function factory( k ) {
	var gamma = gammaFactory( k/2.0, 0.5 );
	return quantile;

	/**
	* Evaluates the quantile function for a chi distribution.
	*
	* @private
	* @param {Probability} p - input value
	* @returns {number} evaluated quantile function
	*
	* @example
	* var y = quantile( 0.3 );
	* // returns <number>
	*/
	function quantile( p ) {
		return sqrt( gamma( p ) );
	}
}
Returns a function for evaluating the quantile function for a chi distribution with degrees of freedom `k`.

@param {NonNegativeNumber} k - degrees of freedom
@returns {Function} quantile function

@example
var quantile = factory( 0.4 );

var y = quantile( 0.9 );
// returns ~1.1

y = quantile( 1.0 );
// returns Infinity