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Is it possible to use argsort in descending order?
...00)
>>> n = 30
>>> timeit (-avgDists).argsort()[:n]
1.93 µs ± 6.68 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
>>> timeit avgDists.argsort()[::-1][:n]
1.64 µs ± 3.39 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
>>> timeit avg...
HTML5 Canvas vs. SVG vs. div
What is the best approach for creating elements on the fly and being able to move them around? For example, let's say I want to create a rectangle, circle and polygon and then select those objects and move them around.
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Getting indices of True values in a boolean list
...;> %timeit list(compress(xrange(len(t)), t))
1000 loops, best of 3: 696 µs per loop
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Measure time in Linux - time vs clock vs getrusage vs clock_gettime vs gettimeofday vs timespec_get?
...r, hopefully not, wall-clock?)
What is the precision of the clock? (s, ms, µs, or faster?)
After how much time does the clock wrap around? Or is there some mechanism to avoid this?
Is the clock monotonic, or will it change with changes in the system time (via NTP, time zone, daylight savings time, ...
How do you get the magnitude of a vector in Numpy?
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In [4]: %timeit np.sqrt((a*a).sum(axis=1))
100000 loops, best of 3: 15.6 µs per loop
In [5]: %timeit np.sqrt(np.einsum('ij,ij->i',a,a))
100000 loops, best of 3: 8.71 µs per loop
or vectors:
In [5]: a = np.arange(100000)
In [6]: %timeit np.sqrt(a.dot(a))
10000 loops, best of 3: 80.8 µs p...
How to access the ith column of a NumPy multidimensional array?
.... Using the copied version is much faster:
%timeit A_c1_ref.sum() # ~248 µs
%timeit A_c1_copy.sum() # ~12.8 µs
This is due to the different number of strides mentioned before:
A_c1_ref.strides[0] # 40000 bytes
A_c1_copy.strides[0] # 4 bytes
Although it might seem that using column copies...
Rank items in an array using Python/NumPy, without sorting array twice
...)
%%timeit -n10000 -r5
x = (rankdata(l) - 1).astype(int)
>>> 128 µs ± 2.72 µs per loop (mean ± std. dev. of 5 runs, 10000 loops each)
%%timeit -n10000 -r5
a = np.array(l)
r = a.argsort().argsort()
>>> 69.1 µs ± 464 ns per loop (mean ± std. dev. of 5 runs, 10000 loops each)...
Python, compute list difference
...ange(10)
b = range(10/2)
timeit[diff(a, b)]
100000 loops, best of 3: 1.97 µs per loop
timeit[set_diff(a, b)]
100000 loops, best of 3: 2.71 µs per loop
timeit[diff_lamb_hension(a, b)]
100000 loops, best of 3: 2.1 µs per loop
timeit[diff_lamb_filter(a, b)]
100000 loops, best of 3: 3.58 µs per ...
Is the size of C “int” 2 bytes or 4 bytes?
...xteen bits of storage:
UINT_MAX 65535 // 2¹⁶ - 1
Thus we can see that unsigned int require (at least) 16 bits, which is where you get the two bytes (assuming CHAR_BIT is 8)... and later when that limit increased to 2³² - 1, people were stating 4 bytes instead...
How do I get user IP address in django?
... answered May 12 '11 at 9:38
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