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hist030_TRatioPlot_residual.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/// \date September 2023
16/// \author Paul Gessinger
17
19{
21 auto c1 = new TCanvas("c1", "fit residual simple");
22 auto h1 = new TH1D("h1", "h1", 50, -5, 5);
23 h1->FillRandom("gaus", 2000);
24 h1->Fit("gaus", "0");
25 h1->GetXaxis()->SetTitle("x");
26 auto rp1 = new TRatioPlot(h1);
27 rp1->Draw();
28 rp1->GetLowerRefYaxis()->SetTitle("ratio");
29 rp1->GetUpperRefYaxis()->SetTitle("entries");
30}
R__EXTERN TStyle * gStyle
Definition TStyle.h:442
The Canvas class.
Definition TCanvas.h:23
1-D histogram with a double per channel (see TH1 documentation)
Definition TH1.h:693
virtual void FillRandom(TF1 *f1, Int_t ntimes=5000, TRandom *rng=nullptr)
Definition TH1.cxx:3499
TAxis * GetXaxis()
Definition TH1.h:340
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:3875
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:44
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:1642
return c1
Definition legend1.C:41
TH1F * h1
Definition legend1.C:5