xref: /petsc/src/mat/impls/aij/seq/bas/basfactor.c (revision 4e278199b78715991f5c71ebbd945c1489263e6c)
1 
2 #include <../src/mat/impls/aij/seq/aij.h>
3 #include <../src/mat/impls/sbaij/seq/sbaij.h>
4 #include <../src/mat/impls/aij/seq/bas/spbas.h>
5 
6 PetscErrorCode MatICCFactorSymbolic_SeqAIJ_Bas(Mat fact,Mat A,IS perm,const MatFactorInfo *info)
7 {
8   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
9   Mat_SeqSBAIJ   *b;
10   PetscErrorCode ierr;
11   PetscBool      perm_identity,missing;
12   PetscInt       reallocs=0,i,*ai=a->i,*aj=a->j,am=A->rmap->n,*ui;
13   const PetscInt *rip,*riip;
14   PetscInt       j;
15   PetscInt       d;
16   PetscInt       ncols,*cols,*uj;
17   PetscReal      fill=info->fill,levels=info->levels;
18   IS             iperm;
19   spbas_matrix   Pattern_0, Pattern_P;
20 
21   PetscFunctionBegin;
22   if (A->rmap->n != A->cmap->n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be square matrix, rows %D columns %D",A->rmap->n,A->cmap->n);
23   ierr = MatMissingDiagonal(A,&missing,&d);CHKERRQ(ierr);
24   if (missing) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Matrix is missing diagonal entry %D",d);
25   ierr = ISIdentity(perm,&perm_identity);CHKERRQ(ierr);
26   ierr = ISInvertPermutation(perm,PETSC_DECIDE,&iperm);CHKERRQ(ierr);
27 
28   /* ICC(0) without matrix ordering: simply copies fill pattern */
29   if (!levels && perm_identity) {
30     ierr  = PetscMalloc1(am+1,&ui);CHKERRQ(ierr);
31     ui[0] = 0;
32 
33     for (i=0; i<am; i++) {
34       ui[i+1] = ui[i] + ai[i+1] - a->diag[i];
35     }
36     ierr = PetscMalloc1(ui[am]+1,&uj);CHKERRQ(ierr);
37     cols = uj;
38     for (i=0; i<am; i++) {
39       aj    = a->j + a->diag[i];
40       ncols = ui[i+1] - ui[i];
41       for (j=0; j<ncols; j++) *cols++ = *aj++;
42     }
43   } else { /* case: levels>0 || (levels=0 && !perm_identity) */
44     ierr = ISGetIndices(iperm,&riip);CHKERRQ(ierr);
45     ierr = ISGetIndices(perm,&rip);CHKERRQ(ierr);
46 
47     /* Create spbas_matrix for pattern */
48     ierr = spbas_pattern_only(am, am, ai, aj, &Pattern_0);CHKERRQ(ierr);
49 
50     /* Apply the permutation */
51     ierr = spbas_apply_reordering(&Pattern_0, rip, riip);CHKERRQ(ierr);
52 
53     /* Raise the power */
54     ierr = spbas_power(Pattern_0, (int) levels+1, &Pattern_P);CHKERRQ(ierr);
55     ierr = spbas_delete(Pattern_0);CHKERRQ(ierr);
56 
57     /* Keep only upper triangle of pattern */
58     ierr = spbas_keep_upper(&Pattern_P);CHKERRQ(ierr);
59 
60     /* Convert to Sparse Row Storage  */
61     ierr = spbas_matrix_to_crs(Pattern_P, NULL, &ui, &uj);CHKERRQ(ierr);
62     ierr = spbas_delete(Pattern_P);CHKERRQ(ierr);
63   } /* end of case: levels>0 || (levels=0 && !perm_identity) */
64 
65   /* put together the new matrix in MATSEQSBAIJ format */
66 
67   b               = (Mat_SeqSBAIJ*)(fact)->data;
68   b->singlemalloc = PETSC_FALSE;
69 
70   ierr = PetscMalloc1(ui[am]+1,&b->a);CHKERRQ(ierr);
71 
72   b->j    = uj;
73   b->i    = ui;
74   b->diag = NULL;
75   b->ilen = NULL;
76   b->imax = NULL;
77   b->row  = perm;
78   b->col  = perm;
79 
80   ierr = PetscObjectReference((PetscObject)perm);CHKERRQ(ierr);
81   ierr = PetscObjectReference((PetscObject)perm);CHKERRQ(ierr);
82 
83   b->icol          = iperm;
84   b->pivotinblocks = PETSC_FALSE; /* need to get from MatFactorInfo */
85   ierr             = PetscMalloc1(am+1,&b->solve_work);CHKERRQ(ierr);
86   ierr             = PetscLogObjectMemory((PetscObject)(fact),(ui[am]-am)*(sizeof(PetscInt)+sizeof(MatScalar)));CHKERRQ(ierr);
87   b->maxnz         = b->nz = ui[am];
88   b->free_a        = PETSC_TRUE;
89   b->free_ij       = PETSC_TRUE;
90 
91   (fact)->info.factor_mallocs   = reallocs;
92   (fact)->info.fill_ratio_given = fill;
93   if (ai[am] != 0) {
94     (fact)->info.fill_ratio_needed = ((PetscReal)ui[am])/((PetscReal)ai[am]);
95   } else {
96     (fact)->info.fill_ratio_needed = 0.0;
97   }
98   /*  (fact)->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqAIJ_inplace; */
99   PetscFunctionReturn(0);
100 }
101 
102 PetscErrorCode MatCholeskyFactorNumeric_SeqAIJ_Bas(Mat B,Mat A,const MatFactorInfo *info)
103 {
104   Mat            C = B;
105   Mat_SeqSBAIJ   *b=(Mat_SeqSBAIJ*)C->data;
106   IS             ip=b->row,iip = b->icol;
107   PetscErrorCode ierr;
108   const PetscInt *rip,*riip;
109   PetscInt       mbs=A->rmap->n,*bi=b->i,*bj=b->j;
110 
111   MatScalar    *ba     = b->a;
112   PetscReal    shiftnz = info->shiftamount;
113   PetscReal    droptol = -1;
114   PetscBool    perm_identity;
115   spbas_matrix Pattern, matrix_L,matrix_LT;
116   PetscReal    mem_reduction;
117 
118   PetscFunctionBegin;
119   /* Reduce memory requirements:   erase values of B-matrix */
120   ierr = PetscFree(ba);CHKERRQ(ierr);
121   /*   Compress (maximum) sparseness pattern of B-matrix */
122   ierr = spbas_compress_pattern(bi, bj, mbs, mbs, SPBAS_DIAGONAL_OFFSETS,&Pattern, &mem_reduction);CHKERRQ(ierr);
123   ierr = PetscFree(bi);CHKERRQ(ierr);
124   ierr = PetscFree(bj);CHKERRQ(ierr);
125 
126   ierr = PetscInfo1(NULL,"    compression rate for spbas_compress_pattern %g \n",(double)mem_reduction);CHKERRQ(ierr);
127 
128   /* Make Cholesky decompositions with larger Manteuffel shifts until no more    negative diagonals are found. */
129   ierr = ISGetIndices(ip,&rip);CHKERRQ(ierr);
130   ierr = ISGetIndices(iip,&riip);CHKERRQ(ierr);
131 
132   if (info->usedt) {
133     droptol = info->dt;
134   }
135   for (ierr = NEGATIVE_DIAGONAL; ierr == NEGATIVE_DIAGONAL;)
136   {
137     ierr = spbas_incomplete_cholesky(A, rip, riip, Pattern, droptol, shiftnz,&matrix_LT);CHKERRQ(ierr);
138     if (ierr == NEGATIVE_DIAGONAL) {
139       shiftnz *= 1.5;
140       if (shiftnz < 1e-5) shiftnz=1e-5;
141       ierr = PetscInfo1(NULL,"spbas_incomplete_cholesky found a negative diagonal. Trying again with Manteuffel shift=%g\n",(double)shiftnz);CHKERRQ(ierr);
142     }
143   }
144   ierr = spbas_delete(Pattern);CHKERRQ(ierr);
145 
146   ierr = PetscInfo1(NULL,"    memory_usage for  spbas_incomplete_cholesky  %g bytes per row\n", (double)(PetscReal) (spbas_memory_requirement(matrix_LT)/ (PetscReal) mbs));CHKERRQ(ierr);
147 
148   ierr = ISRestoreIndices(ip,&rip);CHKERRQ(ierr);
149   ierr = ISRestoreIndices(iip,&riip);CHKERRQ(ierr);
150 
151   /* Convert spbas_matrix to compressed row storage */
152   ierr = spbas_transpose(matrix_LT, &matrix_L);CHKERRQ(ierr);
153   ierr = spbas_delete(matrix_LT);CHKERRQ(ierr);
154   ierr = spbas_matrix_to_crs(matrix_L, &ba, &bi, &bj);CHKERRQ(ierr);
155   b->i =bi; b->j=bj; b->a=ba;
156   ierr = spbas_delete(matrix_L);CHKERRQ(ierr);
157 
158   /* Set the appropriate solution functions */
159   ierr = ISIdentity(ip,&perm_identity);CHKERRQ(ierr);
160   if (perm_identity) {
161     (B)->ops->solve          = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
162     (B)->ops->solvetranspose = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
163     (B)->ops->forwardsolve   = MatForwardSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
164     (B)->ops->backwardsolve  = MatBackwardSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
165   } else {
166     (B)->ops->solve          = MatSolve_SeqSBAIJ_1_inplace;
167     (B)->ops->solvetranspose = MatSolve_SeqSBAIJ_1_inplace;
168     (B)->ops->forwardsolve   = MatForwardSolve_SeqSBAIJ_1_inplace;
169     (B)->ops->backwardsolve  = MatBackwardSolve_SeqSBAIJ_1_inplace;
170   }
171 
172   C->assembled    = PETSC_TRUE;
173   C->preallocated = PETSC_TRUE;
174 
175   ierr = PetscLogFlops(C->rmap->n);CHKERRQ(ierr);
176   PetscFunctionReturn(0);
177 }
178 
179 PetscErrorCode MatFactorGetSolverType_seqaij_bas(Mat A,MatSolverType *type)
180 {
181   PetscFunctionBegin;
182   *type = MATSOLVERBAS;
183   PetscFunctionReturn(0);
184 }
185 
186 PETSC_INTERN PetscErrorCode MatGetFactor_seqaij_bas(Mat A,MatFactorType ftype,Mat *B)
187 {
188   PetscInt       n = A->rmap->n;
189   PetscErrorCode ierr;
190 
191   PetscFunctionBegin;
192   ierr = MatCreate(PetscObjectComm((PetscObject)A),B);CHKERRQ(ierr);
193   ierr = MatSetSizes(*B,n,n,n,n);CHKERRQ(ierr);
194   if (ftype == MAT_FACTOR_ICC) {
195     ierr = MatSetType(*B,MATSEQSBAIJ);CHKERRQ(ierr);
196     ierr = MatSeqSBAIJSetPreallocation(*B,1,MAT_SKIP_ALLOCATION,NULL);CHKERRQ(ierr);
197 
198     (*B)->ops->iccfactorsymbolic     = MatICCFactorSymbolic_SeqAIJ_Bas;
199     (*B)->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqAIJ_Bas;
200     ierr = PetscObjectComposeFunction((PetscObject)*B,"MatFactorGetSolverType_C",MatFactorGetSolverType_seqaij_bas);CHKERRQ(ierr);
201     ierr = PetscStrallocpy(MATORDERINGND,(char**)&(*B)->preferredordering[MAT_FACTOR_LU]);CHKERRQ(ierr);
202     ierr = PetscStrallocpy(MATORDERINGND,(char**)&(*B)->preferredordering[MAT_FACTOR_CHOLESKY]);CHKERRQ(ierr);
203   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Factor type not supported");
204   (*B)->factortype = ftype;
205 
206   ierr = PetscFree((*B)->solvertype);CHKERRQ(ierr);
207   ierr = PetscStrallocpy(MATSOLVERBAS,&(*B)->solvertype);CHKERRQ(ierr);
208   (*B)->canuseordering = PETSC_TRUE;
209   ierr = PetscStrallocpy(MATORDERINGNATURAL,(char**)&(*B)->preferredordering[MAT_FACTOR_ICC]);CHKERRQ(ierr);
210   PetscFunctionReturn(0);
211 }
212