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Reference Guide
hlHisto4.C File Reference

Detailed Description

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

A 1D histogram is created. Then an highlight method is connected to the histogram. Moving the mouse on the histogram will open a new canvas showing in real time a zoom around the highlighted bin.

TText *info = nullptr;
TH1 *hz = nullptr;
void HighlightZoom(TVirtualPad *pad, TObject *obj, Int_t xhb, Int_t yhb)
auto h = dynamic_cast<TH1F *>(obj);
if(!h) return;
auto Canvas2 = (TCanvas *)gROOT->GetListOfCanvases()->FindObject("Canvas2");
if (!h->IsHighlight()) { // after highlight disabled
if (Canvas2) delete Canvas2;
if (hz) { delete hz; hz = nullptr; }
if (info) info->SetTitle("");
if (!Canvas2) {
Canvas2 = new TCanvas("Canvas2", "Canvas2", 605, 0, 400, 400);
if (hz) hz->Draw(); // after reopen this canvas
if (!hz) {
hz = (TH1 *)h->Clone("hz");
hz->SetTitle(TString::Format("%s (zoomed)", hz->GetTitle()));
Int_t zf = hz->GetNbinsX()*0.05; // zoom factor
hz->GetXaxis()->SetRange(xhb-zf, xhb+zf);
void hlHisto4()
auto Canvas1 = new TCanvas("Canvas1", "", 0, 0, 600, 400);
auto f1 = new TF1("f1", "x*gaus(0) + [3]*abs(sin(x)/x)", -50.0, 50.0);
f1->SetParameters(20.0, 4.0, 1.0, 20.0);
auto h1 = new TH1F("h1", "Test random numbers", 200, -50.0, 50.0);
h1->FillRandom("f1", 100000);
h1->Fit(f1, "Q");
info = new TText(0.0, h1->GetMaximum()*0.7, "please move the mouse over the frame");
// configure highlight at the end when histogram is already painted
#define h(i)
Definition: RSha256.hxx:106
int Int_t
Definition: RtypesCore.h:45
const Bool_t kFALSE
Definition: RtypesCore.h:101
@ kGray
Definition: Rtypes.h:65
@ kRed
Definition: Rtypes.h:66
@ kCannotPick
Definition: TObject.h:374
#define gROOT
Definition: TROOT.h:404
R__EXTERN TStyle * gStyle
Definition: TStyle.h:414
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
virtual void SetRange(Int_t first=0, Int_t last=0)
Set the viewing range for the axis using bin numbers.
Definition: TAxis.cxx:952
The Canvas class.
Definition: TCanvas.h:23
1-Dim function class
Definition: TF1.h:213
virtual void SetParameters(const Double_t *params)
Definition: TF1.h:649
1-D histogram with a float per channel (see TH1 documentation)}
Definition: TH1.h:577
TH1 is the base class of all histogram classes in ROOT.
Definition: TH1.h:58
void SetTitle(const char *title) override
Change (i.e.
Definition: TH1.cxx:6700
TAxis * GetXaxis()
Definition: TH1.h:322
virtual void FillRandom(const char *fname, Int_t ntimes=5000, TRandom *rng=nullptr)
Fill histogram following distribution in function fname.
Definition: TH1.cxx:3513
virtual TFitResultPtr Fit(const char *formula, Option_t *option="", Option_t *goption="", Double_t xmin=0, Double_t xmax=0)
Fit histogram with function fname.
Definition: TH1.cxx:3894
virtual Double_t GetMaximum(Double_t maxval=FLT_MAX) const
Return maximum value smaller than maxval of bins in the range, unless the value has been overridden b...
Definition: TH1.cxx:8412
virtual Int_t GetNbinsX() const
Definition: TH1.h:295
void Draw(Option_t *option="") override
Draw this histogram with options.
Definition: TH1.cxx:3060
virtual void SetHighlight(Bool_t set=kTRUE)
Set highlight (enable/disable) mode for the histogram by default highlight mode is disable.
Definition: TH1.cxx:4455
virtual void SetStats(Bool_t stats=kTRUE)
Set statistics option on/off.
Definition: TH1.cxx:8857
virtual void SetTitle(const char *title="")
Set the title of the TNamed.
Definition: TNamed.cxx:164
const char * GetTitle() const override
Returns title of object.
Definition: TNamed.h:48
Mother of all ROOT objects.
Definition: TObject.h:41
void SetBit(UInt_t f, Bool_t set)
Set or unset the user status bits as specified in f.
Definition: TObject.cxx:775
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition: TObject.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:2345
void SetGridColor(Color_t color=0)
Definition: TStyle.h:354
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
TH1F * h1
Definition: legend1.C:5
TF1 * f1
Definition: legend1.C:11
March 2018
Jan Musinsky

Definition in file hlHisto4.C.