From: Wolfgang Bangerth Date: Sun, 15 Jan 2006 00:32:13 +0000 (+0000) Subject: Document the fevalues module. X-Git-Tag: v8.0.0~12633 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0e2b077d3954902483eef3114ff22fb19e2e7c74;p=dealii.git Document the fevalues module. git-svn-id: https://svn.dealii.org/trunk@12031 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/doc/doxygen/headers/fe.h b/deal.II/doc/doxygen/headers/fe.h index f0bf7ee1fd..c1f5140bfd 100644 --- a/deal.II/doc/doxygen/headers/fe.h +++ b/deal.II/doc/doxygen/headers/fe.h @@ -65,6 +65,33 @@ /** * @defgroup feaccess Finite element access/FEValues classes * + * The classes in this module are used when one wants to assemble matrices or + * vectors. They link finite elements, quadrature objects, and mappins: the + * finite element classes describes a finite element space on a unit cell + * (i.e. the unit line segment, square, or cube @f$[0,1]^d@f$), the quadrature + * classes describe where quadrature points are located and what weight they + * have, and the mapping classes describe how to map a point from the unit + * cell to a real cell and back. Since integration happens at quadrature + * points on the real cell, and needs to know their location as well as the + * values and gradients of finite element shape functions at these points. The + * FEValues class coordinates getting this information. For integrations on + * faces (for example for integration on the boundary, or interfaces between + * cells), the FEFaceValues class offers similar functionality as the FEValues + * class does for cells. Finally, the FESubfaceValues class offers the + * possibility to ingrate on parts of faces if the neighboring cell is refined + * and the present cell shares only a part of its face with the neighboring + * cell. + * + * The last member of this group, the UpdateFlags enumeration, is used as an + * optimization: instead of letting the FEValues class compute every possible + * piece of data relating to a given finite element on a cell, you have to + * specify up front which information you are actually interested in. The + * UpdateFlags enumeration is used to offer symbolic names denoting what you + * want the FEValues class to compute. + * + * All these classes are used in all tutorial programs from step-3 onward, and + * are described there in significant detail. + * * @ingroup feall */