* multigrid preconditioner from the HYPRE suite. Note that PETSc has to be
* configured with HYPRE (e.g. with \--download-hypre=1).
*
- * The preconditioner does support parallel distributed computations. See
+ * This preconditioner does support parallel distributed computations. See
* step-40 for an example.
*
+ * This class can be used as a preconditioner for linear solvers. It
+ * also provides a `vmult()` function (implemented in the
+ * PreconditionBase base class) that, when called, performs one
+ * multigrid cycle. By default, this is a V-cycle, but the
+ * AdditionalData class allows to also select a W-cycle.
+ *
* @ingroup PETScWrappers
*/
class PreconditionBoomerAMG : public PreconditionBase
* many processors. SSOR, on the other hand, gets more Jacobi-like on many
* processors.
*
+ * This class can be used as a preconditioner for linear solvers. It
+ * also provides a `vmult()` function (implemented in the
+ * PreconditionBase base class) that, when called, performs one
+ * multigrid cycle. By default, this is a V-cycle, but the
+ * AdditionalData class allows to also select a W-cycle.
+ *
* @ingroup TrilinosWrappers
* @ingroup Preconditioners
*/
* on the Trilinos MueLu implementation, which is a black-box preconditioner
* that works well for many PDE-based linear problems. The interface of
* PreconditionerAMGMueLu is the same as the interface of PreconditionerAMG
- * except for the higher_order_elements parameter which does not exist in
+ * (which, instead of the Trilinos package MueLu is built on the older
+ * Trilinos package ML). The only functional difference between the two
+ * classes is the `higher_order_elements` parameter which does not exist in
* PreconditionerAMGMueLu.
*
+ * This class can be used as a preconditioner for linear solvers. It
+ * also provides a `vmult()` function (implemented in the
+ * PreconditionBase base class) that, when called, performs one
+ * multigrid cycle. By default, this is a V-cycle, but the
+ * AdditionalData class allows to also select a W-cycle.
+ *
* @note You need to configure Trilinos with MueLU support for this
* preconditioner to work.
*