1: #include <../src/mat/impls/aij/mpi/mpiaij.h> 2: /*@C
3: MatCreateMPIAIJSELL - Creates a sparse parallel matrix whose local
4: portions are stored as SEQAIJSELL matrices (a matrix class that inherits
5: from SEQAIJ but performs some operations in SELL format). The same
6: guidelines that apply to MPIAIJ matrices for preallocating the matrix
7: storage apply here as well.
9: Collective
11: Input Parameters:
12: + comm - MPI communicator
13: . m - number of local rows (or PETSC_DECIDE to have calculated if M is given)
14: This value should be the same as the local size used in creating the
15: y vector for the matrix-vector product y = Ax.
16: . n - This value should be the same as the local size used in creating the
17: x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have
18: calculated if N is given) For square matrices n is almost always m.
19: . M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)
20: . N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)
21: . d_nz - number of nonzeros per row in DIAGONAL portion of local submatrix
22: (same value is used for all local rows)
23: . d_nnz - array containing the number of nonzeros in the various rows of the
24: DIAGONAL portion of the local submatrix (possibly different for each row)
25: or NULL, if d_nz is used to specify the nonzero structure.
26: The size of this array is equal to the number of local rows, i.e 'm'.
27: For matrices you plan to factor you must leave room for the diagonal entry and
28: put in the entry even if it is zero.
29: . o_nz - number of nonzeros per row in the OFF-DIAGONAL portion of local
30: submatrix (same value is used for all local rows).
31: - o_nnz - array containing the number of nonzeros in the various rows of the
32: OFF-DIAGONAL portion of the local submatrix (possibly different for
33: each row) or NULL, if o_nz is used to specify the nonzero
34: structure. The size of this array is equal to the number
35: of local rows, i.e 'm'.
37: Output Parameter:
38: . A - the matrix
40: Notes:
41: If the *_nnz parameter is given then the *_nz parameter is ignored
43: m,n,M,N parameters specify the size of the matrix, and its partitioning across
44: processors, while d_nz,d_nnz,o_nz,o_nnz parameters specify the approximate
45: storage requirements for this matrix.
47: If PETSC_DECIDE or PETSC_DETERMINE is used for a particular argument on one
48: processor than it must be used on all processors that share the object for
49: that argument.
51: The user MUST specify either the local or global matrix dimensions
52: (possibly both).
54: The parallel matrix is partitioned such that the first m0 rows belong to
55: process 0, the next m1 rows belong to process 1, the next m2 rows belong
56: to process 2 etc.. where m0,m1,m2... are the input parameter 'm'.
58: The DIAGONAL portion of the local submatrix of a processor can be defined
59: as the submatrix which is obtained by extraction the part corresponding
60: to the rows r1-r2 and columns r1-r2 of the global matrix, where r1 is the
61: first row that belongs to the processor, and r2 is the last row belonging
62: to the this processor. This is a square mxm matrix. The remaining portion
63: of the local submatrix (mxN) constitute the OFF-DIAGONAL portion.
65: If o_nnz, d_nnz are specified, then o_nz, and d_nz are ignored.
67: When calling this routine with a single process communicator, a matrix of
68: type SEQAIJSELL is returned. If a matrix of type MPIAIJSELL is desired
69: for this type of communicator, use the construction mechanism:
70: MatCreate(...,&A); MatSetType(A,MPIAIJSELL); MatMPIAIJSetPreallocation(A,...);
72: Options Database Keys:
73: . -mat_aijsell_eager_shadow - Construct shadow matrix upon matrix assembly; default is to take a "lazy" approach, performing this step the first time the matrix is applied
75: Level: intermediate
77: .seealso: MatCreate(), MatCreateSeqAIJSELL(), MatSetValues()
78: @*/
79: PetscErrorCodeMatCreateMPIAIJSELL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt M,PetscInt N,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[],Mat *A) 80: {
82: PetscMPIInt size;
85: MatCreate(comm,A);
86: MatSetSizes(*A,m,n,M,N);
87: MPI_Comm_size(comm,&size);
88: if (size > 1) {
89: MatSetType(*A,MATMPIAIJSELL);
90: MatMPIAIJSetPreallocation(*A,d_nz,d_nnz,o_nz,o_nnz);
91: } else {
92: MatSetType(*A,MATSEQAIJSELL);
93: MatSeqAIJSetPreallocation(*A,d_nz,d_nnz);
94: }
95: return(0);
96: }
98: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJSELL(Mat,MatType,MatReuse,Mat*);
100: PetscErrorCode MatMPIAIJSetPreallocation_MPIAIJSELL(Mat B,PetscInt d_nz,const PetscInt d_nnz[],PetscInt o_nz,const PetscInt o_nnz[])101: {
102: Mat_MPIAIJ *b = (Mat_MPIAIJ*)B->data;
106: MatMPIAIJSetPreallocation_MPIAIJ(B,d_nz,d_nnz,o_nz,o_nnz);
107: MatConvert_SeqAIJ_SeqAIJSELL(b->A, MATSEQAIJSELL, MAT_INPLACE_MATRIX, &b->A);
108: MatConvert_SeqAIJ_SeqAIJSELL(b->B, MATSEQAIJSELL, MAT_INPLACE_MATRIX, &b->B);
109: return(0);
110: }
112: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJSELL(Mat A,MatType type,MatReuse reuse,Mat *newmat)113: {
115: Mat B = *newmat;
118: if (reuse == MAT_INITIAL_MATRIX) {
119: MatDuplicate(A,MAT_COPY_VALUES,&B);
120: }
122: PetscObjectChangeTypeName((PetscObject) B, MATMPIAIJSELL);
123: PetscObjectComposeFunction((PetscObject)B,"MatMPIAIJSetPreallocation_C",MatMPIAIJSetPreallocation_MPIAIJSELL);
124: *newmat = B;
125: return(0);
126: }
128: PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJSELL(Mat A)129: {
133: MatSetType(A,MATMPIAIJ);
134: MatConvert_MPIAIJ_MPIAIJSELL(A,MATMPIAIJSELL,MAT_INPLACE_MATRIX,&A);
135: return(0);
136: }
138: /*MC
139: MATAIJSELL - MATAIJSELL = "AIJSELL" - A matrix type to be used for sparse matrices.
141: This matrix type is identical to MATSEQAIJSELL when constructed with a single process communicator,
142: and MATMPIAIJSELL otherwise. As a result, for single process communicators,
143: MatSeqAIJSetPreallocation() is supported, and similarly MatMPIAIJSetPreallocation() is supported
144: for communicators controlling multiple processes. It is recommended that you call both of
145: the above preallocation routines for simplicity.
147: Options Database Keys:
148: . -mat_type aijsell - sets the matrix type to "AIJSELL" during a call to MatSetFromOptions()
150: Level: beginner
152: .seealso: MatCreateMPIAIJSELL(), MATSEQAIJSELL, MATMPIAIJSELL
153: M*/