How to remove the row names or column names from a matrix in R?

R ProgrammingServer Side ProgrammingProgramming

To remove the row names or column names from a matrix, we just need to set them to NULL, in this way all the names will be nullified. For example, if we have a matrix M that contain row names and column names then we can remove those names by using the command colnames(M)<-NULL for columns and rownames(M)<-NULL for rows.

Example

 Live Demo

M1<-matrix(1:100,ncol=10)
M1

Output

    [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,]  1   11 21 31 41 51 61 71 81 91
[2,]  2   12 22 32 42 52 62 72 82 92
[3,]  3   13 23 33 43 53 63 73 83 93
[4,]  4   14 24 34 44 54 64 74 84 94
[5,]  5   15 25 35 45 55 65 75 85 95
[6,]  6   16 26 36 46 56 66 76 86 96
[7,]  7 17 27 37 47 57 67 77 87 97
[8,]  8 18 28 38 48 58 68 78 88 98
[9,]  9 19 29 39 49 59 69 79 89 99
[10,] 10 20 30 40 50 60 70 80 90 100

Example

colnames(M1)<-LETTERS[1:10]
M1

Output

      A  B  C  D E F G H I J
[1,] 1 11 21 31 41 51 61 71 81 91
[2,] 2 12 22 32 42 52 62 72 82 92
 [3,] 3 13 23 33 43 53 63 73 83 93
[4,] 4 1 4 24 34 44 54 64 74 84 94
[5,] 5 15 25 35 45 55 65 75 85 95
[6,] 6 16 26 36 46 56 66 76 86 96
[7,] 7 17 27 37 47 57 67 77 87 97
[8,] 8 18 28 38 48 58 68 78 88 98
[9,] 9 19 29 39 49 59 69 79 89 99
[10,] 10 20 30 40 50 60 70 80 90 100

Example

colnames(M1)<-NULL
M1

Output

  [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 1 11 21 31 41 51 61 71 81 91
[2,] 2 12 22 32 42 52 62 72 82 92
[3,] 3 13 23 33 43 53 63 73 83 93
[4,] 4 14 24 34 44 54 64 74 84 94
[5,] 5 15 25 35 45 55 65 75 85 95
[6,] 6 16 26 36 46 56 66 76 86 96
[7,] 7 17 27 37 47 57 67 77 87 97
[8,] 8 18 28 38 48 58 68 78 88 98
[9,] 9 19 29 39 49 59 69 79 89 99
[10,] 10 20 30 40 50 60 70 80 90 100

Example

rownames(M1)<-letters[1:10]
M1

Output

[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
 a 1 11 21 31 41 51 61 71 81 91
b 2 12 22 32 42 52 62 72 82 92
c 3 13 23 33 43 53 63 73 83 93
d 4 14 24 34 44 54 64 74 84 94
e 5 15 25 35 45 55 65 75 85 95
f 6 16 26 36 46 56 66 76 86 96
g 7 17 27 37 47 57 67 77 87 97
h 8 18 28 38 48 58 68 78 88 98
i 9 19 29 39 49 59 69 79 89 99
j 10 20 30 40 50 60 70 80 90 100

Example

rownames(M1)<-NULL
M1

Output

  [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 1 11 21 31 41 51 61 71 81 91
[2,] 2 12 22 32 42 52 62 72 82 92
[3,] 3 13 23 33 43 53 63 73 83 93
[4,] 4 14 24 34 44 54 64 74 84 94
[5,] 5 15 25 35 45 55 65 75 85 95
[6,] 6 16 26 36 46 56 66 76 86 96
[7,] 7 17 27 37 47 57 67 77 87 97
[8,] 8 18 28 38 48 58 68 78 88 98
[9,] 9 19 29 39 49 59 69 79 89 99
[10,] 10 20 30 40 50 60 70 80 90 100

Example

 Live Demo

M2<-matrix(rnorm(50),nrow=10)
M2

Output

      [,1]        [,2]       [,3]         [,4]     [,5]
[1,]  0.6802874   0.2144306  -1.4145804  0.62402960 -0.5938315
[2,]  0.4536187   0.5653905   0.6312822  2.56036083  0.7728485
[3,]  2.1096132  -0.7314662   0.3260058 -0.98057417 -0.3724911
[4,] -0.5953890   0.6637290  -1.6762956 -1.61804847  0.8662887
[5,] -0.7562208  -0.9417305  -1.7037116  0.60382315 -0.5236230
[6,] -1.2611174  -2.1865329  -0.2465629 -2.00149510 -1.0256434
[7,]  0.7827362  -0.8577172   1.1250864 -1.13954661  0.3187836
[8,] -0.8423010  -1.7105257  -0.2722357 -0.05741225 -0.9454204
[9,] -0.8249438   0.7572876   0.5679531  0.43816230 -1.5323482
[10,] 1.0914719  -0.9003930   0.7307768 -0.12886355 -1.5271211

Example

colnames(M2)<-c("S1","S2","S3","S4","S5")
M2

Output

         S1             S2        S3          S4          S5
[1,] -0.21369037  -0.26807549   0.5780368   0.403231225 -0.3898034
[2,] -1.05153856  -0.91487726  -0.2038823   0.904563419  0.4286243
[3,] -0.10755935   0.36254026  -1.3386091  -0.218132138  0.3148615
[4,]  0.73045398  -0.09284451  -0.1476228  -1.196201762  1.3801728
[5,]  2.32148727  -1.51292926   1.7808169  -0.135465061 -0.8747653
[6,]  1.03602597   1.12718811   0.6376310  -0.009445365 -1.4074674
[7,] -0.05036301  -1.04252829  -0.8978156  -1.079780864  0.3735876
[8,]  1.01912253   1.28759140   0.1640043  -1.126854167 -0.2303916
[9,]  0.93337641  -1.24223632   0.6052778  -0.003241698  0.2684704
[10,] 0.30957289  -1.39528971  -0.7803917   0.946891126 -0.9375629

Example

colnames(M2)<-NULL
M2

Output

        [,1] [,2] [,3] [,4] [,5]
[1,] -0.21369037 -0.26807549 0.5780368 0.403231225 -0.3898034
 [2,] -1.05153856 -0.91487726 -0.2038823 0.904563419 0.4286243
[3,] -0.10755935 0.36254026 -1.3386091 -0.218132138 0.3148615
[4,] 0.73045398 - 0.09284451 -0.1476228 -1.196201762 1.3801728
[5,] 2.32148727 -1.51292926 1.7808169 -0.135465061 -0.8747653
[6,] 1.03602597 1.12718811 0.6376310 -0.009445365 -1.4074674
[7,] -0.05036301 -1.04252829 -0.8978156 -1.079780864 0.3735876
[8,] 1.01912253 1.28759140 0.1640043 -1.126854167 - 0.2303916
[9,] 0.93337641 - 1.24223632 0.6052778 -0.003241698 0.2684704
[10,] 0.30957289 -1.39528971 -0.780391 0.946891126 -0.9375629

Example

rownames(M2)<-c("R1","R2","R3","R4","R5","R6","R7","R8","R9","R10")
M2

Output

    [,1] [,2] [,3] [,4] [,5]
R1 -0.21369037 - 0.26807549 0.5780368 0.403231225 -0.3898034
 R2 -1.05153856 -0.91487726 -0.2038823 0.904563419 0.4286243
 R3 -0.10755935 0.36254026 -1.3386091 -0.218132138 0.3148615
 R4 0.73045398 -0.09284451 -0.1476228 -1.196201762 1.3801728
R5 2.32148727 -1.51292926 1.7808169 -0.135465061 -0.8747653
R6 1.03602597 1.12718811 0.6376310 -0.009445365 - 1.4074674
R7 -0.05036301 -1.04252829 -0.8978156 -1.079780864 0.3735876
 R8 1.01912253 1.28759140 0.1640043 -1.126854167 -0.2303916
R9 0.93337641 -1.24223632 0.6052778 -0.003241698 0.2684704
R10 0.30957289 -1.39528971 -0.7803917 0.946891126 -0.9375629

Example

rownames(M2)<-NULL
M2

Output

      [,1] [,2] [,3] [,4] [,5]
[1,] -0.21369037 -0.26807549 0.5780368 0.403231225 -0.3898034
[2,] -1.05153856 -0.91487726 -0.2038823 0.904563419 0.4286243
[3,] -0.10755935 0.36254026 -1.3386091 -0.218132138 0.3148615
[4,] 0.73045398 -0.09284451 -0.1476228 - 1.196201762 1.3801728
[5,] 2.32148727 -1.51292926 1.7808169 -0.135465061 -0.8747653
[6,] 1.03602597 1.12718811 0.6376310 -0.009445365 -1.4074674
[7,] -0.05036301 -1.04252829 -0.8978156 - 1.079780864 0.3735876
[8,] 1.01912253 1.28759140 0.1640043 -1.126854167 -0.2303916
[9,] 0.93337641 -1.24223632 0.6052778 -0.003241698 0.2684704
[10,] 0.30957289 -1.39528971 -0.7803917 0.946891126 -0.9375629
raja
Published on 16-Oct-2020 15:47:24
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