说明：  用RBF神经网络逼近已知函数，也可以在得知输入输出的情况下用RBF逼近任意函数，非线性线性都行
(The RBF neural network can be used to approximate the known function, and the RBF can also be used to approximate any function when the input and output are known. Nonlinear linearity is acceptable.)