FEM2D_POISSON_SPARSE_ELL
A 2D Poisson Problem in an L-shaped Region

FEM2D_POISSON_SPARSE_ELL is a C++ library which sets up the geometry and data for a Poisson problem in an L-shaped region for solution by FEM2D_POISSON_SPARSE.

This mesh, which uses 65 nodes, was created by starting with a crude mesh, and having it refined by TRIANGULATION_REFINE and renumbered by TRIANGULATION_RCM.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

FEM2D_POISSON_SPARSE_ELL is available in a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

FEM2D_POISSON_SPARSE, a C++ program which solves a 2D Poisson problem, using a sparse matrix solver, and user input.

FEM2D_POISSON_SPARSE_BAFFLE, a C++ library which defines the geometry of a rectangle channel containing 13 hexagonal baffles, as well as boundary conditions for a given Poisson problem, and is called by fem2d_poisson_sparse as part of a solution procedure.

FEM2D_POISSON_SPARSE_LAKE, a C++ library which defines the geometry of a lake-shaped region, as well as boundary conditions for a given Poisson problem, and is called by fem2d_poisson_sparse as part of a solution procedure.

Source Code:

• ell.cpp, the user-supplied routines to evaluate the right hand side, linear coefficient, and boundary conditions;
• ell_output.txt, output from a run of the program;
• ell_nodes.txt, a text file containing a list, for each node, of its X and Y coordinates;
• ell_nodes.png, a PNG image of the nodes;
• ell_elements.txt, a text file containing a list, for each element, of the three nodes that compose it;
• ell_elements.png, a PNG image of the element mesh;
• ell_solution.txt, a text file containing the solution U at each node (X,Y);

You can go up one level to the C++ source code page.