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Why is Go so slow (compared to Java)?
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The 6g and 8g compilers are not particularly optimising, so the code they produce isn't particularly fast.
They're designed to run fast themselves and produce code that's OK (there is a bit of optimisation). gccgo uses GCC's existi...
Computational complexity of Fibonacci Sequence
I understand Big-O notation, but I don't know how to calculate it for many functions. In particular, I've been trying to figure out the computational complexity of the naive version of the Fibonacci sequence:
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Why is i++ not atomic?
...crement operation atomic; it involves synchronization at both the software and hardware levels that need not be present in an ordinary increment.
You could make the argument that i++ should have been designed and documented as specifically performing an atomic increment, so that a non-atomic increm...
What causes imported Maven project in Eclipse to use Java 1.5 instead of Java 1.6 by default and how
I imported a Maven project and it used Java 1.5 even though I have 1.6 configured as my Eclipse default Preferences->Java->Installed JREs .
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How to add an extra column to a NumPy array
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I think a more straightforward solution and faster to boot is to do the following:
import numpy as np
N = 10
a = np.random.rand(N,N)
b = np.zeros((N,N+1))
b[:,:-1] = a
And timings:
In [23]: N = 10
In [24]: a = np.random.rand(N,N)
In [25]: %timeit b = np.hstac...
Efficient way to apply multiple filters to pandas DataFrame or Series
I have a scenario where a user wants to apply several filters to a Pandas DataFrame or Series object. Essentially, I want to efficiently chain a bunch of filtering (comparison operations) together that are specified at run-time by the user.
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What is the difference between “int” and “uint” / “long” and “ulong”?
I know about int and long (32-bit and 64-bit numbers), but what are uint and ulong ?
5 Answers
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Why is rbindlist “better” than rbind?
I am going through documentation of data.table and also noticed from some of the conversations over here on SO that rbindlist is supposed to be better than rbind .
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Removing duplicates from a list of lists
...pby(k))
[[1, 2], [3], [4], [5, 6, 2]]
itertools often offers the fastest and most powerful solutions to this kind of problems, and is well worth getting intimately familiar with!-)
Edit: as I mention in a comment, normal optimization efforts are focused on large inputs (the big-O approach) becaus...
javascript: recursive anonymous function?
...ive the function a name, even when you're creating the function as a value and not a "function declaration" statement. In other words:
(function foo() { foo(); })();
is a stack-blowing recursive function. Now, that said, you probably don't may not want to do this in general because there are som...