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Subset MLX array

Source: R/subset-assignment.R, R/subset.R
mlx_subset.Rd

MLX subsetting is like base R with a few differences:

Usage

# S3 method for class 'mlx'
x[...] <- value

# S3 method for class 'mlx'
x[..., drop = FALSE]

Arguments

x

An mlx array, or an R array/matrix/vector that will be converted via as_mlx().

...

Indices for each dimension. Provide one per axis; omitted indices select the full extent. Logical indices recycle to the dimension length.

value

Value to assign, typically an mlx or R array

drop

Should dimensions be dropped? (default: FALSE)

Value

The subsetted MLX object.

Details

  • drop = FALSE by default.

  • Indices containing NA give an error.

  • Single indices on a 2D or higher array are only allowed for assignment. For example, if x is a matrix, x[x < 0] <- 0 is OK but subset <- x[x < 0] is not. Use mlx_flatten() explicitly for subsetting.

  • There is one exception: as in R, a single numeric matrix index selects individual elements. The number of columns must match the rank of x; each row gives coordinates for one element. The return value from subsetting is a flat mlx vector.

  • mlx vectors, logical masks, and matrices behave the same as their R equivalents.

  • Duplicate assignments like x[c(1,1)] <- 2:3 are undefined behaviour.

  • Character indices are not supported as MLX has no concept of dimension names.

See also

mlx.core.take

Examples

x <- mlx_matrix(1:9, 3, 3)
x[1, ]
#> mlx array [1 x 3]
#>   dtype: float32
#>   device: cpu
#>   values:
#>      [,1] [,2] [,3]
#> [1,]    1    4    7