From 6248d772bf79b689d54e36931c8f1e5a7f04860d Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Thu, 27 Oct 2016 20:42:11 -0600
Subject: [PATCH] Add necessary .prm file. Update docs.

In the olden times, the .prm file was created automatically when it was
not found, but this is no longer the case following #3122.
---
 examples/step-28/doc/intro.dox   |  2 +-
 examples/step-28/doc/results.dox | 20 ++++++++++++++++++--
 examples/step-28/project.prm     | 14 ++++++++++++++
 3 files changed, 33 insertions(+), 3 deletions(-)
 create mode 100644 examples/step-28/project.prm

diff --git a/examples/step-28/doc/intro.dox b/examples/step-28/doc/intro.dox
index a9969b3e40..cd8506b765 100644
--- a/examples/step-28/doc/intro.dox
+++ b/examples/step-28/doc/intro.dox
@@ -638,7 +638,7 @@ iterations on the next set of meshes.
 
 The program is controlled by a parameter file, using the ParameterHandler
 class already mentioned in the step-19 example program. We will show a
-parameter file in the results section of this section. For the moment suffice
+parameter file in the results section of this tutorial. For the moment suffice
 it to say that it controls the polynomial degree of the finite elements used,
 the number of energy groups (even though all that is presently implemented are
 the coefficients for a 2-group problem), the tolerance where to stop the
diff --git a/examples/step-28/doc/results.dox b/examples/step-28/doc/results.dox
index 728763f23a..63c6f6f660 100644
--- a/examples/step-28/doc/results.dox
+++ b/examples/step-28/doc/results.dox
@@ -1,11 +1,27 @@
 <h1>Results</h1>
 
+We can run the program with the following input file:
+@code
+# Listing of Parameters
+# ---------------------
+# Polynomial degree of the finite element to be used
+set Finite element degree     = 2
+
+# The number of energy different groups considered
+set Number of energy groups   = 2
 
-The output of this program consist of the console output, a file 
+# Inner power iterations are stopped when the change in k_eff falls below this
+# tolerance
+set Power iteration tolerance = 1e-12
+
+# Number of refinement cycles to be performed
+set Refinement cycles         = 5
+@endcode
+The output of this program then consists of the console output, a file 
 named ``convergence_table'' to record main results of mesh iteration, 
 and the graphical output in vtu format.
 
-When we set Polynomial_Order to 2, we got following console output:
+The console output looks like this:
 @code
 Cycle 0:
    Numbers of active cells:       1156 1156 
diff --git a/examples/step-28/project.prm b/examples/step-28/project.prm
new file mode 100644
index 0000000000..aaf9c3db5b
--- /dev/null
+++ b/examples/step-28/project.prm
@@ -0,0 +1,14 @@
+# Listing of Parameters
+# ---------------------
+# Polynomial degree of the finite element to be used
+set Finite element degree     = 2
+
+# The number of energy different groups considered
+set Number of energy groups   = 2
+
+# Inner power iterations are stopped when the change in k_eff falls below this
+# tolerance
+set Power iteration tolerance = 1e-12
+
+# Number of refinement cycles to be performed
+set Refinement cycles         = 5
-- 
2.39.5