From Anna Kreshuk

New tutorial illustrating teh new TMath::Vavilov function


git-svn-id: http://root.cern.ch/svn/root/trunk@11538 27541ba8-7e3a-0410-8455-c3a389f83636

tutorials/vavilov.C

+#include "TMath.h"
+#include "TCanvas.h"
+#include "TRandom.h"
+#include "TGraph.h"
+   
+void vavilov()
+{
+   //test of the TMath::Vavilov distribution
+   Int_t n = 1000;
+   Double_t *x  = new Double_t[n];
+   Double_t *y1 = new Double_t[n];
+   Double_t *y2 = new Double_t[n];
+   Double_t *y3 = new Double_t[n];
+   Double_t *y4 = new Double_t[n];
+
+   TRandom r;
+   for (Int_t i=0; i<n; i++) {
+      x[i]  = r.Uniform(-2, 10);
+      y1[i] = TMath::Vavilov(x[i], 0.3, 0.5);
+      y2[i] = TMath::Vavilov(x[i], 0.15, 0.5);
+      y3[i] = TMath::Vavilov(x[i], 0.25, 0.5);
+      y4[i] = TMath::Vavilov(x[i], 0.05, 0.5);
+   }
+
+   TCanvas *c1 = new TCanvas("c1", "Vavilov density");
+   c1->SetGrid();
+   c1->SetHighLightColor(19);
+   TGraph *gr1 = new TGraph(n, x, y1);
+   TGraph *gr2 = new TGraph(n, x, y2);
+   TGraph *gr3 = new TGraph(n, x, y3);
+   TGraph *gr4 = new TGraph(n, x, y4);
+   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);
+}