How to create three-dimensional arrays of different sizes in R?

A three-dimensional array can have matrices of different size and they are not necessarily to be square or rectangular. Also, all the elements in an array are of same data type. To create a three-dimensional array of different size we would need to use the proper number of rows and columns within the array function.

Example

 Live Demo

A1<-array(c(1:4,5:8,9:12),c(2,2,3))
A1

Output

, , 1
[,1] [,2]
[1,] 1 3
[2,] 2 4
, , 2
[,1] [,2]
[1,] 5 7
[2,] 6 8
, , 3
[,1] [,2]
[1,] 9 11
[2,] 10 12

Example

 Live Demo

A2<-array(c(rpois(4,1),rpois(4,5),rpois(4,8)),c(2,2,3))
A2

Output

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

Example

 Live Demo

A3<-array(c(rpois(10,1),rpois(10,5),rpois(10,8)),c(2,5,3))
A3

Output

, , 1
[,1] [,2] [,3] [,4] [,5]
[1,] 1 0 1 1 0
[2,] 2 0 1 1 1
, , 2
[,1] [,2] [,3] [,4] [,5]
[1,] 7 4 8 5 4
[2,] 4 4 6 4 6
, , 3
[,1] [,2] [,3] [,4] [,5]
[1,] 5 4 11 9 7
[2,] 3 9 10 11 4

Example

 Live Demo

A4<-array(c(rnorm(25,1,0.25),rnorm(25,5,3.2),rnorm(25,125,8)),c(5,5,3))
A4

Output

, , 1
         [,1]       [,2]    [,3]       [,4]    [,5]
[1,] 0.9965280 1.2496879 1.0314247 0.708599 0.8077254
[2,] 0.7922626 1.0025704 0.7009782 1.142506 0.7445184
[3,] 1.0053649 0.5531278 1.4328092 1.385334 1.0892912
[4,] 0.9793857 1.3234864 0.5553419 1.215801 1.1023305
[5,] 1.3995579 1.0262346 1.2721514 1.394952 0.6184446
, , 2
         [,1]    [,2]       [,3]     [,4] [,5]
[1,] 6.174299 6.038592 12.470821 1.722607 1.069005
[2,] 3.789770 8.430932 8.747260 7.552801 3.886604
[3,] 1.730295 2.493142 3.465323 3.507519 3.834119
[4,] 6.075908 7.348407 4.118381 6.081857 4.167369
[5,] 4.130724 6.829041 7.469443 3.409544 5.808045
, , 3
      [,1]       [,2]     [,3]    [,4]    [,5]
[1,] 110.6113 119.8429 121.6303 122.9954 140.5715
[2,] 125.5317 122.1797 135.2451 119.5165 122.9406
[3,] 124.0559 119.0249 135.1922 114.0559 112.1363
[4,] 118.1446 119.0530 134.6688 118.8334 124.4825
[5,] 120.2941 109.3362 119.8095 129.1414 127.6529

Example

 Live Demo

A5<-array(c(rexp(25,1.25),rexp(25,3.2),rexp(25,1.37)),c(5,5,3))
A5

Output

, , 1
      [,1]       [,2]       [,3]       [,4]       [,5]
[1,] 1.3964752 0.14365375 0.1244120 0.006844883 0.1649243
[2,] 0.4146687 0.74798876 1.3172895 0.273072680 1.9675031
[3,] 0.5640029 0.05317204 0.1365023 1.139974748 0.4691554
[4,] 3.4377135 0.40737835 0.1296337 3.827344957 0.3062992
[5,] 0.5489296 0.68912311 0.9960337 1.891826684 0.6505368
, , 2
         [,1]        [,2]       [,3]       [,4]    [,5]
[1,] 0.461391444 0.14704248 1.7219179 0.26808968 0.01277777
[2,] 0.002633461 0.02843441 0.5924807 0.59324483 1.34762650
[3,] 0.296192070 0.38350989 0.3453407 0.14514950 0.21145723
[4,] 0.137173681 0.34683067 0.9046680 0.05949873 0.42690397
[5,] 0.171683422 0.12761626 0.3183557 0.01596812 0.04222600
, , 3
         [,1]       [,2]       [,3]       [,4]    [,5]
[1,] 0.7641526 0.78719016 0.96282362 0.02212902 0.3261842
[2,] 1.1584192 1.20147453 0.03766346 0.30549609 1.1452613
[3,] 0.5849248 1.97291039 0.52678525 0.78435948 0.0107882
[4,] 2.1916248 0.09176414 1.40056593 1.11841176 0.7624021
[5,] 0.1565796 1.35400081 0.26728881 0.36045571 0.3076494

Nizamuddin Siddiqui

Updated on: 08-Dec-2020

661 Views

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