改进欧拉方法求解常微分方程的初值问题.-Improved Euler method

由点的三维坐标，进行批量计算所在点的局部曲面的法向量，法向量中x赋值给予，y,z计算得出。然后计算欧拉角表示的坐标(From the point of three-dimensional coordinates, batch calculation of the local surface of the normal vector, the normal vector x assignment given, y, Z calculation. Then calculate the coordin