{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Hsimple\n",
    " This program creates :\n",
    "   - a one dimensional histogram\n",
    "   - a two dimensional histogram\n",
    "   - a profile histogram\n",
    "   - a memory-resident ntuple\n",
    "\n",
    " These objects are filled with some random numbers and saved on a file.\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "**Author:** Wim Lavrijsen, Enric Tejedor  \n",
    "<i><small>This notebook tutorial was automatically generated with <a href= \"https://github.com/root-project/root/blob/master/documentation/doxygen/converttonotebook.py\">ROOTBOOK-izer</a> from the macro found in the ROOT repository  on Sunday, January 23, 2022 at 09:31 AM.</small></i>"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "from ROOT import TCanvas, TFile, TProfile, TNtuple, TH1F, TH2F\n",
    "from ROOT import gROOT, gBenchmark, gRandom, gSystem\n",
    "import ctypes"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Create a new canvas, and customize it."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "c1 = TCanvas( 'c1', 'Dynamic Filling Example', 200, 10, 700, 500 )\n",
    "c1.SetFillColor( 42 )\n",
    "c1.GetFrame().SetFillColor( 21 )\n",
    "c1.GetFrame().SetBorderSize( 6 )\n",
    "c1.GetFrame().SetBorderMode( -1 )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Create a new ROOT binary machine independent file.\n",
    "Note that this file may contain any kind of ROOT objects, histograms,\n",
    "pictures, graphics objects, detector geometries, tracks, events, etc..\n",
    "This file is now becoming the current directory."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "hfile = gROOT.FindObject( 'py-hsimple.root' )\n",
    "if hfile:\n",
    "   hfile.Close()\n",
    "hfile = TFile( 'py-hsimple.root', 'RECREATE', 'Demo ROOT file with histograms' )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Create some histograms, a profile histogram and an ntuple"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "hpx    = TH1F( 'hpx', 'This is the px distribution', 100, -4, 4 )\n",
    "hpxpy  = TH2F( 'hpxpy', 'py vs px', 40, -4, 4, 40, -4, 4 )\n",
    "hprof  = TProfile( 'hprof', 'Profile of pz versus px', 100, -4, 4, 0, 20 )\n",
    "ntuple = TNtuple( 'ntuple', 'Demo ntuple', 'px:py:pz:random:i' )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Set canvas/frame attributes."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "hpx.SetFillColor( 48 )\n",
    "\n",
    "gBenchmark.Start( 'hsimple' )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Initialize random number generator."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "gRandom.SetSeed()\n",
    "rannor, rndm = gRandom.Rannor, gRandom.Rndm"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "For speed, bind and cache the Fill member functions,"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "histos = [ 'hpx', 'hpxpy', 'hprof', 'ntuple' ]\n",
    "for name in histos:\n",
    "   exec('%sFill = %s.Fill' % (name,name))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Fill histograms randomly."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "px_ref, py_ref = ctypes.c_double(), ctypes.c_double()\n",
    "kUPDATE = 1000\n",
    "for i in range( 25000 ):\n",
    " # Generate random values. Use ctypes to pass doubles by reference\n",
    "   rannor( px_ref, py_ref )\n",
    " # Retrieve the generated values\n",
    "   px = px_ref.value\n",
    "   py = py_ref.value\n",
    "   \n",
    "   pz = px*px + py*py\n",
    "   random = rndm(1)\n",
    "\n",
    " # Fill histograms.\n",
    "   hpx.Fill( px )\n",
    "   hpxpy.Fill( px, py )\n",
    "   hprof.Fill( px, pz )\n",
    "   ntuple.Fill( px, py, pz, random, i )\n",
    "\n",
    " # Update display every kUPDATE events.\n",
    "   if i and i%kUPDATE == 0:\n",
    "      if i == kUPDATE:\n",
    "         hpx.Draw()\n",
    "\n",
    "      c1.Modified()\n",
    "      c1.Update()\n",
    "\n",
    "      if gSystem.ProcessEvents():            # allow user interrupt\n",
    "         break"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Destroy member functions cache."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "for name in histos:\n",
    "   exec('del %sFill' % name)\n",
    "del histos\n",
    "\n",
    "gBenchmark.Show( 'hsimple' )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Save all objects in this file."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "hpx.SetFillColor( 0 )\n",
    "hfile.Write()\n",
    "hpx.SetFillColor( 48 )\n",
    "c1.Modified()\n",
    "c1.Update()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Note that the file is automatically closed when application terminates\n",
    "or when the file destructor is called."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Draw all canvases "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "%jsroot on\n",
    "from ROOT import gROOT \n",
    "gROOT.GetListOfCanvases().Draw()"
   ]
  }
 ],
 "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"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}