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Create MLX array from R object

as_mlx.Rd

Create MLX array from R object

Usage

as_mlx(
  x,
  dtype = c("float32", "float64", "bool", "complex64", "int8", "int16", "int32", "int64",
    "uint8", "uint16", "uint32", "uint64"),
  device = mlx_default_device()
)

Arguments

x

Numeric, logical, or complex vector, matrix, or array to convert

dtype

Data type for the MLX array. One of:

  • Floating point: "float32", "float64"

  • Integer signed: "int8", "int16", "int32", "int64"

  • Integer unsigned: "uint8", "uint16", "uint32", "uint64"

  • Other: "bool", "complex64"

If not specified, defaults to "float32" for numeric, "bool" for logical, and "complex64" for complex inputs.

device

Device: "gpu" (default) or "cpu"

Value

An object of class mlx

Details

Default type behavior

When dtype is not specified:

  • Numeric vectors/arrays (including R integers from 1:10) → float32

  • Logical vectors/arrays → bool

  • Complex vectors/arrays → complex64

Integer types require explicit dtype

Important: R integer vectors (like 1:10) convert to float32 by default. To create integer MLX arrays, you must explicitly specify dtype:

x <- as_mlx(1:10, dtype = "int32")  # Creates int32 array
x <- as_mlx(1:10)                    # Creates float32 array

This design avoids unintentional integer promotion, since R creates integers in many contexts where floating-point is intended.

Supported integer types

  • Signed: int8 (-128 to 127), int16, int32, int64

  • Unsigned: uint8 (0 to 255), uint16, uint32, uint64

Type precision notes

  • float64 is supported but emits a warning and downcasts to float32

  • Integer arithmetic may promote types (e.g., int32 + int32 might → int64)

  • Mixed integer/float operations promote to float

Missing values

MLX does not have an NA sentinel. When you pass numeric NA values from R, they are stored as NaN inside MLX and returned to R as NaN. Use is.nan() on MLX arrays (method provided) if you need to detect them.

See also

mlx.core.array

mlx-methods

Examples

# Default float32 for numeric
x <- as_mlx(c(1.5, 2.5, 3.5))
mlx_dtype(x)  # "float32"
#> [1] "float32"

# R integers also default to float32
x <- as_mlx(1:10)
mlx_dtype(x)  # "float32"
#> [1] "float32"

# Explicit integer types
x_int <- as_mlx(1:10, dtype = "int32")
mlx_dtype(x_int)  # "int32"
#> [1] "int32"

# Unsigned integers
x_uint <- as_mlx(c(0, 128, 255), dtype = "uint8")

# Logical → bool
mask <- as_mlx(c(TRUE, FALSE, TRUE))
mlx_dtype(mask)  # "bool"
#> [1] "bool"