Actual source code: aijbaij.c


  2: #include <../src/mat/impls/baij/seq/baij.h>

  4: PETSC_INTERN PetscErrorCode MatConvert_SeqBAIJ_SeqAIJ(Mat A, MatType newtype, MatReuse reuse, Mat *newmat)
  5: {
  6:   Mat          B;
  7:   Mat_SeqAIJ  *b;
  8:   PetscBool    roworiented;
  9:   Mat_SeqBAIJ *a  = (Mat_SeqBAIJ *)A->data;
 10:   PetscInt     bs = A->rmap->bs, *ai = a->i, *aj = a->j, n = A->rmap->N / bs, i, j, k;
 11:   PetscInt    *rowlengths, *rows, *cols, maxlen            = 0, ncols;
 12:   MatScalar   *aa = a->a;

 14:   if (reuse == MAT_REUSE_MATRIX) {
 15:     B = *newmat;
 16:     for (i = 0; i < n; i++) maxlen = PetscMax(maxlen, (ai[i + 1] - ai[i]));
 17:   } else {
 18:     PetscMalloc1(n * bs, &rowlengths);
 19:     for (i = 0; i < n; i++) {
 20:       maxlen = PetscMax(maxlen, (ai[i + 1] - ai[i]));
 21:       for (j = 0; j < bs; j++) rowlengths[i * bs + j] = bs * (ai[i + 1] - ai[i]);
 22:     }
 23:     MatCreate(PetscObjectComm((PetscObject)A), &B);
 24:     MatSetType(B, MATSEQAIJ);
 25:     MatSetSizes(B, A->rmap->n, A->cmap->n, A->rmap->N, A->cmap->N);
 26:     MatSetBlockSizes(B, A->rmap->bs, A->cmap->bs);
 27:     MatSeqAIJSetPreallocation(B, 0, rowlengths);
 28:     PetscFree(rowlengths);
 29:   }
 30:   b           = (Mat_SeqAIJ *)B->data;
 31:   roworiented = b->roworiented;

 33:   MatSetOption(B, MAT_ROW_ORIENTED, PETSC_FALSE);
 34:   PetscMalloc1(bs, &rows);
 35:   PetscMalloc1(bs * maxlen, &cols);
 36:   for (i = 0; i < n; i++) {
 37:     for (j = 0; j < bs; j++) rows[j] = i * bs + j;
 38:     ncols = ai[i + 1] - ai[i];
 39:     for (k = 0; k < ncols; k++) {
 40:       for (j = 0; j < bs; j++) cols[k * bs + j] = bs * (*aj) + j;
 41:       aj++;
 42:     }
 43:     MatSetValues(B, bs, rows, bs * ncols, cols, aa, INSERT_VALUES);
 44:     aa += ncols * bs * bs;
 45:   }
 46:   PetscFree(cols);
 47:   PetscFree(rows);
 48:   MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY);
 49:   MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY);
 50:   MatSetOption(B, MAT_ROW_ORIENTED, roworiented);

 52:   if (reuse == MAT_INPLACE_MATRIX) {
 53:     MatHeaderReplace(A, &B);
 54:   } else *newmat = B;
 55:   return 0;
 56: }

 58: #include <../src/mat/impls/aij/seq/aij.h>

 60: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqBAIJ_Preallocate(Mat A, PetscInt **nnz)
 61: {
 62:   PetscInt    m, n, bs = PetscAbs(A->rmap->bs);
 63:   PetscInt   *ii;
 64:   Mat_SeqAIJ *Aa = (Mat_SeqAIJ *)A->data;

 66:   MatGetSize(A, &m, &n);
 67:   PetscCalloc1(m / bs, nnz);
 68:   PetscMalloc1(bs, &ii);

 70:   /* loop over all potential blocks in the matrix to see if the potential block has a nonzero */
 71:   for (PetscInt i = 0; i < m / bs; i++) {
 72:     for (PetscInt k = 0; k < bs; k++) ii[k] = Aa->i[i * bs + k];
 73:     for (PetscInt j = 0; j < n / bs; j++) {
 74:       for (PetscInt k = 0; k < bs; k++) {
 75:         for (; ii[k] < Aa->i[i * bs + k + 1] && Aa->j[ii[k]] < (j + 1) * bs; ii[k]++) {
 76:           if (Aa->j[ii[k]] >= j * bs) {
 77:             /* found a nonzero in the potential block so allocate for that block and jump to check the next potential block */
 78:             (*nnz)[i]++;
 79:             goto theend;
 80:           }
 81:         }
 82:       }
 83:     theend:;
 84:     }
 85:   }
 86:   PetscFree(ii);
 87:   return 0;
 88: }

 90: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqBAIJ(Mat A, MatType newtype, MatReuse reuse, Mat *newmat)
 91: {
 92:   Mat          B;
 93:   Mat_SeqAIJ  *a = (Mat_SeqAIJ *)A->data;
 94:   Mat_SeqBAIJ *b;
 95:   PetscInt     m = A->rmap->N, n = A->cmap->N, *rowlengths, bs = PetscAbs(A->rmap->bs);

 97:   if (reuse != MAT_REUSE_MATRIX) {
 98:     MatConvert_SeqAIJ_SeqBAIJ_Preallocate(A, &rowlengths);
 99:     MatCreate(PetscObjectComm((PetscObject)A), &B);
100:     MatSetSizes(B, m, n, m, n);
101:     MatSetType(B, MATSEQBAIJ);
102:     MatSeqBAIJSetPreallocation(B, bs, 0, rowlengths);
103:     PetscFree(rowlengths);
104:   } else B = *newmat;

106:   if (bs == 1) {
107:     b = (Mat_SeqBAIJ *)(B->data);

109:     PetscArraycpy(b->i, a->i, m + 1);
110:     PetscArraycpy(b->ilen, a->ilen, m);
111:     PetscArraycpy(b->j, a->j, a->nz);
112:     PetscArraycpy(b->a, a->a, a->nz);

114:     MatSetOption(B, MAT_ROW_ORIENTED, PETSC_TRUE);
115:     MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY);
116:     MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY);
117:   } else {
118:     /* reuse may not be equal to MAT_REUSE_MATRIX, but the basic converter will reallocate or replace newmat if this value is not used */
119:     /* if reuse is equal to MAT_INITIAL_MATRIX, it has been appropriately preallocated before                                          */
120:     /*                      MAT_INPLACE_MATRIX, it will be replaced with MatHeaderReplace below                                        */
121:     MatConvert_Basic(A, newtype, MAT_REUSE_MATRIX, &B);
122:   }

124:   if (reuse == MAT_INPLACE_MATRIX) {
125:     MatHeaderReplace(A, &B);
126:   } else *newmat = B;
127:   return 0;
128: }