i<3; i++) {
      g[i] = new TGraph(10, x, y);
      g[i]->SetMarkerStyle(20);
      g[i]->SetMarkerColor(i+2);
      for (int j=0; j<10; j++) y[j] = y[j]-1;
      mg->Add(g[i]);
   }
   mg->Draw("APL");
   mg->SetTitle("Global title; X Axis; Y Axis");

   canvas->cd(3);
   TText *t3 = new TText(.5,.9,"CHAMBER 3");
   t3->SetTextAlign(22);
   t3->SetTextFont(43);
   t3->SetTextSize(20);
   t3->Draw();
}
7

I have to insert the text only in the pad3, the problem it si that insert the text befor drawing or after drawing, the text don’t see it.

8

Is that macro working for you ? … if yes do the same …

9

where is the difference? I have also put the text befor the draw and don’t work, instead in your macro yes, why?

thank you

10

Where do you want the text ? in pad 1 ? 2 ? 3 ?

I took the example of you 1st macro … it was in pad 3…

11

Ok here is the example with the text on Pad 1:

{
   TCanvas *canvas = new TCanvas("canvas","canvas");
   canvas->Divide(3,1);

   canvas->cd(1);
   TGraph *g[3];
   Double_t x[10] = {0,1,2,3,4,5,6,7,8,9};
   Double_t y[10] = {1,2,3,4,5,5,4,3,2,1};
   TMultiGraph *mg = new TMultiGraph();

   for (int i=0; i<3; i++) {
      g[i] = new TGraph(10, x, y);
      g[i]->SetMarkerStyle(20);
      g[i]->SetMarkerColor(i+2);
      for (int j=0; j<10; j++) y[j] = y[j]-1;
      mg->Add(g[i]);
   }
   mg->Draw("APL");
   mg->SetTitle("Global title; X Axis; Y Axis");

   canvas->cd(1);
   TText *t1 = new TText(.5,.9,"CHAMBER 1");
   t1->SetNDC(true);
   t1->SetTextAlign(22);
   t1->SetTextFont(43);
   t1->SetTextSize(20);
   t1->Draw();
}
12

The problem it isn’t where i would like the text, because it is easy change pad, it’s enough change c->cd()

I have tried to insert my data graph in your macro, in place of the cycle for, but don’t work. why?

thank you :wink:

13

I am sorry but I do not understand what you mean.
Send me a running macro (your first example did not work), showing what is wrong …
That’s very unclear for me right now…

14

Ok , maybe it was the legend that created a problem because now work!!

Thank you very much for the help :wink: