1. source.nb
2. source.cdf
3. source.txt

This Demonstration considers solutions of the Poisson elliptic partial differential equation (PDE) $-\nabla^2 u=f(x,y)$ on a rectangular grid. Eight numerical methods are based on either Neumann or Dirichlet boundary conditions and nonuniform grid spacing in the $x$ and $y$ directions. Different source functions $f(x,y)$ are supported.