6 Older Mesh Routines

These routines have a simpler, but less flexible interface than the general routines described in Section 3. Because they are easy to implement in terms of the new routines, they will remain part of the framework indefinitely. These routines always use the default mesh, as returned by FEM_Mesh_default_read and FEM_Mesh_default_write.

void FEM_Set_elem(int elType,int nEl,int doublePerEl,int nodePerEl);
void FEM_Get_elem(int elType,int *nEl,int *doublePerEl,int *nodePerEl);
SUBROUTINE FEM_Set_elem(elType,nEl,doublePerEl,nodePerEl)
INTEGER, INTENT(IN) :: elType,nEl,doublePerEl,nodePerEl
SUBROUTINE FEM_Get_elem(elType,nEl,doublePerEl,nodePerEl)
INTEGER, INTENT(IN) :: elType
INTEGER, INTENT(OUT) :: nEl,doublePerEl,nodePerEl

Describe/retreive the number and type of elements. ElType is a user-defined small, unique element type tag. nEl is the number of elements being registered. doublesPerEl and nodePerEl are the number of doubles of user data, and nodes (respectively) associated with each element.

doublePerEl or nodePerEl may be zero, indicating that no user data or connectivity data (respectively) is associated with the element.

You can make this and any other mesh setup calls in any order--there is no need to make them in linearly increasing order. However, for a given type of element FEM_Set_elem must be called before setting that element's connectivity or data.

void FEM_Set_elem_conn(int elType,const int *conn);
void FEM_Get_elem_conn(int elType,int *conn);
SUBROUTINE FEM_Set_elem_conn_r(elType,conn)
INTEGER, INTENT(IN) :: elType
INTEGER, INTENT(IN), dimension(nodePerEl,nEl) :: conn
SUBROUTINE FEM_Get_elem_conn_r(elType,conn)
INTEGER, INTENT(IN) :: elType
INTEGER, INTENT(OUT), dimension(nodePerEl,nEl) :: conn
SUBROUTINE FEM_Set_elem_conn_c(elType,conn)
INTEGER, INTENT(IN) :: elType
INTEGER, INTENT(IN), dimension(nEl,nodePerEl) :: conn
SUBROUTINE FEM_Get_elem_conn_c(elType,conn)
INTEGER, INTENT(IN) :: elType
INTEGER, INTENT(OUT), dimension(nEl,nodePerEl) :: conn

Describe/retreive the element connectivity array for this element type. The connectivity array is indexed by the element number, and gives the indices of the nodes surrounding the element. It is hence nodePerEl*nEl integers long.

The C version array indices are zero-based, and must be stored in row-major order (a given element's surrounding nodes are stored contiguously in the conn array). The Fortran version indices are one-based, and are available in row-major (named _r) and column-major (named _c) versions. We recommend row-major storage because it results in better cache utilization (because the nodes around an element are stored contiguously).

In this older interface, ghost nodes are indicated by invalid,

void FEM_Set_node(int nNode,int doublePerNode);
void FEM_Get_node(int *nNode,int *doublePerNode);
SUBROUTINE FEM_Set_node(nNode,doublePerNode)
INTEGER, INTENT(IN) :: nNode,doublePerNode
SUBROUTINE FEM_Get_node(nNode,doublePerNode)
INTEGER, INTENT(OUT) :: nNode,doublePerNode

Describe/retreive the number of nodes and doubles of user data associated with each node. There is only one type of node, so no nodeType identifier is needed.

doublePerNode may be zero, indicating that no user data is associated with each node.