4.1 Mesh Routines

int FEM_Mesh_allocate(void);
INTEGER FUNCTION :: FEM_Mesh_allocate()

Create a new local mesh object. The mesh is initially empty, but it is a setting mesh, so call FEM_Mesh_data to fill the mesh with data.

int FEM_Mesh_deallocate(int mesh);
SUBROUTINE FEM_Mesh_deallocate(mesh)
INTEGER, INTENT(IN) :: mesh

Destroy this local mesh object, and its associated data.

int FEM_Mesh_copy(int mesh);
INTEGER FUNCTION FEM_Mesh_copy(mesh)
INTEGER, INTENT(IN) :: mesh

Create a new mesh object with a separate copy of the data stored in this old mesh object.

void FEM_Mesh_write(int mesh,const char *prefix,int partNo,int nParts);
SUBROUTINE FEM_Mesh_write(mesh,prefix,partNo,nParts)
INTEGER, INTENT(IN) :: mesh
INTEGER, INTENT(IN) :: partNo,nParts
character (LEN=*), INTENT(IN) :: prefix

Write this mesh to the file ``prefix_vppartNo_nParts.dat''.

By convention, partNo begins at 0; but no index conversion is performed so you can assign any meaning to partNo and nParts. In particular, this routine is not collective-you can read any mesh from any processor. For example, if prefix is ``foo/bar'', the data for the first of 7 chunks would be stored in ``foo/bar_vp0_7.dat'' and could be read using FEM_Mesh_read('foo/bar',0,7).

Meshes are stored in a machine-portable format internal to FEM. The format is currently ASCII based, but it is subject to change. We strongly recommend using the FEM routines to read and write these files rather than trying to prepare or parse them yourself.

int FEM_Mesh_read(const char *prefix,int partNo,int nParts);
INTEGER FUNCTION :: FEM_Mesh_read(prefix,partNo,nParts)
INTEGER, INTENT(IN) :: partNo,nParts
character (LEN=*), INTENT(IN) :: prefix

Read a new mesh from the file ``prefix_vppartNo_nParts.dat''. The new mesh begins in getting mode, so you can read the data out of the mesh using calls to FEM_Mesh_data.

int FEM_Mesh_broadcast(int mesh,int fromRank,FEM_Comm_t comm_context);
INTEGER FUNCTION :: FEM_Mesh_broadcast(mesh,fromRank,comm_context)
INTEGER, INTENT(IN) :: mesh,fromRank,comm_context

Take the mesh mesh on processor fromRank (normally 0), partition the mesh into one piece per processor (in the MPI communicator comm_context, and return each processor its own piece of the partitioned mesh. This call is collective, but only processor fromRank needs to pass in a mesh; the mesh value is ignored on other processors.

For example, if rank 0 has a mesh named ``src'', we can partition src for all the processors by executing:

  m=FEM_Mesh_broadcast(src,0,MPI_COMM_WORLD);

The new, partitioned mesh is in getting mode, so you can read the partitioned data using calls to FEM_Mesh_data. This call does not affect mesh in any way.

int FEM_Mesh_reduce(int mesh,int toRank,FEM_Comm_t comm_context);
INTEGER FUNCTION :: FEM_Mesh_reduce(mesh,toRank,comm_context);
INTEGER, INTENT(IN) :: mesh,toRank,comm_context

This call is the reverse operation of FEM_Mesh_broadcast: each processor passes in a mesh in mesh, the mesh is assembled, and the function returns the assembled mesh to processor toRank. This call is collective, but only processor toRank is returned a mesh; all other processors are returned the non-mesh value 0.

The new, reassembled mesh is in getting mode. This call does not affect mesh.