##
Class notes for 2006/02/09

### Different linear solvers

Discuss other iterative linear solvers + preconditioners and UMFPACK.

The UMFPACK solver is distributed with deal.II, but for
license reasons, we do not enable it by default. If you
want to use it, you have to do the following steps:

```
./configure --with-umfpack
make all
```

This builds the UMFPACK solver and adds support for it in
the library. After that, you will be able to use the
solver in the simplest possible way (note that the solver
overwrites the right hand side vector with the solution,
so only one vector has to be passed to it):
```
SparseDirectUMFPACK solver;
solution = system_rhs;
solver.solve (system_matrix, solution);
```

### Boundary integrals

We discuss boundary integrals by looking at
step-7.
### Vector-valued finite elements

This is explained in
step-8.