xref: /petsc/src/mat/impls/aij/seq/bas/basfactor.c (revision 9767453c85a88b60d52ea72032faaafc609f88f5)
1 
2 
3 #include <petsc.h>
4 #include <petscksp.h>
5 #include "private/kspimpl.h"
6 #include "petscpc.h"
7 #include "../src/mat/impls/aij/seq/aij.h"
8 #include "../src/mat/impls/sbaij/seq/sbaij.h"
9 #include "../src/mat/impls/aij/seq/bas/spbas.h"
10 
11 #undef __FUNCT__
12 #define __FUNCT__ "MatICCFactorSymbolic_SeqAIJ_Bas"
13 PetscErrorCode MatICCFactorSymbolic_SeqAIJ_Bas(Mat fact,Mat A,IS perm,const MatFactorInfo *info)
14 {
15   Mat_SeqAIJ         *a = (Mat_SeqAIJ*)A->data;
16   Mat_SeqSBAIJ       *b;
17   PetscErrorCode     ierr;
18   PetscTruth         perm_identity,missing;
19   PetscInt           reallocs=0,i,*ai=a->i,*aj=a->j,am=A->rmap->n,*ui;
20   const PetscInt     *rip,*riip;
21   PetscInt           j;
22   PetscInt           d;
23   PetscInt           ncols,*cols,*uj;
24   PetscReal          fill=info->fill,levels=info->levels;
25   IS                 iperm;
26   spbas_matrix       Pattern_0, Pattern_P;
27 
28   PetscFunctionBegin;
29   if (A->rmap->n != A->cmap->n) SETERRQ2(PETSC_ERR_ARG_WRONG,"Must be square matrix, rows %D columns %D",A->rmap->n,A->cmap->n);
30   ierr = MatMissingDiagonal(A,&missing,&d);CHKERRQ(ierr);
31   if (missing) SETERRQ1(PETSC_ERR_ARG_WRONGSTATE,"Matrix is missing diagonal entry %D",d);
32   ierr = ISIdentity(perm,&perm_identity);CHKERRQ(ierr);
33   ierr = ISInvertPermutation(perm,PETSC_DECIDE,&iperm);CHKERRQ(ierr);
34 
35 
36   /* ICC(0) without matrix ordering: simply copies fill pattern */
37   if (!levels && perm_identity) {
38     ierr = PetscMalloc((am+1)*sizeof(PetscInt),&ui);CHKERRQ(ierr);
39     ui[0] = 0;
40 
41     for (i=0; i<am; i++) {
42       ui[i+1] = ui[i] + ai[i+1] - a->diag[i];
43     }
44     ierr = PetscMalloc((ui[am]+1)*sizeof(PetscInt),&uj);CHKERRQ(ierr);
45     cols = uj;
46     for (i=0; i<am; i++) {
47       aj    = a->j + a->diag[i];
48       ncols = ui[i+1] - ui[i];
49       for (j=0; j<ncols; j++) *cols++ = *aj++;
50     }
51   } else { /* case: levels>0 || (levels=0 && !perm_identity) */
52     ierr = ISGetIndices(iperm,&riip);CHKERRQ(ierr);
53     ierr = ISGetIndices(perm,&rip);CHKERRQ(ierr);
54 
55     // Create spbas_matrix for pattern
56     ierr = spbas_pattern_only(am, am, ai, aj, &Pattern_0); CHKERRQ(ierr);
57 
58     // Apply the permutation
59     ierr = spbas_apply_reordering( &Pattern_0, rip, riip); CHKERRQ(ierr);
60 
61     // Raise the power
62     ierr = spbas_power( Pattern_0, (int) levels+1, &Pattern_P);
63     CHKERRQ(ierr);
64     ierr = spbas_delete( Pattern_0 ); CHKERRQ(ierr);
65 
66     // Keep only upper triangle of pattern
67     ierr = spbas_keep_upper( &Pattern_P );
68 
69     // Convert to Sparse Row Storage
70     ierr = spbas_matrix_to_crs(Pattern_P, NULL, &ui, &uj); CHKERRQ(ierr);
71     ierr = spbas_delete(Pattern_P);CHKERRQ(ierr);
72   } /* end of case: levels>0 || (levels=0 && !perm_identity) */
73 
74   /* put together the new matrix in MATSEQSBAIJ format */
75 
76   b    = (Mat_SeqSBAIJ*)(fact)->data;
77   b->singlemalloc = PETSC_FALSE;
78   ierr = PetscMalloc((ui[am]+1)*sizeof(MatScalar),&b->a);CHKERRQ(ierr);
79   b->j    = uj;
80   b->i    = ui;
81   b->diag = 0;
82   b->ilen = 0;
83   b->imax = 0;
84   b->row  = perm;
85   b->col  = perm;
86   ierr    = PetscObjectReference((PetscObject)perm);CHKERRQ(ierr);
87   ierr    = PetscObjectReference((PetscObject)perm);CHKERRQ(ierr);
88   b->icol = iperm;
89   b->pivotinblocks = PETSC_FALSE; /* need to get from MatFactorInfo */
90   ierr    = PetscMalloc((am+1)*sizeof(PetscScalar),&b->solve_work);CHKERRQ(ierr);
91   ierr = PetscLogObjectMemory((fact),(ui[am]-am)*(sizeof(PetscInt)+sizeof(MatScalar)));CHKERRQ(ierr);
92   b->maxnz   = b->nz = ui[am];
93   b->free_a  = PETSC_TRUE;
94   b->free_ij = PETSC_TRUE;
95 
96   (fact)->info.factor_mallocs    = reallocs;
97   (fact)->info.fill_ratio_given  = fill;
98   if (ai[am] != 0) {
99     (fact)->info.fill_ratio_needed = ((PetscReal)ui[am])/((PetscReal)ai[am]);
100   } else {
101     (fact)->info.fill_ratio_needed = 0.0;
102   }
103   /*  (fact)->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqAIJ_inplace; */
104   PetscFunctionReturn(0);
105 }
106 
107 
108 #undef __FUNCT__
109 #define __FUNCT__ "MatCholeskyFactorNumeric_SeqAIJ_Bas"
110 PetscErrorCode MatCholeskyFactorNumeric_SeqAIJ_Bas(Mat B,Mat A,const MatFactorInfo *info)
111 {
112   Mat            C = B;
113   Mat_SeqSBAIJ   *b=(Mat_SeqSBAIJ*)C->data;
114   IS             ip=b->row,iip = b->icol;
115   PetscErrorCode ierr;
116   const PetscInt *rip,*riip;
117   PetscInt       mbs=A->rmap->n,*bi=b->i,*bj=b->j;
118 
119   MatScalar      *ba=b->a;
120   PetscReal      shiftnz = info->shiftnz;
121   PetscReal      droptol = -1;
122   PetscTruth     perm_identity;
123   spbas_matrix   Pattern, matrix_L,matrix_LT;
124   PetscReal    mem_reduction;
125 
126   PetscFunctionBegin;
127   // Reduce memory requirements:
128   //   erase values of B-matrix
129   ierr = PetscFree(ba); CHKERRQ(ierr);
130   //   Compress (maximum) sparseness pattern of B-matrix
131   ierr = spbas_compress_pattern(bi, bj, mbs, mbs, SPBAS_DIAGONAL_OFFSETS,&Pattern, &mem_reduction);CHKERRQ(ierr);
132   ierr = PetscFree(bi); CHKERRQ(ierr);
133   ierr = PetscFree(bj); CHKERRQ(ierr);
134 
135   ierr = PetscInfo1(PETSC_NULL,"    compression rate for spbas_compress_pattern %G \n",mem_reduction);CHKERRQ(ierr);
136 
137   // Make Cholesky decompositions with larger Manteuffel shifts until no more
138   // negative diagonals are found.
139   ierr  = ISGetIndices(ip,&rip);CHKERRQ(ierr);
140   ierr  = ISGetIndices(iip,&riip);CHKERRQ(ierr);
141 
142   if (info->usedt) {
143     droptol = info->dt;
144   }
145   for (ierr = NEGATIVE_DIAGONAL; ierr == NEGATIVE_DIAGONAL; )
146   {
147      ierr  = spbas_incomplete_cholesky( A, rip, riip, Pattern, droptol, shiftnz,
148                                         &matrix_LT);
149      if (ierr == NEGATIVE_DIAGONAL)
150      {
151         shiftnz *= 1.5;
152         if (shiftnz < 1e-5) shiftnz=1e-5;
153         ierr = PetscInfo1(PETSC_NULL,"spbas_incomplete_cholesky found a negative diagonal. Trying again with Manteuffel shift=%G\n",shiftnz);CHKERRQ(ierr);
154      }
155   }
156   CHKERRQ(ierr);
157   ierr = spbas_delete(Pattern); CHKERRQ(ierr);
158 
159   ierr = PetscInfo1(PETSC_NULL,"    memory_usage for  spbas_incomplete_cholesky  %G bytes per row\n",
160               (PetscReal) spbas_memory_requirement( matrix_LT)/ (PetscReal) mbs);CHKERRQ(ierr);
161 
162   ierr = ISRestoreIndices(ip,&rip);CHKERRQ(ierr);
163   ierr = ISRestoreIndices(iip,&riip);CHKERRQ(ierr);
164 
165   // Convert spbas_matrix to compressed row storage
166   ierr = spbas_transpose(matrix_LT, &matrix_L); CHKERRQ(ierr);
167   ierr = spbas_delete(matrix_LT); CHKERRQ(ierr);
168 #if defined(foo)
169   { ierr = spbas_dump("factorL",matrix_L); CHKERRQ(ierr);}
170 #endif
171   ierr = spbas_matrix_to_crs(matrix_L, &ba, &bi, &bj); CHKERRQ(ierr);
172   b->i=bi; b->j=bj; b->a=ba;
173   ierr = spbas_delete(matrix_L); CHKERRQ(ierr);
174 
175   // Set the appropriate solution functions
176   ierr = ISIdentity(ip,&perm_identity);CHKERRQ(ierr);
177   if (perm_identity){
178     (B)->ops->solve           = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
179     (B)->ops->solvetranspose  = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
180     (B)->ops->forwardsolve    = MatForwardSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
181     (B)->ops->backwardsolve   = MatBackwardSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
182   } else {
183     (B)->ops->solve           = MatSolve_SeqSBAIJ_1_inplace;
184     (B)->ops->solvetranspose  = MatSolve_SeqSBAIJ_1_inplace;
185     (B)->ops->forwardsolve    = MatForwardSolve_SeqSBAIJ_1_inplace;
186     (B)->ops->backwardsolve   = MatBackwardSolve_SeqSBAIJ_1_inplace;
187   }
188 
189   C->assembled    = PETSC_TRUE;
190   C->preallocated = PETSC_TRUE;
191   ierr = PetscLogFlops(C->rmap->n);CHKERRQ(ierr);
192 
193   // Optionally, print the factor matrix to file
194 #if defined(foo)
195   {
196      FILE * factfile = fopen("factorL","w");
197      if (!factfile) CHKERRQ((PetscErrorCode) 10);
198      for (i=0; i<mbs; i++)
199      {
200         for (j=bi[i]; j<bi[i+1]; j++)
201         {
202             fprintf(factfile,"%d %d %e\n",i,bj[j],ba[j]);
203         }
204      }
205      fclose(factfile);
206   }
207 #endif
208   PetscFunctionReturn(0);
209 }
210 
211 EXTERN_C_BEGIN
212 #undef __FUNCT__
213 #define __FUNCT__ "MatGetFactor_seqaij_bas"
214 PetscErrorCode MatGetFactor_seqaij_bas(Mat A,MatFactorType ftype,Mat *B)
215 {
216   PetscInt           n = A->rmap->n;
217   PetscErrorCode     ierr;
218 
219   PetscFunctionBegin;
220   ierr = MatCreate(((PetscObject)A)->comm,B);CHKERRQ(ierr);
221   ierr = MatSetSizes(*B,n,n,n,n);CHKERRQ(ierr);
222   if (ftype == MAT_FACTOR_ICC) {
223     ierr = MatSetType(*B,MATSEQSBAIJ);CHKERRQ(ierr);
224     ierr = MatSeqSBAIJSetPreallocation(*B,1,MAT_SKIP_ALLOCATION,PETSC_NULL);CHKERRQ(ierr);
225     (*B)->ops->iccfactorsymbolic     = MatICCFactorSymbolic_SeqAIJ_Bas;
226     (*B)->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqAIJ_Bas;
227   } else SETERRQ(PETSC_ERR_SUP,"Factor type not supported");
228   (*B)->factor = ftype;
229   PetscFunctionReturn(0);
230 }
231 EXTERN_C_END
232