大约有 20,000 项符合查询结果（耗时：0.0475秒） [XML]
How do you detect where two line segments intersect? [closed]
...
There’s a nice approach to this problem that uses vector cross products. Define the 2-dimensional vector cross product v × w to be vx wy − vy wx.
Suppose the two line segments run from p to p + r and from q to q + s. Then any point on the first...
Abstract class in Java
What is an "abstract class" in Java?
14 Answers
14
...
Add Keypair to existing EC2 instance
...n). I would however like to gain SSH access to these instances, is it possible to create a new Keypair and apply it to the instances so I can SSH in? Obtaining the exisiting pem file for the keypair the instances were created under is currently not an option.
...
Why can't I have abstract static methods in C#?
I've been working with providers a fair bit lately, and I came across an interesting situation where I wanted to have an abstract class that had an abstract static method. I read a few posts on the topic, and it sort of made sense, but is there a nice clear explanation?
...
Counting the occurrences / frequency of array elements
In Javascript, I'm trying to take an initial array of number values and count the elements inside it. Ideally, the result would be two new arrays, the first specifying each unique element, and the second containing the number of times each element occurs. However, I'm open to suggestions on the form...
Why is super.super.method(); not allowed in Java?
I read this question and thought that would easily be solved (not that it isn't solvable without) if one could write:
22...
Semicolon before self-invoking function? [duplicate]
What is the benefit of using semicolon before a self-invoking function in JavaScript? I saw this approach in few popular jQuery plugins and I'm curious to find if this is the next awesome thing in JavaScript that I don't know.
...
Why are Perl 5's function prototypes bad?
...
Prototypes aren't bad if used correctly. The difficulty is that Perl's prototypes don't work the way people often expect them to. People with a background in other programming languages tend to expect prototypes to provide a mechanism for chec...
Generate a random point within a circle (uniformly)
...chimedes would have.
How can we generate a point uniformly in a triangle ABC, where |AB|=|BC|? Let's make this easier by extending to a parallelogram ABCD. It's easy to generate points uniformly in ABCD. We uniformly pick a random point X on AB and Y on BC and choose Z such that XBYZ is a parallelo...
Pandas DataFrame column to list [duplicate]
I am pulling a subset of data from a column based on conditions in another column being met.
4 Answers
...