FDM method的用法和樣例：
例句
- The nonlinear differential equations are solved using finite difference method.
用有限差分法求解非線性微分方程組。 - The FDM is applied to the numeric discreteness of control equations under the new coordinates and the corresponding programs are developed.
採用有限差分法對新坐標系中的模型控制方程進行了數值離散，根據差分格式編製了相應的計算程序。
