Actual source code: sorder.c
petsc-3.13.6 2020-09-29
2: /*
3: Provides the code that allows PETSc users to register their own
4: sequential matrix Ordering routines.
5: */
6: #include <petsc/private/matimpl.h>
7: #include <petscmat.h>
9: PetscFunctionList MatOrderingList = 0;
10: PetscBool MatOrderingRegisterAllCalled = PETSC_FALSE;
12: extern PetscErrorCode MatGetOrdering_Flow_SeqAIJ(Mat,MatOrderingType,IS*,IS*);
14: PetscErrorCode MatGetOrdering_Flow(Mat mat,MatOrderingType type,IS *irow,IS *icol)
15: {
17: SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot do default flow ordering for matrix type");
18: #if !defined(PETSC_USE_DEBUG)
19: return(0);
20: #endif
21: }
23: PETSC_INTERN PetscErrorCode MatGetOrdering_Natural(Mat mat,MatOrderingType type,IS *irow,IS *icol)
24: {
26: PetscInt n,i,*ii;
27: PetscBool done;
28: MPI_Comm comm;
31: PetscObjectGetComm((PetscObject)mat,&comm);
32: MatGetRowIJ(mat,0,PETSC_FALSE,PETSC_TRUE,&n,NULL,NULL,&done);
33: MatRestoreRowIJ(mat,0,PETSC_FALSE,PETSC_TRUE,NULL,NULL,NULL,&done);
34: if (done) { /* matrix may be "compressed" in symbolic factorization, due to i-nodes or block storage */
35: /*
36: We actually create general index sets because this avoids mallocs to
37: to obtain the indices in the MatSolve() routines.
38: ISCreateStride(PETSC_COMM_SELF,n,0,1,irow);
39: ISCreateStride(PETSC_COMM_SELF,n,0,1,icol);
40: */
41: PetscMalloc1(n,&ii);
42: for (i=0; i<n; i++) ii[i] = i;
43: ISCreateGeneral(PETSC_COMM_SELF,n,ii,PETSC_COPY_VALUES,irow);
44: ISCreateGeneral(PETSC_COMM_SELF,n,ii,PETSC_OWN_POINTER,icol);
45: } else {
46: PetscInt start,end;
48: MatGetOwnershipRange(mat,&start,&end);
49: ISCreateStride(comm,end-start,start,1,irow);
50: ISCreateStride(comm,end-start,start,1,icol);
51: }
52: ISSetIdentity(*irow);
53: ISSetIdentity(*icol);
54: return(0);
55: }
57: /*
58: Orders the rows (and columns) by the lengths of the rows.
59: This produces a symmetric Ordering but does not require a
60: matrix with symmetric non-zero structure.
61: */
62: PETSC_INTERN PetscErrorCode MatGetOrdering_RowLength(Mat mat,MatOrderingType type,IS *irow,IS *icol)
63: {
65: PetscInt n,*permr,*lens,i;
66: const PetscInt *ia,*ja;
67: PetscBool done;
70: MatGetRowIJ(mat,0,PETSC_FALSE,PETSC_TRUE,&n,&ia,&ja,&done);
71: if (!done) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_SUP,"Cannot get rows for matrix");
73: PetscMalloc2(n,&lens,n,&permr);
74: for (i=0; i<n; i++) {
75: lens[i] = ia[i+1] - ia[i];
76: permr[i] = i;
77: }
78: MatRestoreRowIJ(mat,0,PETSC_FALSE,PETSC_TRUE,NULL,&ia,&ja,&done);
80: PetscSortIntWithPermutation(n,lens,permr);
82: ISCreateGeneral(PETSC_COMM_SELF,n,permr,PETSC_COPY_VALUES,irow);
83: ISCreateGeneral(PETSC_COMM_SELF,n,permr,PETSC_COPY_VALUES,icol);
84: PetscFree2(lens,permr);
85: return(0);
86: }
88: /*@C
89: MatOrderingRegister - Adds a new sparse matrix ordering to the matrix package.
91: Not Collective
93: Input Parameters:
94: + sname - name of ordering (for example MATORDERINGND)
95: - function - function pointer that creates the ordering
97: Level: developer
99: Sample usage:
100: .vb
101: MatOrderingRegister("my_order", MyOrder);
102: .ve
104: Then, your partitioner can be chosen with the procedural interface via
105: $ MatOrderingSetType(part,"my_order)
106: or at runtime via the option
107: $ -pc_factor_mat_ordering_type my_order
109: .seealso: MatOrderingRegisterDestroy(), MatOrderingRegisterAll()
110: @*/
111: PetscErrorCode MatOrderingRegister(const char sname[],PetscErrorCode (*function)(Mat,MatOrderingType,IS*,IS*))
112: {
116: MatInitializePackage();
117: PetscFunctionListAdd(&MatOrderingList,sname,function);
118: return(0);
119: }
121: #include <../src/mat/impls/aij/mpi/mpiaij.h>
122: /*@C
123: MatGetOrdering - Gets a reordering for a matrix to reduce fill or to
124: improve numerical stability of LU factorization.
126: Collective on Mat
128: Input Parameters:
129: + mat - the matrix
130: - type - type of reordering, one of the following:
131: $ MATORDERINGNATURAL_OR_ND - Nested dissection unless matrix is SBAIJ then it is natural
132: $ MATORDERINGNATURAL - Natural
133: $ MATORDERINGND - Nested Dissection
134: $ MATORDERING1WD - One-way Dissection
135: $ MATORDERINGRCM - Reverse Cuthill-McKee
136: $ MATORDERINGQMD - Quotient Minimum Degree
138: Output Parameters:
139: + rperm - row permutation indices
140: - cperm - column permutation indices
142: Options Database Key:
143: + -mat_view_ordering draw - plots matrix nonzero structure in new ordering
144: - -pc_factor_mat_ordering_type <nd,natural,..> - ordering to use with PCs based on factorization, LU, ILU, Cholesky, ICC
146: Level: intermediate
148: Notes:
149: This DOES NOT actually reorder the matrix; it merely returns two index sets
150: that define a reordering. This is usually not used directly, rather use the
151: options PCFactorSetMatOrderingType()
153: The user can define additional orderings; see MatOrderingRegister().
155: These are generally only implemented for sequential sparse matrices.
157: The external packages that PETSc can use for direct factorization such as SuperLU do not accept orderings provided by
158: this call.
161: fill, reordering, natural, Nested Dissection,
162: One-way Dissection, Cholesky, Reverse Cuthill-McKee,
163: Quotient Minimum Degree
165: .seealso: MatOrderingRegister(), PCFactorSetMatOrderingType(), MatColoring, MatColoringCreate()
166: @*/
167: PetscErrorCode MatGetOrdering(Mat mat,MatOrderingType type,IS *rperm,IS *cperm)
168: {
170: PetscInt mmat,nmat,mis,m;
171: PetscErrorCode (*r)(Mat,MatOrderingType,IS*,IS*);
172: PetscBool flg = PETSC_FALSE,isseqdense,ismpidense,ismpiaij,ismpibaij,ismpisbaij,ismpiaijcusparse,iselemental,flg1;
178: if (!mat->assembled) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
179: if (mat->factortype) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
181: PetscStrcmp(type,MATORDERINGNATURAL_OR_ND,&flg1);
182: if (flg1) {
183: PetscBool isseqsbaij;
184: PetscObjectTypeCompareAny((PetscObject)mat,&isseqsbaij,MATSEQSBAIJ,MATSEQBAIJ,NULL);
185: if (isseqsbaij) {
186: type = MATORDERINGNATURAL;
187: } else {
188: type = MATORDERINGND;
189: }
190: }
192: /* This code is terrible. MatGetOrdering() multiple dispatch should use matrix and this code should move to impls/aij/mpi. */
193: PetscObjectTypeCompare((PetscObject)mat,MATMPIAIJ,&ismpiaij);
194: if (ismpiaij) { /* Reorder using diagonal block */
195: Mat Ad,Ao;
196: const PetscInt *colmap;
197: IS lrowperm,lcolperm;
198: PetscInt i,rstart,rend,*idx;
199: const PetscInt *lidx;
201: MatMPIAIJGetSeqAIJ(mat,&Ad,&Ao,&colmap);
202: MatGetOrdering(Ad,type,&lrowperm,&lcolperm);
203: MatGetOwnershipRange(mat,&rstart,&rend);
204: /* Remap row index set to global space */
205: ISGetIndices(lrowperm,&lidx);
206: PetscMalloc1(rend-rstart,&idx);
207: for (i=0; i+rstart<rend; i++) idx[i] = rstart + lidx[i];
208: ISRestoreIndices(lrowperm,&lidx);
209: ISDestroy(&lrowperm);
210: ISCreateGeneral(PetscObjectComm((PetscObject)mat),rend-rstart,idx,PETSC_OWN_POINTER,rperm);
211: ISSetPermutation(*rperm);
212: /* Remap column index set to global space */
213: ISGetIndices(lcolperm,&lidx);
214: PetscMalloc1(rend-rstart,&idx);
215: for (i=0; i+rstart<rend; i++) idx[i] = rstart + lidx[i];
216: ISRestoreIndices(lcolperm,&lidx);
217: ISDestroy(&lcolperm);
218: ISCreateGeneral(PetscObjectComm((PetscObject)mat),rend-rstart,idx,PETSC_OWN_POINTER,cperm);
219: ISSetPermutation(*cperm);
220: return(0);
221: }
223: /* this chunk of code is REALLY bad, should maybe get the ordering from the factor matrix,
224: then those that don't support orderings will handle their cases themselves. */
225: PetscObjectTypeCompare((PetscObject)mat,MATSEQDENSE,&isseqdense);
226: PetscObjectTypeCompare((PetscObject)mat,MATMPIDENSE,&ismpidense);
227: PetscObjectTypeCompare((PetscObject)mat,MATMPIAIJCUSPARSE,&ismpiaijcusparse);
228: PetscObjectTypeCompare((PetscObject)mat,MATMPIBAIJ,&ismpibaij);
229: PetscObjectTypeCompare((PetscObject)mat,MATMPISBAIJ,&ismpisbaij);
230: PetscObjectTypeCompare((PetscObject)mat,MATELEMENTAL,&iselemental);
231: if (isseqdense || ismpidense || ismpibaij || ismpisbaij || ismpiaijcusparse || iselemental) {
232: MatGetLocalSize(mat,&m,NULL);
233: /*
234: These matrices only give natural ordering
235: */
236: ISCreateStride(PETSC_COMM_SELF,m,0,1,cperm);
237: ISCreateStride(PETSC_COMM_SELF,m,0,1,rperm);
238: ISSetIdentity(*cperm);
239: ISSetIdentity(*rperm);
240: return(0);
241: }
243: if (!mat->rmap->N) { /* matrix has zero rows */
244: ISCreateStride(PETSC_COMM_SELF,0,0,1,cperm);
245: ISCreateStride(PETSC_COMM_SELF,0,0,1,rperm);
246: ISSetIdentity(*cperm);
247: ISSetIdentity(*rperm);
248: return(0);
249: }
251: MatGetLocalSize(mat,&mmat,&nmat);
252: if (mmat != nmat) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be square matrix, rows %D columns %D",mmat,nmat);
254: MatOrderingRegisterAll();
255: PetscFunctionListFind(MatOrderingList,type,&r);
256: if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Unknown or unregistered type: %s",type);
258: PetscLogEventBegin(MAT_GetOrdering,mat,0,0,0);
259: (*r)(mat,type,rperm,cperm);
260: ISSetPermutation(*rperm);
261: ISSetPermutation(*cperm);
262: /* Adjust for inode (reduced matrix ordering) only if row permutation is smaller the matrix size */
263: ISGetLocalSize(*rperm,&mis);
264: if (mmat > mis) {MatInodeAdjustForInodes(mat,rperm,cperm);}
265: PetscLogEventEnd(MAT_GetOrdering,mat,0,0,0);
268: PetscOptionsHasName(((PetscObject)mat)->options,((PetscObject)mat)->prefix,"-mat_view_ordering",&flg);
269: if (flg) {
270: Mat tmat;
271: MatPermute(mat,*rperm,*cperm,&tmat);
272: MatViewFromOptions(tmat,(PetscObject)mat,"-mat_view_ordering");
273: MatDestroy(&tmat);
274: }
275: return(0);
276: }
278: PetscErrorCode MatGetOrderingList(PetscFunctionList *list)
279: {
281: *list = MatOrderingList;
282: return(0);
283: }