xref: /petsc/src/mat/impls/aij/seq/mattransposematmult.c (revision ffa8c5705e8ab2cf85ee1d14dbe507a6e2eb5283)
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(0);
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   PetscCheckFalse(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) {
46     PetscCall(MatSetType(C,((PetscObject)B)->type_name));
47   }
48   PetscCall(MatSetUp(C));
49 
50   /* create additional data structure for the product */
51   PetscCall(PetscNew(&atb));
52   PetscCall(MatCreateMAIJ(A,dofm,&atb->mA));
53   PetscCall(MatCreateVecs(atb->mA,&atb->ct,&atb->bt));
54   C->product->data    = atb;
55   C->product->destroy = MatDestroy_SeqDense_MatTransMatMult;
56 
57   if (C->product->type == MATPRODUCT_AtB) {
58     C->ops->transposematmultnumeric = MatTMatTMultNumeric_SeqAIJ_SeqDense;
59   } else {
60     C->ops->mattransposemultnumeric = MatTMatTMultNumeric_SeqAIJ_SeqDense;
61   }
62   PetscFunctionReturn(0);
63 }
64 
65 PetscErrorCode MatTMatTMultNumeric_SeqAIJ_SeqDense(Mat A,Mat B,Mat C)
66 {
67   PetscInt            i,j,m=A->rmap->n,n=A->cmap->n,blda,clda;
68   PetscInt            mdof = C->cmap->N;
69   const PetscScalar   *Barray;
70   PetscScalar         *Carray;
71   Mat_MatTransMatMult *atb;
72   Vec                 bt,ct;
73 
74   PetscFunctionBegin;
75   MatCheckProduct(C,3);
76   PetscCheckFalse(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]);
77   atb = (Mat_MatTransMatMult *)C->product->data;
78   PetscCheck(atb,PETSC_COMM_SELF,PETSC_ERR_PLIB,"Missing product struct");
79   bt = atb->bt;
80   ct = atb->ct;
81 
82   PetscCall(MatDenseGetArrayRead(B,&Barray));
83   PetscCall(MatDenseGetLDA(B,&blda));
84   PetscCall(MatDenseGetArrayWrite(C,&Carray));
85   PetscCall(MatDenseGetLDA(C,&clda));
86   if (C->product->type == MATPRODUCT_AtB) { /* transpose local array of B, then copy it to vector bt */
87     const PetscScalar *ctarray;
88     PetscScalar       *btarray;
89 
90     PetscCall(VecGetArrayWrite(bt,&btarray));
91     for (j=0; j<mdof; j++) {
92       for (i=0; i<m; i++) btarray[i*mdof + j] = Barray[j*blda + i];
93     }
94     PetscCall(VecRestoreArrayWrite(bt,&btarray));
95 
96     /* compute ct = mA^T * cb */
97     PetscCall(MatMultTranspose(atb->mA,bt,ct));
98 
99     /* transpose local array of ct to matrix C */
100     PetscCall(VecGetArrayRead(ct,&ctarray));
101     for (j=0; j<mdof; j++) {
102       for (i=0; i<n; i++) Carray[j*clda + i] = ctarray[i*mdof + j];
103     }
104     PetscCall(VecRestoreArrayRead(ct,&ctarray));
105   } else {
106     const PetscScalar *btarray;
107     PetscScalar       *ctarray;
108 
109     if (blda == B->rmap->n) {
110       PetscCall(VecPlaceArray(ct,Barray));
111     } else {
112       PetscInt bn = B->cmap->n;
113       PetscInt bm = B->rmap->n;
114 
115       PetscCall(VecGetArrayWrite(ct,&ctarray));
116       for (j=0; j<bn; j++) {
117         for (i=0; i<bm; i++) ctarray[j*bm + i] = Barray[j*blda + i];
118       }
119       PetscCall(VecRestoreArrayWrite(ct,&ctarray));
120     }
121 
122     PetscCall(MatMult(atb->mA,ct,bt));
123     if (blda == B->rmap->n) {
124       PetscCall(VecResetArray(ct));
125     }
126     PetscCall(VecGetArrayRead(bt,&btarray));
127     for (j=0; j<mdof; j++) {
128       for (i=0; i<m; i++) Carray[j*clda + i] = btarray[i*mdof + j];
129     }
130     PetscCall(VecRestoreArrayRead(bt,&btarray));
131   }
132   PetscCall(MatDenseRestoreArrayRead(B,&Barray));
133   PetscCall(MatDenseRestoreArray(C,&Carray));
134   PetscFunctionReturn(0);
135 }
136