3 Mesh Nodes and Elements

These routines describe and retreive the finite element mesh for this computation. A mesh, from the framework's perspective, is a list of elements, nodes, and other data that describes the computational domain. The FEM framework provides extensive support for creating, manipulating, and partitioning meshes.

A serial mesh consists of a single large piece. It's usually easiest to read and write serial meshes to existing, non-parallel file formats, and it can be easier to manipulate serial meshes. By contrast, a parallel mesh consists of several pieces, called chunks or partitions. Different processors can work on different pieces of a parallel mesh, so most of the computation is done using parallel meshes. A simple program might create or read in a single serial mesh in init, get a local chunk of the partitioned¹mesh in driver, and work on that chunk for the rest of the program. A more complex program might set an initial mesh in init; then get, work on, reassemble and repartition the mesh several times in driver via FEM_Update_mesh.