From: Matthias Maier Date: Thu, 9 Mar 2017 22:05:51 +0000 (-0600) Subject: Finish reformatting Section 2, rephrase section about incompatible changes X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=13c5e98c74fb73f1a3ebebfc87a504747f0e3a6b;p=release-papers.git Finish reformatting Section 2, rephrase section about incompatible changes --- diff --git a/8.5/paper.tex b/8.5/paper.tex index f7d3f66..6f71c03 100644 --- a/8.5/paper.tex +++ b/8.5/paper.tex @@ -468,46 +468,50 @@ updated to use \verb|FESeries::Fourier|. \subsection{Matrix-free operators} -In order to facilitate the usage of matrix-free methods, a \verb!MatrixFreeOperator::Base! class has been introduced, -implementing various interfaces to matrix-vector products and the necessary operations for the interface residuals according to \cite{JanssenKanschat2011} in -the context of the geometric multigrids. Furthermore, the class is compatible with the linear operator framework and provides an interface to a Jacobi preconditioner. -The derived classes only need to implement the \verb!apply_add()! method that is -used in the \verb!vmult()! functions, and a method to compute the diagonal entries of the underlying matrix. -The \verb!MatrixFreeOperator! namespace contains implementations of \verb!MatrixFreeOperators::LaplaceOperator! and -\verb!MatrixFreeOperators::MassOperator!. -The updated step-37 tutorial program makes use of these facilities and -explains their usage in detail. Using the matrix-free mass operator, -\verb!VectorTools::project! has become much faster than the previous -matrix-based approach for elements supported by \verb!MatrixFree! and also -works in parallel with MPI. +In order to facilitate the usage of matrix-free methods, a +\verb!MatrixFreeOperator::Base! class has been introduced, implementing +various interfaces to matrix-vector products and the necessary operations +for the interface residuals according to \cite{JanssenKanschat2011} in the +context of the geometric multigrids. Furthermore, the class is compatible +with the linear operator framework and provides an interface to a Jacobi +preconditioner. The derived classes only need to implement the +\verb!apply_add()! method that is used in the \verb!vmult()! functions, and +a method to compute the diagonal entries of the underlying matrix. The +\verb!MatrixFreeOperator! namespace contains implementations of +\verb!MatrixFreeOperators::LaplaceOperator! and +\verb!MatrixFreeOperators::MassOperator!. The updated step-37 tutorial +program makes use of these facilities and explains their usage in detail. +Using the matrix-free mass operator, \verb!VectorTools::project! has become +much faster than the previous matrix-based approach for elements supported +by \verb!MatrixFree! and also works in parallel with MPI. \subsection{Incompatible changes} -\subsubsection{incompatible change 1} - -High-order Lagrange elements, both continuous \verb!FE_Q! and discontinuous -\verb!FE_DGQ! types, now use the nodal points of the Gauss--Lobatto -quadrature formula as support points, rather than the previous equidistant -ones. For cubic polynomials and higher, the point distribution has thus changed and -thus the entries in solution vectors will look different as compared to the previous version. Note, however, -that using the Gauss--Lobatto points as nodal points results in a much more -stable interpolation, including better iteration counts in most iterative -solvers. - -\subsubsection{Other incompatible changes} - -No \texttt{long double} instantiations any more - -ParameterGUI moved to separate repo - -The -\href{https://www.dealii.org/8.5.0/doxygen/deal.II/changes_between_8_4_and_8_5.html}{file - that lists all changes for this release} (see \cite{changes85}) -lists another around 20 -incompatible changes, but none of these should in fact be visible in -typical user codes. Some remove previously deprecated classes and -functions, and the majority change internal interfaces that are not -typically used in user codes. +The 8.5.0 release includes around 20 +\href{https://www.dealii.org/8.5.0/doxygen/deal.II/changes_between_8_4_and_8_5.html}{ +incompatible changes}; see \cite{changes85}. The majority of these changes +should not be visible to typical user codes; some remove previously +deprecated classes and functions, and the majority change internal +interfaces that are not typically used in user codes. However, a number of +incompatible changes a worth mentioning. +\begin{itemize} + \item High-order Lagrange elements, both continuous \verb!FE_Q! and + discontinuous \verb!FE_DGQ! types, now use the nodal points of the + Gauss--Lobatto quadrature formula as support points, rather than the + previous equidistant ones. For cubic polynomials and higher, the point + distribution has thus changed and, consequently, the entries in + solution vectors will look different as compared to the previous + version. Note, however, that using the Gauss--Lobatto points as nodal + points results in a much more stable interpolation, including better + iteration counts in most iterative solvers. + \item + The library does not instantiate template versions with \texttt{long + double} any more. If you need template versions with \texttt{long + double} make sure to include the corresponding \texttt{templates.h} + header file. + \item + The \texttt{ParameterGUI} has been moved to a separate repository. +\end{itemize}