function log1mexp( x ) {
	var ax;
	if ( isnan( x ) ) {
		return NaN;
	}
	if ( x === 0.0 ) {
		return NINF;
	}
	ax = abs( x );
	if ( 0.0 < ax && ax <= LN2 ) {
		return ln( -expm1( -ax ) );
	}
	// Case: |x| > ln(2)
	return log1p( -exp( -ax ) );
}
Computes the natural logarithm of \\( 1-\exp(-|x|) \\).

@param {number} x - input value
@returns {number} function value

@example
var v = log1mexp( 1.1 );
// returns ~-0.40477

@example
var v = log1mexp( 0.0 );
// returns -Infinity

@example
var v = log1mexp( NaN );
// returns NaN