A function that takes two integers representing the numbers of rows and columns in a matrix and returns a matrix of these dimensions in which the value of each cell is the product of the row number x column number.
matDims <- function(nr=sample(1:20,size=1),nc=sample(1:20,size=1)){
mat = matrix(0,nr=nr,nc=nc)
for (r in 1:nr){
for (c in 1:nc){
mat[r,c] = r*c
}}
return(mat)
}
matDims()
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13]
## [1,] 1 2 3 4 5 6 7 8 9 10 11 12 13
## [2,] 2 4 6 8 10 12 14 16 18 20 22 24 26
## [3,] 3 6 9 12 15 18 21 24 27 30 33 36 39
## [4,] 4 8 12 16 20 24 28 32 36 40 44 48 52
## [5,] 5 10 15 20 25 30 35 40 45 50 55 60 65
## [6,] 6 12 18 24 30 36 42 48 54 60 66 72 78
## [7,] 7 14 21 28 35 42 49 56 63 70 77 84 91
## [8,] 8 16 24 32 40 48 56 64 72 80 88 96 104
## [9,] 9 18 27 36 45 54 63 72 81 90 99 108 117
## [10,] 10 20 30 40 50 60 70 80 90 100 110 120 130
## [11,] 11 22 33 44 55 66 77 88 99 110 121 132 143
## [12,] 12 24 36 48 60 72 84 96 108 120 132 144 156
## [13,] 13 26 39 52 65 78 91 104 117 130 143 156 169
## [14,] 14 28 42 56 70 84 98 112 126 140 154 168 182
## [15,] 15 30 45 60 75 90 105 120 135 150 165 180 195
## [,14] [,15] [,16] [,17] [,18] [,19]
## [1,] 14 15 16 17 18 19
## [2,] 28 30 32 34 36 38
## [3,] 42 45 48 51 54 57
## [4,] 56 60 64 68 72 76
## [5,] 70 75 80 85 90 95
## [6,] 84 90 96 102 108 114
## [7,] 98 105 112 119 126 133
## [8,] 112 120 128 136 144 152
## [9,] 126 135 144 153 162 171
## [10,] 140 150 160 170 180 190
## [11,] 154 165 176 187 198 209
## [12,] 168 180 192 204 216 228
## [13,] 182 195 208 221 234 247
## [14,] 196 210 224 238 252 266
## [15,] 210 225 240 255 270 285