{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "303095f4",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([37.2, 37.6, 36.8])"
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import numpy as np\n",
    "\n",
    "X = np.array([[1.2, 1.5, 1.8],\n",
    "               [1.3, 1.4, 1.9],\n",
    "               [1.1, 1.6, 1.7]])\n",
    "y = np.array([5, 10, 9]).T\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "X.dot(y)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "9670b1f2",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(3, 3)"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X.shape"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "b1ab79e0",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "797 ns ± 37.9 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)\n"
     ]
    }
   ],
   "source": [
    "%timeit X.dot(y)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "4d088725",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "17.9 µs ± 257 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)\n"
     ]
    }
   ],
   "source": [
    "%%timeit\n",
    "total = []\n",
    "for i in range(X.shape[0]):\n",
    "    each_price = 0\n",
    "    for j in range(X.shape[1]):\n",
    "        each_price += X[i,j] * y[j]\n",
    "#         each_price = each_price + X[i,j] * y[j]\n",
    "    total.append(round(each_price, 1))\n",
    "total  "
   ]
  },
  {
   "cell_type": "markdown",
   "id": "df3dfeec",
   "metadata": {},
   "source": [
    "# #第二题"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "81dc806e",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 9, 6, 1, 1, 2, 8, 7, 3, 5, 6, 3, 5, 3, 5, 8, 8, 2, 8, 1, 7, 8,\n",
       "       7, 2, 1, 2, 9, 9, 4, 9])"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "np.random.seed(1)\n",
    "X = np.random.randint(1, 10, size=30)\n",
    "X"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "adb7722a",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[6, 9, 6],\n",
       "       [1, 1, 2],\n",
       "       [8, 7, 3],\n",
       "       [5, 6, 3],\n",
       "       [5, 3, 5],\n",
       "       [8, 8, 2],\n",
       "       [8, 1, 7],\n",
       "       [8, 7, 2],\n",
       "       [1, 2, 9],\n",
       "       [9, 4, 9]])"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X.reshape(10,-1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "6d0d6242",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[6, 9, 6],\n",
       "       [1, 1, 2],\n",
       "       [8, 7, 3],\n",
       "       [5, 6, 3],\n",
       "       [5, 3, 5],\n",
       "       [8, 8, 2],\n",
       "       [8, 1, 7],\n",
       "       [8, 7, 2],\n",
       "       [1, 2, 9],\n",
       "       [9, 4, 9]])"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X1 = X.reshape(-1 ,3)\n",
    "X1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "a5854aeb",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 2, 3, 3, 5, 2, 7, 2, 9, 9])"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1 = X1[:, 2]\n",
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "id": "3c001e71",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([False,  True,  True,  True, False,  True, False,  True, False,\n",
       "       False])"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1 <= 3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "id": "35b66010",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([2, 3, 3, 2, 2])"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "temp1 = last1[last1 <= 3]\n",
    "temp1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "id": "b41674c8",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(array([1, 2, 3, 5, 7], dtype=int64),)"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "np.where(last1 <= 3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "id": "42b271c0",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 2, 3, 3, 5, 2, 7, 2, 9, 9])"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "id": "ce487a19",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 5])"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "temp2 =  last1[(last1 > 3) & (last1 <= 6)]\n",
    "temp2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "id": "82b9f3ad",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([7, 9, 9])"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "temp3 =  last1[last1 > 6]\n",
    "temp3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "id": "f28879be",
   "metadata": {},
   "outputs": [],
   "source": [
    "last1[last1 <= 3] = 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "id": "4dc020af",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 0, 0, 0, 5, 0, 7, 0, 9, 9])"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "id": "e475fd7b",
   "metadata": {},
   "outputs": [],
   "source": [
    "last1[(last1 > 3) & (last1 <= 6)] = 1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "id": "cfeff15c",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 0, 0, 0, 1, 0, 7, 0, 9, 9])"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "id": "dda79074",
   "metadata": {},
   "outputs": [],
   "source": [
    "last1[last1 > 6] = 2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "id": "9ee04243",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 0, 0, 0, 1, 0, 2, 0, 2, 2])"
      ]
     },
     "execution_count": 21,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1 "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "id": "255d8986",
   "metadata": {},
   "outputs": [],
   "source": [
    "X_train = X1[:, 0:2]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "id": "6587e601",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[6, 9],\n",
       "       [1, 1],\n",
       "       [8, 7],\n",
       "       [5, 6],\n",
       "       [5, 3],\n",
       "       [8, 8],\n",
       "       [8, 1],\n",
       "       [8, 7],\n",
       "       [1, 2],\n",
       "       [9, 4]])"
      ]
     },
     "execution_count": 23,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "id": "78de1d84",
   "metadata": {},
   "outputs": [],
   "source": [
    "y_train = last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "id": "06103c3e",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 0, 0, 0, 1, 0, 2, 0, 2, 2])"
      ]
     },
     "execution_count": 25,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "y_train"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "id": "b01a5a6f",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[1, 1],\n",
       "       [8, 7],\n",
       "       [5, 6],\n",
       "       [8, 8],\n",
       "       [8, 7]])"
      ]
     },
     "execution_count": 26,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train[y_train == 0]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "id": "54c10551",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([False,  True,  True,  True, False,  True, False,  True, False,\n",
       "       False])"
      ]
     },
     "execution_count": 27,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "y_train == 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "id": "e1eb67be",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[6, 9],\n",
       "       [5, 3]])"
      ]
     },
     "execution_count": 28,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train[y_train == 1]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "id": "da29cec8",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[8, 1],\n",
       "       [1, 2],\n",
       "       [9, 4]])"
      ]
     },
     "execution_count": 29,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train[y_train == 2]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "27d8f581",
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
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  "kernelspec": {
   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
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  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
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   "file_extension": ".py",
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   "pygments_lexer": "ipython3",
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