{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 41,
   "id": "fd50f54d",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([37.2, 37.6, 36.8])"
      ]
     },
     "execution_count": 41,
     "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",
    "\n",
    "Y = np.array([5,10,9]).T\n",
    "\n",
    "X.dot(Y)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "id": "8b22cb4a",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(3, 3)"
      ]
     },
     "execution_count": 42,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X.shape"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "id": "bbef7ab3",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "963 ns ± 20.9 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each)\n"
     ]
    }
   ],
   "source": [
    "%timeit X.dot(Y)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "id": "33143bac",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "16.3 µs ± 173 ns per loop (mean ± std. dev. of 7 runs, 100,000 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": "531e04e3",
   "metadata": {},
   "source": [
    "# 第二题"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 47,
   "id": "e8c1b618",
   "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": 47,
     "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": 48,
   "id": "42e4691b",
   "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": 48,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X.reshape(-1,3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 49,
   "id": "2fcdc70b",
   "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": 49,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X1 = X.reshape(-1 ,3)\n",
    "X1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 50,
   "id": "dd6264eb",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 2, 3, 3, 5, 2, 7, 2, 9, 9])"
      ]
     },
     "execution_count": 50,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1 = X1[:, 2]\n",
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 51,
   "id": "5c08677b",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([False,  True,  True,  True, False,  True, False,  True, False,\n",
       "       False])"
      ]
     },
     "execution_count": 51,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1 <= 3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 52,
   "id": "3a0ab05d",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([2, 3, 3, 2, 2])"
      ]
     },
     "execution_count": 52,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "temp1 = last1[last1 <= 3]\n",
    "temp1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 53,
   "id": "2c55c6d4",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(array([1, 2, 3, 5, 7], dtype=int64),)"
      ]
     },
     "execution_count": 53,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "np.where(last1 <= 3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 54,
   "id": "09e25915",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 2, 3, 3, 5, 2, 7, 2, 9, 9])"
      ]
     },
     "execution_count": 54,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 55,
   "id": "5733adf3",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 5])"
      ]
     },
     "execution_count": 55,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "temp2 =  last1[(last1 > 3) & (last1 <= 6)]\n",
    "temp2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 56,
   "id": "390d173f",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([7, 9, 9])"
      ]
     },
     "execution_count": 56,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "temp3 =  last1[last1 > 6]\n",
    "temp3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 57,
   "id": "da7b652b",
   "metadata": {},
   "outputs": [],
   "source": [
    "last1[last1 <= 3] = 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 58,
   "id": "d830c247",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([6, 0, 0, 0, 5, 0, 7, 0, 9, 9])"
      ]
     },
     "execution_count": 58,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 59,
   "id": "945ad281",
   "metadata": {},
   "outputs": [],
   "source": [
    "last1[(last1 > 3) & (last1 <= 6)] = 1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 60,
   "id": "732374a9",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 0, 0, 0, 1, 0, 7, 0, 9, 9])"
      ]
     },
     "execution_count": 60,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 61,
   "id": "85719b27",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 0, 0, 0, 1, 0, 2, 0, 2, 2])"
      ]
     },
     "execution_count": 61,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "last1[last1 > 6] = 2\n",
    "last1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 62,
   "id": "e0b3baa5",
   "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": 62,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train = X1[:, 0:2]\n",
    "X_train"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 63,
   "id": "05e1907c",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 0, 0, 0, 1, 0, 2, 0, 2, 2])"
      ]
     },
     "execution_count": 63,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "Y_train = last1\n",
    "Y_train"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 65,
   "id": "130a4dda",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[1, 1],\n",
       "       [8, 7],\n",
       "       [5, 6],\n",
       "       [8, 8],\n",
       "       [8, 7]])"
      ]
     },
     "execution_count": 65,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train[Y_train == 0]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 66,
   "id": "c33848c9",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([False,  True,  True,  True, False,  True, False,  True, False,\n",
       "       False])"
      ]
     },
     "execution_count": 66,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "Y_train == 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 67,
   "id": "a56448cb",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[6, 9],\n",
       "       [5, 3]])"
      ]
     },
     "execution_count": 67,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train[Y_train == 1]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 68,
   "id": "ac8a7b14",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[8, 1],\n",
       "       [1, 2],\n",
       "       [9, 4]])"
      ]
     },
     "execution_count": 68,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "X_train[Y_train == 2]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "b497e945",
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.10.11"
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 "nbformat": 4,
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