| # Mathieu Blondel, September 2010 | |
| # License: BSD 3 clause | |
| import numpy as np | |
| from numpy import linalg | |
| import cvxopt | |
| import cvxopt.solvers | |
| def linear_kernel(x1, x2): | |
| return np.dot(x1, x2) |
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亮亮（@ccwang002）| Mar, 2015 | CC 3.0 BY license
如果內容有誤，你可以用任何管道發訊息轟炸我，或用底下的 gist comment 留言。
每個檔案都會是一個主題，主題底下會列出一些資源。資源的最後會有一個學習目標，方便讓你評估自己學到什麼程度。學習目標會給一個明確的任務，我盡量讓它能跟（宅宅的）日常生活結合。通常只要完成前一、二個目標就行了，這也不是功課所以不一定要給我看。如果你不介意給我看，我會分享我主觀的建議，但大部份的任務是沒有絕對的正確答案。只要能解決問題都是好方法。
| # -*- coding: utf-8 -*- | |
| """ | |
| SCAN: A Structural Clustering Algorithm for Networks | |
| As described in http://ualr.edu/nxyuruk/publications/kdd07.pdf | |
| """ | |
| from collections import deque | |
| import numpy as np | |
| from scipy.sparse import csr_matrix |
Beautiful is better than ugly. Explicit is better than implicit.
I frequently deal with collections of things in the programs I write. Collections of droids, jedis, planets, lightsabers, starfighters, etc. When programming in Python, these collections of things are usually represented as lists, sets and dictionaries. Oftentimes, what I want to do with collections is to transform them in various ways. Comprehensions is a powerful syntax for doing just that. I use them extensively, and it's one of the things that keep me coming back to Python. Let me show you a few examples of the incredible usefulness of comprehensions.
All of the tasks presented in the examples can be accomplished with the extensive standard library available in Python. These solutions would arguably be more terse and efficient in some cases. I don't have anything against the standard library. To me there is a certain
A lot of math grad school is reading books and papers and trying to understand what's going on. The difficulty is that reading math is not like reading a mystery thriller, and it's not even like reading a history book or a New York Times article.
The main issue is that, by the time you get to the frontiers of math, the words to describe the concepts don't really exist yet. Communicating these ideas is a bit like trying to explain a vacuum cleaner to someone who has never seen one, except you're only allowed to use words that are four letters long or shorter.
What can you say?
Sometimes we need to open Setting's Preferences not of our app, but of the iPhone itself. What should we do to acomplish this?
[UPDATE: Added Wallet And Apple Pay below]
[UPDATE: Changed prefs for Bluetooth]
| package main | |
| import ( | |
| "bufio" | |
| "fmt" | |
| "log" | |
| "os" | |
| "syscall" | |
| "time" | |
| ) |
| """ | |
| RALIGN - Rigid alignment of two sets of points in k-dimensional | |
| Euclidean space. Given two sets of points in | |
| correspondence, this function computes the scaling, | |
| rotation, and translation that define the transform TR | |
| that minimizes the sum of squared errors between TR(X) | |
| and its corresponding points in Y. This routine takes | |
| O(n k^3)-time. | |
| Inputs: |
| # Transforming the vanilla recursive fib into the iterative DP version | |
| # through a series of mechanical steps. | |
| # | |
| # For more on converting recursive algorithms into iterative ones, see: | |
| # http://blog.moertel.com/posts/2013-05-11-recursive-to-iterative.html | |
| # original function | |
| def fib(n): |
| # Execute an executable under gdb, printing a call stack if we get a crash. | |
| gdb -return-child-result -quiet -batch \ | |
| -ex "set env MALLOC_CHECK_=3" \ | |
| -ex "set print thread-events off" \ | |
| -ex run \ | |
| -ex "thread apply all backtrace full" \ | |
| -ex "quit" \ | |
| $* |