From 779eba69864ad12182ba08f61aaeb452cb19d2a3 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Uwe=20K=C3=B6cher?= <koecher@hsu-hamburg.de>
Date: Wed, 17 Sep 2014 09:33:13 +0200
Subject: [PATCH] Updated Documentation. Again, in the Introduction section of
 the step-20 tutorial a class InverseMatrix appears. Now its changed to use
 IterativeInverse<..> in all places to match with the code.

---
 examples/step-20/doc/intro.dox | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/examples/step-20/doc/intro.dox b/examples/step-20/doc/intro.dox
index 74b1ae3569..dbea94c603 100644
--- a/examples/step-20/doc/intro.dox
+++ b/examples/step-20/doc/intro.dox
@@ -483,7 +483,13 @@ matrix and the mass matrix, respectively:
 template <int dim>
 void MixedLaplaceProblem<dim>::solve ()
 {
-  const InverseMatrix m_inverse (system_matrix.block(0,0));
+  PreconditionIdentity identity;
+  IterativeInverse<Vector<double> > m_inverse;
+  m_inverse.initialize(system_matrix.block(0,0), identity);
+  m_inverse.solver.select("cg");
+  static ReductionControl inner_control(1000, 0., 1.e-13);
+  m_inverse.solver.set_control(inner_control);
+
   Vector<double> tmp (solution.block(0).size());
 
   {
@@ -600,8 +606,11 @@ the approximate Schur complement, i.e. we need code like this:
     ApproximateSchurComplement
       approximate_schur_complement (system_matrix);
 
-    InverseMatrix<ApproximateSchurComplement>
-      preconditioner (approximate_schur_complement)
+    IterativeInverse<Vector<double> >
+      preconditioner;
+    preconditioner.initialize(approximate_schur_complement, identity);
+    preconditioner.solver.select("cg");
+    preconditioner.solver.set_control(inner_control);
 @endcode
 
 That's all!
@@ -622,12 +631,15 @@ look like this:
     ApproximateSchurComplement
       approximate_schur_complement (system_matrix);
 
-    InverseMatrix<ApproximateSchurComplement>
-      preconditioner (approximate_schur_complement);
+    IterativeInverse<Vector<double> >
+      preconditioner;
+    preconditioner.initialize(approximate_schur_complement, identity);
+    preconditioner.solver.select("cg");
+    preconditioner.solver.set_control(inner_control);
 
-    SolverControl solver_control (system_matrix.block(0,0).m(),
-                                  1e-6*schur_rhs.l2_norm());
-    SolverCG<>    cg (solver_control);
+    SolverControl solver_control (solution.block(1).size(),
+                                  1e-12*schur_rhs.l2_norm());
+    SolverCG<> cg (solver_control);
 
     cg.solve (schur_complement, solution.block(1), schur_rhs,
               preconditioner);
-- 
2.39.5