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What is the difference between Ruby 1.8 and Ruby 1.9
I'm not clear on the differences between the "current" version of Ruby (1.8) and the "new" version (1.9). Is there an "easy" or a "simple" explanation of the differences and why it is so different?
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How does numpy.histogram() work?
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169
A bin is range that represents the width of a single bar of the histogram along the X-axis. Yo...
What's the difference between RANK() and DENSE_RANK() functions in oracle?
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10 Answers
10
Active
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Efficient way to apply multiple filters to pandas DataFrame or Series
...numpy) allow for boolean indexing, which will be much more efficient:
In [11]: df.loc[df['col1'] >= 1, 'col1']
Out[11]:
1 1
2 2
Name: col1
In [12]: df[df['col1'] >= 1]
Out[12]:
col1 col2
1 1 11
2 2 12
In [13]: df[(df['col1'] >= 1) & (df['col1'] <=1 )]
Out...
What's the 'Ruby way' to iterate over two arrays at once
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>> @budget = [ 100, 150, 25, 105 ]
=> [100, 150, 25, 105]
>> @actual = [ 120, 100, 50, 100 ]
=> [120, 100, 50, 100]
>> @budget.zip @actual
=> [[100, 120], [150, 100], [25, 50], [105, 100]]
>> @budget.zip(@actual...
Finding the index of elements based on a condition using python list comprehension
...nstead of a list.
>>> import numpy
>>> a = numpy.array([1, 2, 3, 1, 2, 3])
>>> a
array([1, 2, 3, 1, 2, 3])
>>> numpy.where(a > 2)
(array([2, 5]),)
>>> a > 2
array([False, False, True, False, False, True], dtype=bool)
>>> a[numpy.where(a ...
PHP: merge two arrays while keeping keys instead of reindexing?
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You can simply 'add' the arrays:
>> $a = array(1, 2, 3);
array (
0 => 1,
1 => 2,
2 => 3,
)
>> $b = array("a" => 1, "b" => 2, "c" => 3)
array (
'a' => 1,
'b' => 2,
'c' => 3,
)
>> $a + $b
array (
0 => 1,
1 => 2,
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What's the difference between “mod” and “remainder”?
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145
There is a difference between modulus and remainder. For example:
-21 mod 4 is 3 because -21 ...
Are list-comprehensions and functional functions faster than “for loops”?
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154
The following are rough guidelines and educated guesses based on experience. You should timeit...