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ratioplot2.C File Reference

Detailed Description

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Example of a fit residual plot.

Creates a histogram filled with random numbers from a gaussian distribution and fits it with a standard gaussian function. The result is passed to the TRatioPlot constructor. Additionally, after calling TRatioPlot::Draw the upper and lower y axis titles are modified. Confidence interval bands are automatically drawn on the bottom (but can be disabled by draw option nobands).

void ratioplot2() {
auto c1 = new TCanvas("c1", "fit residual simple");
auto h1 = new TH1D("h1", "h1", 50, -5, 5);
h1->FillRandom("gaus", 2000);
h1->Fit("gaus", "0");
h1->GetXaxis()->SetTitle("x");
auto rp1 = new TRatioPlot(h1);
rp1->Draw();
rp1->GetLowerRefYaxis()->SetTitle("ratio");
rp1->GetUpperRefYaxis()->SetTitle("entries");
}
R__EXTERN TStyle * gStyle
Definition TStyle.h:436
The Canvas class.
Definition TCanvas.h:23
1-D histogram with a double per channel (see TH1 documentation)
Definition TH1.h:671
virtual void FillRandom(TF1 *f1, Int_t ntimes=5000, TRandom *rng=nullptr)
Definition TH1.cxx:3530
TAxis * GetXaxis()
Definition TH1.h:325
virtual TFitResultPtr Fit(const char *formula, Option_t *option="", Option_t *goption="", Double_t xmin=0, Double_t xmax=0)
Fit histogram with function fname.
Definition TH1.cxx:3906
virtual void SetTitle(const char *title="")
Set the title of the TNamed.
Definition TNamed.cxx:164
Class for displaying ratios, differences and fit residuals.
Definition TRatioPlot.h:43
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:1640
return c1
Definition legend1.C:41
TH1F * h1
Definition legend1.C:5
Author
Paul Gessinger

Definition in file ratioplot2.C.