repl.txt

{{alias}}( arr, initial, mapper, reducer[, thisArg] )
    Performs a map-reduce operation for each element in an array and returns the
    accumulated result.

    When invoked, the mapping function is provided three arguments:

    - value: array element.
    - index: element index.
    - arr: input array.

    When invoked, the reducing function is provided four arguments:

    - accumulator: accumulated value.
    - value: result after applying the mapping function to the current array
    element.
    - index: element index.
    - arr: input array.

    If provided an empty array, the function returns the initial value.

    When provided an ndarray, the function performs a single-pass map-reduce
    operation over the entire input ndarray (i.e., higher-order ndarray
    dimensions are flattened to a single-dimension).

    Parameters
    ----------
    arr: ArrayLikeObject|ndarray
        Input array.

    initial: any
        Accumulator value used in the first invocation of the reduction
        function.

    mapper: Function
        Mapping function.

    reducer: Function
        Reducing function.

    thisArg: any (optional)
        Execution context for the reducing function.

    Returns
    -------
    out: any
        Accumulated result.

    Examples
    --------
    // array-like object:
    > var f1 = {{alias:@stdlib/utils/nary-function}}( {{alias:@stdlib/math/base/special/abs}}, 1 );
    > var f2 = {{alias:@stdlib/utils/nary-function}}( {{alias:@stdlib/number/float64/base/add}}, 2 );
    > var arr = [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ];
    > var out = {{alias}}( arr, 0.0, f1, f2 )
    21.0

    // ndarray:
    > arr = {{alias:@stdlib/ndarray/array}}( arr, { 'shape': [ 2, 3 ] } );
    > out = {{alias}}( arr, 0.0, f1, f2 )
    21.0

    See Also
    --------