From: hartmann Date: Wed, 14 Mar 2001 18:15:53 +0000 (+0000) Subject: Doc update. New classes Polynomial, LagrangeEquidistant, TensorProductPolynomials... X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=59df52067b3aa705caea1aa7d0a4c01c853bd72c;p=dealii-svn.git Doc update. New classes Polynomial, LagrangeEquidistant, TensorProductPolynomials; new Mapping argument for all FEValues classes, and for GridOut::write_gnuplot, GridOut::write_eps. New functionality of the Boundary class. FiniteElemente::get_support_points function removed. git-svn-id: https://svn.dealii.org/trunk@4209 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/doc/news/2001/c-3-1.html b/deal.II/doc/news/2001/c-3-1.html index 45dd84fbe9..f55ac2a373 100644 --- a/deal.II/doc/news/2001/c-3-1.html +++ b/deal.II/doc/news/2001/c-3-1.html @@ -35,14 +35,18 @@ documentation, etc. (GK 2001/03/14)

-
  • - New: The finite element classes have been redesigned from - scratch to allow also elements that depend on the actual cell - shape, like Raviart-Thomas, BDM or edge elements. Presently, we - have implemented continuous and discontinous Lagrange elements, - that can be easily extended to higher degree. E.g. for - continuous FEs we've already implemented elements up to degree - four, for discontinuous FEs up to degree 10. +

  • + +

    New Design of FiniteElements + and Mappings

    + + New: The finite element + classes have been redesigned from scratch to allow also + elements that depend on the actual cell shape, like + Raviart-Thomas, BDM or edge elements. We have implemented + continuous Lagrange elements up to degree four and discontinous + Lagrange elements up to degree 10. They can be easily extended + to higher degree.

    @@ -50,7 +54,7 @@ documentation, etc. between unit and real cell. In future we won't be restricted to Q1 mapping any more, but we will have Qp mappings of arbitrary degree p. Presently - implemented are mappings up to degree four in 2d, and degree + implemented are mappings up to degree 10 in 2d, and degree three in 3d. This allows to approximate curved boundaries not only by straight lines (linear approximation) but also by quadratic, cubic, etc approximation. The finite elements will @@ -61,13 +65,16 @@ documentation, etc.

    The new implementation uses a totally new structure of - communication between FEValues, the - FiniteElements and the Mappings. Despite of this, - the new structure will almost not be 'visible' to the user of + communication between FEValues, the + FiniteElements and the Mappings. Despite of this, the new + structure will almost not be 'visible' to the user of deal.II as we tried to retain the interface - to the user (mainly that of FEValues) as far as - possible. + to the user (mainly that of FEValues) as far as possible.
    + +

    (RH & GK 2001/03/13)

    @@ -101,6 +108,39 @@ documentation, etc.

    base

      +
    1. + New: The class TensorProductPolynomials<dim> + performs the tensor product of 1d polynomials, computes its + values, its first and second derivatives. If n + polynomials are given to the constructor of this class, it + constructs ndim tensor product + polynomials. +
      + (RH 2001/03/14) +

      + +
    2. + New: LagrangeEquidistant is a new + class derived from Polynomial + providing the 1d Lagrange interpolation of degree + n of n+1 equidistant support points + in [0,1]. It is implemented up to degree 10. + This class is used for the implementation of the continuous and + discontinuous Lagrange elements. +
      + (RH 2001/03/14) +

      + +
    3. + New: The new Polynomial class can + be used as base class for all 1d polynomials. It stores the + coefficients of the polynomial and uses the Horner scheme to + evaluate values and all derivates. +
      + (RH 2001/03/14) +

      +
    4. New: function contract for two arguments of Tensor<1,dim> @@ -149,14 +189,16 @@ documentation, etc.

      lac

        -
      1. +

      2. + Removed: The explicite instantiations of SparseMatrix are removed as a - prerelease of gcc3.0 fails to compile it. Now the user of - SparseMatrix needs to include + class="class">SparseMatrix<long double> are + removed as a prerelease of gcc3.0 fails to compile it. A user + of SparseMatrix<long double> + needs now to include lac/include/lac/sparse_matrix.templates.h into his - source file and to use a different compiler, e.g. gcc 2.95.2 or - a future version of gcc3.0 (that will then hopefully fixed). + source file and to use an appropriate compiler, e.g. gcc2.95.2 or + a future version of gcc3.0 (that will then hopefully be fixed).
        (RH 2001/03/14)

        @@ -193,8 +235,81 @@ documentation, etc.

        deal.II

          +
        1. + Removed: The function FiniteElemente::get_support_points + is removed as the FiniteElement + cannot know the position of the support points by itself. This is + because the support points depend on the unit support points + (known to the FiniteElement class) + but they also depend on the mapping. + + In future the support points can be computed using a FEValues object initialized with the Mapping and a Quadrature that uses the unit support + points as quadrature points. +
          + (RH 2001/03/14) +

          + +
        2. + New: The class Boundary has two new + functions get_intermediate_points_on_line and get_intermediate_points_on_quad that + needs to be implemented in derived classes only if GridOut is used with MappingQ of degree p>2. +
          + (RH 2001/03/14) +

          + +
        3. + + New: The functions GridOut::write_gnuplot and GridOut::write_eps now take a pointer to + a Mapping object as additional + argument. This allows to write grids in 2d whereby cells with a + curved boundary are transformed by the given Mapping class. The default mapping is + MappingQ1. Note, that the grids do + not show the `original' domain with boundaries described by the + Boundary classes but the + discretized domain whose boundary cells are transformed using the + given mapping. +

          + There are also a new GnuplotFlags::n_boundary_face_points and + EpsFlags::n_boundary_face_points + variables to set the number of additional points written + to represent the curved boundary faces. +
          + (RH 2001/03/14) +

          + +
        4. + New: The constructor of the FEValues + and FE(Sub)FaceValues classes now + take a pointer to Mapping object as + additional argument. This is the new possibility to combine a + FiniteElement with an arbitrary + Mapping, see also New FE and Mapping Design. +

          + +

          + There still exists a constructor of FEValues without a Mapping argument that uses a MappingQ1 by default. +
          + (RH 2001/03/14) +

          +
        5. - We now unconditionally include + Changed: We now unconditionally include deal.II/include/grid/tria_accessor.templates.h (which containts some inline functions for triangulation accessor classes) into @@ -207,7 +322,7 @@ documentation, etc.

        6. - The class GridReordering::Cell has + New: The class GridReordering::Cell has now a copy constructor to work around a bug in a gcc3.0 snapshot.