function logpmf( x ) {
		var ldenom;
		var lnum;
		if ( isnan( x ) ) {
			return NaN;
		}
		if (
			isNonNegativeInteger( x ) &&
			mins <= x &&
			x <= maxs
		) {
			lnum = fln( n ) + fln( K ) + fln( N - n ) + fln( N - K );
			ldenom = fln( N ) + fln( x ) + fln( n - x );
			ldenom += fln( K - x ) + fln( N - K + x - n );
			return lnum - ldenom;
		}
		return NINF;
	}
Evaluates the natural logarithm of the probability mass function (PMF) for a hypergeometric distribution.

@private
@param {number} x - input value
@returns {number} evaluated logPMF