xref: /petsc/src/mat/impls/aij/seq/mattransposematmult.c (revision fbf9dbe564678ed6eff1806adbc4c4f01b9743f4)
1 
2 /*
3   Defines matrix-matrix product routines for
4           C = A^T * B and C = A * B^t
5   with A SeqAIJ and B SeqDense
6 */
7 
8 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
9 #include <../src/mat/impls/dense/seq/dense.h>
10 
11 PetscErrorCode MatDestroy_SeqDense_MatTransMatMult(void *data)
12 {
13   Mat_MatTransMatMult *atb = (Mat_MatTransMatMult *)data;
14 
15   PetscFunctionBegin;
16   PetscCall(MatDestroy(&atb->mA));
17   PetscCall(VecDestroy(&atb->bt));
18   PetscCall(VecDestroy(&atb->ct));
19   PetscCall(PetscFree(atb));
20   PetscFunctionReturn(PETSC_SUCCESS);
21 }
22 
23 static PetscErrorCode MatTMatTMultNumeric_SeqAIJ_SeqDense(Mat, Mat, Mat);
24 
25 PETSC_INTERN PetscErrorCode MatTMatTMultSymbolic_SeqAIJ_SeqDense(Mat A, Mat B, PetscReal fill, Mat C)
26 {
27   Mat_MatTransMatMult *atb;
28   PetscBool            cisdense;
29   PetscInt             dofm;
30 
31   PetscFunctionBegin;
32   MatCheckProduct(C, 4);
33   PetscCheck(!C->product->data, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Extra product struct not empty");
34   PetscCheck(C->product->type == MATPRODUCT_ABt || C->product->type == MATPRODUCT_AtB, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Not for product type %s", MatProductTypes[C->product->type]);
35 
36   /* create output dense matrix C */
37   if (C->product->type == MATPRODUCT_AtB) {
38     PetscCall(MatSetSizes(C, A->cmap->n, B->cmap->N, A->cmap->n, B->cmap->N));
39     dofm = B->cmap->n;
40   } else {
41     PetscCall(MatSetSizes(C, A->rmap->n, B->rmap->N, A->rmap->n, B->rmap->N));
42     dofm = B->rmap->n;
43   }
44   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &cisdense, MATSEQDENSE, MATSEQDENSECUDA, ""));
45   if (!cisdense) PetscCall(MatSetType(C, ((PetscObject)B)->type_name));
46   PetscCall(MatSetUp(C));
47 
48   /* create additional data structure for the product */
49   PetscCall(PetscNew(&atb));
50   PetscCall(MatCreateMAIJ(A, dofm, &atb->mA));
51   PetscCall(MatCreateVecs(atb->mA, &atb->ct, &atb->bt));
52   C->product->data    = atb;
53   C->product->destroy = MatDestroy_SeqDense_MatTransMatMult;
54 
55   if (C->product->type == MATPRODUCT_AtB) {
56     C->ops->transposematmultnumeric = MatTMatTMultNumeric_SeqAIJ_SeqDense;
57   } else {
58     C->ops->mattransposemultnumeric = MatTMatTMultNumeric_SeqAIJ_SeqDense;
59   }
60   PetscFunctionReturn(PETSC_SUCCESS);
61 }
62 
63 PetscErrorCode MatTMatTMultNumeric_SeqAIJ_SeqDense(Mat A, Mat B, Mat C)
64 {
65   PetscInt             i, j, m = A->rmap->n, n = A->cmap->n, blda, clda;
66   PetscInt             mdof = C->cmap->N;
67   const PetscScalar   *Barray;
68   PetscScalar         *Carray;
69   Mat_MatTransMatMult *atb;
70   Vec                  bt, ct;
71 
72   PetscFunctionBegin;
73   MatCheckProduct(C, 3);
74   PetscCheck(C->product->type == MATPRODUCT_ABt || C->product->type == MATPRODUCT_AtB, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Not for product type %s", MatProductTypes[C->product->type]);
75   atb = (Mat_MatTransMatMult *)C->product->data;
76   PetscCheck(atb, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Missing product struct");
77   bt = atb->bt;
78   ct = atb->ct;
79 
80   PetscCall(MatDenseGetArrayRead(B, &Barray));
81   PetscCall(MatDenseGetLDA(B, &blda));
82   PetscCall(MatDenseGetArrayWrite(C, &Carray));
83   PetscCall(MatDenseGetLDA(C, &clda));
84   if (C->product->type == MATPRODUCT_AtB) { /* transpose local array of B, then copy it to vector bt */
85     const PetscScalar *ctarray;
86     PetscScalar       *btarray;
87 
88     PetscCall(VecGetArrayWrite(bt, &btarray));
89     for (j = 0; j < mdof; j++) {
90       for (i = 0; i < m; i++) btarray[i * mdof + j] = Barray[j * blda + i];
91     }
92     PetscCall(VecRestoreArrayWrite(bt, &btarray));
93 
94     /* compute ct = mA^T * cb */
95     PetscCall(MatMultTranspose(atb->mA, bt, ct));
96 
97     /* transpose local array of ct to matrix C */
98     PetscCall(VecGetArrayRead(ct, &ctarray));
99     for (j = 0; j < mdof; j++) {
100       for (i = 0; i < n; i++) Carray[j * clda + i] = ctarray[i * mdof + j];
101     }
102     PetscCall(VecRestoreArrayRead(ct, &ctarray));
103   } else {
104     const PetscScalar *btarray;
105     PetscScalar       *ctarray;
106 
107     if (blda == B->rmap->n) {
108       PetscCall(VecPlaceArray(ct, Barray));
109     } else {
110       PetscInt bn = B->cmap->n;
111       PetscInt bm = B->rmap->n;
112 
113       PetscCall(VecGetArrayWrite(ct, &ctarray));
114       for (j = 0; j < bn; j++) {
115         for (i = 0; i < bm; i++) ctarray[j * bm + i] = Barray[j * blda + i];
116       }
117       PetscCall(VecRestoreArrayWrite(ct, &ctarray));
118     }
119 
120     PetscCall(MatMult(atb->mA, ct, bt));
121     if (blda == B->rmap->n) PetscCall(VecResetArray(ct));
122     PetscCall(VecGetArrayRead(bt, &btarray));
123     for (j = 0; j < mdof; j++) {
124       for (i = 0; i < m; i++) Carray[j * clda + i] = btarray[i * mdof + j];
125     }
126     PetscCall(VecRestoreArrayRead(bt, &btarray));
127   }
128   PetscCall(MatDenseRestoreArrayRead(B, &Barray));
129   PetscCall(MatDenseRestoreArray(C, &Carray));
130   PetscFunctionReturn(PETSC_SUCCESS);
131 }
132