function unarynd( arrays, shape, fcn ) {
	return recurse( arrays[ 0 ], arrays[ 1 ], shape.length, shape, 0, fcn );
}
Applies a unary callback to elements in an n-dimensional nested input array and assigns results to elements in an n-dimensional nested output array.

## Notes

-   The function assumes that the input and output arrays have the same shape.

@param {ArrayLikeObject} arrays - array-like object containing one input nested array and one output nested array
@param {NonNegativeIntegerArray} shape - array shape
@param {Callback} fcn - unary callback
@returns {void}

@example
var onesnd = require( '@stdlib/array/base/onesnd' );
var zerosnd = require( '@stdlib/array/base/zerosnd' );

function scale( x ) {
    return x * 10.0;
}

var shape = [ 2, 2 ];

var x = onesnd( shape );
var y = zerosnd( shape );

unarynd( [ x, y ], shape, scale );

console.log( y );
// => [ [ 10.0, 10.0 ], [ 10.0, 10.0 ] ]