Take a subset along an arbitrary dimension

take(x, along, indices, drop = FALSE)

Arguments

x: matrix or array to subset
along: dimension to subset along
indices: the indices to select
drop: should the dimensions of the array be simplified? Defaults to FALSE which is the opposite of the useful R default.

Examples

x <- array(seq_len(3 * 4 * 5), c(3, 4, 5))
take(x, 3, 1)
#> , , 1
#> 
#>      [,1] [,2] [,3] [,4]
#> [1,]    1    4    7   10
#> [2,]    2    5    8   11
#> [3,]    3    6    9   12
#> 
take(x, 2, 1)
#> , , 1
#> 
#>      [,1]
#> [1,]    1
#> [2,]    2
#> [3,]    3
#> 
#> , , 2
#> 
#>      [,1]
#> [1,]   13
#> [2,]   14
#> [3,]   15
#> 
#> , , 3
#> 
#>      [,1]
#> [1,]   25
#> [2,]   26
#> [3,]   27
#> 
#> , , 4
#> 
#>      [,1]
#> [1,]   37
#> [2,]   38
#> [3,]   39
#> 
#> , , 5
#> 
#>      [,1]
#> [1,]   49
#> [2,]   50
#> [3,]   51
#> 
take(x, 1, 1)
#> , , 1
#> 
#>      [,1] [,2] [,3] [,4]
#> [1,]    1    4    7   10
#> 
#> , , 2
#> 
#>      [,1] [,2] [,3] [,4]
#> [1,]   13   16   19   22
#> 
#> , , 3
#> 
#>      [,1] [,2] [,3] [,4]
#> [1,]   25   28   31   34
#> 
#> , , 4
#> 
#>      [,1] [,2] [,3] [,4]
#> [1,]   37   40   43   46
#> 
#> , , 5
#> 
#>      [,1] [,2] [,3] [,4]
#> [1,]   49   52   55   58
#> 
take(x, 3, 1, drop = TRUE)
#>      [,1] [,2] [,3] [,4]
#> [1,]    1    4    7   10
#> [2,]    2    5    8   11
#> [3,]    3    6    9   12
take(x, 2, 1, drop = TRUE)
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    1   13   25   37   49
#> [2,]    2   14   26   38   50
#> [3,]    3   15   27   39   51
take(x, 1, 1, drop = TRUE)
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    1   13   25   37   49
#> [2,]    4   16   28   40   52
#> [3,]    7   19   31   43   55
#> [4,]   10   22   34   46   58