 ROOT   Reference Guide twoscales.C File Reference

## Detailed Description  Example of macro illustrating how to superimpose two histograms with different scales in the "same" pad. #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++) {
hint1->SetBinContent(i,sum);
}
//scale hint1 to the pad coordinates
Float_t rightmax = 1.1*hint1->GetMaximum();
hint1->SetLineColor(kRed);
hint1->Scale(scale);
hint1->Draw("same");
//draw an axis on the right side
axis->SetLineColor(kRed);
axis->Draw();
}

Definition in file twoscales.C.

TRandom::Gaus
virtual Double_t Gaus(Double_t mean=0, Double_t sigma=1)
Samples a random number from the standard Normal (Gaussian) Distribution with the given mean and sigm...
Definition: TRandom.cxx:263
TRandom.h
Float_t
float Float_t
Definition: RtypesCore.h:57
TStyle.h
Int_t
int Int_t
Definition: RtypesCore.h:45
TH1::SetBinContent
virtual void SetBinContent(Int_t bin, Double_t content)
Set bin content see convention for numbering bins in TH1::GetBin In case the bin number is greater th...
Definition: TH1.cxx:8677
TCanvas.h
h1
TH1F * h1
Definition: legend1.C:5
TH1::GetBinContent
virtual Double_t GetBinContent(Int_t bin) const
Return content of bin number bin.
Definition: TH1.cxx:4906
gStyle
R__EXTERN TStyle * gStyle
Definition: TStyle.h:412
kFALSE
const Bool_t kFALSE
Definition: RtypesCore.h:92
TH1::Fill
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition: TH1.cxx:3274
gRandom
R__EXTERN TRandom * gRandom
Definition: TRandom.h:62
kRed
@ kRed
Definition: Rtypes.h:66
TStyle::SetOptStat
void SetOptStat(Int_t stat=1)
The type of information printed in the histogram statistics box can be selected via the parameter mod...
Definition: TStyle.cxx:1592
TGaxis::SetLabelColor
void SetLabelColor(Int_t labelcolor)
Definition: TGaxis.h:104
twoscales
Definition: twoscales.py:1
TGaxis.h
sum
static long int sum(long int i)
Definition: Factory.cxx:2272
TObject::Draw
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition: TObject.cxx:197
TCanvas
Definition: TCanvas.h:23
TGaxis
Definition: TGaxis.h:23
TH1F
1-D histogram with a float per channel (see TH1 documentation)}
Definition: TH1.h:572
TH1::GetMaximum
virtual Double_t GetMaximum(Double_t maxval=FLT_MAX) const
Return maximum value smaller than maxval of bins in the range, unless the value has been overridden b...
Definition: TH1.cxx:8005
TH1.h
TH1::Scale
virtual void Scale(Double_t c1=1, Option_t *option="")
Multiply this histogram by a constant c1.
Definition: TH1.cxx:6245
TH1::Draw
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition: TH1.cxx:2997
c1
return c1
Definition: legend1.C:41