{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Simple ROOTbook (Python)\n",
"
\n",
"This simple ROOTbook shows how to create a [histogram](https://root.cern.ch/doc/master/classTH1F.html), [fill it](https://root.cern.ch/doc/master/classTH1.html#a77e71290a82517d317ea8d05e96b6c4a) and [draw it](https://root.cern.ch/doc/master/classTH1.html#aa53a024a9e94d5ec91e3ef49e49563da).\n",
"\n",
"Let's start importing the [ROOT](https://root.cern.ch) module, which gives us access to all [ROOT](https://root.cern.ch) classes."
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"data": {
"application/javascript": [
"IPython.CodeCell.config_defaults.highlight_modes['magic_text/x-c++src'] = {'reg':[/^%%cpp/]};"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"name": "stdout",
"output_type": "stream",
"text": [
"Welcome to JupyROOT 6.07/07\n"
]
}
],
"source": [
"import ROOT"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"In order to activate the interactive visualisation we can use the [JSROOT](https://root.cern.ch/js/) magic:"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"%jsroot on"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Now we will create a [histogram](https://root.cern.ch/doc/master/classTH1F.html) specifying its title and axes titles:\n"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"h = ROOT.TH1F(\"myHisto\",\"My Histo;X axis;Y axis\",64, -4, 4)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Time to create a random generator and fill our histogram:"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"rndmGenerator = ROOT.TRandom3()\n",
"for i in xrange(1000):\n",
" rndm = rndmGenerator.Gaus()\n",
" h.Fill(rndm)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We can now draw the histogram. We will at first create a [canvas](https://root.cern.ch/doc/master/classTCanvas.html), the entity which in ROOT holds graphics primitives. Note that thanks to [JSROOT](https://root.cern.ch/js/), this is not a static plot but an interactive visualisation. Try to play with it and save it as image when you are satisfied!"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {
"collapsed": false
},
"outputs": [
{
"data": {
"text/html": [
"\n",
"\n",
"
\n",
"\n",
"\n"
],
"text/plain": [
""
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"c = ROOT.TCanvas()\n",
"h.Draw()\n",
"c.Draw()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We'll try now to beautify the plot a bit, for example filling the histogram with a colour and setting a grid on the canvas."
]
},
{
"cell_type": "code",
"execution_count": 9,
"metadata": {
"collapsed": false
},
"outputs": [
{
"data": {
"text/html": [
"\n",
"\n",
"
\n",
"\n",
"\n"
],
"text/plain": [
""
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"h.SetFillColor(ROOT.kBlue-10)\n",
"c.SetGrid()\n",
"h.Draw()\n",
"c.Draw()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Alright: we are done with our first step into the ROOTbooks world!"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 2",
"language": "python",
"name": "python2"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 2
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython2",
"version": "2.7.10"
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"nbformat_minor": 0
}