Logo ROOT  
Reference Guide
ratioplot4.py
Go to the documentation of this file.
1 ## \file
2 ## \ingroup tutorial_hist
3 ## \notebook
4 ## Example that shows custom dashed lines on the lower plot, specified by a vector of floats.
5 ##
6 ## By default, dashed lines are drawn at certain points. You can either disable them, or specify
7 ## where you want them to appear.
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 
19 c1 = ROOT.TCanvas("c1", "fit residual simple")
20 h1 = ROOT.TH1D("h1", "h1", 50, -5, 5)
21 h1.FillRandom("gaus", 2000)
22 h1.Fit("gaus")
23 h1.GetXaxis().SetTitle("x")
24 h1.GetYaxis().SetTitle("y")
25 
26 rp1 = ROOT.TRatioPlot(h1)
27 
28 lines = ROOT.std.vector('double')()
29 for i in range(-3,4):lines.push_back(i)
30 rp1.SetGridlines(lines)
31 
32 rp1.Draw()
33 rp1.GetLowerRefGraph().SetMinimum(-4)
34 rp1.GetLowerRefGraph().SetMaximum(4)
35 
36 c1.Update()