Split single data column in R in NA
I have a large dataset that I want to split into separate units. Right now, these locks are marked with NA, but how do I split them? Sample set:
df=matrix(c(1,2,3,4,NA,6,7,8,NA,10,11,12),ncol=1,byrow=TRUE)
gives us
[,1]
[1,] 1
[2,] 2
[3,] 3
[4,] 4
[5,] NA
[6,] 6
[7,] 7
[8,] 8
[9,] NA
[10,] 10
[11,] 11
[12,] 12
I would like these three to be stored in separate variables, so
a
[,1]
[1,] 1
[2,] 2
[3,] 3
[4,] 4
b
[,1]
[1,] 6
[2,] 7
[3,] 8
c
[,1]
[1,] 10
[2,] 11
[3,] 12
+3
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2 answers
I wasn't sure if you meant a true matrix or data.frame by "dataset". Here's an example data.frame, the matrix would be like
df <- data.frame(a=c(1,2,3,4,NA,6,7,8,NA,10,11,12))
gg <- ifelse(is.na(df$a),NA, cumsum(is.na(df$a)))
split(df, gg)
We just use it gg
as a new variable to count each time we see NA so that we can divide the sections into groups. We also store the NA values to omit for splitting. And finally, split()
with this new categorical variable, does what we want.
$`0`
a
1 1
2 2
3 3
4 4
$`1`
a
6 6
7 7
8 8
$`2`
a
10 10
11 11
12 12
+1
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