doc/v634/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");

}

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

TRangeDynCast
ROOT::Detail::TRangeCast< T, true > TRangeDynCast
TRangeDynCast is an adapter class that allows the typed iteration through a TCollection.
Definition TCollection.h:358

r
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t r
Definition TGWin32VirtualXProxy.cxx:168

TGraph.h

TMath.h

TRandom.h

ROOT::Detail::TRangeCast
Definition TCollection.h:311

TCanvas
The Canvas class.
Definition TCanvas.h:23

TF1
1-Dim function class
Definition TF1.h:233

TF1::GetRandom
virtual Double_t GetRandom(TRandom *rng=nullptr, Option_t *opt=nullptr)
Return a random number following this function shape.
Definition TF1.cxx:2192

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

TH1F
1-D histogram with a float per channel (see TH1 documentation)
Definition TH1.h:622

TH1::Fill
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition TH1.cxx:3344

TH1::Draw
void Draw(Option_t *option="") override
Draw this histogram with options.
Definition TH1.cxx:3066

TH1::Scale
virtual void Scale(Double_t c1=1, Option_t *option="")
Multiply this histogram by a constant c1.
Definition TH1.cxx:6625

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 probability density function.
Definition TMath.cxx:2778