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Reverse

Source: R/api.R, R/api-generics.R
nv_reverse.Rd

Reverses the order of elements along the given axes, every axis by default. You can also use rev(), which always reverses along every axis.

Usage

nv_reverse(x, axes = NULL)

Arguments

x

(arrayish)
One input. Can be any data type. An R value materializes at its default data type.

axes

(integer() | NULL)
Axes to reverse. Negative values count from the end, i.e. -1 refers to the last axis. If NULL (default), reverses along every axis.

Value

(arrayish)
Has the same shape and data type as x.

The rev() generic

rev() reverses along every axis, which puts the elements in the same order as base::rev() does (base R flattens the array to a vector first, whereas rev() on an anvl array keeps the shape).

See also

prim_reverse() for the underlying primitive.

Examples

# the order along axis 1 is flipped
x <- nv_array(c(1, 2, 3, 4, 5))
nv_reverse(x)
#> AnvlArray
#>  5
#>  4
#>  3
#>  2
#>  1
#> [ CPUf32{5} ] 

m <- nv_matrix(1:6, nrow = 2)
nv_reverse(m) # every axis
#> AnvlArray
#>  6 4 2
#>  5 3 1
#> [ CPUi32{2,3} ] 
nv_reverse(m, axes = 2L) # columns only
#> AnvlArray
#>  5 3 1
#>  6 4 2
#> [ CPUi32{2,3} ]