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Fastest way to find second (third…) highest/lowest value in vector or column
R offers max and min, but I do not see a really fast way to find another value in the order, apart from sorting the whole vector and then picking a value x from this vector.
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Replacing NAs with latest non-NA value
...ke to "fill forward" NAs with the closest previous non-NA value. A simple example, using vectors (instead of a data.frame ) is the following:
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Why doesn't Python have a sign function?
...ed behavior for edge cases - which sometimes might require the call to cmp(x,0).
I don't know why it's not a built-in, but I have some thoughts.
copysign(x,y):
Return x with the sign of y.
Most importantly, copysign is a superset of sign! Calling copysign with x=1 is the same as a sign functi...
How can I use numpy.correlate to do autocorrelation?
...n should be the highest because the signal is identical to itself, so you expected that the first element in the autocorrelation result array would be the greatest. However, the correlation is not starting at a time difference of 0. It starts at a negative time difference, closes to 0, and then goes...
Find object in list that has attribute equal to some value (that meets any condition)
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next((x for x in test_list if x.value == value), None)
This gets the first item from the list that matches the condition, and returns None if no item matches. It's my preferred single-expression form.
However,
for x in test_li...
Max return value if empty query
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int maxShoeSize = Workers.Where(x => x.CompanyId == 8)
.Select(x => x.ShoeSize)
.DefaultIfEmpty(0)
.Max();
The zero in DefaultIfEmpty is not necessa...
How do you rotate a two dimensional array?
Inspired by Raymond Chen's post , say you have a 4x4 two dimensional array, write a function that rotates it 90 degrees. Raymond links to a solution in pseudo code, but I'd like to see some real world stuff.
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What's the best way to bundle static resources in a Go program? [closed]
...hey need to go. However, I'd also like to be able to simply distribute an executable with as few files/dependencies as possible. Is there a good way to bundle the HTML/CSS/JS with the executable, so users only have to download and worry about one file?
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Which is faster in Python: x**.5 or math.sqrt(x)?
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math.sqrt(x) is significantly faster than x**0.5.
import math
N = 1000000
%%timeit
for i in range(N):
z=i**.5
10 loops, best of 3: 156 ms per loop
%%timeit
for i in range(N):
z=math.sqrt(i)
10 loops, best of 3: 9...
Short description of the scoping rules?
What exactly are the Python scoping rules?
9 Answers
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