function mgf( t ) {
		var ret;
		if ( isnan( t ) ) {
			return NaN;
		}
		if ( t === 0.0 ) {
			return 1.0;
		}
		// Case: t not equal to zero
		ret = exp( t*a ) * expm1( t*n );
		ret /= n * expm1( t );
		return ret;
	}
Evaluates the moment-generating function (MGF) of a discrete uniform distribution.

@private
@param {number} t - input value
@returns {number} evaluated MGF

@example
var y = mgf( 0.5 );
// returns <number>