五点差分格式解重调和问题，采用适当的技巧将其分解成两个Possion方程求解-Five-point difference scheme solution Biharmonic

用改进的经典的五点差分格式去求解二维椭圆偏微分方程，对学习微分方程数值解十分有帮助-Improved classic five-point difference scheme to solve the two-dimensional elliptic partial differential equations, numerical solution of differential equations to study very helpful

十字区域，由五个相等的单位正方形组成，用五点差分格式求解下面的Poisson方程第一边值问题，程序能适应任何步长(solve poisson equation in ten area)