Logo ROOT   6.10/09
Reference Guide
twoscales.C File Reference

Detailed Description

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pict1_twoscales.C.png
#include "TCanvas.h"
#include "TStyle.h"
#include "TH1.h"
#include "TGaxis.h"
#include "TRandom.h"
void twoscales()
{
TCanvas *c1 = new TCanvas("c1","hists with different scales",600,400);
//create/fill draw h1
TH1F *h1 = new TH1F("h1","my histogram",100,-3,3);
Int_t i;
for (i=0;i<10000;i++) h1->Fill(gRandom->Gaus(0,1));
h1->Draw();
c1->Update();
//create hint1 filled with the bins integral of h1
TH1F *hint1 = new TH1F("hint1","h1 bins integral",100,-3,3);
Float_t sum = 0;
for (i=1;i<=100;i++) {
sum += h1->GetBinContent(i);
hint1->SetBinContent(i,sum);
}
//scale hint1 to the pad coordinates
Float_t rightmax = 1.1*hint1->GetMaximum();
Float_t scale = gPad->GetUymax()/rightmax;
hint1->SetLineColor(kRed);
hint1->Scale(scale);
hint1->Draw("same");
//draw an axis on the right side
TGaxis *axis = new TGaxis(gPad->GetUxmax(),gPad->GetUymin(),
gPad->GetUxmax(), gPad->GetUymax(),0,rightmax,510,"+L");
axis->SetLineColor(kRed);
axis->SetLabelColor(kRed);
axis->Draw();
}
Author
Rene Brun

Definition in file twoscales.C.