FEM2D_POISSON_ELL is a FORTRAN library which defines the geometry of an L-shaped region and other data needed in order to execute the FEM2D_POISSON program.
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.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
FEM2D_POISSON_ELL is available in a C++ version and a FORTRAN90 version and a MATLAB version.
FEM2D_POISSON, a C++ program which applies the finite element method to a 2D Poisson problem, with user input.
You can go up one level to the C++ source code page.