How to create a column of absolute values in data frames stored in R list?
To create a column of absolute values in data frames stored in R list, we can follow the below steps −
First of all, create a list of data frames.
Then, use lapply function to create a column of absolute values in data frames stored in the list.
Example
Create the list of data frames
Using data.frame function to create data frames and list function to create the list of those data frames −
df1<-data.frame(x=sample(-20:10,25))
df2<-data.frame(x=sample(-20:10,25))
List<-list(df1,df2)
List
Output
On executing, the above script generates the below output(this output will vary on your system due to randomization) −
[[1]]
x
1 -5
2 -19
3 -14
4 1
5 0
6 -3
7 -12
8 9
9 7
10 -13
11 -18
12 -15
13 -10
14 -17
15 -1
16 4
17 -9
18 -11
19 -6
20 -20
21 10
22 8
23 -8
24 3
25 -7
[[2]]
x
1 -7
2 -16
3 10
4 -8
5 -5
6 2
7 -18
8 -6
9 -13
10 5
11 -17
12 9
13 -15
14 -9
15 8
16 -10
17 -2
18 -20
19 6
20 -4
21 -3
22 -1
23 -14
24 7
25 0Create a column of absolute values
Using lapply function to create a column of absolute values in data frames df1 and df2 stored in the list called List as shown below −
df1<-data.frame(x=sample(-20:10,25))
df2<-data.frame(x=sample(-20:10,25))
List<-list(df1,df2)
lapply(List,function(x) {
+ x$Absolute<-abs(x$x)
+ return(x)
+ })Output
[[1]]
x Absolute
1 -6 6
2 3 3
3 -12 12
4 -3 3
5 -9 9
6 -1 1
7 -5 5
8 10 10
9 -4 4
10 4 4
11 -7 7
12 9 9
13 -13 13
14 -8 8
15 -11 11
16 -20 20
17 -16 16
18 -2 2
19 -18 18
20 7 7
21 -17 17
22 1 1
23 0 0
24 8 8
25 6 6
[[2]]
x Absolute
1 -7 7
2 -3 3
3 -5 5
4 -1 1
5 -17 17
6 5 5
7 -13 13
8 0 0
9 -19 19
10 -2 2
11 -6 6
12 -18 18
13 3 3
14 -10 10
15 -9 9
16 6 6
17 7 7
18 -15 15
19 -4 4
20 -16 16
21 2 2
22 9 9
23 4 4
24 1 1
25 -20 20
Published on 10-Nov-2021 06:08:33
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