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Is there an R function for finding the index of an element in a vector?
...rks on vectors :
x <- sample(1:10)
x
# [1] 4 5 9 3 8 1 6 10 7 2
match(c(4,8),x)
# [1] 1 5
match only returns the first encounter of a match, as you requested. It returns the position in the second argument of the values in the first argument.
For multiple matching, %in% is the way to...
Is there a way to pass optional parameters to a function?
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The Python 2 documentation, 7.6. Function definitions gives you a couple of ways to detect whether a caller supplied an optional parameter.
First, you can use special formal parameter syntax *. If the function definition has a formal p...
Return two and more values from a method
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amenthes
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answered Dec 25 '09 at 11:35
Aditya MukherjiAditya Mukherji...
How to split a sequence into two pieces by predicate?
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By using partition method:
scala> List(1,2,3,4).partition(x => x % 2 == 0)
res0: (List[Int], List[Int]) = (List(2, 4),List(1, 3))
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Logging framework incompatibility
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112
You are mixing the 1.5.6 version of the jcl bridge with the 1.6.0 version of the slf4j-api; this...
Finding the index of elements based on a condition using python list comprehension
...t all, but just deal with the values—[value for value in a if value > 2]. Usually dealing with indexes means you're not doing something the best way.
If you do need an API similar to Matlab's, you would use numpy, a package for multidimensional arrays and numerical math in Python which is heavi...
How to append multiple values to a list in Python
...ny other thing that provides a sequence of values.
>>> lst = [1, 2]
>>> lst.append(3)
>>> lst.append(4)
>>> lst
[1, 2, 3, 4]
>>> lst.extend([5, 6, 7])
>>> lst.extend((8, 9, 10))
>>> lst
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> lst...
How do I replace NA values with zeros in an R dataframe?
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Regex to match a digit two or four times
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2 Answers
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Unique combination of all elements from two (or more) vectors
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this maybe what you are after
> expand.grid(a,b)
Var1 Var2
1 ABC 2012-05-01
2 DEF 2012-05-01
3 GHI 2012-05-01
4 ABC 2012-05-02
5 DEF 2012-05-02
6 GHI 2012-05-02
7 ABC 2012-05-03
8 DEF 2012-05-03
9 GHI 2012-05-03
10 ABC 2012-05-04
11 DEF 2012-05-04
12 GHI 2012-0...