From: Wolfgang Bangerth Date: Tue, 3 Dec 2013 13:54:24 +0000 (+0000) Subject: Add a few comments as suggested by Denis Davydov. X-Git-Tag: v8.1.0~120 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1379f36f35aa8093dc2ac0292367510b381e884f;p=dealii.git Add a few comments as suggested by Denis Davydov. git-svn-id: https://svn.dealii.org/trunk@31852 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/include/deal.II/fe/fe.h b/deal.II/include/deal.II/fe/fe.h index 31fb8c8cb7..40b4c742c5 100644 --- a/deal.II/include/deal.II/fe/fe.h +++ b/deal.II/include/deal.II/fe/fe.h @@ -114,12 +114,12 @@ namespace hp * FEValues fe_values (mapping, fe, dummy_quadrature, * update_quadrature_points); * fe_values.reinit (cell); - * Point& mapped_point = fe_values.quadrature_point (i); + * Point mapped_point = fe_values.quadrature_point (i); * @endcode * * Alternatively, the points can be transformed one-by-one: * @code - * const vector >& unit_points = + * const vector > &unit_points = * fe.get_unit_support_points(); * * Point mapped_point = @@ -129,6 +129,13 @@ namespace hp * If the mapping of all support points is needed, the first variant should * be preferred for efficiency. * + * @note Finite elements' implementation of the get_unit_support_points() + * returns these points in the same order as shape functions. As a consequence, + * the quadrature points accessed above are also ordered in this way. The + * order of shape functions is typically documented in the class documentation + * of the various finite element classes. + * + * *

Notes on the implementation of derived classes

* * The following sections list the information to be provided by @@ -1315,7 +1322,7 @@ public: /** * Return the support points of the trial functions on the unit cell, if the - * derived finite element defines some. Finite elements that allow some + * derived finite element defines them. Finite elements that allow some * kind of interpolation operation usually have support points. On the other * hand, elements that define their degrees of freedom by, for example, * moments on faces, or as derivatives, don't have support points. In that @@ -1327,6 +1334,20 @@ public: * function. * * See the class documentation for details on support points. + * + * @note Finite elements' implementation of this function + * returns these points in the same order as shape functions. The + * order of shape functions is typically documented in the class documentation + * of the various finite element classes. In particular, shape functions (and + * consequently the mapped quadrature points discussed in the class documentation + * of this class) will then traverse first those shape functions + * located on vertices, then on lines, then on quads, etc. + * + * @note If this element implements support points, then it will return one + * such point per shape function. Since multiple shape functions may be defined + * at the same location, the support points returned here may be duplicated. An + * example would be an element of the kind FESystem(FE_Q(1),3) + * for which each support point would appear three times in the returned array. */ const std::vector > & get_unit_support_points () const;