From: Guido Kanschat Date: Wed, 9 May 2001 10:06:29 +0000 (+0000) Subject: documentation on support points X-Git-Tag: v8.0.0~19224 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2c5628ac944a4f99175bef1717b25d635d571405;p=dealii.git documentation on support points git-svn-id: https://svn.dealii.org/trunk@4567 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/deal.II/include/fe/fe_base.h b/deal.II/deal.II/include/fe/fe_base.h index 2e5fae4816..3e7fbe1998 100644 --- a/deal.II/deal.II/include/fe/fe_base.h +++ b/deal.II/deal.II/include/fe/fe_base.h @@ -223,6 +223,35 @@ class FiniteElementData * transfer, respectively. * * + * @section{Support points} + * + * Since a @ref{FiniteElement} does not have information on the actual + * grid cell, it can only provide support points on the unit + * cell. Support points on the actual grid cell must be computed by + * mapping these points. The class used for this kind of operation is + * @ref{FEValues}. In most cases, code of the following type will + * serve to provide the mapped support points. + * + * @begin{verbatim} + * Quadrature dummy_quadrature (fe.get_unit_support_points()); + * FEValues fe_values (mapping, fe, dummy_quadrature, + * update_q_points); + * fe_values.reinit (cell); + * Point& mapped_point = fe_values.quadrature_point (i); + * @end{verbatim} + * + * Alternatively, the points can be transformed one-by-one: + * @begin{verbatim} + * const vector >& unit_points = + * fe.get_unit_support_points(); + * + * Point mapped_point = + * mapping.transform_unit_to_real_cell (cell, unit_points[i]); + * @end{verbatim} + * This is a shortcut, and as all shortcuts should be used cautiously. + * If the mapping of all support points is needed, the first variant should + * be preferred for efficiency. + * * \subsection{Finite elements in one dimension} * * Finite elements in one dimension need only set the @p{restriction} @@ -320,7 +349,7 @@ class FiniteElementData * introduced from the two sides are unique; it is able to handle the fact * that the constraints for some of the dofs are entered more than once. * - * @author Wolfgang Bangerth, 1998, Guido Kanschat, 2001 + * @author Wolfgang Bangerth, 1998, Ralf Hartmann, Guido Kanschat, 2001 */ template class FiniteElementBase : public Subscriptor, @@ -630,6 +659,9 @@ class FiniteElementBase : public Subscriptor, * returned by the * @p{cell->get_dof_indices} * function. + * + * See the class documentation + * for details on support points. */ const std::vector > & get_unit_support_points () const; @@ -695,6 +727,9 @@ class FiniteElementBase : public Subscriptor, * that returned by the * @p{cell->get_dof_indices} * function. + * + * See the class documentation + * for details on support points. */ const std::vector > & get_unit_face_support_points () const;