大约有 800 项符合查询结果（耗时：0.0160秒） [XML]
Cosmic Rays: what is the probability they will affect a program?
...M, then the failure probability would be
60 × 20 × 1024²
1 - (1 - 1.4e-15) = 1.8e-6 a.k.a. "5 nines"
Error checking can help to reduce the aftermath of failure. Also, because of more compact size of chips as commented by Joe, the failure rate could be differen...
How do I efficiently iterate over each entry in a Java Map?
...rror Units
test3_UsingForEachAndJava8 avgt 10 0.308 ± 0.021 µs/op
test10_UsingEclipseMap avgt 10 0.309 ± 0.009 µs/op
test1_UsingWhileAndMapEntry avgt 10 0.380 ± 0.014 µs/op
test6_UsingForAndIterator avgt 10 0.387 ± 0.016 µs/op
test2_Us...
Generate a random point within a circle (uniformly)
...
Oh, nice! To be clear, when you say random(min_radius², max_radius²), do you mean something equivalent to random() * (max_radius² - min_radius²) + min_radius², where random() returns a uniform value between 0 and 1?
– aioobe
Jul 31 '1...
Find element's index in pandas Series
...randint(0,10,10000))
In [9]: %timeit s[s == 5]
1000 loops, best of 3: 203 µs per loop
In [12]: i = Index(s)
In [13]: %timeit i.get_loc(5)
1000 loops, best of 3: 226 µs per loop
As Viktor points out, there is a one-time creation overhead to creating an index (its incurred when you actually DO ...
Cartesian product of x and y array points into single array of 2D points
...1000)]
Test results:
In [2]: test_all(*(x100 * 2))
repeat_product:
67.5 µs ± 633 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
dstack_product:
67.7 µs ± 1.09 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)
cartesian_product:
33.4 µs ± 558 ns per loop (mean ± std....
How to determine whether a Pandas Column contains a particular value
...10]: x = pd.Series(range(1000000))
In [13]: timeit 999999 in x.values
567 µs ± 25.6 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
In [15]: timeit x.isin([999999]).any()
9.54 ms ± 291 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
In [16]: timeit (x == 999999).any()
6....
Why isn't my Pandas 'apply' function referencing multiple columns working? [closed]
... that an intermediate result is being cached. 1000 loops, best of
3: 481 µs per loop
Example 2: vectorize using pandas.apply():
%%timeit
df['a'] % df['c']
The slowest run took 458.85 times longer than the fastest. This could
mean that an intermediate result is being cached. 10000 loops...
iPhone: How to get current milliseconds?
...if portability is a priority for you.
iPhone 4S
CACurrentMediaTime: 1.33 µs/call
gettimeofday: 1.38 µs/call
[NSDate timeIntervalSinceReferenceDate]: 1.45 µs/call
CFAbsoluteTimeGetCurrent: 1.48 µs/call
[[NSDate date] timeIntervalSince1970]: 4.93 µs/call
iPad 3
CACurrentMediaTime: 1.25 µs/c...
Circle line-segment collision detection algorithm?
...ithm
// compute the euclidean distance between A and B
LAB = sqrt( (Bx-Ax)²+(By-Ay)² )
// compute the direction vector D from A to B
Dx = (Bx-Ax)/LAB
Dy = (By-Ay)/LAB
// the equation of the line AB is x = Dx*t + Ax, y = Dy*t + Ay with 0 <= t <= LAB.
// compute the distance between the po...
How to compare Unicode characters that “look alike”?
...ain(string[] args)
{
char first = 'μ';
char second = 'µ';
// Technically you only need to normalize U+00B5 to obtain U+03BC, but
// if you're unsure which character is which, you can safely normalize both
string firstNormalized = first.ToString().Normal...