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"source": [
"# hist029_TRatioPlot_simple\n",
"Example creating a simple ratio plot of two histograms using the `pois` division option.\n",
"Two histograms are set up and filled with random numbers. The constructor of `TRatioPlot`\n",
"takes the to histograms, name and title for the object, drawing options for the histograms (`hist` and `E` in this case)\n",
"and a drawing option for the output graph.\n",
"Inspired by the tutorial of Paul Gessinger.\n",
"\n",
"\n",
"\n",
"\n",
"**Author:** Alberto Ferro \n",
"This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, May 19, 2026 at 08:12 PM."
]
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{
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"id": "919fe692",
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"text/html": [
"\n",
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"\n",
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"source": [
"import ROOT\n",
"\n",
"ROOT.gStyle.SetOptStat(0)\n",
"\n",
"c1 = ROOT.TCanvas(\"c1\", \"A ratio example\")\n",
"h1 = ROOT.TH1D(\"h1\", \"h1\", 50, 0, 10)\n",
"h2 = ROOT.TH1D(\"h2\", \"h2\", 50, 0, 10)\n",
"f1 = ROOT.TF1(\"f1\", \"exp(- x/[0] )\")\n",
"f1.SetParameter(0,3)\n",
"\n",
"h1.FillRandom(f1, 1900)\n",
"h2.FillRandom(f1, 2000)\n",
"h1.Sumw2()\n",
"h2.Scale(1.9/2.)\n",
"\n",
"h1.GetXaxis().SetTitle(\"x\")\n",
"h1.GetYaxis().SetTitle(\"y\")\n",
"\n",
"rp = ROOT.TRatioPlot(h1,h2)\n",
"\n",
"c1.SetTicks(0,1)\n",
"rp.GetLowYaxis().SetNdivisions(505)\n",
"c1.Update()\n",
"c1.Draw()\n",
"rp.Draw()"
]
},
{
"cell_type": "markdown",
"id": "67ee40d9",
"metadata": {},
"source": [
"Draw all canvases "
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "85067a71",
"metadata": {
"collapsed": false,
"execution": {
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"\n",
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},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"from ROOT import gROOT \n",
"gROOT.GetListOfCanvases().Draw()"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 3",
"language": "python",
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