中文说明：用有限差分法来解偏微分方程，采用高斯——赛德尔迭代方法，并用前后两次迭代差的矩阵的无穷范数作为是否停止迭代的依据。
English Description：
The finite difference method is used to solve the partial differential equations. The Gauss Seidel iterative method is used. The infinite norm of the matrix difference between the two iterations is used as the basis for stopping the iteration.