大约有 42,000 项符合查询结果（耗时：0.0546秒） [XML]
Principal component analysis in Python
I'd like to use principal component analysis (PCA) for dimensionality reduction. Does numpy or scipy already have it, or do I have to roll my own using numpy.linalg.eigh ?
...
When to use nested classes and classes nested in modules?
I'm pretty familiar with when to use subclasses and modules, but more recently I've been seeing nested classes like this:
5...
In a PHP project, what patterns exist to store, access and organize helper objects? [closed]
How do you organize and manage your helper objects like the database engine, user notification, error handling and so on in a PHP based, object oriented project?
...
When should you branch?
When working with a SCM system, when should you branch?
12 Answers
12
...
How to make git mark a deleted and a new file as a file move?
I've moved a file manually and then I've modified it. According to Git, it is a new file and a removed file. Is there any way to force Git into treating it as a file move?
...
Need for predictable random generator
I'm a web-game developer and I got a problem with random numbers. Let's say that a player has 20% chance to get a critical hit with his sword. That means, 1 out of 5 hits should be critical. The problem is I got very bad real life results — sometimes players get 3 crits in 5 hits, sometimes none i...
How to check whether an object is a date?
I have an annoying bug in on a webpage:
20 Answers
20
...
Is a Java hashmap search really O(1)?
I've seen some interesting claims on SO re Java hashmaps and their O(1) lookup time. Can someone explain why this is so? Unless these hashmaps are vastly different from any of the hashing algorithms I was bought up on, there must always exist a dataset that contains collisions.
...
What is the most elegant way to remove a path from the $PATH variable in Bash?
Or more generally, how do I remove an item from a colon-separated list in a Bash environment variable?
33 Answers
...
How to automatically install Ansible Galaxy roles?
All my Ansible playbooks/roles are checked in to my git repo.
8 Answers
8
...