Insert a dimension into an rray

rray_expand() inserts a new dimension at the axis dimension. This expands the number of dimensions of x by 1.

rray_expand(x, axis)

Arguments

x	An rray.
axis	An integer of size 1 specifying the location of the new dimension.

Value

x with a new dimension inserted at the axis.

Details

Dimension names are kept through the insertion of the new dimension.

Examples

x <- rray(1:10, c(5, 2))
x <- rray_set_row_names(x, letters[1:5])
x <- rray_set_col_names(x, c("c1", "c2"))

# (5, 2)
# Add dimension to the front
# (1, 5, 2) = 1 row, 5 cols, 2 deep
rray_expand(x, 1)
#> <rray<int>[,5,2][1]>
#> , , c1
#> 
#>      a b c d e
#> [1,] 1 2 3 4 5
#> 
#> , , c2
#> 
#>      a b c d  e
#> [1,] 6 7 8 9 10
#> 

# (5, 2)
# Add dimension to the middle
# (5, 1, 2) = 5 rows, 1 col, 2 deep
rray_expand(x, 2)
#> <rray<int>[,1,2][5]>
#> , , c1
#> 
#>   [,1]
#> a    1
#> b    2
#> c    3
#> d    4
#> e    5
#> 
#> , , c2
#> 
#>   [,1]
#> a    6
#> b    7
#> c    8
#> d    9
#> e   10
#> 

# (5, 2)
# Add dimension to the end
# (5, 2, 1) = 5 rows, 2 cols, 1 deep
rray_expand(x, 3)
#> <rray<int>[,2,1][5]>
#> , , 1
#> 
#>   c1 c2
#> a  1  6
#> b  2  7
#> c  3  8
#> d  4  9
#> e  5 10
#> 

# In some cases this is different than a simple
# rray_reshape() because the dimension names
# follow the original dimension position
# - 5 row names follow to the new 5 column position
# - 2 col names follow to the new 2 deep position
# - result has no row names because that is the new axis
rray_expand(x, 1)
#> <rray<int>[,5,2][1]>
#> , , c1
#> 
#>      a b c d e
#> [1,] 1 2 3 4 5
#> 
#> , , c2
#> 
#>      a b c d  e
#> [1,] 6 7 8 9 10
#> 

# A reshape, on the other hand,
# drops all dimension names
rray_reshape(x, c(1, 5, 2))
#> <rray<int>[,5,2][1]>
#> , , 1
#> 
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    1    2    3    4    5
#> 
#> , , 2
#> 
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    6    7    8    9   10
#>