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“Cloning” row or column vectors
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Here's an elegant, Pythonic way to do it:
>>> array([[1,2,3],]*3)
array([[1, 2, 3],
[1, 2, 3],
[1, 2, 3]])
>>> array([[1,2,3],]*3).transpose()
array([[1, 1, 1],
[2, 2, 2],
[3, 3, 3]])
the problem with [16] seems to be that the transpose ha...
How to iterate for loop in reverse order in swift?
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14 Answers
14
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How to find the kth smallest element in the union of two sorted arrays?
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17 Answers
17
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All combinations of a list of lists
... need itertools.product:
>>> import itertools
>>> a = [[1,2,3],[4,5,6],[7,8,9,10]]
>>> list(itertools.product(*a))
[(1, 4, 7), (1, 4, 8), (1, 4, 9), (1, 4, 10), (1, 5, 7), (1, 5, 8), (1, 5, 9), (1, 5, 10), (1, 6, 7), (1, 6, 8), (1, 6, 9), (1, 6, 10), (2, 4, 7), (2, 4, 8),...
How to round float numbers in javascript?
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17 Answers
17
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Truncate Two decimal places without rounding
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21 Answers
21
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Reorder levels of a factor without changing order of values
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121
Use the levels argument of factor:
df <- data.frame(f = 1:4, g = letters[1:4])
df
# f g
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What is Bit Masking?
...s an example of extracting a subset of the bits in the value:
Mask: 00001111b
Value: 01010101b
Applying the mask to the value means that we want to clear the first (higher) 4 bits, and keep the last (lower) 4 bits. Thus we have extracted the lower 4 bits. The result is:
Mask: 00001111b
Valu...