该函数用来计算任意函数的一阶偏导数(数值方法),仿真图是速度、距离、幅度三维图像，包括 MUSIC算法，ESPRIT算法 ROOT-MUSIC算法。- This function is used to calculate the arbitrary function of the first order partial derivative (numerical methods), FIG simulation speed, distance, amplitude three-dimensional image, Including the MUSIC algorithm, ESPRIT algorithm ROOT-MUSIC algorithm.