From 824932a9fea6e241b6df6be79e5fc8d43fbbb0cd Mon Sep 17 00:00:00 2001 From: bangerth Date: Wed, 9 Jul 2014 13:05:58 +0000 Subject: [PATCH] Augment documentation. git-svn-id: https://svn.dealii.org/trunk@33125 0785d39b-7218-0410-832d-ea1e28bc413d --- deal.II/include/deal.II/lac/solver_cg.h | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/deal.II/include/deal.II/lac/solver_cg.h b/deal.II/include/deal.II/lac/solver_cg.h index 4c01b49cc4..b2daa7336e 100644 --- a/deal.II/include/deal.II/lac/solver_cg.h +++ b/deal.II/include/deal.II/lac/solver_cg.h @@ -1,7 +1,7 @@ // --------------------------------------------------------------------- // $Id$ // -// Copyright (C) 1998 - 2013 by the deal.II authors +// Copyright (C) 1998 - 2014 by the deal.II authors // // This file is part of the deal.II library. // @@ -37,10 +37,14 @@ class PreconditionIdentity; /*@{*/ /** - * Preconditioned cg method for symmetric positive definite matrices. - * - * For the requirements on matrices and vectors in order to work with - * this class, see the documentation of the Solver base class. + * Preconditioned cg method for symmetric positive definite matrices. This + * class is used first in step-3 and step-4, but is used in many other + * tutorial programs as well. Like all other solver classes, it can work on + * any kind of vector and matrix as long as they satisfy certain requirements + * (for the requirements on matrices and vectors in order to work with this + * class, see the documentation of the Solver base class). The type of the + * solution vector must be passed as template argument, and defaults to + * dealii::Vector. * * Like all other solver classes, this class has a local structure * called @p AdditionalData which is used to pass additional @@ -48,10 +52,11 @@ class PreconditionIdentity; * a switch allowing for additional output for the computation of * eigenvalues of the matrix. * - *

Eigenvalue computation

+ * @note This version of CG is taken from D. Braess's book "Finite + * Elements". It requires a symmetric preconditioner (i.e., for example, SOR + * is not a possible choice). * - * See Y. Saad: "Iterative methods for Sparse Linear Systems", section - * 6.7.3 for details. + *

Eigenvalue computation

* * The cg-method performs an orthogonal projection of the original * preconditioned linear system to another system of smaller @@ -71,8 +76,8 @@ class PreconditionIdentity; * sqrt(beta_0)/alpha_0, ..., sqrt(beta_{m-2)/alpha_{m-2}}. * The eigenvalues of this matrix can be computed by postprocessing. * - * This version of CG is taken from Braess: "Finite Elements". It - * requires a symmetric preconditioner, i.e. SOR is not feasible. + * See Y. Saad: "Iterative methods for Sparse Linear Systems", section + * 6.7.3 for details. * * @author W. Bangerth, G. Kanschat, R. Becker and F.-T. Suttmeier */ -- 2.39.5