Add more comments and reference a paper.

diff --git a/doc/doxygen/references.bib b/doc/doxygen/references.bib
index ef87c6a1f22f7fa11b2477dd59bea622571463d3..72d2f092248ddff7bf7dd14d7b93f21bef92f159 100644 (file)
--- a/doc/doxygen/references.bib
+++ b/doc/doxygen/references.bib
@@ -44,6 +44,18 @@
   url =     {https://doi.org/10.1007/s10915-019-01102-1}
 }
 
+@article{KronbichlerWall2018,
+  author    = {Kronbichler, Martin and Wall, Wolfgang A.},
+  title     = {A Performance Comparison of Continuous and Discontinuous Galerkin Methods with Fast Multigrid Solvers},
+  journal   = {SIAM Journal on Scientific Computing},
+  year      = {2018},
+  volume    = {40},
+  number    = {5},
+  pages     = {A3423--A3448},
+  url       = {https://epubs.siam.org/doi/10.1137/16M110455X},
+  doi       = {10.1137/16M110455X}
+}
+
 %-------------------------------------------------------------------------------
 % Step 10
 %-------------------------------------------------------------------------------

diff --git a/examples/step-7/doc/results.dox b/examples/step-7/doc/results.dox
index ee404b73823ed9fe4ebd9a084a51143e33fe79e2..2c1906923fa19202b2473899f258cbf724562835 100644 (file)
--- a/examples/step-7/doc/results.dox
+++ b/examples/step-7/doc/results.dox
@@ -296,3 +296,9 @@ linear system solver we use in this program is not perfect -- its run
 time grows faster than proportional to the linear system size -- and
 picking a better linear solver might be appropriate for this kind of
 comparison.
+
+To see how a comparison of this kind could work, take a look at
+@cite KronbichlerWall2018 , and specifically Figure 5
+that illustrates the error as a function of compute time for
+a number of polynomial degrees (as well as a number of different ways
+to discretize the equation used there).