# How to create a matrix without column and row indices in R?

To create a matrix without column and row indices, we first need to create the matrix and then prmatrix function can be used to convert that matrix without column and row indices but we would need to provide the number of rows inside the function. For example, if we have a matrix M that contains 5 rows and 5 columns then it can be converted to a matrix without column and row indices using prmatrix(M,rowlab=rep("",5),collab=rep("",5)).

## Example

Live Demo

M1<-matrix(rnorm(25),ncol=5)
M1

## Output

         [,1]       [,2]       [,3]    [,4]       [,5]
[1,] -0.3524287 0.4753824 -0.7817841 0.4452398 1.5483299
[2,] 0.7659213 0.8160877 -0.9124624 0.3859241 -0.3645244
[3,] -0.7511866 0.4664604 -2.3584599 0.2926155 0.0354159
[4,] -0.2477745 -0.7132980 -0.6503972 -0.3519619 -0.7805707
[5,] 0.5781549 -0.1417311 -0.4956891 1.1003766 0.2343090

## Example

prmatrix(M1,rowlab=rep("",5),collab=rep("",5))

## Output

-0.3524287 0.4753824 -0.7817841 0.4452398 1.5483299
0.7659213 0.8160877 -0.9124624 0.3859241 -0.3645244
-0.7511866 0.4664604 -2.3584599 0.2926155 0.0354159
-0.2477745 -0.7132980 -0.6503972 -0.3519619 -0.7805707
0.5781549 -0.1417311 -0.4956891 1.1003766 0.2343090

## Example

Live Demo

M2<-matrix(rpois(81,2),ncol=9)
M2

## Output

   [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
[1,] 3    1    3    2    0    2    0    2    4
[2,] 3    0    1    4    0    3    2    1    2
[3,] 4    3    2    1    4    3    3    3    4
[4,] 0    2    3    3    1    2    2    3    4
[5,] 1    1    2    3    2    1    2    4    1
[6,] 2    3    0    1    1    2    4    3    2
[7,] 6    3    0    1    2    0    1    1    1
[8,] 6    3    3    2    5    1    0    0    0
[9,] 4    1    2    3    2    2    0    1    3

## Example

prmatrix(M2,rowlab=rep("",9),collab=rep("",9))

## Output

3 1 3 2 0 2 0 2 4
3 0 1 4 0 3 2 1 2
4 3 2 1 4 3 3 3 4
0 2 3 3 1 2 2 3 4
1 1 2 3 2 1 2 4 1
2 3 0 1 1 2 4 3 2
6 3 0 1 2 0 1 1 1
6 3 3 2 5 1 0 0 0
4 1 2 3 2 2 0 1 3

## Example

Live Demo

M3<-matrix(rexp(36,1.27),ncol=2)
M3

## Output

      [,1]          [,2]
[1,] 1.90172301 0.17485982
[2,] 0.72992558 1.22893098
[3,] 0.34723400 0.03796494
[4,] 0.03941449 1.95001158
[5,] 1.04126572 1.14392629
[6,] 0.25201154 0.57012496
[7,] 1.30187720 0.96230866
[8,] 1.13920057 1.40368354
[9,] 1.41180402 0.12139199
[10,] 0.53137688 0.01768795
[11,] 0.05370309 1.69081321
[12,] 1.13580395 0.11810967
[13,] 0.56185639 1.44204980
[14,] 1.51025894 0.23696430
[15,] 1.26819806 0.07203026
[16,] 0.30501141 0.14618651
[17,] 0.93060957 0.07317170
[18,] 0.92067027 0.08642117

## Example

prmatrix(M3,rowlab=rep("",18),collab=rep("",18))

## Output

1.90172301 0.17485982
0.72992558 1.22893098
0.34723400 0.03796494
0.03941449 1.95001158
1.04126572 1.14392629
0.25201154 0.57012496
1.30187720 0.96230866
1.13920057 1.40368354
1.41180402 0.12139199
0.53137688 0.01768795
0.05370309 1.69081321
1.13580395 0.11810967
0.56185639 1.44204980
1.51025894 0.23696430
1.26819806 0.07203026
0.30501141 0.14618651
0.93060957 0.07317170
0.92067027 0.08642117

## Example

Live Demo

M4<-matrix(runif(40,2,5),nrow=20)
M4

## Output

      [,1]       [,2]
[1,] 2.884068 2.732077
[2,] 3.694684 2.517772
[3,] 4.165912 3.924986
[4,] 3.752682 2.414989
[5,] 3.199349 4.666055
[6,] 2.365035 3.800645
[7,] 3.121915 2.395140
[8,] 2.147690 2.463121
[9,] 4.697216 4.965934
[10,] 2.094644 4.681206
[11,] 4.071888 2.360031
[12,] 3.047279 2.485864
[13,] 2.921051 4.556291
[14,] 4.655183 4.367924
[15,] 4.727901 3.647091
[16,] 4.807526 4.086226
[17,] 2.193533 2.246970
[18,] 3.198273 3.197613
[19,] 2.371362 3.260453
[20,] 4.070255 3.981377

## Example

prmatrix(M4,rowlab=rep("",20),collab=rep("",20))

## Output

2.884068 2.732077
3.694684 2.517772
4.165912 3.924986
3.752682 2.414989
3.199349 4.666055
2.365035 3.800645
3.121915 2.395140
2.147690 2.463121
4.697216 4.965934
2.094644 4.681206
4.071888 2.360031
3.047279 2.485864
2.921051 4.556291
4.655183 4.367924
4.727901 3.647091
4.807526 4.086226
2.193533 2.246970
3.198273 3.197613
2.371362 3.260453
4.070255 3.981377