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How do I sort one vector based on values of another
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answered Oct 14 '09 at 21:47
Ian FellowsIan Fellows
16k1010 gold badges4444 silver badges6363 bronze badges
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How to drop columns by name in a data frame
... function. For example :
R> df <- data.frame(x=1:5, y=2:6, z=3:7, u=4:8)
R> df
x y z u
1 1 2 3 4
2 2 3 4 5
3 3 4 5 6
4 4 5 6 7
5 5 6 7 8
Then you can use the which function and the - operator in column indexation :
R> df[ , -which(names(df) %in% c("z","u"))]
x y
1 1 2
2 2 3
3 3 4...
List of lists changes reflected across sublists unexpectedly
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14 Answers
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How can I sort a dictionary by key?
What would be a nice way to go from {2:3, 1:89, 4:5, 3:0} to {1:89, 2:3, 3:0, 4:5} ?
I checked some posts but they all use the "sorted" operator that returns tuples.
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Numpy: Divide each row by a vector element
...e is the doc.
– sazary
Apr 8 '15 at 4:10
2
a visual example
– PlsWork
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Iterate a list with indexes in Python
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>>> a = [3,4,5,6]
>>> for i, val in enumerate(a):
... print i, val
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0 3
1 4
2 5
3 6
>>>
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Shuffle two list at once with same order
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answered Apr 25 '14 at 9:45
sshashank124sshashank124
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finding and replacing elements in a list
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>>> a= [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1]
>>> for n, i in enumerate(a):
... if i == 1:
... a[n] = 10
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>>> a
[10, 2, 3, 4, 5, 10, 2, 3, 4, 5, 10]
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If vs. Switch Speed
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answered Jan 14 '09 at 23:16
Konrad RudolphKonrad Rudolph
461k118118 gold badges863863 silver badges11101110 bronze badges
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Easiest way to upgrade eclipse 3.7 to 4.2 (Juno)
So since Eclipse juno is based on 4.2 instead of 3.7, what is the easiest way to upgrade to it, short of installing a separate copy of juno and re-installing all my existing plugins from 3.7 into it?
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