{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<CENTER><img src=\"opendata-top-transblack.png\" style=\"width:60%\"></CENTER>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<CENTER><h1>Simple pyROOT notebook example using TLorentz Vectors</h1></CENTER>"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "application/javascript": [
       "\n",
       "require(['notebook'],\n",
       "  function() {\n",
       "    IPython.CodeCell.config_defaults.highlight_modes['magic_text/x-c++src'] = {'reg':[/^%%cpp/]};\n",
       "    console.log(\"JupyROOT - %%cpp magic configured\");\n",
       "  }\n",
       ");\n"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Welcome to JupyROOT 6.08/04\n"
     ]
    }
   ],
   "source": [
    "import ROOT"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "## f = ROOT.TFile.Open(\"mc_105986.ZZ.root\")\n",
    "## f = ROOT.TFile.Open(\"mc_147770.Zee.root\")\n",
    "f = ROOT.TFile.Open(\"http://opendata.atlas.cern/release/samples/MC/mc_147770.Zee.root\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "c = ROOT.TCanvas(\"testCanvas\",\"a first way to plot a variable\",800,600)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "t = f.Get(\"mini\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "h = ROOT.TH1F(\"variable\",\"Example plot: Number of Leptons\",4,0,4)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "h_Mll = ROOT.TH1F(\"h_Mll\",\"Invariant mass of the two Leptons\",50,0,200)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "for event in t:\n",
    "    \"\"\"This is the cut #1: request at least 2 leptons\"\"\"\n",
    "    if t.lep_n > 1:\n",
    "        \"\"\"Let's define one TLorentz vector for each, e.i. two vectors!\"\"\"\n",
    "        leadingLep = ROOT.TLorentzVector(t.lep_pt[0], t.lep_eta[0], t.lep_phi[0], t.lep_E[0])\n",
    "        secondLep  = ROOT.TLorentzVector(t.lep_pt[1], t.lep_eta[1], t.lep_phi[1], t.lep_E[1])\n",
    "\n",
    "        \"\"\"Next line does the addition of the two TLorentz vectors above and so,\n",
    "           we can ask the mass very easy\"\"\"\n",
    "        TL_ll = leadingLep + secondLep\n",
    "        \n",
    "        \"\"\"We devide the value of the combined vector by 1000 to get the value in GeV\"\"\"\n",
    "        mll = TL_ll.M()/1000.\n",
    "        h_Mll.Fill(mll,w)\n",
    "\n",
    "print \"Done!\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "\"\"\"Now les't plot the mass of the lepton-lepton system\"\"\"\n",
    "h_Mll.Draw()\n",
    "c.Draw()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
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