大约有 5,600 项符合查询结果（耗时：0.0289秒） [XML]
Principal component analysis in Python
...nalysis
Usage:
p = PCA( A, fraction=0.90 )
In:
A: an array of e.g. 1000 observations x 20 variables, 1000 rows x 20 columns
fraction: use principal components that account for e.g.
90 % of the total variance
Out:
p.U, p.d, p.Vt: from numpy.linalg.svd, A = U . d . Vt
p.di...
Understanding generators in Python
... x = x + 1
if x % 3 == 0:
yield x
for a in mygen(100):
print a
There is a loop in the generator that runs from 0 to n, and if the loop variable is a multiple of 3, it yields the variable.
During each iteration of the for loop the generator is executed. If it is the f...
How do I install Python OpenCV through Conda?
...deo can be opened, I wanted to confirm that I could extract a frame (frame 100) as an array. In openCV 2.4.9, the command for this was cap.set(cv2.cv.CV_CAP_PROP_POS_FRAMES, 100). In openCV 3.2.0, the equivalent command has changed to cap.set(cv2.CAP_PROP_POS_FRAMES, 100)
– oll...
Truncate a string straight JavaScript
...wered Dec 5 '18 at 17:36
mandrei100mandrei100
13111 silver badge44 bronze badges
...
How to scale a UIImageView proportionally?
...e. The following code is not tested.
CGSize kMaxImageViewSize = {.width = 100, .height = 100};
CGSize imageSize = image.size;
CGFloat aspectRatio = imageSize.width / imageSize.height;
CGRect frame = imageView.frame;
if (kMaxImageViewSize.width / aspectRatio <= kMaxImageViewSize.height)
{
fr...
C++ lambda with captures as a function pointer
...SBKerrek SB
415k7676 gold badges781781 silver badges10021002 bronze badges
3
...
Error Code: 2013. Lost connection to MySQL server during query
...imeout and a suitable value (in seconds) - for example: --net_read_timeout=100.
For reference see here and here.
share
|
improve this answer
|
follow
|
...
What is the difference between `sorted(list)` vs `list.sort()`?
...'s our setup:
import timeit
setup = """
import random
lists = [list(range(10000)) for _ in range(1000)] # list of lists
for l in lists:
random.shuffle(l) # shuffle each list
shuffled_iter = iter(lists) # wrap as iterator so next() yields one at a time
"""
And here's our results for a list of...
How do I toggle an element's class in pure JavaScript?
... classes + class1;
}
.red {
background-color: red
}
div {
width: 100px;
height: 100px;
margin-bottom: 10px;
border: 1px solid black;
}
<div class="does red redAnother " onclick="toogleClass(this, 'red')"></div>
<div class="does collapse navbar-collapse " onclic...
Why not use Double or Float to represent currency?
...y do
you have left?
System.out.println(1.03 - .42);
prints out 0.6100000000000001.
The right way to solve this problem is
to use BigDecimal, int or long
for monetary calculations.
Though BigDecimal has some caveats (please see currently accepted answer).
...