|
1 | 1 | { |
2 | | - "nbformat": 4, |
3 | | - "nbformat_minor": 2, |
4 | | - "metadata": {}, |
5 | | - "cells": [ |
| 2 | + "nbformat": 4, |
| 3 | + "nbformat_minor": 2, |
| 4 | + "metadata": {}, |
| 5 | + "cells": [ |
| 6 | + { |
| 7 | + "metadata": {}, |
| 8 | + "source": [ |
| 9 | + "def gaussian_elimination(a):\n", |
| 10 | + " # 前進消去\n", |
| 11 | + " for i in range(len(a)):\n", |
| 12 | + " # pivot倍で行を割る\n", |
| 13 | + " pivot = a[i][i]\n", |
| 14 | + " for j in range(i, len(a[i])):\n", |
| 15 | + " a[i][j] /= pivot\n", |
| 16 | + "\n", |
| 17 | + " # i + 1行目以降を掃き出す\n", |
| 18 | + " for j in range(i + 1, len(a)):\n", |
| 19 | + " factor = a[j][i]\n", |
| 20 | + " for k in range(i, len(a[i])):\n", |
| 21 | + " a[j][k] -= factor * a[i][k]\n", |
| 22 | + "\n", |
| 23 | + " # 後退代入\n", |
| 24 | + " x = [0 for _ in range(len(a[0]) - 1)]\n", |
| 25 | + " for i in reversed(range(len(a))):\n", |
| 26 | + " x[i] = a[i][len(a[i]) - 1]\n", |
| 27 | + " for j in range(i):\n", |
| 28 | + " a[j][len(a[i]) - 1] -= a[j][i] * x[i]\n", |
| 29 | + " return x\n", |
| 30 | + "\n", |
| 31 | + "\n", |
| 32 | + "print(gaussian_elimination([[0, -2, 3, 2], [-1, 3, -2, 1], [1, -1, 6, 11]]))" |
| 33 | + ], |
| 34 | + "cell_type": "code", |
| 35 | + "outputs": [ |
6 | 36 | { |
7 | | - "metadata": {}, |
8 | | - "source": [ |
9 | | - "def gaussian_elimination(a):\n", |
10 | | - " # \u524d\u9032\u6d88\u53bb\n", |
11 | | - " for i in range(len(a)):\n", |
12 | | - " # pivot\u500d\u3067\u884c\u3092\u5272\u308b\n", |
13 | | - " pivot = a[i][i]\n", |
14 | | - " for j in range(i, len(a[i])):\n", |
15 | | - " a[i][j] /= pivot\n", |
16 | | - "\n", |
17 | | - " # i+1\u884c\u76ee\u4ee5\u964d\u3092\u6383\u304d\u51fa\u3059\n", |
18 | | - " for j in range(i + 1, len(a)):\n", |
19 | | - " factor = a[j][i]\n", |
20 | | - " for k in range(i, len(a[i])):\n", |
21 | | - " a[j][k] -= factor * a[i][k]\n", |
22 | | - " # \u5f8c\u9000\u4ee3\u5165\n", |
23 | | - " x = [0 for _ in range(len(a[0]) - 1)]\n", |
24 | | - " for i in reversed(range(len(a))):\n", |
25 | | - " x[i] = a[i][len(a[i]) - 1]\n", |
26 | | - " for j in range(i):\n", |
27 | | - " a[j][len(a[i]) - 1] -= a[j][i] * x[i]\n", |
28 | | - " return x\n", |
29 | | - "\n", |
30 | | - "\n", |
31 | | - "print(gaussian_elimination([[0, -2, 3, 2], [-1, 3, -2, 1], [1, -1, 6, 11]]))" |
32 | | - ], |
33 | | - "cell_type": "code", |
34 | | - "outputs": [ |
35 | | - { |
36 | | - "output_type": "error", |
37 | | - "ename": "ZeroDivisionError", |
38 | | - "evalue": "division by zero", |
39 | | - "traceback": [ |
40 | | - "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m", |
41 | | - "\u001b[0;31mZeroDivisionError\u001b[0m Traceback (most recent call last)", |
42 | | - "Cell \u001b[0;32mIn [1], line 23\u001b[0m\n\u001b[1;32m 19\u001b[0m a[j][\u001b[39mlen\u001b[39m(a[i]) \u001b[39m-\u001b[39m \u001b[39m1\u001b[39m] \u001b[39m-\u001b[39m\u001b[39m=\u001b[39m a[j][i] \u001b[39m*\u001b[39m x[i]\n\u001b[1;32m 20\u001b[0m \u001b[39mreturn\u001b[39;00m x\n\u001b[0;32m---> 23\u001b[0m \u001b[39mprint\u001b[39m(gaussian_elimination([[\u001b[39m0\u001b[39m, \u001b[39m-\u001b[39m\u001b[39m2\u001b[39m, \u001b[39m3\u001b[39m, \u001b[39m2\u001b[39m], [\u001b[39m-\u001b[39m\u001b[39m1\u001b[39m, \u001b[39m3\u001b[39m, \u001b[39m-\u001b[39m\u001b[39m2\u001b[39m, \u001b[39m1\u001b[39m], [\u001b[39m1\u001b[39m, \u001b[39m-\u001b[39m\u001b[39m1\u001b[39m, \u001b[39m6\u001b[39m, \u001b[39m11\u001b[39m]]))\n", |
43 | | - "Cell \u001b[0;32mIn [1], line 7\u001b[0m, in \u001b[0;36mgaussian_elimination\u001b[0;34m(a)\u001b[0m\n\u001b[1;32m 5\u001b[0m pivot \u001b[39m=\u001b[39m a[i][i]\n\u001b[1;32m 6\u001b[0m \u001b[39mfor\u001b[39;00m j \u001b[39min\u001b[39;00m \u001b[39mrange\u001b[39m(i, \u001b[39mlen\u001b[39m(a[i])):\n\u001b[0;32m----> 7\u001b[0m a[i][j] \u001b[39m/\u001b[39m\u001b[39m=\u001b[39m pivot\n\u001b[1;32m 9\u001b[0m \u001b[39m# i+1\u884c\u76ee\u4ee5\u964d\u3092\u6383\u304d\u51fa\u3059\u001b[39;00m\n\u001b[1;32m 10\u001b[0m \u001b[39mfor\u001b[39;00m j \u001b[39min\u001b[39;00m \u001b[39mrange\u001b[39m(i \u001b[39m+\u001b[39m \u001b[39m1\u001b[39m, \u001b[39mlen\u001b[39m(a)):\n", |
44 | | - "\u001b[0;31mZeroDivisionError\u001b[0m: division by zero" |
45 | | - ] |
46 | | - } |
47 | | - ], |
48 | | - "execution_count": null |
| 37 | + "output_type": "error", |
| 38 | + "ename": "ZeroDivisionError", |
| 39 | + "evalue": "division by zero", |
| 40 | + "traceback": [ |
| 41 | + "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m", |
| 42 | + "\u001b[0;31mZeroDivisionError\u001b[0m Traceback (most recent call last)", |
| 43 | + "Cell \u001b[0;32mIn [1], line 24\u001b[0m\n\u001b[1;32m 20\u001b[0m a[j][\u001b[39mlen\u001b[39m(a[i]) \u001b[39m-\u001b[39m \u001b[39m1\u001b[39m] \u001b[39m-\u001b[39m\u001b[39m=\u001b[39m a[j][i] \u001b[39m*\u001b[39m x[i]\n\u001b[1;32m 21\u001b[0m \u001b[39mreturn\u001b[39;00m x\n\u001b[0;32m---> 24\u001b[0m \u001b[39mprint\u001b[39m(gaussian_elimination([[\u001b[39m0\u001b[39m, \u001b[39m-\u001b[39m\u001b[39m2\u001b[39m, \u001b[39m3\u001b[39m, \u001b[39m2\u001b[39m], [\u001b[39m-\u001b[39m\u001b[39m1\u001b[39m, \u001b[39m3\u001b[39m, \u001b[39m-\u001b[39m\u001b[39m2\u001b[39m, \u001b[39m1\u001b[39m], [\u001b[39m1\u001b[39m, \u001b[39m-\u001b[39m\u001b[39m1\u001b[39m, \u001b[39m6\u001b[39m, \u001b[39m11\u001b[39m]]))\n", |
| 44 | + "Cell \u001b[0;32mIn [1], line 7\u001b[0m, in \u001b[0;36mgaussian_elimination\u001b[0;34m(a)\u001b[0m\n\u001b[1;32m 5\u001b[0m pivot \u001b[39m=\u001b[39m a[i][i]\n\u001b[1;32m 6\u001b[0m \u001b[39mfor\u001b[39;00m j \u001b[39min\u001b[39;00m \u001b[39mrange\u001b[39m(i, \u001b[39mlen\u001b[39m(a[i])):\n\u001b[0;32m----> 7\u001b[0m a[i][j] \u001b[39m/\u001b[39m\u001b[39m=\u001b[39m pivot\n\u001b[1;32m 9\u001b[0m \u001b[39m# i + 1行目以降を掃き出す\u001b[39;00m\n\u001b[1;32m 10\u001b[0m \u001b[39mfor\u001b[39;00m j \u001b[39min\u001b[39;00m \u001b[39mrange\u001b[39m(i \u001b[39m+\u001b[39m \u001b[39m1\u001b[39m, \u001b[39mlen\u001b[39m(a)):\n", |
| 45 | + "\u001b[0;31mZeroDivisionError\u001b[0m: division by zero" |
| 46 | + ] |
49 | 47 | } |
50 | | - ] |
| 48 | + ], |
| 49 | + "execution_count": null |
| 50 | + } |
| 51 | + ] |
51 | 52 | } |
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