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What makes Lisp macros so special?
...of using Lisp macros. As someone who wants to understand the buzz, please explain what makes this feature so powerful.
14 A...
MIN and MAX in C
Where are MIN and MAX defined in C, if at all?
14 Answers
14
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What is a race condition?
When writing multithreaded applications, one of the most common problems experienced is race conditions.
18 Answers
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How to calculate a logistic sigmoid function in Python?
...
This should do it:
import math
def sigmoid(x):
return 1 / (1 + math.exp(-x))
And now you can test it by calling:
>>> sigmoid(0.458)
0.61253961344091512
Update: Note that the above was mainly intended as a straight one-to-one translation of the given ex...
What does the construct x = x || y mean?
I am debugging some JavaScript, and can't explain what this || does?
12 Answers
12
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Using Default Arguments in a Function
... declaration as follows so you can do what you want:
function foo($blah, $x = null, $y = null) {
if (null === $x) {
$x = "some value";
}
if (null === $y) {
$y = "some other value";
}
code here!
}
This way, you can make a call like foo('blah', null, 'non-defa...
Reference — What does this symbol mean in PHP?
...is is a collection of questions that come up every now and then about syntax in PHP. This is also a Community Wiki, so everyone is invited to participate in maintaining this list.
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Cartesian product of x and y array points into single array of 2D points
I have two numpy arrays that define the x and y axes of a grid. For example:
13 Answers
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How do I create test and train samples from one dataframe with pandas?
...y distributed random numbers between 0 and 1.
– R. Max
Jun 10 '14 at 18:43
5
Can someone explain ...
Distinct in Linq based on only one field of the table
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Try this:
table1.GroupBy(x => x.Text).Select(x => x.FirstOrDefault());
This will group the table by Text and use the first row from each groups resulting in rows where Text is distinct.
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