使用高阶累积量对MPSK信号进行调制识别，快速扩展随机生成树算法，该函数用来计算任意函数的一阶偏导数(数值方法)。- Using high-order cumulants of MPSK signal modulation recognition, Rapid expansion of random spanning tree algorithm, This function is used to calculate the arbitrary function of the first order partial derivative (numerical methods).