function subBy( N, x, sx, ox, y, sy, oy, z, sz, oz, clbk, thisArg ) {
	return mapBy2( N, x, sx, ox, y, sy, oy, z, sz, oz, sub, clbk, thisArg );
}
Performs element-wise subtraction of two strided arrays via a callback function and assigns each result to an element in an output strided array.

@param {NonNegativeInteger} N - number of indexed elements
@param {Collection} x - input array/collection
@param {integer} sx - `x` stride length
@param {NonNegativeInteger} ox - starting `x` index
@param {Collection} y - input array/collection
@param {integer} sy - `y` stride length
@param {NonNegativeInteger} oy - starting `y` index
@param {Collection} z - destination array/collection
@param {integer} sz - `z` stride length
@param {NonNegativeInteger} oz - starting `z` index
@param {Callback} clbk - callback
@param {*} [thisArg] - callback execution context
@returns {Collection} `z`

@example
function accessor( values ) {
    return values;
}

var x = [ 11.0, 12.0, 13.0, 14.0, 15.0 ];
var y = [ 8.0, 7.0, 6.0, 5.0, 4.0 ];
var z = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];

subBy( x.length, x, 1, 0, y, 1, 0, z, 1, 0, accessor );

console.log( z );
// => [ 3.0, 5.0, 7.0, 9.0, 11.0 ]