lecture-week03-math-and-csv.ipynb

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 "metadata": {
  "name": "lecture-week03-math-and-csv"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "help(math.exp)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Help on built-in function exp in module math:\n",
        "\n",
        "exp(...)\n",
        "    exp(x)\n",
        "    \n",
        "    Return e raised to the power of x.\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "help(math.sqrt)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Help on built-in function sqrt in module math:\n",
        "\n",
        "sqrt(...)\n",
        "    sqrt(x)\n",
        "    \n",
        "    Return the square root of x.\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "math.sqrt(9)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 6,
       "text": [
        "3.0"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "math.exp(15)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 7,
       "text": [
        "3269017.3724721107"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "e**15"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 8,
       "text": [
        "3269017.372472108"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "math.log(3269017.372472108)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 9,
       "text": [
        "15.0"
       ]
      }
     ],
     "prompt_number": 9
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "help(math.log)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Help on built-in function log in module math:\n",
        "\n",
        "log(...)\n",
        "    log(x[, base])\n",
        "    \n",
        "    Return the logarithm of x to the given base.\n",
        "    If the base not specified, returns the natural logarithm (base e) of x.\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 10
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "math.log(3269017.372472108, 10)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 11,
       "text": [
        "6.514417228548777"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "So that's what the math module does.  You --\n",
      "\n",
      " * import it for use by typing 'import math'\n",
      " * and from then on all of the functionality is available as math.*, e.g. math.sqrt(...)"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "fp = open('/usr/local/notebooks/quartet/q1.csv')\n",
      "print fp.read()"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10,8.04\r\n",
        "8,6.95\r\n",
        "13,7.58\r\n",
        "9,8.81\r\n",
        "11,8.33\r\n",
        "14,9.96\r\n",
        "6,7.24\r\n",
        "4,4.26\r\n",
        "12,10.84\r\n",
        "7,4.82\r\n",
        "5,5.68\r\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 12
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import csv\n",
      "fp = open('/usr/local/notebooks/quartet/q1.csv', 'rb')\n",
      "r = csv.reader(fp)\n",
      "for item in r:\n",
      "    print 'new line'\n",
      "    print item"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "new line\n",
        "['10', '8.04']\n",
        "new line\n",
        "['8', '6.95']\n",
        "new line\n",
        "['13', '7.58']\n",
        "new line\n",
        "['9', '8.81']\n",
        "new line\n",
        "['11', '8.33']\n",
        "new line\n",
        "['14', '9.96']\n",
        "new line\n",
        "['6', '7.24']\n",
        "new line\n",
        "['4', '4.26']\n",
        "new line\n",
        "['12', '10.84']\n",
        "new line\n",
        "['7', '4.82']\n",
        "new line\n",
        "['5', '5.68']\n"
       ]
      }
     ],
     "prompt_number": 14
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import csv\n",
      "fp = open('/usr/local/notebooks/quartet/q1.csv', 'rb')\n",
      "r = csv.reader(fp)\n",
      "for item in r:\n",
      "    x = float(item[0])\n",
      "    y = float(item[1])\n",
      "    print x, y"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10.0 8.04\n",
        "8.0 6.95\n",
        "13.0 7.58\n",
        "9.0 8.81\n",
        "11.0 8.33\n",
        "14.0 9.96\n",
        "6.0 7.24\n",
        "4.0 4.26\n",
        "12.0 10.84\n",
        "7.0 4.82\n",
        "5.0 5.68\n"
       ]
      }
     ],
     "prompt_number": 18
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import csv\n",
      "fp = open('/usr/local/notebooks/quartet/q1.csv', 'rb')\n",
      "r = csv.reader(fp)\n",
      "\n",
      "xx = []\n",
      "yy = []\n",
      "\n",
      "for item in r:\n",
      "    x, y = item\n",
      "    x = float(x)\n",
      "    y = float(y)\n",
      "    xx.append(x)\n",
      "    yy.append(y)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 21
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "xx"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 22,
       "text": [
        "[10.0, 8.0, 13.0, 9.0, 11.0, 14.0, 6.0, 4.0, 12.0, 7.0, 5.0]"
       ]
      }
     ],
     "prompt_number": 22
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "yy"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 23,
       "text": [
        "[8.04, 6.95, 7.58, 8.81, 8.33, 9.96, 7.24, 4.26, 10.84, 4.82, 5.68]"
       ]
      }
     ],
     "prompt_number": 23
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def fn():\n",
      "    aa = [9, \"a string\"]\n",
      "    return aa\n",
      "\n",
      "bb = fn()\n",
      "a = bb[0]\n",
      "b = bb[1]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 27
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "a\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 28,
       "text": [
        "9"
       ]
      }
     ],
     "prompt_number": 28
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "b"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 29,
       "text": [
        "'a string'"
       ]
      }
     ],
     "prompt_number": 29
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "a, b = fn()"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 30
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "a\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 31,
       "text": [
        "9"
       ]
      }
     ],
     "prompt_number": 31
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "b"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "pyout",
       "prompt_number": 32,
       "text": [
        "'a string'"
       ]
      }
     ],
     "prompt_number": 32
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "To sum up the csv module so far,\n",
      "\n",
      " * csv.reader(fp) reads in lines one at a time from fp, and breaks them up based on commas.\n",
      " * treat csv.reader(...) as if they are lists, return lists.\n",
      " * remember to open your file handle fp with the 'rb', i.e. open(filename, 'rb')\n"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": []
    }
   ],
   "metadata": {}
  }
 ]
}