doc/v606/mathStudent_8C.html

#include "TMath.h"

#include "TF1.h"

#include "TCanvas.h"

#include <Riostream.h>

#include "TLegend.h"

#include "TLegendEntry.h"


void mathStudent()

{

   //drawing the set of student density functions

   //normal(0, 1) density drawn for comparison

   TCanvas *DistCanvas = new TCanvas("DistCanvas", "Distribution graphs", 10, 10, 800, 650);

   DistCanvas->SetFillColor(17);

   DistCanvas->Divide(2, 2);

   DistCanvas->cd(1);

   gPad->SetGrid();

   gPad->SetFrameFillColor(19);

   TLegend *leg = new TLegend(0.6, 0.7, 0.89, 0.89);


   TF1* fgaus = new TF1("gaus", "TMath::Gaus(x, [0], [1], [2])", -5, 5);

   fgaus->SetTitle("Student density");

   fgaus->SetLineStyle(2);

   fgaus->SetLineWidth(1);

   fgaus->SetParameters(0, 1, kTRUE);

   leg->AddEntry(fgaus->DrawCopy(), "Normal(0,1)", "l");


   TF1* student = new TF1("student", "TMath::Student(x,[0])", -5, 5);

   //student->SetTitle("Student density");

   student->SetLineWidth(1);

   student->SetParameter(0, 10);

   student->SetLineColor(4);

   leg->AddEntry(student->DrawCopy("lsame"), "10 degrees of freedom", "l");


   student->SetParameter(0, 3);

   student->SetLineColor(2);

   leg->AddEntry(student->DrawCopy("lsame"), "3 degrees of freedom", "l");


   student->SetParameter(0, 1);

   student->SetLineColor(1);

   leg->AddEntry(student->DrawCopy("lsame"), "1 degree of freedom", "l");


   leg->Draw();


   //drawing the set of student cumulative probability functions

   DistCanvas->cd(2);

   gPad->SetFrameFillColor(19);

   gPad->SetGrid();

   TF1 *studentI = new TF1("studentI", "TMath::StudentI(x, [0])", -5, 5);

   studentI->SetTitle("Student cumulative dist.");

   studentI->SetLineWidth(1);

   TLegend *leg2 = new TLegend(0.6, 0.4, 0.89, 0.6);


   studentI->SetParameter(0, 10);

   studentI->SetLineColor(4);

   leg2->AddEntry(studentI->DrawCopy(), "10 degrees of freedom", "l");


   studentI->SetParameter(0, 3);

   studentI->SetLineColor(2);

   leg2->AddEntry(studentI->DrawCopy("lsame"), "3 degrees of freedom", "l");


   studentI->SetParameter(0, 1);

   studentI->SetLineColor(1);

   leg2->AddEntry(studentI->DrawCopy("lsame"), "1 degree of freedom", "l");

   leg2->Draw();


   //drawing the set of F-dist. densities

   TF1* fDist = new TF1("fDist", "TMath::FDist(x, [0], [1])", 0, 2);

   fDist->SetTitle("F-Dist. density");

   fDist->SetLineWidth(1);

   TLegend* legF1 = new TLegend(0.7, 0.7, 0.89, 0.89);


   DistCanvas->cd(3);

   gPad->SetFrameFillColor(19);

   gPad->SetGrid();


   fDist->SetParameters(1, 1);

   fDist->SetLineColor(1);

   legF1->AddEntry(fDist->DrawCopy(), "N=1 M=1", "l");


   fDist->SetParameter(1, 10);

   fDist->SetLineColor(2);

   legF1->AddEntry(fDist->DrawCopy("lsame"), "N=1 M=10", "l");


   fDist->SetParameters(10, 1);

   fDist->SetLineColor(8);

   legF1->AddEntry(fDist->DrawCopy("lsame"), "N=10 M=1", "l");


   fDist->SetParameters(10, 10);

   fDist->SetLineColor(4);

   legF1->AddEntry(fDist->DrawCopy("lsame"), "N=10 M=10", "l");


   legF1->Draw();


   //drawing the set of F cumulative dist.functions

   TF1* fDistI = new TF1("fDist", "TMath::FDistI(x, [0], [1])", 0, 2);

   fDistI->SetTitle("Cumulative dist. function for F");

   fDistI->SetLineWidth(1);

   TLegend* legF2 = new TLegend(0.7, 0.3, 0.89, 0.5);


   DistCanvas->cd(4);

   gPad->SetFrameFillColor(19);

   gPad->SetGrid();

   fDistI->SetParameters(1, 1);

   fDistI->SetLineColor(1);

   legF2->AddEntry(fDistI->DrawCopy(), "N=1 M=1", "l");


   fDistI->SetParameters(1, 10);

   fDistI->SetLineColor(2);

   legF2->AddEntry(fDistI->DrawCopy("lsame"), "N=1 M=10", "l");


   fDistI->SetParameters(10, 1);

   fDistI->SetLineColor(8);

   legF2->AddEntry(fDistI->DrawCopy("lsame"), "N=10 M=1", "l");


   fDistI->SetParameters(10, 10);

   fDistI->SetLineColor(4);

   legF2->AddEntry(fDistI->DrawCopy("lsame"), "N=10 M=10", "l");


   legF2->Draw();

   DistCanvas->cd();

}