function incrnansumabs() {
	var sum = incrsumabs();
	return accumulator;

	/**
	* If provided a value, the accumulator function returns an updated sum. If not provided a value, the accumulator function returns the current sum.
	*
	* @private
	* @param {number} [x] - new value
	* @returns {(number|null)} sum or null
	*/
	function accumulator( x ) {
		if ( arguments.length === 0 || isnan( x ) ) {
			return sum();
		}
		return sum( x );
	}
}
Returns an accumulator function which incrementally computes a sum of absolute values, ignoring `NaN` values.

@returns {Function} accumulator function

@example
var accumulator = incrnansumabs();

var sum = accumulator();
// returns null

sum = accumulator( 2.0 );
// returns 2.0

sum = accumulator( NaN );
// returns 2.0

sum = accumulator( -5.0 );
// returns 7.0

sum = accumulator();
// returns 7.0