function unaryBy( arrays, shape, strides, fcn, clbk ) {
	var thisArg;
	var xget;
	var yset;
	var x;
	var y;

	if ( arguments.length > 5 ) {
		thisArg = arguments[ 5 ];
	}
	x = arrays[ 0 ];
	if ( isAccessorArray( x ) ) {
		xget = accessorGetter( dtype( x ) );
	}
	y = arrays[ 1 ];
	if ( isAccessorArray( y ) ) {
		yset = accessorSetter( dtype( y ) );
	}
	if ( xget || yset ) {
		xget = xget || getter( dtype( x ) );
		yset = yset || setter( dtype( y ) );
		return accessors( arrays, shape, strides, [ xget, yset ], fcn, clbk, thisArg ); // eslint-disable-line max-len
	}
	return strided( arrays, shape, strides, fcn, clbk, thisArg );
}
Applies a unary function to each element retrieved from a strided input array according to a callback function and assigns results to a strided output array.

@param {ArrayLikeObject<Collection>} arrays - array-like object containing one input array and one output array
@param {NonNegativeIntegerArray} shape - array-like object containing a single element, the number of indexed elements
@param {IntegerArray} strides - array-like object containing the stride lengths for the input and output arrays
@param {Function} fcn - unary function to apply to callback return values
@param {Callback} clbk - callback
@param {*} [thisArg] - callback execution context
@returns {void}

@example
var abs = require( '@stdlib/math/base/special/abs' );

function accessor( v ) {
    return v * 2.0;
}

var x = [ 1.0, -2.0, 3.0, -4.0, 5.0 ];
var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];

var shape = [ x.length ];
var strides = [ 1, 1 ];

unaryBy( [ x, y ], shape, strides, abs, accessor );

console.log( y );
// => [ 2.0, 4.0, 6.0, 8.0, 10.0 ]