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How to Correctly Use Lists in R?
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Why do these two expressions not return the same result?
x = list(1, 2, 3, 4); x2 = list(1:4)
A list can contain any other class as each element. So you can have a list where the first element is a character vector, the second is a data frame, etc. In this case, you have created two different ...
How to perform element-wise multiplication of two lists?
...gahooagahooa
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Pandas get topmost n records within each group
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Algorithm to return all combinations of k elements from n
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virtualenvwrapper and Python 3
I installed python 3.3.1 on ubuntu lucid and successfully created a virtualenv as below
9 Answers
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How to access the ith column of a NumPy multidimensional array?
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>>> test[:,0]
array([1, 3, 5])
Similarly,
>>> test[1,:]
array([3, 4])
lets you access rows. This is covered in Section 1.4 (Indexing) of the NumPy reference. This is quick, at least in my experience. It's certainly much quicker tha...
All possible array initialization syntaxes
...s above, the first two could replace the string[] on the left with var (C# 3+), as the information on the right is enough to infer the proper type. The third line must be written as displayed, as array initialization syntax alone is not enough to satisfy the compiler's demands. The fourth could also...
Add new row to dataframe, at specific row-index, not appended?
...ll:
existingDF <- as.data.frame(matrix(seq(20),nrow=5,ncol=4))
r <- 3
newrow <- seq(4)
insertRow <- function(existingDF, newrow, r) {
existingDF[seq(r+1,nrow(existingDF)+1),] <- existingDF[seq(r,nrow(existingDF)),]
existingDF[r,] <- newrow
existingDF
}
> insertRow(existi...
Jasmine.js comparing arrays
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Just did the test and it works with toEqual
please find my test:
http://jsfiddle.net/7q9N7/3...
How to get the Power of some Integer in Swift language?
...(radix), Double(power)))
}
// ...
// Then you can do this...
let i = 2 ^^ 3
// ... or
println("2³ = \(2 ^^ 3)") // Prints 2³ = 8
I used two carets so you can still use the XOR operator.
Update for Swift 3
In Swift 3 the "magic number" precedence is replaced by precedencegroups:
precedencegro...