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graphtext.C
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1/// \file
2/// \ingroup tutorial_graphs
3/// \notebook
4/// Draw a graph with text attached to each point.
5/// The text is drawn in a TExec function attached to the TGraph,
6/// therefore if the a graph's point is
7/// moved interactively, the text will be automatically updated.
8///
9/// \macro_image
10/// \macro_code
11///
12/// \author Olivier Couet
13
14void graphtext() {
15 TCanvas *c = new TCanvas("c","A Simple Graph Example with Text",700,500);
16 c->SetGrid();
17
18 const Int_t n = 10;
19 auto gr = new TGraph(n);
20 gr->SetTitle("A Simple Graph Example with Text");
21 gr->SetMarkerStyle(20);
22 auto ex = new TExec("ex","drawtext();");
24
25 Double_t x, y;
26 for (Int_t i=0;i<n;i++) {
27 x = i*0.1;
28 y = 10*sin(x+0.2);
29 gr->SetPoint(i,x,y);
30
31 }
32 gr->Draw("ALP");
33}
34
35void drawtext()
36{
37 Int_t i,n;
38 Double_t x,y;
39 TLatex l;
40
41 l.SetTextSize(0.025);
42 l.SetTextFont(42);
43 l.SetTextAlign(21);
44 l.SetTextColor(kBlue);
45
46 auto g = (TGraph*)gPad->GetListOfPrimitives()->FindObject("Graph");
47 n = g->GetN();
48
49 for (i=0; i<n; i++) {
50 g->GetPoint(i,x,y);
51 l.PaintText(x,y+0.2,Form("(%4.2f,%4.2f)",x,y));
52 }
53}
54
#define c(i)
Definition RSha256.hxx:101
#define g(i)
Definition RSha256.hxx:105
int Int_t
Definition RtypesCore.h:45
double Double_t
Definition RtypesCore.h:59
@ kBlue
Definition Rtypes.h:66
double sin(double)
char * Form(const char *fmt,...)
#define gPad
virtual void SetMarkerStyle(Style_t mstyle=1)
Set the marker style.
Definition TAttMarker.h:40
virtual void SetTextSize(Float_t tsize=1)
Set the text size.
Definition TAttText.h:46
The Canvas class.
Definition TCanvas.h:23
TExec is a utility class that can be used to execute a C++ command when some event happens in a pad.
Definition TExec.h:28
A TGraph is an object made of two arrays X and Y with npoints each.
Definition TGraph.h:41
virtual void SetPoint(Int_t i, Double_t x, Double_t y)
Set x and y values for point number i.
Definition TGraph.cxx:2284
virtual void SetTitle(const char *title="")
Change (i.e.
Definition TGraph.cxx:2339
virtual void Draw(Option_t *chopt="")
Draw this graph with its current attributes.
Definition TGraph.cxx:769
TList * GetListOfFunctions() const
Definition TGraph.h:118
To draw Mathematical Formula.
Definition TLatex.h:18
virtual void Add(TObject *obj)
Definition TList.h:87
void drawtext(double x, double y, int f, const char *s)
Definition fonts.C:1
Double_t y[n]
Definition legend1.C:17
Double_t x[n]
Definition legend1.C:17
const Int_t n
Definition legend1.C:16
TGraphErrors * gr
Definition legend1.C:25
Double_t ex[n]
Definition legend1.C:17
auto * l
Definition textangle.C:4