function nanmaxBy( N, x, strideX, offsetX, clbk, thisArg ) {
	var max;
	var ix;
	var o;
	var v;
	var i;

	if ( N <= 0 ) {
		return NaN;
	}
	o = arraylike2object( x );
	if ( o.accessorProtocol ) {
		return accessors( N, o, strideX, offsetX, clbk, thisArg );
	}
	if ( N === 1 || strideX === 0 ) {
		v = clbk.call( thisArg, x[ offsetX ], 0, offsetX, x );
		if ( v === void 0 ) {
			return NaN;
		}
		return v;
	}
	ix = offsetX;
	for ( i = 0; i < N; i++ ) {
		max = clbk.call( thisArg, x[ ix ], i, ix, x );
		if ( max === max && max !== void 0 ) {
			break;
		}
		ix += strideX;
	}
	if ( i === N ) {
		return NaN;
	}
	i += 1;
	for ( i; i < N; i++ ) {
		ix += strideX;
		v = clbk.call( thisArg, x[ ix ], i, ix, x );
		if ( v === void 0 || isnan( v ) ) {
			continue;
		}
		if ( v > max || ( v === max && isPositiveZero( v ) ) ) {
			max = v;
		}
	}
	return max;
}
Computes the maximum value of a strided array via a callback function, ignoring `NaN` values.

@param {PositiveInteger} N - number of indexed elements
@param {Collection} x - input array/collection
@param {integer} strideX - index increment
@param {NonNegativeInteger} offsetX - starting index
@param {Callback} clbk - callback
@param {*} [thisArg] - execution context
@returns {number} maximum value

@example
var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, NaN, 0.0, -1.0, -3.0 ];

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

var v = nanmaxBy( x.length, x, 1, 0, accessor );
// returns 8.0