Fancy Indexing.ipynb

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   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15])"
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import numpy as np\n",
    "\n",
    "x = np.arange(16)\n",
    "x"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
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     "end_time": "2020-06-08T14:05:54.582276Z",
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "x[3]"
   ]
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   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
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     "end_time": "2020-06-08T14:06:02.171091Z",
     "start_time": "2020-06-08T14:06:02.163097Z"
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   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([3, 4, 5, 6, 7, 8])"
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     "execution_count": 3,
     "metadata": {},
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   "source": [
    "x[3:9]"
   ]
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   "execution_count": 4,
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([3, 5, 7])"
      ]
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     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "x[3:9:2]"
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   "execution_count": 5,
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "[3, 5, 8]"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "[x[3], x[5], x[8]]"
   ]
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   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "ExecuteTime": {
     "end_time": "2020-06-08T14:06:40.443244Z",
     "start_time": "2020-06-08T14:06:40.438246Z"
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   },
   "outputs": [],
   "source": [
    "ind = [3, 5, 6]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "ExecuteTime": {
     "end_time": "2020-06-08T14:06:44.081796Z",
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     "data": {
      "text/plain": [
       "array([3, 5, 6])"
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     "execution_count": 7,
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   ],
   "source": [
    "x[ind]"
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   "cell_type": "code",
   "execution_count": 8,
   "metadata": {
    "ExecuteTime": {
     "end_time": "2020-06-08T14:10:18.449662Z",
     "start_time": "2020-06-08T14:10:18.439668Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[0, 2],\n",
       "       [1, 3]])"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "ind = np.array([[0,2], [1, 3]])\n",
    "x[ind]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {
    "ExecuteTime": {
     "end_time": "2020-06-08T14:12:31.385596Z",
     "start_time": "2020-06-08T14:12:31.379599Z"
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   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[ 0,  1,  2,  3],\n",
       "       [ 4,  5,  6,  7],\n",
       "       [ 8,  9, 10, 11],\n",
       "       [12, 13, 14, 15]])"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "X = x.reshape(4, -1)\n",
    "X"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {
    "ExecuteTime": {
     "end_time": "2020-06-08T14:13:09.956199Z",
     "start_time": "2020-06-08T14:13:09.949202Z"
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   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([ 1,  6, 11])"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "row = np.array([0, 1, 2])\n",
    "column = np.array([1, 2, 3])\n",
    "X[row, column]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
    "ExecuteTime": {
     "end_time": "2020-06-08T14:13:27.797844Z",
     "start_time": "2020-06-08T14:13:27.791848Z"
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 2, 3])"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "X[0, column]"
   ]
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   "cell_type": "code",
   "execution_count": 13,
   "metadata": {
    "ExecuteTime": {
     "end_time": "2020-06-08T14:13:41.572599Z",
     "start_time": "2020-06-08T14:13:41.566604Z"
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   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[ 1,  2,  3],\n",
       "       [ 5,  6,  7],\n",
       "       [ 9, 10, 11],\n",
       "       [13, 14, 15]])"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X[:, column]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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