该函数用来计算任意函数的一阶偏导数(数值方法),最小均方误差（MMSE）的算法，采用加权网络中节点强度和权重都是幂率分布的模型。- This function is used to calculate the arbitrary function of the first order partial derivative (numerical methods), Minimum mean square error (MMSE) algorithm, Using weighted model nodes in the network strength and weight are power law distribution.