fix references, update results

diff --git a/doc/doxygen/headers/mg.h b/doc/doxygen/headers/mg.h
index b4ec80edfc0be0a1959812e9b9c5b8cd7916b813..d1a4235b1e6e7a8998f4919f2d437f0d791b03ae 100644 (file)
--- a/doc/doxygen/headers/mg.h
+++ b/doc/doxygen/headers/mg.h
@@ -42,7 +42,7 @@
  * Finally, we have several auxiliary classes, namely MGLevelObject,
  * which stores an object on each level*
  * 
- * See the step-16 and step-39 example programs on how to use this
+ * See the step-16, step-16b, and step-39 example programs on how to use this
  * functionality.
 
  * <h3>Multigrid and hanging nodes</h3>

diff --git a/doc/doxygen/tutorial/tutorial.h.in b/doc/doxygen/tutorial/tutorial.h.in
index de339bdb6fdd0090e7269ce1bf03d1a848b00124..d00e83a9283e6573f628337fc9492d68784af4e4 100644 (file)
--- a/doc/doxygen/tutorial/tutorial.h.in
+++ b/doc/doxygen/tutorial/tutorial.h.in
@@ -199,6 +199,12 @@
  *       </td></tr>
  *
  *   <tr valign="top">
+ *       <td>step-16b</td>
+ *       <td> A variant of step-16 but with MeshWorker for assembly: Multigrid
+ *       preconditioning of the Laplace equation on adaptive meshes.
+ *       </td></tr>
+ *
+ *   <tr valign="top">
  *       <td>step-17</td>
  *       <td> Using PETSc for linear algebra; running
  *       in parallel on clusters of computers linked together by MPI.
@@ -742,6 +748,7 @@
  *     </td>
  *     <td>
  *       step-16,
+ *       step-16b
  *       step-31,
  *       step-32,
  *       step-37,

diff --git a/examples/step-16/doc/results.dox b/examples/step-16/doc/results.dox
index eef49e52155639ef38b134187678e5d090a25fc3..d03a6a0c2a4c79b7d1b2f560cf4f47255631cfc9 100644 (file)
--- a/examples/step-16/doc/results.dox
+++ b/examples/step-16/doc/results.dox
@@ -10,58 +10,57 @@ More importantly, we would like to see if the multigrid method really improved
 the solver performance. Therefore, here is the textual output:
 
 <pre>
-DEAL::Cycle 0
-DEAL::   Number of active cells:       20
-DEAL::   Number of degrees of freedom: 25 (by level: 8, 25)
-DEAL:cg::Starting value 0.510691
-DEAL:cg::Convergence step 6 value 4.59193e-14
-DEAL::Cycle 1
-DEAL::   Number of active cells:       41
-DEAL::   Number of degrees of freedom: 52 (by level: 8, 25, 41)
-DEAL:cg::Starting value 0.455356
-DEAL:cg::Convergence step 8 value 3.09682e-13
-DEAL::Cycle 2
-DEAL::   Number of active cells:       80
-DEAL::   Number of degrees of freedom: 100 (by level: 8, 25, 61, 52)
-DEAL:cg::Starting value 0.394469
-DEAL:cg::Convergence step 9 value 1.96993e-13
-DEAL::Cycle 3
-DEAL::   Number of active cells:       161
-DEAL::   Number of degrees of freedom: 190 (by level: 8, 25, 77, 160)
-DEAL:cg::Starting value 0.322156
-DEAL:cg::Convergence step 9 value 2.94418e-13
-DEAL::Cycle 4
-DEAL::   Number of active cells:       311
-DEAL::   Number of degrees of freedom: 364 (by level: 8, 25, 86, 227, 174)
-DEAL:cg::Starting value 0.279667
-DEAL:cg::Convergence step 10 value 3.45746e-13
-DEAL::Cycle 5
-DEAL::   Number of active cells:       593
-DEAL::   Number of degrees of freedom: 667 (by level: 8, 25, 89, 231, 490, 96)
-DEAL:cg::Starting value 0.215917
-DEAL:cg::Convergence step 10 value 1.03758e-13
-DEAL::Cycle 6
-DEAL::   Number of active cells:       1127
-DEAL::   Number of degrees of freedom: 1251 (by level: 8, 25, 89, 274, 760, 417, 178)
-DEAL:cg::Starting value 0.185906
-DEAL:cg::Convergence step 10 value 3.40351e-13
-DEAL::Cycle 7
-DEAL::   Number of active cells:       2144
-DEAL::   Number of degrees of freedom: 2359 (by level: 8, 25, 89, 308, 779, 1262, 817)
-DEAL:cg::Starting value 0.141519
-DEAL:cg::Convergence step 10 value 5.74965e-13
+Cycle 0
+   Number of active cells:       80
+   Number of degrees of freedom: 89 (by level: 8, 25, 89)
+  Number of CG iterations: 8
+
+Cycle 1
+   Number of active cells:       158
+   Number of degrees of freedom: 183 (by level: 8, 25, 89, 138)
+  Number of CG iterations: 9
+
+Cycle 2
+   Number of active cells:       302
+   Number of degrees of freedom: 352 (by level: 8, 25, 89, 223, 160)
+  Number of CG iterations: 10
+
+Cycle 3
+   Number of active cells:       578
+   Number of degrees of freedom: 649 (by level: 8, 25, 89, 231, 494, 66)
+  Number of CG iterations: 10
+
+Cycle 4
+   Number of active cells:       1100
+   Number of degrees of freedom: 1218 (by level: 8, 25, 89, 274, 764, 417, 126)
+  Number of CG iterations: 10
+
+Cycle 5
+   Number of active cells:       2096
+   Number of degrees of freedom: 2317 (by level: 8, 25, 89, 304, 779, 1214, 817)
+  Number of CG iterations: 11
+
+Cycle 6
+   Number of active cells:       3986
+   Number of degrees of freedom: 4366 (by level: 8, 25, 89, 337, 836, 2270, 897, 1617)
+  Number of CG iterations: 10
+
+Cycle 7
+   Number of active cells:       7574
+   Number of degrees of freedom: 8350 (by level: 8, 25, 89, 337, 1086, 2835, 2268, 1789, 3217)
+  Number of CG iterations: 11
 </pre>
 
-That's almost perfect multigrid performance: 12 orders of magnitude in
-10 iteration steps, and almost independent of the mesh size. That's
+That's almost perfect multigrid performance: the linear residual gets reduced by 12 orders of
+magnitude in 10 iteration steps, and the results are almost independent of the mesh size. That's
 obviously in part due to the simple nature of the problem solved, but
 it shows the power of multigrid methods.
 
 
 <h3> Possible extensions </h3>
 
-We encourage you to switch on timing output by calling the function
-LogStream::log_execution_time() of the deallog object and compare to
+
+We encourage you to switch generate timings for the solve() call and compare to
 step 6. You will see that the multigrid method has quite an overhead
 on coarse meshes, but that it always beats other methods on fine
 meshes because of its optimal complexity.
@@ -78,8 +77,9 @@ example. In that case, it would be simpler if one could use a black-box
 preconditioner that uses some sort of multigrid hierarchy for good performance
 but can figure out level matrices and similar things by itself. Algebraic
 multigrid methods do exactly this, and we will use them in step-31 for the
-solution of a Stokes problemm and in step-32 and step-40 for a parallel
-variation.
+solution of a Stokes problem and in step-32 and step-40 for a parallel
+variation. That said, a parallel version of this example program with MPI is found
+as step-50.
 
 Finally, one may want to think how to use geometric multigrid for other kinds of
 problems, specifically @ref vector_valued "vector valued problems". This is the

diff --git a/examples/step-16b/CMakeLists.txt b/examples/step-16b/CMakeLists.txt
index 63aa9a9952cbda7a06877a007006c871d6fbddc2..b19f8f2a2a290ab5aa6f90b696210ed0d10f807e 100644 (file)
--- a/examples/step-16b/CMakeLists.txt
+++ b/examples/step-16b/CMakeLists.txt
@@ -1,5 +1,5 @@
 ##
-#  CMake script for the step-16 tutorial program:
+#  CMake script for the step-16b tutorial program:
 ##
 
 # Set the name of the project and target: