xref: /petsc/src/mat/impls/shell/shellcnv.c (revision 41319c1d5552f348d23e48b083e7c7a8d8d00d36)
1 #include <petsc/private/matimpl.h>        /*I "petscmat.h" I*/
2 
3 PetscErrorCode MatConvert_Shell(Mat oldmat, MatType newtype,MatReuse reuse,Mat *newmat)
4 {
5   Mat            mat;
6   Vec            in,out;
7   MPI_Comm       comm;
8   PetscScalar    *array;
9   PetscInt       *dnnz,*onnz,*dnnzu,*onnzu;
10   PetscInt       cst,Nbs,mbs,nbs,rbs,cbs;
11   PetscInt       im,i,m,n,M,N,*rows,start;
12   PetscErrorCode ierr;
13 
14   PetscFunctionBegin;
15   ierr = PetscObjectGetComm((PetscObject)oldmat,&comm);CHKERRQ(ierr);
16 
17   ierr = MatGetOwnershipRange(oldmat,&start,NULL);CHKERRQ(ierr);
18   ierr = MatGetOwnershipRangeColumn(oldmat,&cst,NULL);CHKERRQ(ierr);
19   ierr = MatCreateVecs(oldmat,&in,&out);CHKERRQ(ierr);
20   ierr = MatGetLocalSize(oldmat,&m,&n);CHKERRQ(ierr);
21   ierr = MatGetSize(oldmat,&M,&N);CHKERRQ(ierr);
22   ierr = PetscMalloc1(m,&rows);CHKERRQ(ierr);
23 
24   ierr = MatCreate(comm,&mat);CHKERRQ(ierr);
25   ierr = MatSetSizes(mat,m,n,M,N);CHKERRQ(ierr);
26   ierr = MatSetType(mat,newtype);CHKERRQ(ierr);
27   ierr = MatSetBlockSizesFromMats(mat,oldmat,oldmat);CHKERRQ(ierr);
28   ierr = MatGetBlockSizes(mat,&rbs,&cbs);CHKERRQ(ierr);
29   mbs  = m/rbs;
30   nbs  = n/cbs;
31   Nbs  = N/cbs;
32   cst  = cst/cbs;
33   ierr = PetscMalloc4(mbs,&dnnz,mbs,&onnz,mbs,&dnnzu,mbs,&onnzu);CHKERRQ(ierr);
34   for (i=0; i<mbs; i++) {
35     dnnz[i]  = nbs;
36     onnz[i]  = Nbs - nbs;
37     dnnzu[i] = PetscMax(nbs - i,0);
38     onnzu[i] = PetscMax(Nbs - (cst + nbs),0);
39   }
40   ierr = MatXAIJSetPreallocation(mat,PETSC_DECIDE,dnnz,onnz,dnnzu,onnzu);CHKERRQ(ierr);
41   ierr = PetscFree4(dnnz,onnz,dnnzu,onnzu);CHKERRQ(ierr);
42   ierr = VecSetOption(in,VEC_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
43   ierr = MatSetUp(mat);CHKERRQ(ierr);
44   for (i=0; i<N; i++) {
45     PetscInt j;
46 
47     ierr = VecZeroEntries(in);CHKERRQ(ierr);
48     ierr = VecSetValue(in,i,1.,INSERT_VALUES);CHKERRQ(ierr);
49     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
50     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
51     ierr = MatMult(oldmat,in,out);CHKERRQ(ierr);
52     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
53     for (j=0, im = 0; j<m; j++) {
54       if (PetscAbsScalar(array[j]) == 0.0) continue;
55       rows[im]  = j+start;
56       array[im] = array[j];
57       im++;
58     }
59     ierr = MatSetValues(mat,im,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
60     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
61   }
62   ierr = PetscFree(rows);CHKERRQ(ierr);
63   ierr = VecDestroy(&in);CHKERRQ(ierr);
64   ierr = VecDestroy(&out);CHKERRQ(ierr);
65   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
66   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
67   if (reuse == MAT_INPLACE_MATRIX) {
68     ierr = MatHeaderReplace(oldmat,&mat);CHKERRQ(ierr);
69   } else {
70     *newmat = mat;
71   }
72   PetscFunctionReturn(0);
73 }
74 
75 static PetscErrorCode MatGetDiagonal_CF(Mat A,Vec X)
76 {
77   Mat            B;
78   PetscErrorCode ierr;
79 
80   PetscFunctionBegin;
81   ierr = MatShellGetContext(A,&B);CHKERRQ(ierr);
82   if (!B) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_PLIB,"Missing user matrix");
83   ierr = MatGetDiagonal(B,X);CHKERRQ(ierr);
84   PetscFunctionReturn(0);
85 }
86 
87 static PetscErrorCode MatMult_CF(Mat A,Vec X,Vec Y)
88 {
89   Mat            B;
90   PetscErrorCode ierr;
91 
92   PetscFunctionBegin;
93   ierr = MatShellGetContext(A,&B);CHKERRQ(ierr);
94   if (!B) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_PLIB,"Missing user matrix");
95   ierr = MatMult(B,X,Y);CHKERRQ(ierr);
96   PetscFunctionReturn(0);
97 }
98 
99 static PetscErrorCode MatMultTranspose_CF(Mat A,Vec X,Vec Y)
100 {
101   Mat            B;
102   PetscErrorCode ierr;
103 
104   PetscFunctionBegin;
105   ierr = MatShellGetContext(A,&B);CHKERRQ(ierr);
106   if (!B) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_PLIB,"Missing user matrix");
107   ierr = MatMultTranspose(B,X,Y);CHKERRQ(ierr);
108   PetscFunctionReturn(0);
109 }
110 
111 static PetscErrorCode MatDestroy_CF(Mat A)
112 {
113   Mat            B;
114   PetscErrorCode ierr;
115 
116   PetscFunctionBegin;
117   ierr = MatShellGetContext(A,&B);CHKERRQ(ierr);
118   if (!B) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_PLIB,"Missing user matrix");
119   ierr = MatDestroy(&B);CHKERRQ(ierr);
120   PetscFunctionReturn(0);
121 }
122 
123 PetscErrorCode MatConvertFrom_Shell(Mat A, MatType newtype,MatReuse reuse,Mat *B)
124 {
125   Mat            M;
126   PetscBool      flg;
127   PetscErrorCode ierr;
128 
129   PetscFunctionBegin;
130   ierr = PetscStrcmp(newtype,MATSHELL,&flg);CHKERRQ(ierr);
131   if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Only conversion to MATSHELL");
132   if (reuse == MAT_INITIAL_MATRIX) {
133     ierr = PetscObjectReference((PetscObject)A);CHKERRQ(ierr);
134     ierr = MatCreateShell(PetscObjectComm((PetscObject)A),A->rmap->n,A->cmap->n,A->rmap->N,A->cmap->N,A,&M);CHKERRQ(ierr);
135     ierr = MatSetBlockSizesFromMats(M,A,A);CHKERRQ(ierr);
136     ierr = MatShellSetOperation(M,MATOP_MULT,          (void (*)(void))MatMult_CF);CHKERRQ(ierr);
137     ierr = MatShellSetOperation(M,MATOP_MULT_TRANSPOSE,(void (*)(void))MatMultTranspose_CF);CHKERRQ(ierr);
138     ierr = MatShellSetOperation(M,MATOP_GET_DIAGONAL,  (void (*)(void))MatGetDiagonal_CF);CHKERRQ(ierr);
139     ierr = MatShellSetOperation(M,MATOP_DESTROY,       (void (*)(void))MatDestroy_CF);CHKERRQ(ierr);
140     *B = M;
141   } else SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_SUP,"Not implemented");
142   PetscFunctionReturn(0);
143 }
144