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Reference Guide
ratioplot2.C
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1/// \file
2/// \ingroup tutorial_hist
3/// \notebook
4/// Example of a fit residual plot.
5///
6/// Creates a histogram filled with random numbers from a gaussian distribution
7/// and fits it with a standard gaussian function. The result is passed to the `TRatioPlot`
8/// constructor. Additionally, after calling `TRatioPlot::Draw` the upper and lower y axis
9/// titles are modified.
10/// Confidence interval bands are automatically drawn on the bottom (but can be disabled by draw option `nobands`.
11///
12/// \macro_image
13/// \macro_code
14///
15/// \author Paul Gessinger
16
17void ratioplot2() {
19 auto c1 = new TCanvas("c1", "fit residual simple");
20 auto h1 = new TH1D("h1", "h1", 50, -5, 5);
21 h1->FillRandom("gaus", 2000);
22 h1->Fit("gaus", "0");
23 h1->GetXaxis()->SetTitle("x");
24 auto rp1 = new TRatioPlot(h1);
25 rp1->Draw();
26 rp1->GetLowerRefYaxis()->SetTitle("ratio");
27 rp1->GetUpperRefYaxis()->SetTitle("entries");
28}
R__EXTERN TStyle * gStyle
Definition: TStyle.h:414
The Canvas class.
Definition: TCanvas.h:23
1-D histogram with a double per channel (see TH1 documentation)}
Definition: TH1.h:617
TAxis * GetXaxis()
Get the behaviour adopted by the object about the statoverflows. See EStatOverflows for more informat...
Definition: TH1.h:319
virtual void FillRandom(const char *fname, Int_t ntimes=5000, TRandom *rng=nullptr)
Fill histogram following distribution in function fname.
Definition: TH1.cxx:3523
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:3904
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:1590
return c1
Definition: legend1.C:41
TH1F * h1
Definition: legend1.C:5