Lec 07 - Creating Arrays.ipynb

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   "cells": [
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Creating Numpy arrays\n",
      "import numpy as np\n",
      "\n",
      "# Converting from a list\n",
      "#Lets start with a list\n",
      "\n",
      "my_list1 = [1,2,3,4]\n",
      "\n",
      "my_array1 = np.array(my_list1)\n",
      "\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Print out array\n",
      "\n",
      "my_array"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 2,
       "text": [
        "array([1, 2, 3, 4])"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Make another list\n",
      "my_list2 = [11,22,33,44]\n",
      "\n",
      "#Make a list of lists\n",
      "my_lists = [my_list1,my_list2]\n",
      "\n",
      "#Make multi-dimensional array\n",
      "my_array2 = np.array(my_lists)\n",
      "\n",
      "#Show array\n",
      "my_array2"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 5,
       "text": [
        "array([[ 1,  2,  3,  4],\n",
        "       [11, 22, 33, 44]])"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Lets get the size of the array\n",
      "my_array2.shape"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 6,
       "text": [
        "(2L, 4L)"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Find out the data tyoe of the array\n",
      "my_array2.dtype"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 7,
       "text": [
        "dtype('int32')"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Making special case arrays\n",
      "\n",
      "#Zeros\n",
      "np.zeros(5)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 8,
       "text": [
        "array([ 0.,  0.,  0.,  0.,  0.])"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Ones\n",
      "np.ones((5,5))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 11,
       "text": [
        "dtype('float64')"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# An empty array\n",
      "\n",
      "np.empty(5)\n",
      "np.empty((3,4))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 13,
       "text": [
        "array([[  1.15117295e-321,   0.00000000e+000,   0.00000000e+000,\n",
        "          0.00000000e+000],\n",
        "       [  0.00000000e+000,   0.00000000e+000,   0.00000000e+000,\n",
        "          0.00000000e+000],\n",
        "       [  0.00000000e+000,   0.00000000e+000,   0.00000000e+000,\n",
        "          0.00000000e+000]])"
       ]
      }
     ],
     "prompt_number": 13
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Identity array\n",
      "np.eye(5)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 16,
       "text": [
        "array([[ 1.,  0.,  0.,  0.,  0.],\n",
        "       [ 0.,  1.,  0.,  0.,  0.],\n",
        "       [ 0.,  0.,  1.,  0.,  0.],\n",
        "       [ 0.,  0.,  0.,  1.,  0.],\n",
        "       [ 0.,  0.,  0.,  0.,  1.]])"
       ]
      }
     ],
     "prompt_number": 16
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Using a range\n",
      "\n",
      "np.arange(5)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 4,
       "text": [
        "array([0, 1, 2, 3, 4])"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": []
    }
   ],
   "metadata": {}
  }
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