Logo ROOT  
Reference Guide
 
Loading...
Searching...
No Matches
hist016_TH1_different_scales_canvas.C
Go to the documentation of this file.
1/// \file
2/// \ingroup tutorial_hist
3/// \notebook
4/// Example of a canvas showing two histograms with different scales.
5/// The second histogram is drawn in a transparent pad
6///
7/// \macro_image
8/// \macro_code
9///
10/// \date November 2022
11/// \author Rene Brun
12
14{
15 TCanvas *c1 = new TCanvas("c1", "transparent pad", 200, 10, 700, 500);
16 TPad *pad1 = new TPad("pad1", "", 0, 0, 1, 1);
17 TPad *pad2 = new TPad("pad2", "", 0, 0, 1, 1);
18 pad2->SetFillStyle(4000); // will be transparent
19 pad1->Draw();
20 pad1->cd();
21
22 TH1F *h1 = new TH1F("h1", "h1", 100, -3, 3);
23 TH1F *h2 = new TH1F("h2", "h2", 100, -3, 3);
24 TRandom r;
25 for (Int_t i = 0; i < 100000; i++) {
26 Double_t x1 = r.Gaus(-1, 0.5);
27 Double_t x2 = r.Gaus(1, 1.5);
28 if (i < 1000)
29 h1->Fill(x1);
30 h2->Fill(x2);
31 }
32 h1->Draw();
33 pad1->Update(); // this will force the generation of the "stats" box
35 ps1->SetX1NDC(0.4);
36 ps1->SetX2NDC(0.6);
37 pad1->Modified();
38 c1->cd();
39
40 // compute the pad range with suitable margins
41 Double_t ymin = 0;
42 Double_t ymax = 2000;
43 Double_t dy = (ymax - ymin) / 0.8; // 10 per cent margins top and bottom
44 Double_t xmin = -3;
45 Double_t xmax = 3;
46 Double_t dx = (xmax - xmin) / 0.8; // 10 per cent margins left and right
47 pad2->Range(xmin - 0.1 * dx, ymin - 0.1 * dy, xmax + 0.1 * dx, ymax + 0.1 * dy);
48 pad2->Draw();
49 pad2->cd();
50 h2->SetLineColor(kRed);
51 h2->Draw("][sames");
52 pad2->Update();
53 TPaveStats *ps2 = (TPaveStats *)h2->GetListOfFunctions()->FindObject("stats");
54 ps2->SetX1NDC(0.65);
55 ps2->SetX2NDC(0.85);
56 ps2->SetTextColor(kRed);
57
58 // draw axis on the right side of the pad
59 TGaxis *axis = new TGaxis(xmax, ymin, xmax, ymax, ymin, ymax, 50510, "+L");
60 axis->SetLabelColor(kRed);
61 axis->Draw();
62}
int Int_t
Definition RtypesCore.h:45
double Double_t
Definition RtypesCore.h:59
@ kRed
Definition Rtypes.h:66
ROOT::Detail::TRangeCast< T, true > TRangeDynCast
TRangeDynCast is an adapter class that allows the typed iteration through a TCollection.
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t r
Option_t Option_t TPoint TPoint const char x2
Option_t Option_t TPoint TPoint const char x1
float xmin
float ymin
float xmax
float ymax
The Canvas class.
Definition TCanvas.h:23
The axis painter class.
Definition TGaxis.h:26
void SetLabelColor(Int_t labelcolor)
Definition TGaxis.h:106
1-D histogram with a float per channel (see TH1 documentation)
Definition TH1.h:645
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition TH1.cxx:3315
void Draw(Option_t *option="") override
Draw this histogram with options.
Definition TH1.cxx:3037
TList * GetListOfFunctions() const
Definition TH1.h:260
TObject * FindObject(const char *name) const override
Find an object in this list using its name.
Definition TList.cxx:576
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition TObject.cxx:292
The most important graphics class in the ROOT system.
Definition TPad.h:28
The histogram statistics painter class.
Definition TPaveStats.h:18
This is the base class for the ROOT Random number generators.
Definition TRandom.h:27
return c1
Definition legend1.C:41
TH1F * h1
Definition legend1.C:5