Repeat an array

• rray_rep() repeats whole axes of x in bulk, i.e. repeat all of the columns 5 times. It can repeat several axes at once, with one times per axis.

• rray_rep_each() repeats each individual element of the axis of x separately, i.e. repeat the first column 2 times, the second column 3 times, and so on. For convenience, you can also provide a single number to repeat each element along the axis the same number of times.

These are the array versions of vctrs::vec_rep() and vctrs::vec_rep_each(), which repeat along the size of a vector rather than along an axis.

Usage

rray_rep(x, ..., times, axes)

rray_rep_each(x, ..., times, axis)

Arguments

x

An array.

...

These dots are for future extensions and must be empty.

times

For rray_rep(), a vector of integers greater than or equal to 0, either size 1 or the size of axes.

For rray_rep_each(), a vector of integers greater than or equal to 0. It is recycled to the dimension of x along axis.

axes

The axes to repeat along, given by position or by title.

axis

The axis to repeat along, given by position or by title.

Value

An array with the same dimensions as x, except along the repeated axes.

Details

Names repeat alongside the data, so a repeated axis can come back with duplicate names. Every other axis keeps its names untouched. The titles of x are kept.

Examples

x <- array(1:6, c(3, 2))

# All rows in bulk, twice
rray_rep(x, times = 2, axes = 1)
#>      [,1] [,2]
#> [1,]    1    4
#> [2,]    2    5
#> [3,]    3    6
#> [4,]    1    4
#> [5,]    2    5
#> [6,]    3    6

# Each row individually, twice
rray_rep_each(x, times = 2, axis = 1)
#>      [,1] [,2]
#> [1,]    1    4
#> [2,]    1    4
#> [3,]    2    5
#> [4,]    2    5
#> [5,]    3    6
#> [6,]    3    6

# Columns rather than rows
rray_rep(x, times = 2, axes = 2)
#>      [,1] [,2] [,3] [,4]
#> [1,]    1    4    1    4
#> [2,]    2    5    2    5
#> [3,]    3    6    3    6

# Rows and columns, twice each
rray_rep(x, times = 2, axes = c(1, 2))
#>      [,1] [,2] [,3] [,4]
#> [1,]    1    4    1    4
#> [2,]    2    5    2    5
#> [3,]    3    6    3    6
#> [4,]    1    4    1    4
#> [5,]    2    5    2    5
#> [6,]    3    6    3    6

# Rows twice and columns three times
rray_rep(x, times = c(2, 3), axes = c(1, 2))
#>      [,1] [,2] [,3] [,4] [,5] [,6]
#> [1,]    1    4    1    4    1    4
#> [2,]    2    5    2    5    2    5
#> [3,]    3    6    3    6    3    6
#> [4,]    1    4    1    4    1    4
#> [5,]    2    5    2    5    2    5
#> [6,]    3    6    3    6    3    6

# A different number of repeats per row
rray_rep_each(x, times = c(1, 2, 3), axis = 1)
#>      [,1] [,2]
#> [1,]    1    4
#> [2,]    2    5
#> [3,]    2    5
#> [4,]    3    6
#> [5,]    3    6
#> [6,]    3    6

# A different number of repeats per row, by title
z <- rray_set_titles(x, c("row", "col"))
rray_rep_each(z, times = c(1, 2, 3), axis = "row")
#>       col
#> row    [,1] [,2]
#>   [1,]    1    4
#>   [2,]    2    5
#>   [3,]    2    5
#>   [4,]    3    6
#>   [5,]    3    6
#>   [6,]    3    6

# Zeroes drop slices entirely
rray_rep_each(x, times = c(1, 0, 2), axis = 1)
#>      [,1] [,2]
#> [1,]    1    4
#> [2,]    3    6
#> [3,]    3    6

# Names repeat with the data, duplicates and all
y <- array(1:6, c(3, 2), dimnames = list(c("a", "b", "c"), c("x", "y")))
rray_names(rray_rep(y, times = 2, axes = 1))
#> [[1]]
#> [1] "a" "b" "c" "a" "b" "c"
#> 
#> [[2]]
#> [1] "x" "y"
#> 
rray_names(rray_rep_each(y, times = 2, axis = 1))
#> [[1]]
#> [1] "a" "a" "b" "b" "c" "c"
#> 
#> [[2]]
#> [1] "x" "y"
#>