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How does one reorder columns in a data frame?
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Your dataframe has four columns like so df[,c(1,2,3,4)].
Note the first comma means keep all the rows, and the 1,2,3,4 refers to the columns.
To change the order as in the above question do df2[,c(1,3,2,4)]
If you want to output this file as a csv, do write.csv(df2, file...
Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...o similar questions scattered around this site.
tmp <- data.frame(x=gl(2,3, labels=letters[24:25]),
y=gl(3,1,6, labels=letters[1:3]),
z=c(1,2,3,3,3,2))
Using the tidyverse:
The new cool new way to do this is with pivot_wider from tidyr 1.0.0. It returns a...
How to do multiple arguments to map function where one remains the same in python?
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One option is a list comprehension:
[add(x, 2) for x in [1, 2, 3]]
More options:
a = [1, 2, ...
How do I find the duplicates in a list and create another list with them?
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How can building a heap be O(n) time complexity?
...ap. The work required for the siftDown approach is given by the sum
(0 * n/2) + (1 * n/4) + (2 * n/8) + ... + (h * 1).
Each term in the sum has the maximum distance a node at the given height will have to move (zero for the bottom layer, h for the root) multiplied by the number of nodes at that hei...
What is the formal difference in Scala between braces and parentheses, and when should they be used?
..., and only if, the method expects a single parameter. For example:
List(1, 2, 3).reduceLeft{_ + _} // valid, single Function2[Int,Int] parameter
List{1, 2, 3}.reduceLeft(_ + _) // invalid, A* vararg parameter
However, there’s more you need to know to better grasp these rules.
Increased compile c...
In Matplotlib, what does the argument mean in fig.add_subplot(111)?
... a single integer. For example, "111" means "1x1 grid, first subplot" and "234" means "2x3 grid, 4th subplot".
Alternative form for add_subplot(111) is add_subplot(1, 1, 1).
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Split delimited strings in a column and insert as new rows [duplicate]
...is another way of doing it..
df <- read.table(textConnection("1|a,b,c\n2|a,c\n3|b,d\n4|e,f"), header = F, sep = "|", stringsAsFactors = F)
df
## V1 V2
## 1 1 a,b,c
## 2 2 a,c
## 3 3 b,d
## 4 4 e,f
s <- strsplit(df$V2, split = ",")
data.frame(V1 = rep(df$V1, sapply(s, length))...