How to change the order of elements in a list in R?

A list in R can contain many types of elements such as vector, data frame, matrices, etc. Sometimes the order of these elements matter, especially in situations when we have large size elements because it is difficult to view large size elements of a list. This ordering can be done with the help of single square bracket and combine operator c as shown in the below examples.

Example

 Live Demo

List1<-list(df1<-data.frame(x1=rnorm(20),x2=rnorm(20)),df2<-data.frame(y1=rpois(20,2),y2=rpois(20,6)))
names(List1)<-c("df1","df2")
List1

$df1

Output

        x1       x2
1 1.16664910    -0.12690835
2 -0.02385061   0.93010444
3 -0.73161055   -0.37920223
4 -0.17374218   1.74496001
5 -0.52846135   -0.54911936
6 0.15400858    0.26907145
7 0.62521370    -0.26914570
8 -1.29781529   -0.17368829
9 0.58040525    -0.69834218
10 0.73182782   -0.32848811
11 0.68748989   -0.43500960
12 0.18038886   -1.43329773
13 0.13023523   0.67122340
14 1.06490726   -0.50004983
15 1.44445206    -0.03914249
16 -1.30134077   0.16116851
17 1.17845705    0.10204926
18 0.06419740    1.28705524
19 0.21390196    0.41047054
20 -2.02748272   -1.03792946

Example

$df2

Output

   y1  y2
1  1   8
2  3   8
3  5   9
4  0   7
5  3   4
6  1   3
7  2  10
8  0   6
9  1   5
10 1  4
11 2  6
12 0  10
13 2  14
14 3   8
15 5  14
16 2   2
17 0  9
18 1  6
19 1  7
20 4  8

Example

List1<-List1[c("df2","df1")]
List1

$df2

Output

    y1  y2
1   1   8
2   3   8
3   5   9
4   0   7
5   3   4
6   1   3
7   2   10
8   0   6
9   1   5
10  1   4
11  2   6
12  0   10
13  2   14
14  3   8
15  5   14
16  2   2
17  0   9
18  1   6
19  1   7
20  4   8

Example

$df1

Output

         x1       x2
1  1.16664910   -0.12690835
2  -0.02385061   0.93010444
3  -0.73161055   -0.37920223
4  -0.17374218   1.74496001
5  -0.52846135   -0.54911936
6  0.15400858    0.26907145
7  0.62521370   -0.26914570
8  -1.29781529  -0.17368829
9  0.58040525   -0.69834218
10  0.73182782  -0.32848811
11  0.68748989   -0.43500960
12  0.18038886   -1.43329773
13  0.13023523   0.67122340
14  1.06490726   -0.50004983
15  1.44445206   -0.03914249
16  -1.30134077   0.16116851
17  1.17845705    0.10204926
18  0.06419740    1.28705524
19  0.21390196    0.41047054
20  -2.02748272    -1.03792946

Example

 Live Demo

List2<-list(M1<-matrix(1:25,ncol=5),M2<-matrix(26:50,ncol=5))
names(List2)<-c("M1","M2")
List2

Output

$M1
    [,1] [,2] [,3] [,4] [,5]
[1,] 1   6    11    16   21
[2,] 2   7    12    17   22
[3,] 3   8    13    18   23
[4,] 4   9    14    19   24
[5,] 5   10   15    20   25
$M2
     [,1] [,2] [,3] [,4] [,5]
[1,] 26   31   36    41   46
[2,] 27   32   37    42   47
[3,] 28   33   38    43   48
[4,] 29   34   39    44   49
[5,] 30   35   40    45   50

Example

List2<-List2[c("M2","M1")]
List2

Output

$M2
    [,1] [,2] [,3] [,4] [,5]
[1,] 26   31    36   41   46
[2,] 27   32     37  42   47
[3,] 28   33    38   43   48
[4,] 29   34    39  44    49
[5,] 30   35    40   45   50
$M1
   [,1] [,2] [,3] [,4] [,5]
[1,] 1    6    11   16   21
[2,] 2    7    12   17   22
[3,] 3    8    13   18   23
[4,] 4    9    14   19  24
[5,] 5    10   15   20   25

Nizamuddin Siddiqui

e

Updated on: 06-Feb-2021

1K+ Views

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