function mgf( t ) {
		if ( isnan( t ) ) {
			return NaN;
		}
		return mgf0( t, alpha, beta );
	}
Evaluates the moment-generating function (MGF) for a beta distribution.

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

@example
var y = mgf( 2.0 );
// returns <number>