求解二维热传导方程，文档中有过程和matlab程序。
本文利用有限差分法来求二维热传导方程的数值解，通过Matlab编程求解并作图，进而与解析
解做出的图进行比较，画出误差图。(Solving the two-dimensional heat conduction equation, there are procedures and MATLAB programs in the document.
In this paper, the finite difference method is used to find the numerical solution of the two-dimensional heat conduction equation, and is solved and plotted by Matlab programming.
The diagram made by the solution is compared, and the error map is drawn.)