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splines_test.C
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1/// \file
2/// \ingroup tutorial_graphs
3/// \notebook
4/// Examples of use of the spline classes.
5///
6/// \macro_image
7/// \macro_code
8///
9/// \author Federico Carminati
10
11void splines_test(Int_t np=23, Double_t a=-0.5, Double_t b=31)
12{
13 // array of points
14 Double_t *xx=0, *yy=0;
15 TSpline3 *spline3=0;
16 TSpline5 *spline5=0;
17 TLine *line5, *line3;
18 TText *text5, *text3, *textn;
19 char text[20];
20 const Double_t power=0.75;
21
22 // Define the original function
23 TF1 *f=new TF1("f","sin(x)*sin(x/10)",
24 a-0.05*(b-a),b+0.05*(b-a));
25 // Draw function
26 f->Draw("lc");
27
28 // Create text and legend
29 Double_t xx1, yy1, xx2, yy2, dx, dy;
30 gPad->Update();
31 gPad->GetRangeAxis(xx1,yy1,xx2,yy2);
32 dx = xx2-xx1;
33 dy = yy2-yy1;
34 line5=new TLine(xx1+dx*0.3,yy1+dy*1.02,
35 xx1+dx*0.38,yy1+dy*1.02);
36 line5->SetLineColor(kRed);
37 line5->SetLineWidth(2);
38 text5 = new TText(xx1+dx*0.4,
39 yy1+dy*1.03,"quintic spline");
40 text5->SetTextAlign(12);
41 text5->SetTextSize(0.04);
42 line3=new TLine(xx1+dx*0.67,yy1+dy*1.02,
43 xx1+dx*0.75,yy1+dy*1.02);
44 line3->SetLineColor(kGreen);
45 line3->SetLineWidth(2);
46 text3 = new TText(xx1+dx*0.77,
47 yy1+dy*1.03,"third spline");
48 text3->SetTextAlign(12);
49 text3->SetTextSize(0.04);
50 textn = new TText(xx1+dx*0.8,yy1+dy*0.91," ");
51 textn->SetTextAlign(12);
52 textn->SetTextSize(0.04);
53 textn->Draw();
54
55 // Draw legenda
56 line5->Draw();
57 text5->Draw();
58 line3->Draw();
59 text3->Draw();
60
61 for(Int_t nnp=2; nnp<=np; ++nnp) {
62
63 // Calculate the knots
64 if(xx) delete[] xx;
65 xx = new Double_t[nnp];
66 if(yy) delete[] yy;
67 yy = new Double_t[nnp];
68 for (Int_t i=0; i<nnp; ++i) {
69 xx[i]=a+(b-a)*TMath::Power(i/Double_t (nnp-1),power);
70 yy[i]=f->Eval(xx[i]);
71 }
72
73 // Evaluate fifth spline coefficients
74 Double_t eps=(b-a)*1.e-5;
75 if(spline5) delete spline5;
76 spline5 = new TSpline5("Test",xx,f,nnp,"b1e1b2e2",
77 f->Derivative(a),f->Derivative(b),
78 (f->Derivative(a+eps)-f->Derivative(a))/eps,
79 (f->Derivative(b)-f->Derivative(b-eps))/eps);
80
81 spline5->SetLineColor(kRed);
82 spline5->SetLineWidth(3);
83
84 // Draw the quintic spline
85 spline5->Draw("lcsame");
86
87 // Evaluate third spline coefficients
88 if(spline3) delete spline3;
89 spline3 = new TSpline3("Test",xx,yy,nnp,"b1e1",
90 f->Derivative(a),f->Derivative(b));
91
92 spline3->SetLineColor(kGreen);
93 spline3->SetLineWidth(3);
94 spline3->SetMarkerColor(kBlue);
95 spline3->SetMarkerStyle(20);
96 spline3->SetMarkerSize(1.5);
97
98 // Draw the third spline
99 spline3->Draw("lcpsame");
100
101 sprintf(text,"%3d knots",nnp);
102 textn->SetTitle(text);
103 gPad->Update();
104
105 //
106 gSystem->Sleep(500);
107 }
108}
#define b(i)
Definition RSha256.hxx:100
#define f(i)
Definition RSha256.hxx:104
#define a(i)
Definition RSha256.hxx:99
int Int_t
Definition RtypesCore.h:45
double Double_t
Definition RtypesCore.h:59
@ kRed
Definition Rtypes.h:66
@ kGreen
Definition Rtypes.h:66
@ kBlue
Definition Rtypes.h:66
R__EXTERN TSystem * gSystem
Definition TSystem.h:559
#define gPad
virtual void SetLineWidth(Width_t lwidth)
Set the line width.
Definition TAttLine.h:43
virtual void SetLineColor(Color_t lcolor)
Set the line color.
Definition TAttLine.h:40
virtual void SetMarkerColor(Color_t mcolor=1)
Set the marker color.
Definition TAttMarker.h:38
virtual void SetMarkerStyle(Style_t mstyle=1)
Set the marker style.
Definition TAttMarker.h:40
virtual void SetMarkerSize(Size_t msize=1)
Set the marker size.
Definition TAttMarker.h:41
virtual void SetTextAlign(Short_t align=11)
Set the text alignment.
Definition TAttText.h:42
virtual void SetTextSize(Float_t tsize=1)
Set the text size.
Definition TAttText.h:47
1-Dim function class
Definition TF1.h:213
Use the TLine constructor to create a simple line.
Definition TLine.h:22
virtual void SetTitle(const char *title="")
Set the title of the TNamed.
Definition TNamed.cxx:164
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition TObject.cxx:267
Class to create third splines to interpolate knots Arbitrary conditions can be introduced for first a...
Definition TSpline.h:201
Class to create quintic natural splines to interpolate knots Arbitrary conditions can be introduced f...
Definition TSpline.h:257
virtual void Draw(Option_t *option="")
Draw this function with its current attributes.
Definition TSpline.cxx:101
virtual void Sleep(UInt_t milliSec)
Sleep milliSec milli seconds.
Definition TSystem.cxx:440
Base class for several text objects.
Definition TText.h:22
TText * text
LongDouble_t Power(LongDouble_t x, LongDouble_t y)
Definition TMath.h:685