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Replacing NAs with latest non-NA value
...,'a',NA,NA,NA,NA,NA,NA,NA,NA,'b','c','d',NA,NA,NA,NA,NA,'e')
xx = rep(x, 1000000)
system.time({ yzoo = na.locf(xx,na.rm=F)})
## user system elapsed
## 2.754 0.667 3.406
system.time({ yrep = repeat.before(xx)})
## user system elapsed
## 0.597 0.199 0.793
Edit
As this ...
Export database schema into SQL file
...DENTITY(1,1)
,DatabaseName VARCHAR(100)
,TableOwner VARCHAR(100)
,TableName VARCHAR(100)
,FieldName VARCHAR(100)
...
Changing specific text's color using NSMutableAttributedString in Swift
...ange: range)
textField = UITextField.init(frame: CGRect(x:10, y:20, width:100, height: 100))
textField.attributedText = mutableAttributedString
SWIFT 4.2
let range = (mainString as NSString).range(of: stringToColor)
let mutableAttributedString = NSMutableAttributedString.init(string: mainStr...
What is the best way to get all the divisors of a number?
...
wow it took 0.01 for calculating all divisors of 100000000 against the 39s that took the dumb way (stopping at n/2) very cool, thank you!
– Andrea Ambu
Oct 5 '08 at 10:20
...
Which is the preferred way to concatenate a string in Python?
...(b):
0.010656118392944336
The end string, therefore, ends up being about 100MB long. That was pretty slow, appending to a list was much faster. That that timing doesn't include the final a.join(). So how long would that take?
a.join(a):
0.43739795684814453
Oups. Turns out even in this case, ap...
in_array() and multidimensional array
...$userdb = Array
(
(0) => Array
(
('uid') => '100',
('name') => 'Sandra Shush',
('url') => 'urlof100'
),
(1) => Array
(
('uid') => '5465',
('name') => 'Stefanie Mcmohn',
('url...
Find unique rows in numpy.array
..., or even better, than the lexsort method:
a = np.random.randint(2, size=(10000, 6))
%timeit np.unique(a.view(np.dtype((np.void, a.dtype.itemsize*a.shape[1])))).view(a.dtype).reshape(-1, a.shape[1])
100 loops, best of 3: 3.17 ms per loop
%timeit ind = np.lexsort(a.T); a[np.concatenate(([True],np....
CSS Display an Image Resized and Cropped
...
width: 400px;
height: 300px;
margin: -75px 0 0 -100px;
}
<div class="crop">
<img src="https://i.stack.imgur.com/wPh0S.jpg" alt="Donald Duck">
</div>
You can use negative margin to move the image around within the <div/>...
What's the role of GetHashCode in the IEqualityComparer in .NET?
... boxes = new Dictionary<Box, string>(boxEqC);
Box redBox = new Box(100, 100, 25);
Box blueBox = new Box(1000, 1000, 25);
boxes.Add(redBox, "red");
boxes.Add(blueBox, "blue");
Using the BoxEqualityComparer.GetHashCode method in your example, both of these boxes have the same hashcode - 1...
simulate background-size:cover on or
...
+100
This is something I pulled my hair out over for a while, but I came across a great solution that doesn't use any script, and can ach...