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Reference Guide
hlHisto2.C
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1/// \file
2/// \ingroup tutorial_hist
3///
4/// This tutorial demonstrates how the highlight mechanism can be used on an histogram.
5/// A 2D histogram is booked an filled with a random gaussian distribution and
6/// drawn with the "col" option.
7/// Then an highlight method is connected to the histogram. Moving the mouse
8/// on the histogram open a new canvas displaying the two X and Y projections
9/// at the highlighted bin.
10///
11/// \macro_code
12///
13/// \date March 2018
14/// \author Jan Musinsky
15
16void Highlight2(TVirtualPad *pad, TObject *obj, Int_t xhb, Int_t yhb);
17
18TText *info;
19
20
21void hlHisto2()
22{
23 auto Canvas = new TCanvas("Canvas", "Canvas", 0, 0, 500, 500);
24 auto h2 = new TH2F("h2", "", 50, -5.0, 5.0, 50, -5.0, 5.0);
25 for (Int_t i = 0; i < 10000; i++) h2->Fill(gRandom->Gaus(), gRandom->Gaus());
26 h2->Draw("col");
27
28 info = new TText(0.0, -4.0, "please move the mouse over the frame");
29 info->SetTextAlign(22);
30 info->SetTextSize(0.04);
31 info->SetTextColor(kRed+1);
32 info->SetBit(kCannotPick);
33 info->Draw();
34 Canvas->Update();
35
36 h2->SetHighlight();
37 Canvas->HighlightConnect("Highlight2(TVirtualPad*,TObject*,Int_t,Int_t)");
38}
39
40
41void Highlight2(TVirtualPad *pad, TObject *obj, Int_t xhb, Int_t yhb)
42{
43 auto h2 = (TH2F *)obj;
44 if(!h2) return;
45 auto CanvasProj = (TCanvas *) gROOT->GetListOfCanvases()->FindObject("CanvasProj");
46 if (!h2->IsHighlight()) { // after highlight disabled
47 if (CanvasProj) delete CanvasProj;
48 return;
49 }
50
51 info->SetTitle("");
52
53 auto px = h2->ProjectionX("_px", yhb, yhb);
54 auto py = h2->ProjectionY("_py", xhb, xhb);
55 px->SetTitle(TString::Format("ProjectionX of biny[%02d]", yhb));
56 py->SetTitle(TString::Format("ProjectionY of binx[%02d]", xhb));
57
58 if (!CanvasProj) {
59 CanvasProj = new TCanvas("CanvasProj", "CanvasProj", 505, 0, 600, 600);
60 CanvasProj->Divide(1, 2);
61 CanvasProj->cd(1);
62 px->Draw();
63 CanvasProj->cd(2);
64 py->Draw();
65 }
66
67 CanvasProj->GetPad(1)->Modified();
68 CanvasProj->GetPad(2)->Modified();
69 CanvasProj->Update();
70}
int Int_t
Definition: RtypesCore.h:43
@ kRed
Definition: Rtypes.h:64
@ kCannotPick
Definition: TObject.h:359
#define gROOT
Definition: TROOT.h:406
R__EXTERN TRandom * gRandom
Definition: TRandom.h:62
virtual void SetTextAlign(Short_t align=11)
Set the text alignment.
Definition: TAttText.h:41
virtual void SetTextColor(Color_t tcolor=1)
Set the text color.
Definition: TAttText.h:43
virtual void SetTextSize(Float_t tsize=1)
Set the text size.
Definition: TAttText.h:46
The Canvas class.
Definition: TCanvas.h:27
2-D histogram with a float per channel (see TH1 documentation)}
Definition: TH2.h:251
virtual void SetTitle(const char *title="")
Set the title of the TNamed.
Definition: TNamed.cxx:164
Mother of all ROOT objects.
Definition: TObject.h:37
void SetBit(UInt_t f, Bool_t set)
Set or unset the user status bits as specified in f.
Definition: TObject.cxx:694
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition: TObject.cxx:195
virtual Double_t Gaus(Double_t mean=0, Double_t sigma=1)
Samples a random number from the standard Normal (Gaussian) Distribution with the given mean and sigm...
Definition: TRandom.cxx:263
static TString Format(const char *fmt,...)
Static method which formats a string using a printf style format descriptor and return a TString.
Definition: TString.cxx:2311
Base class for several text objects.
Definition: TText.h:23
TVirtualPad is an abstract base class for the Pad and Canvas classes.
Definition: TVirtualPad.h:51