emacs-ipython-notebook/tests/notebook/nbformat3/Running Code.ipynb

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 "metadata": {
  "name": "",
  "signature": "sha256:344aa301a0ce679ebf87e2d1dd206cf3784854cde5fedc34109f38710aef680c"
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 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Running Code in the IPython Notebook"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "First and foremost, the IPython Notebook is an interactive environment for writing and running Python code."
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Code cells allow you to enter and run Python code"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "\n",
      "<script type=\"text/javascript\">\n",
      "var _toggle=false;\n",
      "var hl = function (id, on){\n",
      "    $(id)[0].style.background = '';\n",
      "    if (on) {\n",
      "        $(id)[0].style.background = 'lightcyan';\n",
      "    }\n",
      "};\n",
      "</script>\n",
      "\n",
      "Run a code cell using `shift-enter` or pressing the <button><i class=\"icon-play\"></i></button> button in the <a href=\"#\" onMouseover=\"hl('#maintoolbar-container', 1)\" onMouseout=\"hl('#maintoolbar-container', 0)\">toolbar</a> above:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "a = 10"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "print(a)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Managing the IPython Kernel"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Code is run in a separate process called the IPython Kernel.  The Kernel can be interrupted or restarted.  Try running the following cell and then hit the <button><i class='icon-stop'></i></button> button in the <a href=\"#\" onMouseover=\"hl('#maintoolbar-container', 1)\" onMouseout=\"hl('#maintoolbar-container', 0)\">toolbar</a> above."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import time\n",
      "time.sleep(10)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "If the Kernel dies you will be prompted to restart it. Here we call the low-level system libc.time routine with the wrong argument via\n",
      "ctypes to segfault the Python interpreter:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import sys\n",
      "from ctypes import CDLL\n",
      "# This will crash a Linux or Mac system; equivalent calls can be made on Windows\n",
      "dll = 'dylib' if sys.platform == 'darwin' else 'so.6'\n",
      "libc = CDLL(\"libc.%s\" % dll) \n",
      "libc.time(-1)  # BOOM!!"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "All of the goodness of IPython works"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Here are two system aliases:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "pwd"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 1,
       "text": [
        "u'/Users/bgranger/Documents/Computing/IPython/code/ipython/examples/Notebook/Tutorials'"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "ls"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Basic Output.ipynb                    Plotting with Matplotlib.ipynb        data.csv\r\n",
        "Custom Display Logic.ipynb            Running Code.ipynb                    \u001b[34mimages\u001b[m\u001b[m/\r\n",
        "Display System.ipynb                  Typesetting Math Using MathJax.ipynb\r\n",
        "Markdown Cells.ipynb                  User Interface.ipynb\r\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Any command line program can be run using `!` with string interpolation from Python variables:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "message = 'The IPython notebook is great!'\n",
      "# note: the echo command does not run on Windows, it's a unix command.\n",
      "!echo $message"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The IPython notebook is great!\r\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Tab completion works:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import numpy"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "numpy.random."
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Shift-Tab on selection, or after `(` brings up a tooltip with the docstring:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "numpy.random.rand("
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Adding `?` opens the docstring in the pager below:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magic?"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 8
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Exceptions are formatted nicely:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "x = 1\n",
      "y = 4\n",
      "z = y/(1-x)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "ename": "ZeroDivisionError",
       "evalue": "integer division or modulo by zero",
       "output_type": "pyerr",
       "traceback": [
        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mZeroDivisionError\u001b[0m                         Traceback (most recent call last)",
        "\u001b[0;32m<ipython-input-6-dc39888fd1d2>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[0mx\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;36m1\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      2\u001b[0m \u001b[0my\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;36m4\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 3\u001b[0;31m \u001b[0mz\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0my\u001b[0m\u001b[0;34m/\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0mx\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
        "\u001b[0;31mZeroDivisionError\u001b[0m: integer division or modulo by zero"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Working with external code"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "There are a number of ways of getting external code into code cells."
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Pasting code with `>>>` prompts works as expected:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      ">>> the_world_is_flat = 1\n",
      ">>> if the_world_is_flat:\n",
      "...     print(\"Be careful not to fall off!\")"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Be careful not to fall off!\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "The `%load` magic lets you load code from URLs or local files:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%load?"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 8
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%matplotlib inline"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 9
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%load http://matplotlib.org/mpl_examples/showcase/integral_demo.py"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 10
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\"\"\"\n",
      "Plot demonstrating the integral as the area under a curve.\n",
      "\n",
      "Although this is a simple example, it demonstrates some important tweaks:\n",
      "\n",
      "    * A simple line plot with custom color and line width.\n",
      "    * A shaded region created using a Polygon patch.\n",
      "    * A text label with mathtext rendering.\n",
      "    * figtext calls to label the x- and y-axes.\n",
      "    * Use of axis spines to hide the top and right spines.\n",
      "    * Custom tick placement and labels.\n",
      "\"\"\"\n",
      "import numpy as np\n",
      "import matplotlib.pyplot as plt\n",
      "from matplotlib.patches import Polygon\n",
      "\n",
      "\n",
      "def func(x):\n",
      "    return (x - 3) * (x - 5) * (x - 7) + 85\n",
      "\n",
      "\n",
      "a, b = 2, 9 # integral limits\n",
      "x = np.linspace(0, 10)\n",
      "y = func(x)\n",
      "\n",
      "fig, ax = plt.subplots()\n",
      "plt.plot(x, y, 'r', linewidth=2)\n",
      "plt.ylim(ymin=0)\n",
      "\n",
      "# Make the shaded region\n",
      "ix = np.linspace(a, b)\n",
      "iy = func(ix)\n",
      "verts = [(a, 0)] + list(zip(ix, iy)) + [(b, 0)]\n",
      "poly = Polygon(verts, facecolor='0.9', edgecolor='0.5')\n",
      "ax.add_patch(poly)\n",
      "\n",
      "plt.text(0.5 * (a + b), 30, r\"$\\int_a^b f(x)\\mathrm{d}x$\",\n",
      "         horizontalalignment='center', fontsize=20)\n",
      "\n",
      "plt.figtext(0.9, 0.05, '$x$')\n",
      "plt.figtext(0.1, 0.9, '$y$')\n",
      "\n",
      "ax.spines['right'].set_visible(False)\n",
      "ax.spines['top'].set_visible(False)\n",
      "ax.xaxis.set_ticks_position('bottom')\n",
      "\n",
      "ax.set_xticks((a, b))\n",
      "ax.set_xticklabels(('$a$', '$b$'))\n",
      "ax.set_yticks([])\n",
      "\n",
      "plt.show()\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "display_data",
       "png": "iVBORw0KGgoAAAANSUhEUgAAAW8AAAEMCAYAAAALXDfgAAAABHNCSVQICAgIfAhkiAAAAAlwSFlz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\nOOvWpWj0aAqHDNG4toUU3lIx
       "text": [
        "<matplotlib.figure.Figure at 0x108604e50>"
       ]
      }
     ],
     "prompt_number": 11
    }
   ],
   "metadata": {}
  }
 ]
}