说明：  重磁异常的正演模型模拟,该程序的目的在于计算出重力异常，重力x，z方向的导数异常 ,以及磁场的垂直分量异常的系数矩阵
(Gravity and magnetic anomalies of the forward model simulation, the program aims to calculate the gravity anomaly, gravity and x, z direction of the derivative of an exception, as well as the vertical component of magnetic field anomaly coefficient matrix)