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hlHisto3.C File Reference

Detailed Description

This tutorial demonstrates how the highlight mechanism can be used on a ntuple.

The ntuple in hsimple.root is drawn with three differents selection. Moving the mouse ove the two 1D representation display the on 2D plot the events contributing to the highlighted bin.

TList *list1 = 0;
TList *list2 = 0;
void InitGraphs(TNtuple *nt, TH1F *histo);
void Highlight3(TVirtualPad *pad, TObject *obj, Int_t xhb, Int_t yhb);
void hlHisto3()
auto dir = gROOT->GetTutorialDir();
if (!gInterpreter->IsLoaded(dir.Data())) gInterpreter->LoadMacro(dir.Data());
auto file = (TFile*)gROOT->ProcessLineFast("hsimple(1)");
if (!file) return;
TNtuple *ntuple;
file->GetObject("ntuple", ntuple);
if (!ntuple) return;
const char *cut = "pz > 3.0";
TCanvas *Canvas1 = new TCanvas("Canvas1", "Canvas1", 0, 0, 700, 500);
Canvas1->Divide(1, 2);
TCanvas *Canvas2 = new TCanvas("Canvas2", "Canvas2", 705, 0, 500, 500);
// Case1, histo1, pz distribution
ntuple->Draw("pz>>histo1(100, 2.0, 12.0)", cut);
auto histo1 = (TH1F *)gPad->FindObject("histo1");
auto info1 = new TText(7.0, histo1->GetMaximum()*0.6,
"please move the mouse over the frame");
// Case2, histo2, px*py*pz distribution
ntuple->Draw("(px*py*pz)>>histo2(100, -50.0, 50.0)", cut);
auto histo2 = (TH1F *)gPad->FindObject("histo2");
auto info2 = new TText(10.0, histo2->GetMaximum()*0.6, info1->GetTitle());
// Common graph (all entries, all histo bins)
ntuple->Draw("px:py", cut);
auto gcommon = (TGraph *)gPad->FindObject("Graph");
gcommon->SetBit(kCanDelete, kFALSE); // will be redraw
auto htemp = (TH2F *)gPad->FindObject("htemp");
// Must be last
ntuple->Draw("px:py:pz", cut, "goff");
histo1->SetUniqueID(1); // mark as case1
histo2->SetUniqueID(2); // mark as case2
InitGraphs(ntuple, histo1);
InitGraphs(ntuple, histo2);
void InitGraphs(TNtuple *nt, TH1F *histo)
Double_t *px = nt->GetV1();
Double_t *py = nt->GetV2();
Double_t *pz = nt->GetV3();
auto list = new TList();
if (histo->GetUniqueID() == 1) list1 = list;
else if (histo->GetUniqueID() == 2) list2 = list;
else return;
Int_t nbins = histo->GetNbinsX();
Int_t bin;
for (bin = 0; bin < nbins; bin++) {
g = new TGraph();
g->SetName(TString::Format("g%sbin_%d", histo->GetName(), bin+1));
Double_t value = 0.0;
for (Long64_t ie = 0; ie < nev; ie++) {
if (histo->GetUniqueID() == 1) value = pz[ie];
if (histo->GetUniqueID() == 2) value = px[ie]*py[ie]*pz[ie];
bin = histo->FindBin(value) - 1;
g = (TGraph *)list->At(bin);
if (!g) continue; // under/overflow
g->SetPoint(g->GetN(), py[ie], px[ie]); // reverse as px:py
void Highlight3(TVirtualPad *pad, TObject *obj, Int_t xhb, Int_t yhb)
auto histo = (TH1F *)obj;
if(!histo) return;
TCanvas *Canvas2 = (TCanvas *)gROOT->GetListOfCanvases()->FindObject("Canvas2");
if (!Canvas2) return;
TGraph *gcommon = (TGraph *)Canvas2->FindObject("Graph");
if (!gcommon) return;
TList *list = 0;
if (histo->GetUniqueID() == 1) list = list1; // case1
else if (histo->GetUniqueID() == 2) list = list2; // case2
if (!list) return;
TGraph *g = (TGraph *)list->At(xhb);
if (!g) return;
TVirtualPad *savepad = gPad;
//gcommon->SetTitle(TString::Format("%d / %d", g->GetN(), gcommon->GetN()));
if (histo->IsHighlight()) // don't draw g after highlight disabled
if (g->GetN() > 0) g->Draw("P");
#define g(i)
Definition RSha256.hxx:105
int Int_t
Definition RtypesCore.h:45
const Bool_t kFALSE
Definition RtypesCore.h:92
double Double_t
Definition RtypesCore.h:59
long long Long64_t
Definition RtypesCore.h:73
@ kGreen
Definition Rtypes.h:66
#define gInterpreter
@ kCanDelete
Definition TObject.h:354
@ kCannotPick
Definition TObject.h:359
#define gROOT
Definition TROOT.h:406
#define gPad
virtual Color_t GetLineColor() const
Return the line color.
Definition TAttLine.h:33
The Canvas class.
Definition TCanvas.h:23
virtual void HighlightConnect(const char *slot)
This is "simplification" for function TCanvas::Connect with Highlighted signal for specific slot.
Definition TCanvas.cxx:1633
TVirtualPad * cd(Int_t subpadnumber=0) override
Set current canvas & pad.
Definition TCanvas.cxx:708
void Update() override
Update canvas pad buffers.
Definition TCanvas.cxx:2504
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition TFile.h:54
A TGraph is an object made of two arrays X and Y with npoints each.
Definition TGraph.h:41
virtual void Draw(Option_t *chopt="")
Draw this graph with its current attributes.
Definition TGraph.cxx:769
1-D histogram with a float per channel (see TH1 documentation)}
Definition TH1.h:575
virtual Int_t GetNbinsX() const
Definition TH1.h:296
virtual Bool_t IsHighlight() const
Definition TH1.h:334
virtual Int_t FindBin(Double_t x, Double_t y=0, Double_t z=0)
Return Global bin number corresponding to x,y,z.
Definition TH1.cxx:3680
2-D histogram with a float per channel (see TH1 documentation)}
Definition TH2.h:251
A doubly linked list.
Definition TList.h:44
virtual TObject * At(Int_t idx) const
Returns the object at position idx. Returns 0 if idx is out of range.
Definition TList.cxx:357
virtual const char * GetName() const
Returns name of object.
Definition TNamed.h:47
A simple TTree restricted to a list of float variables only.
Definition TNtuple.h:28
Mother of all ROOT objects.
Definition TObject.h:37
virtual UInt_t GetUniqueID() const
Return the unique object id.
Definition TObject.cxx:377
void Divide(Int_t nx=1, Int_t ny=1, Float_t xmargin=0.01, Float_t ymargin=0.01, Int_t color=0) override
Automatic pad generation by division.
Definition TPad.cxx:1177
TObject * FindObject(const char *name) const override
Search if object named name is inside this pad or in pads inside this pad.
Definition TPad.cxx:2625
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:2331
Base class for several text objects.
Definition TText.h:22
virtual Long64_t GetSelectedRows()
Definition TTree.h:510
virtual Double_t * GetV3()
Definition TTree.h:537
virtual Double_t * GetV1()
Definition TTree.h:533
virtual void Draw(Option_t *opt)
Default Draw method for all objects.
Definition TTree.h:428
virtual Double_t * GetV2()
Definition TTree.h:535
TVirtualPad is an abstract base class for the Pad and Canvas classes.
Definition TVirtualPad.h:51
virtual TVirtualPad * cd(Int_t subpadnumber=0)=0
Definition file.py:1
March 2018
Jan Musinsky

Definition in file hlHisto3.C.