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What are five things you hate about your favorite language? [closed]
... to implement relational division.
I can set a value to NULL, but I can't test it for equality with NULL. I can check IS NULL, but that just complicates code -- needlessly so, in my opinion.
Why do we need to completely respecify the formula for a GROUPed column, rather than setting an alias on th...
MongoDB Aggregation: How to get total records count?
... to $skip and $limit in the pipeline and make a separate call for count. I tested this against fairly large data sets.
– Jpepper
Jun 18 '19 at 18:55
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...
How can I multiply and divide using only bit shifting and adding?
...f use: https://stackoverflow.com/a/12699549/1182653
EDIT2:
One of the fastest ways to divide by integer constants is to exploit the modular arithmetics and Montgomery reduction: What's the fastest way to divide an integer by 3?
...
What are the differences between numpy arrays and matrices? Which one should I use?
...
Actually, timeit tests show ndarray operations such as np.dot(array2, array2) are faster than matrix1*matrix2. This makes sense because matrix is a subclass of ndarray which overrides special methods like __mul__. matrix.__mul__ calls np.dot....
Easiest way to open a download window without navigating away from the page
...doesn't
open the file in a new tab and fires the download pop-up.
This was tested with several file types (docx, xlsx, png, pdf, ...).
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Why would you use an ivar?
... CFAbsoluteTimeGetCurrent();
for (unsigned i = 0; i < kRuns; i++) {
testIVar = i;
}
cft = CFAbsoluteTimeGetCurrent() - cft;
NSLog(@"1: %.1f picoseconds/run", (cft * 10000000000.0) / kRuns);
cft = CFAbsoluteTimeGetCurrent();
for (unsigned i = 0; i < kRuns; i++) {
[self setTestIVar:i];
...
Passing a std::array of unknown size to a function
...r ) {
mulArrayImpl( contig_range<int>(arr), multiplier );
}
(not tested, but design should work).
Then, in your .cpp file:
void mulArrayImpl(contig_range<int> rng, const int multiplier) {
for(auto& e : rng) {
e *= multiplier;
}
}
This has the downside that the code th...
Django ManyToMany filter()
... examples of FOO__in=... style filters in the many-to-many and many-to-one tests. Here is syntax for your specific problem:
users_in_1zone = User.objects.filter(zones__id=<id1>)
# same thing but using in
users_in_1zone = User.objects.filter(zones__in=[<id1>])
# filtering on a few zon...
Can C++ code be valid in both C++03 and C++11 but do different things?
...ssion. Granted, the C++03 one did come up with a warning form Clang when I tested it.
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Test if string is a number in Ruby on Rails
...cases expected.
If they are relatively uncommon casting is definitely fastest.
If false cases are common and you are just checking for ints, comparison vs a transformed state is a good option.
If false cases are common and you are checking floats, regexp is probably the way to go
If performance ...