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Reference Guide
hlHisto2.C File Reference

Detailed Description

This tutorial demonstrates how the highlight mechanism can be used on an histogram.

A 2D histogram is booked an filled with a random gaussian distribution and drawn with the "col" option. Then an highlight method is connected to the histogram. Moving the mouse on the histogram open a new canvas displaying the two X and Y projections at the highlighted bin.

TText *info = nullptr;
void Highlight2(TVirtualPad *pad, TObject *obj, Int_t xhb, Int_t yhb)
{
auto h2 = dynamic_cast<TH2F *>(obj);
if(!h2) return;
auto CanvasProj = (TCanvas *) gROOT->GetListOfCanvases()->FindObject("CanvasProj");
if (!h2->IsHighlight()) { // after highlight disabled
if (CanvasProj) delete CanvasProj;
h2->SetTitle("Disable highlight");
return;
}
if (info) info->SetTitle("");
auto px = h2->ProjectionX("_px", yhb, yhb);
auto py = h2->ProjectionY("_py", xhb, xhb);
px->SetTitle(TString::Format("ProjectionX of biny[%02d]", yhb));
py->SetTitle(TString::Format("ProjectionY of binx[%02d]", xhb));
if (!CanvasProj) {
CanvasProj = new TCanvas("CanvasProj", "CanvasProj", 505, 0, 600, 600);
CanvasProj->Divide(1, 2);
CanvasProj->cd(1);
px->Draw();
CanvasProj->cd(2);
py->Draw();
}
h2->SetTitle(TString::Format("Highlight bin [%02d, %02d]", xhb, yhb).Data());
pad->Modified();
pad->Update();
CanvasProj->GetPad(1)->Modified();
CanvasProj->GetPad(2)->Modified();
CanvasProj->Update();
}
void hlHisto2()
{
auto c1 = new TCanvas("Canvas", "Canvas", 0, 0, 500, 500);
c1->HighlightConnect("Highlight2(TVirtualPad*,TObject*,Int_t,Int_t)");
auto h2 = new TH2F("h2", "", 50, -5.0, 5.0, 50, -5.0, 5.0);
for (Int_t i = 0; i < 10000; i++) h2->Fill(gRandom->Gaus(), gRandom->Gaus());
h2->Draw("col");
info = new TText(0.0, -4.0, "please move the mouse over the frame");
info->SetTextAlign(22);
info->SetTextSize(0.04);
info->SetTextColor(kRed+1);
info->Draw();
c1->Update();
h2->SetHighlight();
}
int Int_t
Definition: RtypesCore.h:45
@ kRed
Definition: Rtypes.h:66
@ kCannotPick
Definition: TObject.h:359
#define gROOT
Definition: TROOT.h:404
R__EXTERN TRandom * gRandom
Definition: TRandom.h:62
virtual void SetTextAlign(Short_t align=11)
Set the text alignment.
Definition: TAttText.h:42
virtual void SetTextColor(Color_t tcolor=1)
Set the text color.
Definition: TAttText.h:44
virtual void SetTextSize(Float_t tsize=1)
Set the text size.
Definition: TAttText.h:47
The Canvas class.
Definition: TCanvas.h:23
2-D histogram with a float per channel (see TH1 documentation)}
Definition: TH2.h:257
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:696
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition: TObject.cxx:197
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:274
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:2336
Base class for several text objects.
Definition: TText.h:22
TVirtualPad is an abstract base class for the Pad and Canvas classes.
Definition: TVirtualPad.h:51
virtual void Modified(Bool_t flag=1)=0
virtual void Update()=0
return c1
Definition: legend1.C:41
Date
March 2018
Author
Jan Musinsky

Definition in file hlHisto2.C.