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How do I get indices of N maximum values in a NumPy array?
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edited Aug 2 '11 at 10:45
answered Aug 2 '11 at 10:32
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Fetch frame count with ffmpeg
...below.
ffprobe: Query the container
ffprobe -v error -select_streams v:0 -show_entries stream=nb_frames -of default=nokey=1:noprint_wrappers=1 input.mp4
This is a fast method.
Not all formats (such as Matroska) will report the number of frames resulting in the output of N/A. See the other met...
Given an array of numbers, return array of products of all other numbers (no division)
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260
An explanation of polygenelubricants method is:
The trick is to construct the arrays (in the c...
How to debug a GLSL shader?
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answered Mar 24 '10 at 17:14
Mr. BernaMr. Berna
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How can I sort arrays and data in PHP?
...te a comparison function. That function takes two elements and must return 0 if these elements are considered equal, a value lower than 0 if the first value is lower and a value higher than 0 if the first value is higher. That's all that's needed:
function cmp(array $a, array $b) {
if ($a['foo']...
Ruby on Rails and Rake problems: uninitialized constant Rake::DSL
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A tweet from DHH earlier. Rake .9.0 breaks Rails and several other things, you need to:
gem "rake", "0.8.7"
in your Gemfile.
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From ND to 1D arrays
...c = a.flatten()
If you just want an iterator, use np.ndarray.flat:
In [20]: d = a.flat
In [21]: d
Out[21]: <numpy.flatiter object at 0x8ec2068>
In [22]: list(d)
Out[22]: [1, 2, 3, 4, 5, 6]
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How do you know what to test when writing unit tests? [closed]
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edited May 23 '17 at 12:10
community wiki
2 re...
pyplot scatter plot marker size
...xamples and the output they produce.
# doubling the width of markers
x = [0,2,4,6,8,10]
y = [0]*len(x)
s = [20*4**n for n in range(len(x))]
plt.scatter(x,y,s=s)
plt.show()
gives
Notice how the size increases very quickly. If instead we have
# doubling the area of markers
x = [0,2,4,6,8,10]
y ...
Find the max of two or more columns with pandas
...df = pd.DataFrame({"A": [1,2,3], "B": [-2, 8, 1]})
>>> df
A B
0 1 -2
1 2 8
2 3 1
>>> df[["A", "B"]]
A B
0 1 -2
1 2 8
2 3 1
>>> df[["A", "B"]].max(axis=1)
0 1
1 8
2 3
and so:
>>> df["C"] = df[["A", "B"]].max(axis=1)
>>> df
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