PLTMG 11.0 is a package for solving elliptic partial differential equations in general regions of the plane. It is based on a family of continuous Lagrange triangular finite elements. PLTMG features options for adaptive h, p, and hp refinement, coarsening, and mesh moving. PLTMG employes several algebraic multilevel solvers for the resulting systems of linear equations. PLTMG provides a suite of continuation options to handle PDEs with parameter dependencies. It also provides options for solving several classes of optimal control and obstacle problems. The package includes an initial mesh generator and several graphics packages. Support for the Bank-Holst parallel adaptive meshing paradigm and corresponding domain decomposition solver are also provided.
PLTMG is provided as Fortran (and a little C) source code. However, this version is no longer backwards compatible with Fortan77. The code has interfaces to X-Windows, MPI, and Michael Holst's OpenGL display tool SG. The X-Windows, MPI, and SG interfaces require libraries that are NOT provided as part of the PLTMG package.
PLTMG is also available from Netlib.
The SG (socket graphics) OpenGL display tool is available from Michael Holst.
MPICH is available from the MPI homepage.
OpenMotif is available from the MotifZone homepage.
Multigraph 1.0 is an algebraic multilevel solver for large sparse systems of linear equations. The package takes as input just the system matrix in a sparse matrix format and constructs a hierarchy of coarse matrices based on the sparse matrix graph. The multigraph solver is included in the PLTMG 9.0 package. The Multigraph 1.0 distribution contains the basic solver routines that can be incorporated into user applications, and a driver program with an X-Windows GUI and graphics package that can be used independently to demonstrate and test the solver.
The directory Matrix 1 contains 18 sparse linear system files corresponding to 6 elliptic PDEs on irregular regions with nonuniform adaptive meshes. The directory Matrix 3 contains 21 sparse linear system files corresponding to 7 constant coefficient PDEs on uniform square meshes. In both directories, each PDE appears for 3 different values of N.