Undefined function or method 'emd' for input arguments of ty

Undefined function or method 'emd' for input arguments of ty Undefined function or method 'y' for input arguments of type Undefined function or method 'u' for input arguments of type Undefined function or method 'pdfbdec' for input arguments o cannot call method "open" of undefined是什么意思 can not call method open of undefined The method IsEmpty(String) is undefined for the type The method getsession() is undefined for the type HttpServle The method selectAll() is undefined for the type productDaoI 用MATLAB求函数极限时出现 Undefined function or variable "x". Call to undefined function mysql_connect() 在Java中这样报错The method SayHi() is undefined for the type AccpT