d2arrayIndices

Creates a 2D array of the given shape, where each element is computed from its row (i) and column (j) indices. Useful when the element value depends on its position in the matrix.

Signature

inline fun <reified T : Any> Multik.d2arrayIndices(
    sizeD1: Int,
    sizeD2: Int,
    init: (i: Int, j: Int) -> T
): D2Array<T>

Parameters

Parameter	Type	Description
`sizeD1`	`Int`	Number of rows. Must be positive.
`sizeD2`	`Int`	Number of columns. Must be positive.
`init`	`(i: Int, j: Int) -> T`	Lambda that receives row index `i` and column index `j`.

Returns: D2Array<T>

Example

val m = mk.d2arrayIndices<Int>(3, 3) { i, j -> i + j }
// [[0, 1, 2],
//  [1, 2, 3],
//  [2, 3, 4]]

val identity = mk.d2arrayIndices<Double>(4, 4) { i, j ->
    if (i == j) 1.0 else 0.0
}

28 February 2026