From cd914279550bebc954c219c4e072e4e64246f2f7 Mon Sep 17 00:00:00 2001
From: Matthias Maier <tamiko@43-1.org>
Date: Wed, 13 Feb 2019 19:00:48 -0600
Subject: [PATCH] Documentation: add some pointers to step-20

---
 doc/doxygen/headers/laoperators.h        | 6 ++++++
 include/deal.II/lac/linear_operator.h    | 3 +++
 include/deal.II/lac/packaged_operation.h | 3 +++
 3 files changed, 12 insertions(+)

diff --git a/doc/doxygen/headers/laoperators.h b/doc/doxygen/headers/laoperators.h
index 64d8bfe40f..49d2a122bd 100644
--- a/doc/doxygen/headers/laoperators.h
+++ b/doc/doxygen/headers/laoperators.h
@@ -89,6 +89,9 @@
  * encapsulation of individual linear operators into blocked linear
  * operator variants.
  *
+ * The step-20 tutorial program has a detailed usage example of the
+ * LinearOperator class.
+ *
  * @note As explained below, when using LinearOperator as <code>res = op_a*x</code>
  * a PackagedOperation class instance is generated behind-the-curtains.
  * Consequently, the user program has to include header files for both classes
@@ -175,6 +178,9 @@
  *   Vector<double> residual =  b - op_a * x; // computes the residual at this point
  * @endcode
  *
+ * The step-20 tutorial program has a detailed usage example of the
+ * PackagedOperation class.
+ *
  *
  * @ingroup LAC
  * @ingroup MATRICES
diff --git a/include/deal.II/lac/linear_operator.h b/include/deal.II/lac/linear_operator.h
index e066190781..ef84db6e25 100644
--- a/include/deal.II/lac/linear_operator.h
+++ b/include/deal.II/lac/linear_operator.h
@@ -151,6 +151,9 @@ null_operator(const LinearOperator<Range, Domain, Payload> &);
  * for linear operators have been provided within the respective
  * TrilinosWrappers (and, in the future, PETScWrappers) namespaces.
  *
+ * @note The step-20 tutorial program has a detailed usage example of the
+ * LinearOperator class.
+ *
  * @author Luca Heltai, Matthias Maier, 2015; Jean-Paul Pelteret, 2016
  *
  * @ingroup LAOperators
diff --git a/include/deal.II/lac/packaged_operation.h b/include/deal.II/lac/packaged_operation.h
index 8c73828e2a..f4da9786af 100644
--- a/include/deal.II/lac/packaged_operation.h
+++ b/include/deal.II/lac/packaged_operation.h
@@ -93,6 +93,9 @@ class PackagedOperation;
  *   y -= residual;
  * @endcode
  *
+ * @note The step-20 tutorial program has a detailed usage example of the
+ * LinearOperator class.
+ *
  * @author Matthias Maier, 2015
  *
  * @ingroup LAOperators
-- 
2.39.5