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Reference Guide
ratioplot3.py
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1 ## \file
2 ## \ingroup tutorial_hist
3 ## \notebook
4 ## Example which shows how you can get the graph of the lower plot and set the y axis range for it.
5 ##
6 ## Since the lower plot is not created until `TRatioPlot::Draw` is called, you can only use the method
7 ## afterwards.
8 ## Inspired by the tutorial of Paul Gessinger.
9 ##
10 ## \macro_image
11 ## \macro_code
12 ##
13 ## \author Alberto Ferro
14 
15 import ROOT
16 
17 ROOT.gStyle.SetOptStat(0)
18 c1 = ROOT.TCanvas("c1", "fit residual simple")
19 c1.SetLogy()
20 
21 h1 = ROOT.TH1D("h1", "h1", 50, -5, 5)
22 h1.FillRandom("gaus", 2000)
23 h1.Fit("gaus")
24 h1.SetMinimum(0.001)
25 h1.GetXaxis().SetTitle("x")
26 h1.GetYaxis().SetTitle("y")
27 
28 rp1 = ROOT.TRatioPlot(h1)
29 rp1.Draw()
30 rp1.GetLowerRefGraph().SetMinimum(-2)
31 rp1.GetLowerRefGraph().SetMaximum(2)
32 
33 c1.Update()