From: bangerth Date: Fri, 25 Jan 2008 05:23:41 +0000 (+0000) Subject: Minor fix. X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1c19801f69054529d7e5a6c5418a396b6e41d847;p=dealii-svn.git Minor fix. git-svn-id: https://svn.dealii.org/trunk@15684 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/examples/step-22/doc/intro.dox b/deal.II/examples/step-22/doc/intro.dox index 112bd3dd4e..5707f01bb8 100644 --- a/deal.II/examples/step-22/doc/intro.dox +++ b/deal.II/examples/step-22/doc/intro.dox @@ -291,7 +291,7 @@ First, in the mixed Laplace equation we had to deal with the question of how to precondition the Schur complement $B^TM^{-1}B$, which was spectrally equivalent to the Laplace operator on the pressure space (because $B$ represents the gradient operator, $B^T$ its adjoint $-\textrm{div}$, and $M$ -the identity (up to the material parameter $K^{-1}$, so $B^TM^{-1}B$ is +the identity (up to the material parameter $K^{-1}$), so $B^TM^{-1}B$ is something like $-\textrm{div} 1 \nabla = -\Delta$) and consequently badly conditioned for small mesh sizes. To this end, we had to come up with an elaborate preconditioning scheme for the Schur complement.