hist032_TRatioPlot_fit_lines.py

## \ingroup tutorial_hist

## \notebook

## Example that shows custom dashed lines on the lower plot, specified by a vector of floats.

##

## By default, dashed lines are drawn at certain points. You can either disable them, or specify

## where you want them to appear.

## Inspired by the tutorial of Paul Gessinger.

##

## \macro_image

## \macro_code

##

## \author Alberto Ferro

import ROOT

ROOT.gStyle.SetOptStat(0)

c1 = ROOT.TCanvas("c1", "fit residual simple")

h1 = ROOT.TH1D("h1", "h1", 50, -5, 5)

h1.FillRandom("gaus", 2000)

h1.Fit("gaus")

h1.GetXaxis().SetTitle("x")

h1.GetYaxis().SetTitle("y")

rp1 = ROOT.TRatioPlot(h1)

lines = ROOT.std.vector('double')()

for i in range(-3,4):lines.push_back(i)

rp1.SetGridlines(lines)

rp1.Draw()

rp1.GetLowerRefGraph().SetMinimum(-4)

rp1.GetLowerRefGraph().SetMaximum(4)

c1.Update()