xref: /petsc/src/mat/impls/aij/seq/bas/basfactor.c (revision b7c853c42524e99073a4955bd48eeb29623ae6ef)
1 
2 #include <petsc.h>
3 #include <petscksp.h>
4 #include "private/kspimpl.h"
5 #include "petscpc.h"
6 #include "../src/mat/impls/aij/seq/aij.h"
7 #include "../src/mat/impls/sbaij/seq/sbaij.h"
8 #include "../src/mat/impls/aij/seq/bas/spbas.h"
9 
10 #undef __FUNCT__
11 #define __FUNCT__ "MatICCFactorSymbolic_SeqAIJ_Bas"
12 PetscErrorCode MatICCFactorSymbolic_SeqAIJ_Bas(Mat fact,Mat A,IS perm,const MatFactorInfo *info)
13 {
14   Mat_SeqAIJ         *a = (Mat_SeqAIJ*)A->data;
15   Mat_SeqSBAIJ       *b;
16   PetscErrorCode     ierr;
17   PetscTruth         perm_identity,missing;
18   PetscInt           reallocs=0,i,*ai=a->i,*aj=a->j,am=A->rmap->n,*ui;
19   const PetscInt     *rip,*riip;
20   PetscInt           j;
21   PetscInt           d;
22   PetscInt           ncols,*cols,*uj;
23   PetscReal          fill=info->fill,levels=info->levels;
24   IS                 iperm;
25   spbas_matrix       Pattern_0, Pattern_P;
26 
27   PetscFunctionBegin;
28   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);
29   ierr = MatMissingDiagonal(A,&missing,&d);CHKERRQ(ierr);
30   if (missing) SETERRQ1(PETSC_ERR_ARG_WRONGSTATE,"Matrix is missing diagonal entry %D",d);
31   ierr = ISIdentity(perm,&perm_identity);CHKERRQ(ierr);
32   ierr = ISInvertPermutation(perm,PETSC_DECIDE,&iperm);CHKERRQ(ierr);
33 
34   /* ICC(0) without matrix ordering: simply copies fill pattern */
35   if (!levels && perm_identity) {
36     ierr = PetscMalloc((am+1)*sizeof(PetscInt),&ui);CHKERRQ(ierr);
37     ui[0] = 0;
38 
39     for (i=0; i<am; i++) {
40       ui[i+1] = ui[i] + ai[i+1] - a->diag[i];
41     }
42     ierr = PetscMalloc((ui[am]+1)*sizeof(PetscInt),&uj);CHKERRQ(ierr);
43     cols = uj;
44     for (i=0; i<am; i++) {
45       aj    = a->j + a->diag[i];
46       ncols = ui[i+1] - ui[i];
47       for (j=0; j<ncols; j++) *cols++ = *aj++;
48     }
49   } else { /* case: levels>0 || (levels=0 && !perm_identity) */
50     ierr = ISGetIndices(iperm,&riip);CHKERRQ(ierr);
51     ierr = ISGetIndices(perm,&rip);CHKERRQ(ierr);
52 
53     /* Create spbas_matrix for pattern */
54     ierr = spbas_pattern_only(am, am, ai, aj, &Pattern_0);CHKERRQ(ierr);
55 
56     /* Apply the permutation */
57     ierr = spbas_apply_reordering( &Pattern_0, rip, riip);CHKERRQ(ierr);
58 
59     /* Raise the power */
60     ierr = spbas_power( Pattern_0, (int) levels+1, &Pattern_P);CHKERRQ(ierr);
61     ierr = spbas_delete( Pattern_0 );CHKERRQ(ierr);
62 
63     /* Keep only upper triangle of pattern */
64     ierr = spbas_keep_upper( &Pattern_P );
65 
66     /* Convert to Sparse Row Storage  */
67     ierr = spbas_matrix_to_crs(Pattern_P, PETSC_NULL, &ui, &uj);CHKERRQ(ierr);
68     ierr = spbas_delete(Pattern_P);CHKERRQ(ierr);
69   } /* end of case: levels>0 || (levels=0 && !perm_identity) */
70 
71   /* put together the new matrix in MATSEQSBAIJ format */
72 
73   b    = (Mat_SeqSBAIJ*)(fact)->data;
74   b->singlemalloc = PETSC_FALSE;
75   ierr = PetscMalloc((ui[am]+1)*sizeof(MatScalar),&b->a);CHKERRQ(ierr);
76   b->j    = uj;
77   b->i    = ui;
78   b->diag = 0;
79   b->ilen = 0;
80   b->imax = 0;
81   b->row  = perm;
82   b->col  = perm;
83   ierr    = PetscObjectReference((PetscObject)perm);CHKERRQ(ierr);
84   ierr    = PetscObjectReference((PetscObject)perm);CHKERRQ(ierr);
85   b->icol = iperm;
86   b->pivotinblocks = PETSC_FALSE; /* need to get from MatFactorInfo */
87   ierr    = PetscMalloc((am+1)*sizeof(PetscScalar),&b->solve_work);CHKERRQ(ierr);
88   ierr = PetscLogObjectMemory((fact),(ui[am]-am)*(sizeof(PetscInt)+sizeof(MatScalar)));CHKERRQ(ierr);
89   b->maxnz   = b->nz = ui[am];
90   b->free_a  = PETSC_TRUE;
91   b->free_ij = PETSC_TRUE;
92 
93   (fact)->info.factor_mallocs    = reallocs;
94   (fact)->info.fill_ratio_given  = fill;
95   if (ai[am] != 0) {
96     (fact)->info.fill_ratio_needed = ((PetscReal)ui[am])/((PetscReal)ai[am]);
97   } else {
98     (fact)->info.fill_ratio_needed = 0.0;
99   }
100   /*  (fact)->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqAIJ_inplace; */
101   PetscFunctionReturn(0);
102 }
103 
104 
105 #undef __FUNCT__
106 #define __FUNCT__ "MatCholeskyFactorNumeric_SeqAIJ_Bas"
107 PetscErrorCode MatCholeskyFactorNumeric_SeqAIJ_Bas(Mat B,Mat A,const MatFactorInfo *info)
108 {
109   Mat            C = B;
110   Mat_SeqSBAIJ   *b=(Mat_SeqSBAIJ*)C->data;
111   IS             ip=b->row,iip = b->icol;
112   PetscErrorCode ierr;
113   const PetscInt *rip,*riip;
114   PetscInt       mbs=A->rmap->n,*bi=b->i,*bj=b->j;
115 
116   MatScalar      *ba=b->a;
117   PetscReal      shiftnz = info->shiftnz;
118   PetscReal      droptol = -1;
119   PetscTruth     perm_identity;
120   spbas_matrix   Pattern, matrix_L,matrix_LT;
121   PetscReal      mem_reduction;
122 
123   PetscFunctionBegin;
124   /* Reduce memory requirements:   erase values of B-matrix */
125   ierr = PetscFree(ba);CHKERRQ(ierr);
126   /*   Compress (maximum) sparseness pattern of B-matrix */
127   ierr = spbas_compress_pattern(bi, bj, mbs, mbs, SPBAS_DIAGONAL_OFFSETS,&Pattern, &mem_reduction);CHKERRQ(ierr);
128   ierr = PetscFree(bi);CHKERRQ(ierr);
129   ierr = PetscFree(bj);CHKERRQ(ierr);
130 
131   ierr = PetscInfo1(PETSC_NULL,"    compression rate for spbas_compress_pattern %G \n",mem_reduction);CHKERRQ(ierr);
132 
133   /* Make Cholesky decompositions with larger Manteuffel shifts until no more    negative diagonals are found. */
134   ierr  = ISGetIndices(ip,&rip);CHKERRQ(ierr);
135   ierr  = ISGetIndices(iip,&riip);CHKERRQ(ierr);
136 
137   if (info->usedt) {
138     droptol = info->dt;
139   }
140   for (ierr = NEGATIVE_DIAGONAL; ierr == NEGATIVE_DIAGONAL; )
141   {
142      ierr  = spbas_incomplete_cholesky( A, rip, riip, Pattern, droptol, shiftnz,&matrix_LT);CHKERRQ(ierr);
143      if (ierr == NEGATIVE_DIAGONAL)
144      {
145         shiftnz *= 1.5;
146         if (shiftnz < 1e-5) shiftnz=1e-5;
147         ierr = PetscInfo1(PETSC_NULL,"spbas_incomplete_cholesky found a negative diagonal. Trying again with Manteuffel shift=%G\n",shiftnz);CHKERRQ(ierr);
148      }
149   }
150   ierr = spbas_delete(Pattern);CHKERRQ(ierr);
151 
152   ierr = PetscInfo1(PETSC_NULL,"    memory_usage for  spbas_incomplete_cholesky  %G bytes per row\n", (PetscReal) spbas_memory_requirement( matrix_LT)/ (PetscReal) mbs);CHKERRQ(ierr);
153 
154   ierr = ISRestoreIndices(ip,&rip);CHKERRQ(ierr);
155   ierr = ISRestoreIndices(iip,&riip);CHKERRQ(ierr);
156 
157   /* Convert spbas_matrix to compressed row storage */
158   ierr = spbas_transpose(matrix_LT, &matrix_L);CHKERRQ(ierr);
159   ierr = spbas_delete(matrix_LT);CHKERRQ(ierr);
160   ierr = spbas_matrix_to_crs(matrix_L, &ba, &bi, &bj);CHKERRQ(ierr);
161   b->i=bi; b->j=bj; b->a=ba;
162   ierr = spbas_delete(matrix_L);CHKERRQ(ierr);
163 
164   /* Set the appropriate solution functions */
165   ierr = ISIdentity(ip,&perm_identity);CHKERRQ(ierr);
166   if (perm_identity){
167     (B)->ops->solve           = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
168     (B)->ops->solvetranspose  = MatSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
169     (B)->ops->forwardsolve    = MatForwardSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
170     (B)->ops->backwardsolve   = MatBackwardSolve_SeqSBAIJ_1_NaturalOrdering_inplace;
171   } else {
172     (B)->ops->solve           = MatSolve_SeqSBAIJ_1_inplace;
173     (B)->ops->solvetranspose  = MatSolve_SeqSBAIJ_1_inplace;
174     (B)->ops->forwardsolve    = MatForwardSolve_SeqSBAIJ_1_inplace;
175     (B)->ops->backwardsolve   = MatBackwardSolve_SeqSBAIJ_1_inplace;
176   }
177 
178   C->assembled    = PETSC_TRUE;
179   C->preallocated = PETSC_TRUE;
180   ierr = PetscLogFlops(C->rmap->n);CHKERRQ(ierr);
181   PetscFunctionReturn(0);
182 }
183 
184 EXTERN_C_BEGIN
185 #undef __FUNCT__
186 #define __FUNCT__ "MatGetFactor_seqaij_bas"
187 PetscErrorCode MatGetFactor_seqaij_bas(Mat A,MatFactorType ftype,Mat *B)
188 {
189   PetscInt           n = A->rmap->n;
190   PetscErrorCode     ierr;
191 
192   PetscFunctionBegin;
193   ierr = MatCreate(((PetscObject)A)->comm,B);CHKERRQ(ierr);
194   ierr = MatSetSizes(*B,n,n,n,n);CHKERRQ(ierr);
195   if (ftype == MAT_FACTOR_ICC) {
196     ierr = MatSetType(*B,MATSEQSBAIJ);CHKERRQ(ierr);
197     ierr = MatSeqSBAIJSetPreallocation(*B,1,MAT_SKIP_ALLOCATION,PETSC_NULL);CHKERRQ(ierr);
198     (*B)->ops->iccfactorsymbolic     = MatICCFactorSymbolic_SeqAIJ_Bas;
199     (*B)->ops->choleskyfactornumeric = MatCholeskyFactorNumeric_SeqAIJ_Bas;
200   } else SETERRQ(PETSC_ERR_SUP,"Factor type not supported");
201   (*B)->factor = ftype;
202   PetscFunctionReturn(0);
203 }
204 EXTERN_C_END
205