1.　　如果matlab有两个函数nargin和nargout，分别返回matlab函数的输入和输出参数的个数。如果采用元组变量varargin和varargout来替代常规的输入和输出参数，则函数就可以接收数目可变的输入和输出参数。-1. If there are two matlab functions nargin and nargout, respectively matlab function back to the input and output parameters of the number. If the tuple variable varargin and varargout to replace conventional input and output parameters, the function can receive a variable number of input and output parameters.