CODEWITHSUNDEEP
arraysr
Ann M
Ann M

Reputation: 249

R - Re-arranging arrays

I apologize since I don't know if theres and specific way to ask this. To simplify everything, I have the following array:

set.seed(4)
data <- array(rexp(12), dim=c(3,2,2))

 , , 1

          [,1]      [,2]
[1,] 0.1716006 0.8026470
[2,] 4.3039449 0.6271484
[3,] 0.8681056 0.7348583

, , 2

           [,1]      [,2]
[1,] 0.44881179 0.8371497
[2,] 0.05069988 2.6802979
[3,] 0.50935005 0.2880769

And I want to obtain an array with [6,2] dimensions like this:

     , 1

              [,1]      [,2]       [,3]        [,4]       [,5]       [,6]
    [1,] 0.1716006 0.8026470  4.3039449   0.6271484  0.8681056  0.7348583

     , 2
          [,1]        [,2]        [,3]        [,4]       [,5]       [,6]
  [1,] 0.44881179 0.8371497  0.05069988  2.6802979  0.50935005  0.2880769

I would like to do this with a for loop since my arrays have [633,333,12] dimensions but everything is welcomed.

Upvotes: 2

Views: 72

Answers (3)

markus
markus

Reputation: 26343

We could use aperm to permute data, where we change the first dimension and second dimension of the array:

data <- aperm(data, perm = c(2, 1, 3))
data
#, , 1
#
#     [,1]      [,2]      [,3]
#[1,] 0.1716006 4.3039449 0.8681056
#[2,] 0.8026470 0.6271484 0.7348583
#
#, , 2
#
#          [,1]       [,2]      [,3]
#[1,] 0.4488118 0.05069988 0.5093501
#[2,] 0.8371497 2.68029789 0.2880769

Now change its dimension with dim<-

dim(data) <- c(1, 6, 2)
data
#, , 1
#
#          [,1]     [,2]     [,3]      [,4]      [,5]      [,6]
#[1,] 0.1716006 0.802647 4.303945 0.6271484 0.8681056 0.7348583
#
#, , 2
#
#          [,1]      [,2]       [,3]     [,4]      [,5]      [,6]
#[1,] 0.4488118 0.8371497 0.05069988 2.680298 0.5093501 0.2880769

Upvotes: 2

MKR
MKR

Reputation: 20085

An option can be as using 3rd dimension of data as:

sapply(1:dim(data)[3],function(x)t(data[,,x]))

#           [,1]       [,2]
# [1,] 0.1716006 0.44881179
# [2,] 0.8026470 0.83714966
# [3,] 4.3039449 0.05069988
# [4,] 0.6271484 2.68029789
# [5,] 0.8681056 0.50935005
# [6,] 0.7348583 0.28807690

Upvotes: 0

moooh
moooh

Reputation: 469

Would this work?

apply(data,3,c)

Upvotes: 1

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