Three dimensional array to list

You can use lapply:

lapply(seq(dim(MyArray)[3]), function(x) MyArray[ , , x])# [[1]]#           [,1]       [,2]      [,3]# [1,] 0.2050745 0.21410846 0.2433970# [2,] 0.9662453 0.93294504 0.1466763# [3,] 0.5775559 0.86977616 0.6950287# [4,] 0.4626039 0.04009952 0.5197830# # [[2]]#           [,1]      [,2]      [,3]# [1,] 0.6323070 0.2684788 0.7232186# [2,] 0.1986486 0.2096121 0.2878846# [3,] 0.3064698 0.7326781 0.8339690# [4,] 0.3068035 0.4559094 0.8783581# # [[3]]#           [,1]      [,2]      [,3]# [1,] 0.9557156 0.9069851 0.3415961# [2,] 0.5287296 0.6292590 0.8291184# [3,] 0.4023539 0.8106378 0.4257489# [4,] 0.7199638 0.2708597 0.6327383

There is a handy function in plyr for this:

alply(MyArray,3)$`1`          [,1]       [,2]       [,3][1,] 0.7643427 0.27546113 0.31131581[2,] 0.6254926 0.19449191 0.04617286[3,] 0.5879341 0.10484810 0.08056612[4,] 0.4423744 0.09046864 0.82333646$`2`          [,1]      [,2]      [,3][1,] 0.3726026 0.3063512 0.4997664[2,] 0.8757070 0.2309768 0.9274503[3,] 0.9269987 0.5751226 0.9347077[4,] 0.4063655 0.4593746 0.4830263$`3`          [,1]       [,2]      [,3][1,] 0.7538325 0.18824996 0.3679285[2,] 0.4985409 0.61026876 0.4134485[3,] 0.3209792 0.60056130 0.8887652[4,] 0.0160972 0.06534362 0.2618056

You can keep the dimension names simply by adding the .dims argument:

dimnames(MyArray) <- Map(paste0, letters[seq_along(dim(MyArray))],                                  lapply(dim(MyArray), seq))alply(MyArray,3,.dims = TRUE)$c1    ba           b1         b2        b3  a1 0.4752803 0.01728003 0.1744352  a2 0.7144411 0.13353980 0.1069188  a3 0.2429445 0.60039428 0.8610824  a4 0.9757289 0.71712288 0.5941202$c2    ba            b1         b2        b3  a1 0.07118296 0.43761119 0.3174442  a2 0.16458581 0.65040897 0.5654846  a3 0.88711374 0.07655825 0.7163768  a4 0.07117881 0.79314705 0.9054457$c3    ba            b1        b2         b3  a1 0.04761279 0.5668479 0.04145537  a2 0.72320804 0.2692747 0.74700930  a3 0.82138686 0.3604211 0.57163369  a4 0.53325169 0.8831302 0.71119421

For fun (since I'm late), here is another one that only uses base R. Like @joran's, it is programmable in the sense you can easily split along any given dimension n:

split.along.dim <- function(a, n)  setNames(lapply(split(a, arrayInd(seq_along(a), dim(a))[, n]),                  array, dim = dim(a)[-n], dimnames(a)[-n]),           dimnames(a)[[n]])identical(split.along.dim(MyArray, n = 3), MyList)# [1] TRUE

It will also preserve all your dimnames if you have any, see for example:

dimnames(MyArray) <- Map(paste0, letters[seq_along(dim(MyArray))],                                 lapply(dim(MyArray), seq))split.along.dim(MyArray, n = 3)