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Apply a function to every row of a matrix or a data frame
...:6, nrow=3, byrow=TRUE)
R> M
[,1] [,2]
[1,] 1 2
[2,] 3 4
[3,] 5 6
R> apply(M, 1, function(x) 2*x[1]+x[2])
[1] 4 10 16
R>
This takes a matrix and applies a (silly) function to each row. You pass extra arguments to the function as fourth, fifth, ... arguments to app...
How to Correctly Use Lists in R?
...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 lis...
What is pseudopolynomial time? How does it differ from polynomial time?
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254
To understand the difference between polynomial time and pseudopolynomial time, we need to start...
Choosing a file in Python with simple Dialog
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edited Aug 26 at 20:40
Try431
20833 silver badges1414 bronze badges
answered Aug 26 '10 at 21:22
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What is the correct way of using C++11's range-based for?
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4 Answers
4
Active
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Getting name of the class from an instance
...g the need.
– Gleno
Aug 3 '13 at 18:41
2
Remember to #import <objc/objc-runtime.h> to able ...
Regex replace uppercase with lowercase letters
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415
You may:
Find: (\w)
Replace With: \L$1
Or select the text, ctrl+K+L.
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How do I replace NA values with zeros in an R dataframe?
...:10), 100, replace = TRUE), 10)
> d <- as.data.frame(m)
V1 V2 V3 V4 V5 V6 V7 V8 V9 V10
1 4 3 NA 3 7 6 6 10 6 5
2 9 8 9 5 10 NA 2 1 7 2
3 1 1 6 3 6 NA 1 4 1 6
4 NA 4 NA 7 10 2 NA 4 1 8
5 1 2 4 NA 2 6 2 6 7 4
6 NA 3 NA NA 10 2 1 10 8 4
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