doc/v624/vavilov_8C.html

#include "TMath.h"

#include "TCanvas.h"

#include "TRandom.h"

#include "TGraph.h"


void vavilov()

{

   Int_t n = 1000;

   Double_t *xvalues  = new Double_t[n];

   Double_t *yvalues1 = new Double_t[n];

   Double_t *yvalues2 = new Double_t[n];

   Double_t *yvalues3 = new Double_t[n];

   Double_t *yvalues4 = new Double_t[n];


   TRandom r;

   for (Int_t i=0; i<n; i++) {

      xvalues[i]  = r.Uniform(-2, 10);

      yvalues1[i] = TMath::Vavilov(xvalues[i], 0.3, 0.5);

      yvalues2[i] = TMath::Vavilov(xvalues[i], 0.15, 0.5);

      yvalues3[i] = TMath::Vavilov(xvalues[i], 0.25, 0.5);

      yvalues4[i] = TMath::Vavilov(xvalues[i], 0.05, 0.5);

   }


   TCanvas *c1 = new TCanvas("c1", "Vavilov density");

   c1->SetGrid();

   c1->SetHighLightColor(19);

   TGraph *gr1 = new TGraph(n, xvalues, yvalues1);

   TGraph *gr2 = new TGraph(n, xvalues, yvalues2);

   TGraph *gr3 = new TGraph(n, xvalues, yvalues3);

   TGraph *gr4 = new TGraph(n, xvalues, yvalues4);

   gr1->SetTitle("TMath::Vavilov density");

   gr1->Draw("ap");

   gr2->Draw("psame");

   gr2->SetMarkerColor(kRed);

   gr3->Draw("psame");

   gr3->SetMarkerColor(kBlue);

   gr4->Draw("psame");

   gr4->SetMarkerColor(kGreen);


   TF1 *f1 = new TF1("f1", "TMath::Vavilov(x, 0.3, 0.5)", -2, 10);


   TH1F *hist = new TH1F("vavilov", "vavilov", 100, -2, 10);

   for (int i=0; i<10000; i++) {

      hist->Fill(f1->GetRandom());

   }

   hist->Scale(1/1200.);

   hist->Draw("same");

}

r
ROOT::R::TRInterface & r
Definition Object.C:4

Int_t
int Int_t
Definition RtypesCore.h:45

Double_t
double Double_t
Definition RtypesCore.h:59

kRed
@ kRed
Definition Rtypes.h:66

kGreen
@ kGreen
Definition Rtypes.h:66

kBlue
@ kBlue
Definition Rtypes.h:66

TCanvas.h

TGraph.h

TMath.h

TRandom.h

TAttMarker::SetMarkerColor
virtual void SetMarkerColor(Color_t mcolor=1)
Set the marker color.
Definition TAttMarker.h:38

TCanvas
The Canvas class.
Definition TCanvas.h:23

TF1
1-Dim function class
Definition TF1.h:213

TF1::GetRandom
virtual Double_t GetRandom(TRandom *rng=nullptr, Option_t *opt=nullptr)
Return a random number following this function shape.
Definition TF1.cxx:2180

TGraph
A TGraph is an object made of two arrays X and Y with npoints each.
Definition TGraph.h:41

TGraph::SetTitle
virtual void SetTitle(const char *title="")
Change (i.e.
Definition TGraph.cxx:2339

TGraph::Draw
virtual void Draw(Option_t *chopt="")
Draw this graph with its current attributes.
Definition TGraph.cxx:769

TH1F
1-D histogram with a float per channel (see TH1 documentation)}
Definition TH1.h:575

TH1::Fill
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition TH1.cxx:3350

TH1::Draw
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition TH1.cxx:3073

TH1::Scale
virtual void Scale(Double_t c1=1, Option_t *option="")
Multiply this histogram by a constant c1.
Definition TH1.cxx:6564

TRandom
This is the base class for the ROOT Random number generators.
Definition TRandom.h:27

c1
return c1
Definition legend1.C:41

n
const Int_t n
Definition legend1.C:16

f1
TF1 * f1
Definition legend1.C:11

TMath::Vavilov
Double_t Vavilov(Double_t x, Double_t kappa, Double_t beta2)
Returns the value of the Vavilov density function.
Definition TMath.cxx:2734