xref: /petsc/src/mat/impls/aij/seq/mattransposematmult.c (revision bfcb38ea38335faa6e7f8d97f6bc6ce9aa2a1dd1)
1 
2 /*
3   Defines matrix-matrix product routines
4           C = A^T * B
5 */
6 
7 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
8 #include <../src/mat/impls/dense/seq/dense.h>
9 
10 PetscErrorCode MatDestroy_SeqDense_MatTransMatMult(Mat A)
11 {
12   PetscErrorCode      ierr;
13   Mat_SeqDense        *a = (Mat_SeqDense*)A->data;
14   Mat_MatTransMatMult *atb = a->atb;
15 
16   PetscFunctionBegin;
17   ierr = MatDestroy(&atb->mA);CHKERRQ(ierr);
18   ierr = VecDestroy(&atb->bt);CHKERRQ(ierr);
19   ierr = VecDestroy(&atb->ct);CHKERRQ(ierr);
20   ierr = (atb->destroy)(A);CHKERRQ(ierr);
21   ierr = PetscFree(atb);CHKERRQ(ierr);
22   PetscFunctionReturn(0);
23 }
24 
25 PetscErrorCode MatTransposeMatMult_SeqAIJ_SeqDense(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)
26 {
27   PetscErrorCode ierr;
28 
29   PetscFunctionBegin;
30   if (scall == MAT_INITIAL_MATRIX) {
31     ierr = PetscLogEventBegin(MAT_TransposeMatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
32     ierr = MatTransposeMatMultSymbolic_SeqAIJ_SeqDense(A,B,fill,C);CHKERRQ(ierr);
33     ierr = PetscLogEventEnd(MAT_TransposeMatMultSymbolic,A,B,0,0);CHKERRQ(ierr);
34   }
35   ierr = PetscLogEventBegin(MAT_TransposeMatMultNumeric,A,B,0,0);CHKERRQ(ierr);
36   ierr = MatTransposeMatMultNumeric_SeqAIJ_SeqDense(A,B,*C);CHKERRQ(ierr);
37   ierr = PetscLogEventEnd(MAT_TransposeMatMultNumeric,A,B,0,0);CHKERRQ(ierr);
38   PetscFunctionReturn(0);
39 }
40 
41 PetscErrorCode MatTransposeMatMultSymbolic_SeqAIJ_SeqDense(Mat A,Mat B,PetscReal fill,Mat *C)
42 {
43   PetscErrorCode      ierr;
44   PetscInt            m=A->rmap->n,n=A->cmap->n,BN=B->cmap->N;
45   Mat_MatTransMatMult *atb;
46   Mat                 Cdense;
47   Vec                 bt,ct;
48   Mat_SeqDense        *c;
49 
50   PetscFunctionBegin;
51   ierr = PetscNew(&atb);CHKERRQ(ierr);
52 
53   /* create output dense matrix C = A^T*B */
54   ierr = MatCreate(PETSC_COMM_SELF,&Cdense);CHKERRQ(ierr);
55   ierr = MatSetSizes(Cdense,n,BN,n,BN);CHKERRQ(ierr);
56   ierr = MatSetType(Cdense,MATSEQDENSE);CHKERRQ(ierr);
57   ierr = MatSeqDenseSetPreallocation(Cdense,NULL);CHKERRQ(ierr);
58 
59   /* create vectors bt and ct to hold locally transposed arrays of B and C */
60   ierr = VecCreate(PETSC_COMM_SELF,&bt);CHKERRQ(ierr);
61   ierr = VecSetSizes(bt,m*BN,m*BN);CHKERRQ(ierr);
62   ierr = VecSetType(bt,VECSTANDARD);CHKERRQ(ierr);
63   ierr = VecCreate(PETSC_COMM_SELF,&ct);CHKERRQ(ierr);
64   ierr = VecSetSizes(ct,n*BN,n*BN);CHKERRQ(ierr);
65   ierr = VecSetType(ct,VECSTANDARD);CHKERRQ(ierr);
66   atb->bt = bt;
67   atb->ct = ct;
68 
69   *C                   = Cdense;
70   c                    = (Mat_SeqDense*)Cdense->data;
71   c->atb               = atb;
72   atb->destroy         = Cdense->ops->destroy;
73   Cdense->ops->destroy = MatDestroy_SeqDense_MatTransMatMult;
74   PetscFunctionReturn(0);
75 }
76 
77 PetscErrorCode MatTransposeMatMultNumeric_SeqAIJ_SeqDense(Mat A,Mat B,Mat C)
78 {
79   PetscErrorCode      ierr;
80   PetscInt            i,j,k,m=A->rmap->n,n=A->cmap->n,BN=B->cmap->N;
81   const PetscScalar   *Barray,*ctarray;
82   PetscScalar         *Carray,*btarray;
83   Mat_SeqDense        *c=(Mat_SeqDense*)C->data;
84   Mat_MatTransMatMult *atb=c->atb;
85   Vec                 bt=atb->bt,ct=atb->ct;
86 
87   PetscFunctionBegin;
88   /* create MAIJ matrix mA from A -- should be done in symbolic phase */
89   ierr = MatDestroy(&atb->mA);CHKERRQ(ierr);
90   ierr = MatCreateMAIJ(A,BN,&atb->mA);CHKERRQ(ierr);
91 
92   /* transpose local arry of B, then copy it to vector bt */
93   ierr = MatDenseGetArrayRead(B,&Barray);CHKERRQ(ierr);
94   ierr = VecGetArray(bt,&btarray);CHKERRQ(ierr);
95 
96   k=0;
97   for (j=0; j<BN; j++) {
98     for (i=0; i<m; i++) btarray[i*BN + j] = Barray[k++];
99   }
100   ierr = VecRestoreArray(bt,&btarray);CHKERRQ(ierr);
101   ierr = MatDenseRestoreArrayRead(B,&Barray);CHKERRQ(ierr);
102 
103   /* compute ct = mA^T * cb */
104   ierr = MatMultTranspose(atb->mA,bt,ct);CHKERRQ(ierr);
105 
106   /* transpose local arry of ct to matrix C */
107   ierr = MatDenseGetArray(C,&Carray);CHKERRQ(ierr);
108   ierr = VecGetArrayRead(ct,&ctarray);CHKERRQ(ierr);
109   k = 0;
110   for (j=0; j<BN; j++) {
111     for (i=0; i<n; i++) Carray[k++] = ctarray[i*BN + j];
112   }
113   ierr = VecRestoreArrayRead(ct,&ctarray);CHKERRQ(ierr);
114   ierr = MatDenseRestoreArray(C,&Carray);CHKERRQ(ierr);
115   PetscFunctionReturn(0);
116 }
117