6.4 Old Sparse Data

Sparse data is typically used to represent boundary conditions. For example, in a structural dynamics program typically some nodes have an imposed force or position. The routines in this section are used to describe this kind of mesh-associated data--data that only applies to some ``sparse'' subset of the nodes or elements.

void FEM_Set_sparse(int S_id,int nRec, const int *nodes,int nodesPerRec, const void *data,int dataPerRec,int dataType);
SUBROUTINE FEM_Set_sparse(S_id,nRec,nodes,nodesPerRec,data,dataPerRec,dataType)
INTEGER, INTENT(IN) :: S_id,nRec,nodesPerRec,dataPerRec,dataType
INTEGER, INTENT(IN) :: nodes(nodesPerRec,nRec)
varies, INTENT(IN) :: data(dataPerRec,nRec)

Register nRec sparse data records with the framework under the number S_id. The first call to FEM_Set_sparse must give a S_id of zero in C (1 in fortran); and subsequent calls to FEM_Set_sparse must give increasing consecutive S_ids.

One sparse data record consists of some number of nodes, listed in the nodes array, and some amount of user data, listed in the data array. Sparse data records are copied into the chunks that contains all that record's listed nodes. Sparse data records are normally used to describe mesh boundary conditions- for node-associated boundary conditions, nodesPerRec is 1; for triangle-associated boundary conditions, nodesPerRec is 3.

In general, nodePerRec gives the number of nodes associated with each sparse data record, and nodes gives the actual node numbers. dataPerRec gives the number of data items associated with each sparse data record, and dataType, one of FEM_BYTE, FEM_INT, FEM_REAL, or FEM_DOUBLE, gives the type of each data item. As usual, you may change or delete the nodes and data arrays after this call returns.

For example, if the first set of sparse data is 17 sparse data records, each containing 2 nodes stored in bNodes and 3 integers stored in bDesc, we would make the call:

/*C version*/ FEM_Set_sparse(0,17, bNodes,2, bDesc,3,FEM_INT); ! Fortran version CALL FEM_Set_sparse(1,17, bNodes,2, bDesc,3,FEM_INT)

void FEM_Set_sparse_elem(int S_id,const int *rec2elem);
SUBROUTINE FEM_Set_sparse_elem(S_id,rec2elem)
INTEGER, INTENT(IN) :: S_id
INTEGER, INTENT(IN) :: rec2elem(2,nRec)

Attach the previously-set sparse records S_id to the given elements. rec2elem consists of pairs of integers--one for each sparse data record. The first integer in the pair is the element type to attach the sparse record to, and the second integer gives the element number within that type. For example, to attach the 3 sparse records at S_id to the elements numbered 10, 11, and 12 of the element type elType, use:

/*C version*/ int rec2elem[]=elType,10, elType,11, elType,12; FEM_Set_sparse_elem(S_id,rec2elem); ! Fortran version integer :: rec2elem(2,3); rec2elem(1,:)=elType rec2elem(2,1)=10; rec2elem(2,2)=11; rec2elem(2,3)=12; CALL FEM_Set_sparse_elem(S_id,rec2elem)

int FEM_Get_sparse_length(int S_id);
void FEM_Get_sparse(int S_id,int *nodes,void *data);
function FEM_Get_sparse_length(S_id);
INTEGER, INTENT(IN) :: S_id
INTEGER, INTENT(OUT) :: FEM_Get_sparse_Length
SUBROUTINE FEM_Get_sparse(S_id,nodes,data);
INTEGER, INTENT(IN) :: S_id
INTEGER, INTENT(OUT) :: nodes(nodesPerRec,FEM_Get_sparse_Length(S_id))
varies, INTENT(OUT) :: data(dataPerRec,FEM_Get_sparse_Length(S_id))

Retrieve the previously registered sparse data from the framework. FEM_Get_sparse_length returns the number of records of sparse data registered under the given S_id; zero indicates no records are available. FEM_Get_sparse returns you the actual nodes (translated to local node numbers) and unchanged user data for these sparse records.