ROOT   Reference Guide
ChebyshevPol.C
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1/// \file
2/// \ingroup tutorial_math
3/// \notebook
4/// Example of Chebyshev polynomials
5/// using new TFormula pre-defined definitions of chebyshev polynomials
6///
7/// \macro_image
8/// \macro_code
9///
10/// \author Lorenzo Moneta
11
12void ChebyshevPol() {
13
14
15 auto legend = new TLegend(0.88,0.4,1.,1.);
16
17 int colors[] = { kRed, kRed+3, kMagenta, kMagenta+3, kBlue, kBlue+3, kCyan+3, kGreen, kGreen+3, kYellow, kOrange };
18
19 for (int degree=0; degree <=10; ++degree) {
20 auto f1 = new TF1("f1",TString::Format("cheb%d",degree),-1,1);
21 // all parameters are zero apart from the one corresponding to the degree
24 f1->SetMinimum(-1.2);
25 f1->SetMaximum(1.2);
26 TString opt = (degree == 0) ? "" : "same";
27 //f1->Print("V");
28 f1->SetNpx(1000);
29 f1->SetTitle("Chebyshev Polynomial");
30 f1->Draw(opt);
32 }
33 legend->Draw();
34}
35
@ kRed
Definition: Rtypes.h:64
@ kOrange
Definition: Rtypes.h:65
@ kGreen
Definition: Rtypes.h:64
@ kMagenta
Definition: Rtypes.h:64
@ kCyan
Definition: Rtypes.h:64
@ kBlue
Definition: Rtypes.h:64
@ kYellow
Definition: Rtypes.h:64
Color * colors
Definition: X3DBuffer.c:21
virtual void SetLineColor(Color_t lcolor)
Set the line color.
Definition: TAttLine.h:40
1-Dim function class
Definition: TF1.h:210
virtual void SetMaximum(Double_t maximum=-1111)
Set the maximum value along Y for this function In case the function is already drawn,...
Definition: TF1.cxx:3396
virtual void SetTitle(const char *title="")
Set function title if title has the form "fffffff;xxxx;yyyy", it is assumed that the function title i...
Definition: TF1.cxx:3551
virtual void SetNpx(Int_t npx=100)
Set the number of points used to draw the function.
Definition: TF1.cxx:3435
virtual void SetMinimum(Double_t minimum=-1111)
Set the minimum value along Y for this function In case the function is already drawn,...
Definition: TF1.cxx:3409
virtual void Draw(Option_t *option="")
Draw this function with its current attributes.
Definition: TF1.cxx:1320
virtual void SetParameter(Int_t param, Double_t value)
Definition: TF1.h:628
This class displays a legend box (TPaveText) containing several legend entries.
Definition: TLegend.h:23
Basic string class.
Definition: TString.h:131
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:2311
TF1 * f1
Definition: legend1.C:11
static constexpr double degree