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Mean per group in a data.frame [duplicate]
...aggregate was designed for:
d <- read.table(text=
'Name Month Rate1 Rate2
Aira 1 12 23
Aira 2 18 73
Aira 3 19 45
Ben 1 53 19
Ben 2 22 87
Ben 3 19 45
Cat 1 22 ...
In Matlab, when is it optimal to use bsxfun?
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152
+500
There ...
Ruby: What is the easiest way to remove the first element from an array?
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11 Answers
11
Active
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How to write a bash script that takes optional input arguments?
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You could use the default-value syntax:
somecommand ${1:-foo}
The above will, as described in Bash Reference Manual - 3.5.3 Shell Parameter Expansion [emphasis mine]:
If parameter is unset or null, the expansion of word is substituted. Otherwise, the value of parameter is ...
Bubble Sort Homework
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127
To explain why your script isn't working right now, I'll rename the variable unsorted to sorte...
Python creating a dictionary of lists
...s import defaultdict
>>> d = defaultdict(list)
>>> a = ['1', '2']
>>> for i in a:
... for j in range(int(i), int(i) + 2):
... d[j].append(i)
...
>>> d
defaultdict(<type 'list'>, {1: ['1'], 2: ['1', '2'], 3: ['2']})
>>> d.items()
[(1, ['1']), (...
Convert Year/Month/Day to Day of Year in Python
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261
There is a very simple solution:
from datetime import datetime
day_of_year = datetime.now().tim...
Calculating frames per second in a game
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19 Answers
19
Active
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How to return a part of an array in Ruby?
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195
Yes, Ruby has very similar array-slicing syntax to Python. Here is the ri documentation for th...