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Circle line-segment collision detection algorithm?
... exdx + eydy - dxh - dyk ) +
ex2 + ey2 -
2exh - 2eyk + h2 + k2 - r2 = 0
Finally,
t2( _d * _d ) + 2t( _e * _d - _d * _c ) + _e * _e - 2( _e*_c ) + _c * _c - r2 = 0
*Where _d is the vector d and * is the dot product.*
And then,
t2( _d * _d ) + 2t( _d * ( _e - _c ) ) + ( _e - _c ) * ( _e - _c ) - r2 = ...
Why does the expression 0 < 0 == 0 return False in Python?
...o say 0 < x <= 5 than to say (0 < x) and (x <= 5).
These are called chained comparisons. And that's a link to the documentation for them.
With the other cases you talk about, the parenthesis force one relational operator to be applied before the other, and so they are no longer chained...
高并发服务端分布式系统设计概要 - C/C++ - 清泛网 - 专注C/C++及内核技术
...说，我这套系统用于微博（就假想我们做一个山寨的推特吧，给他个命名就叫“山推” 好了，以下都叫山推，Stwi），那么，“我关注的人”这一个业务的数据，肯定和“我发了的推文”这个业务的数据是分开存储的，那么我们...
How do I write good/correct package __init__.py files
...
__all__ is very good - it helps guide import statements without automatically importing modules
http://docs.python.org/tutorial/modules.html#importing-from-a-package
using __all__ and import * is redundant, only __all__ is nee...
动态追踪（Dynamic Tracing）技术漫谈 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...，有些问题甚至是我意外发现的。下面就随便举几个例子吧。
第一个例子是，我使用基于 SystemTap 的火焰图工具分析我们线上的 Nginx 进程，结果发现有相当一部分 CPU 时间花费在了一条非常奇怪的代码路径上面。这其实是我一...
How to call a Parent Class's method from Child Class in Python?
...P was asking how to do it without explicitly naming the superclass at the call site (Bar, in this case).
– Adam Rosenfield
Apr 30 '09 at 2:13
8
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Use numpy array in shared memory for multiprocessing
...
To add to @unutbu's (not available anymore) and @Henry Gomersall's answers. You could use shared_arr.get_lock() to synchronize access when needed:
shared_arr = mp.Array(ctypes.c_double, N)
# ...
def f(i): # could be anything numpy accepts as an index such another numpy array
with ...
How do I check if an object has a specific property in JavaScript?
...
I'm really confused by the answers that have been given - most of them are just outright incorrect. Of course you can have object properties that have undefined, null, or false values. So simply reducing the property check to typeo...
What Automatic Resource Management alternatives exist for Scala?
...
For now Scala 2.13 has finally supported: try with resources by using Using :), Example:
val lines: Try[Seq[String]] =
Using(new BufferedReader(new FileReader("file.txt"))) { reader =>
Iterator.unfold(())(_ => Option(reader.readLine()).ma...
Any gotchas using unicode_literals in Python 2.6?
...wo.name
The output of running python one.py is:
Traceback (most recent call last):
File "one.py", line 5, in <module>
print name + two.name
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 4: ordinal not in range(128)
In this example, two.name is an utf-8 encoded...