Elliptic partial differential equations are *boundary value problems*,
where data must be prescribed on the boundary of the solution domain.
The two principal types of boundary conditions are

- Dirichlet boundary conditions, where the solution itself is prescribed along the boundary (like in the example of the multigrid workbench)
- Neumann boundary conditions, where the derivatives of the solution in the normal direction to the boundary are prescribed
- boundary conditions of mixed type

Multigrid methods can be adapted to treat any of these efficiently.

Ulrich Ruede , Thu Feb 2 21:06:44 MEZ 1995

Updated by Craig C. Douglas