
{{alias}}( arrays, shape, fcn )
    Applies a unary callback to elements in a three-dimensional nested input
    array according to elements in a three-dimensional nested mask array and
    assigns results to elements in a three-dimensional nested output array.

    An element in an input array is "masked" if the corresponding element in the
    mask array is non-zero.

    Parameters
    ----------
    arrays: ArrayLikeObject
        Array-like object containing one input nested array, an input nested
        mask array, and one output nested array.

    shape: Array<integer>
        Array shape.

    fcn: Function
        Unary callback.

    Examples
    --------
    > var x = [ [ [ -1.0, -2.0 ], [ -3.0, -4.0 ] ] ];
    > var m = [ [ [ 0, 1 ], [ 0, 0 ] ] ];
    > var y = [ [ [ 0.0, 0.0 ], [ 0.0, 0.0 ] ] ];
    > var shape = [ 1, 2, 2 ];
    > {{alias}}( [ x, m, y ], shape, {{alias:@stdlib/math/base/special/abs}} );
    > y
    [ [ [ 1.0, 0.0 ], [ 3.0, 4.0 ] ] ]

    See Also
    --------

