>>> import numpy as np >>> m = np.mat([[1.,1,1],[1,2,3,],[1,5,1,]]) >>> m matrix([[ 1., 1., 1.], [ 1., 2., 3.], [ 1., 5., 1.]]) >>> m[2:0,:] #错误,选中的元素为0 matrix([], shape=(0, 3), dtype=float64) # 第一种切法 >>> m[-2:…

a = [[1,2],[3,4]] a = np.mat(a) print(a.getA().tolist())…

https://blog.paulhankin.net/fibonacci/ This code, somewhat surprisingly, generates Fibonacci numbers. def fib(n): return (4 << n*(3+n)) // ((4 << 2*n) - (2 << n) - 1) & ((2 << n) - 1) In this blog post, I'll explain where it co…

Github Actions 实践 Github Actions 是 Github 的持续集成服务,通过在 repo 发生特定的行为时执行指定的命令实现自动测试.自动部署等功能. 基本术语 workflow:一次持续集成运行的过程 job:一个workflow由一个或多个job构成 step:一个job由一个或多个step构成,分步完成一个任务 action:一个step可以依次执行一个或多个action workflow 文件 启用 Github Actions 需要在代码仓库中的 .gith…

Spiral Matrix II 螺旋矩阵 Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. For example,Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ] 看博客园有人面试碰到过这个问题,长篇大论看得我头晕…

题目来源 https://leetcode.com/problems/search-a-2d-matrix/ Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted from left to right. The first integer of each…

题目来源 https://leetcode.com/problems/spiral-matrix-ii/ Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. 题意分析 Input: n:integer Output:a matrix decribed as list[list[]] Conditions:输入一个大小,得到一个方形矩阵,然后形成蛇形矩阵 题目…

题目来源 https://leetcode.com/problems/spiral-matrix/ Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. 题意分析 Input: a matrix Output: a list Conditions: 蛇形输出 题目思路 自己本来在想有没有一些不一样的算法,然后发现直接右下左上顺序做就好了,看到…

题目来源: https://leetcode.com/problems/set-matrix-zeroes/ 题意分析: 输入一个m×n矩阵,如果出现有0,那么将对应的行和列都变成0. 题目思路: 简单的一个想法是记录行列哪些出现过0,那么将其对应到的行列转成0. 代码(Python): class Solution(object): def setZeroes(self, matrix): """ :type matrix: List[List[int]] :rtype:…

Coding the Matrix: Linear Algebra through Computer Science Applications 这是一门用python实现矩阵运算的课,第一次作业就感觉对python的提高很大,用到了各种数据类型. 代码如下: ## Task 1 minutes_in_week = 60*24*7 ## Task 2 remainder_without_mod = 2304811-2304811//47*47 ## Task 3 divisible_by_3 =…