of Ainsworth for a complete discussion.
It seem as if this error estimator should only be valid for linear ansatz
- spaces, but no definite answer is given to this question at present.
+ spaces, and there are indications that for higher order ansatz spaces the
+ integrals computed here show superconvergence properties, i.e. they tend
+ to zero faster than the error itself, thus ruling out the values as error
+ indicators.
{\bf Implementation}
\item No other boundary conditions are considered.
\end{itemize}
+
+ The integration along faces with hanging nodes is quite tricky, since one
+ of the elements has to be shifted one level up or down. See the
+ documentation for the #FEFaceValues# class for more information about
+ technical issues regarding this topic.
@author Wolfgang Bangerth, 1998; thanks to Franz-Theo Suttmeier for
clarifications about boundary conditions.