xref: /petsc/src/mat/impls/aij/seq/fdaij.c (revision 040ebd07df7f48cdffac40673e8597e52ed39091)
1 
2 #include <../src/mat/impls/aij/seq/aij.h>
3 #include <../src/mat/impls/baij/seq/baij.h>
4 
5 /*
6     This routine is shared by SeqAIJ and SeqBAIJ matrices,
7     since it operators only on the nonzero structure of the elements or blocks.
8 */
9 #undef __FUNCT__
10 #define __FUNCT__ "MatFDColoringCreate_SeqXAIJ"
11 PetscErrorCode MatFDColoringCreate_SeqXAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
12 {
13   PetscErrorCode ierr;
14   PetscInt       i,n,nrows,N,j,k,m,ncols,col;
15   const PetscInt *is,*row,*ci,*cj;
16   PetscInt       nis=iscoloring->n,*rowhit,bs,bs2,*spidx,nz;
17   IS             *isa;
18   PetscBool      isBAIJ;
19   Mat_SeqAIJ     *spA = (Mat_SeqAIJ*)mat->data;
20   PetscScalar    *A_val=spA->a;
21   PetscScalar    **valaddrhit;
22   MatEntry       *Jentry;
23 
24   PetscFunctionBegin;
25   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
26 
27   /* this is ugly way to get blocksize but cannot call MatGetBlockSize() because AIJ can have bs > 1 */
28   ierr = MatGetBlockSize(mat,&bs);CHKERRQ(ierr);
29   ierr = PetscObjectTypeCompare((PetscObject)mat,MATSEQBAIJ,&isBAIJ);CHKERRQ(ierr);
30   if (!isBAIJ) {
31     bs = 1; /* only bs=1 is supported for non SEQBAIJ matrix */
32   }
33   N         = mat->cmap->N/bs;
34   c->M      = mat->rmap->N/bs;   /* set total rows, columns and local rows */
35   c->N      = mat->cmap->N/bs;
36   c->m      = mat->rmap->N/bs;
37   c->rstart = 0;
38 
39   c->ncolors = nis;
40   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
41   ierr       = PetscMalloc(nis*sizeof(PetscInt*),&c->columns);CHKERRQ(ierr);
42   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
43   ierr       = PetscLogObjectMemory((PetscObject)c,3*nis*sizeof(PetscInt));CHKERRQ(ierr);
44 
45   ierr       = PetscMalloc(spA->nz*sizeof(MatEntry),&Jentry);CHKERRQ(ierr);
46   ierr       = PetscLogObjectMemory((PetscObject)c,spA->nz*sizeof(MatEntry));CHKERRQ(ierr);
47   c->matentry = Jentry;
48 
49   if (isBAIJ) {
50     ierr = MatGetColumnIJ_SeqBAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
51   } else {
52     ierr = MatGetColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
53   }
54 
55   ierr = PetscMalloc2(c->m,PetscInt,&rowhit,c->m,PetscScalar*,&valaddrhit);CHKERRQ(ierr);
56   ierr = PetscMemzero(rowhit,c->m*sizeof(PetscInt));CHKERRQ(ierr);
57 
58   nz = 0;
59   for (i=0; i<nis; i++) { /* loop over colors */
60     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
61     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
62 
63     c->ncolumns[i] = n;
64     if (n) {
65       ierr = PetscMalloc(n*sizeof(PetscInt),&c->columns[i]);CHKERRQ(ierr);
66       ierr = PetscLogObjectMemory((PetscObject)c,n*sizeof(PetscInt));CHKERRQ(ierr);
67       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(PetscInt));CHKERRQ(ierr);
68     } else {
69       c->columns[i] = 0;
70     }
71 
72     /* fast, crude version requires O(N*N) work */
73     bs2   = bs*bs;
74     nrows = 0;
75     for (j=0; j<n; j++) {  /* loop over columns */
76       col    = is[j];
77       row    = cj + ci[col];
78       m      = ci[col+1] - ci[col];
79       nrows += m;
80       for (k=0; k<m; k++) {  /* loop over columns marking them in rowhit */
81         rowhit[*row]       = col + 1;
82         valaddrhit[*row++] = &A_val[bs2*spidx[ci[col] + k]];
83       }
84     }
85     c->nrows[i] = nrows; /* total num of rows for this color */
86 
87     for (j=0; j<N; j++) { /* loop over rows */
88       if (rowhit[j]) {
89         Jentry[nz].row     = j;              /* local row index */
90         Jentry[nz].col     = rowhit[j] - 1;  /* local column index */
91         Jentry[nz].valaddr = valaddrhit[j];  /* address of mat value for this entry */
92         nz++;
93         rowhit[j] = 0.0;                     /* zero rowhit for reuse */
94       }
95     }
96     ierr = ISRestoreIndices(isa[i],&is);CHKERRQ(ierr);
97   }
98   if (nz != spA->nz) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"nz %d != mat->nz %d\n",nz,spA->nz);
99 
100   if (isBAIJ) {
101     ierr = MatRestoreColumnIJ_SeqBAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
102   } else {
103     ierr = MatRestoreColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
104   }
105   ierr = PetscFree2(rowhit,valaddrhit);CHKERRQ(ierr);
106   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
107 
108   c->ctype = IS_COLORING_GHOSTED;
109   if (isBAIJ) {
110     ierr = PetscMalloc(bs*mat->cmap->N*sizeof(PetscScalar),&c->dy);CHKERRQ(ierr);
111   }
112   ierr = VecCreateGhost(PetscObjectComm((PetscObject)mat),mat->rmap->n,PETSC_DETERMINE,0,NULL,&c->vscale);CHKERRQ(ierr);
113   PetscFunctionReturn(0);
114 }
115