Superimpose a histogram over another

ROOT
1

Hello,

I would like to superimpose a histogram over another bigger one in the same canvas (see attachment). The problem is that I need to do it from the command line. I have managed to add the extra pad but I cannot draw the 2nd histogram in it. Is there some kind of a command line example for this?

Thanks,
Vivi

histogram.png622×504 16.5 KB

2

Hi

Maybe

root.cern.ch/root/html/tutorials … ack.C.html

could have the answers you need…

Best

3

Hi again,

The cd() command does not work for me. The 2nd histogram is drawn on the canvas and not in the pad. I think I must somehow activate the pad. Here is my code (the two histograms are: fPt and fEta):

TCanvas* c11 = new TCanvas("c11","c11");
c11->cd();
fEta->Draw();
TPad* p11 = new TPad("p11","p11", 0.25,0.3,0.6,0.7);
p11->cd();
fPt->Draw();
p11->Update();
c11->Update();
4

Try:TCanvas* c11 = new TCanvas("c11","c11"); c11->cd(); fEta->Draw(); TPad* p11 = new TPad("p11","p11", 0.25,0.3,0.6,0.7); p11->Draw(); p11->cd(); fPt->Draw(); p11->Update(); c11->Update();[quote]Is there some kind of a command line example for this?[/quote]The picture seems to indicate you somehow succeeded (at least via the gui), if this is the case, you can then use the file item File/Save/c1.C which will create a file named c1.C which contains the C++ code to reproduce the canvas.

Cheers,
Philippe.

5

Hi again

Try this

TCanvas* c11 = new TCanvas("c11","c11");
c11->cd();
fEta->Draw();
TPad* p11 = new TPad("p11","p11", 0.25,0.3,0.6,0.7);
p11->cd();
fPt->Draw();
p11->Update();
TH1F *htemp = (TH1F*) p11->GetPrimitive("fPt");
c11->cd();
fEta->Draw();
htemp->Draw("sames");
c11->Update();

Cheers

6

Thanks a lot - the c++ generated code did the trick. It finally worked by:

[code]TCanvas* c11 = new TCanvas(“c11”,“c11”);

c11->cd();
fEta->Draw();

TPad* p1 = new TPad(“p1”,“p1”, 0.25,0.3,0.6,0.7);
p1->Draw();
p1->cd();
fPt->Draw();
[/code]

Vivi