#include <ElmDefs.h>
Inheritance diagram for ElmT3gn4bn2D::
Public Methods | |
| ElmT3gn4bn2D () | |
| ~ElmT3gn4bn2D () | |
| virtual void | basisFunc (Vec(real) &N, const Ptv(real) &loc_pt) const |
| virtual void | dLocBasisFunc (Mat(real) &dNloc, const Ptv(real) &loc_pt) const |
| virtual void | d2LocBasisFunc (ArrayGen(real) &d2Nloc, const Ptv(real) &loc_pt) const |
NAME: ElmT3gn4bn2D - definition of 2D constant triangle finite element
DESCRIPTION:
The class is derived from class "ElmT3n2D" and implements the standard two dimensional linear MINI element with 4 nodes, one i the middle and in 3 in the corners. This element is often used in the mixed Stokes problem.
Most of the operations on this element type are defined through virtual functions or member functions of the base class "ElmT3n2d" and "ElmDef". See the documentation of class "ElmT3n2D" and "ElmDef" for further explanation of the interface.
|
|
The only constructor performs all the initialization. |
|
|
|
|
|
calculates the basis (trial) functions over the element. In other words, the routine computes the interpolation functions for functions defined over the element. Functions entering differential equations etc should be interpolated according to these basis functions. The return array "N" can be empty (not ok) at input, the "basisFunc" will redimension the array properly. The length of "N" equals the number of basis function nodes in the element. For isoparametric elements "basisFunc" and "geomtFunc" are identical. However, for mixed finite elements, one may have a bilinear geometry function (four nodes) and, e.g., a constant basis function. The basis function has then only one node (for example in the centroid of the element) and the length of "N" will be 1. Confer subclasses and the FAQ for information on conventions regarding basis function nodes and the ordering. It should be mentioned that class "BasisFuncGrid" is used to assign basis nodes to a grid (class "GridFE" is meant to contain the geometry of the grid, including geometry nodes). Reimplemented from ElmT3n2D. |
|
|
the second order derivatives in the local element coordinates of the functions defined by "basisFunc". Reimplemented from ElmT3n2D. |
|
|
the derivatives in the local element coordinates of the functions defined by "basisFunc." As for the "geomtFunc" and "basisFunc" functions the return array can be empty or have wrong dimension at input. The function will redimension the array properly. Reimplemented from ElmT3n2D. |