说明：  基于matlab的求矩源程序,程序中求出了经典7阶矩,并继续求出了后5阶矩,即一共求出了12阶矩.
(Moment based on matlab source of demand, the program derived a classic 7-order moment, and continue to derive a 5-order moment, namely, to derive a total of 12 moments.)