[R] Transfer a 3-dimensional array to a matrix in R

[William Dunlap]

Or use aperm() (array index permuation):
  > array(aperm(x, c(2,1,3)), c(6,3))
       [,1] [,2] [,3]
  [1,]    1    7   13
  [2,]    4   10   16
  [3,]    2    8   14
  [4,]    5   11   17
  [5,]    3    9   15
  [6,]    6   12   18

Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Tue, Oct 20, 2015 at 11:31 AM, John Laing <john.laing at gmail.com> wrote:
>> x <- array(1:18, dim=c(3, 2, 3))
>> x
> , , 1
>
>      [,1] [,2]
> [1,]    1    4
> [2,]    2    5
> [3,]    3    6
>
> , , 2
>
>      [,1] [,2]
> [1,]    7   10
> [2,]    8   11
> [3,]    9   12
>
> , , 3
>
>      [,1] [,2]
> [1,]   13   16
> [2,]   14   17
> [3,]   15   18
>
>> apply(x, 3, t)
>      [,1] [,2] [,3]
> [1,]    1    7   13
> [2,]    4   10   16
> [3,]    2    8   14
> [4,]    5   11   17
> [5,]    3    9   15
> [6,]    6   12   18
>
>
> On Tue, Oct 20, 2015 at 12:39 PM, Chunyu Dong <dongchunyu2004 at 163.com>
> wrote:
>
>> Hello!
>>
>>
>> Recently I am trying to transfer a large 3-dimensional array to a matrix.
>> For example, a array like:
>> , , 1
>>      [,1] [,2]
>> [1,]    1    4
>> [2,]    2    5
>> [3,]    3    6
>> , , 2
>>      [,1] [,2]
>> [1,]    7   10
>> [2,]    8   11
>> [3,]    9   12
>> , , 3
>>      [,1] [,2]
>> [1,]   13   16
>> [2,]   14   17
>> [3,]   15   18
>>
>>
>> I would like to transfer it to a matrix like:
>> 1        7          13
>> 4        10        16
>> 2        8          14
>> 5        11        17
>> 3        9          15
>> 6        12        18
>>
>>
>> Could you tell me how to do it in R ? Thank you very much!
>>
>>
>> Best regards,
>> Chunyu
>>
>>
>>
>>
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.