Select Elements Along an Axis

Picks one or more elements along axis axis of x. Use this instead of [ or nv_subset when the index to select is provided programmatically.

Usage

nv_select(x, axis, index)

Arguments

x

(arrayish)
Input array.

axis

(integer(1))
Axis to index into. Negative values count from the end, i.e. -1 refers to the last axis.

index

(arrayish)
Scalar or 1D arrayish input (integer).

Value

arrayish
Same data type as x. axis is dropped if index was scalar.

See also

nv_subset() for general subsetting, prim_static_slice().

Examples

m <- nv_matrix(1:6, nrow = 2)
nv_select(m, axis = 2L, index = 2L)
#> AnvlArray
#>  3
#>  4
#> [ CPUi32{2} ] 
nv_select(m, axis = 1L, index = 1L)
#> AnvlArray
#>  1
#>  3
#>  5
#> [ CPUi32{3} ] 
nv_select(m, axis = 2L, index = array(c(1L, 3L)))
#> AnvlArray
#>  1 5
#>  2 6
#> [ CPUi32{2,2} ]