xref: /petsc/src/mat/impls/scatter/mscatter.c (revision 89669be4d29968dc8d4c19ce1b69194a6a561ea4)
1 
2 /*
3    This provides a matrix that applies a VecScatter to a vector.
4 */
5 
6 #include <petsc/private/matimpl.h>        /*I "petscmat.h" I*/
7 #include <petsc/private/vecimpl.h>
8 
9 typedef struct {
10   VecScatter scatter;
11 } Mat_Scatter;
12 
13 /*@
14     MatScatterGetVecScatter - Returns the user-provided scatter set with MatScatterSetVecScatter()
15 
16     Not Collective, but not cannot use scatter if not used collectively on Mat
17 
18     Input Parameter:
19 .   mat - the matrix, should have been created with MatCreateScatter() or have type MATSCATTER
20 
21     Output Parameter:
22 .   scatter - the scatter context
23 
24     Level: intermediate
25 
26 .seealso: `MatCreateScatter()`, `MatScatterSetVecScatter()`, `MATSCATTER`
27 @*/
28 PetscErrorCode  MatScatterGetVecScatter(Mat mat,VecScatter *scatter)
29 {
30   Mat_Scatter *mscatter;
31 
32   PetscFunctionBegin;
33   PetscValidHeaderSpecific(mat,MAT_CLASSID,1);
34   PetscValidPointer(scatter,2);
35   mscatter = (Mat_Scatter*)mat->data;
36   *scatter = mscatter->scatter;
37   PetscFunctionReturn(0);
38 }
39 
40 PetscErrorCode MatDestroy_Scatter(Mat mat)
41 {
42   Mat_Scatter    *scatter = (Mat_Scatter*)mat->data;
43 
44   PetscFunctionBegin;
45   PetscCall(VecScatterDestroy(&scatter->scatter));
46   PetscCall(PetscFree(mat->data));
47   PetscFunctionReturn(0);
48 }
49 
50 PetscErrorCode MatMult_Scatter(Mat A,Vec x,Vec y)
51 {
52   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
53 
54   PetscFunctionBegin;
55   PetscCheck(scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
56   PetscCall(VecZeroEntries(y));
57   PetscCall(VecScatterBegin(scatter->scatter,x,y,ADD_VALUES,SCATTER_FORWARD));
58   PetscCall(VecScatterEnd(scatter->scatter,x,y,ADD_VALUES,SCATTER_FORWARD));
59   PetscFunctionReturn(0);
60 }
61 
62 PetscErrorCode MatMultAdd_Scatter(Mat A,Vec x,Vec y,Vec z)
63 {
64   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
65 
66   PetscFunctionBegin;
67   PetscCheck(scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
68   if (z != y) PetscCall(VecCopy(y,z));
69   PetscCall(VecScatterBegin(scatter->scatter,x,z,ADD_VALUES,SCATTER_FORWARD));
70   PetscCall(VecScatterEnd(scatter->scatter,x,z,ADD_VALUES,SCATTER_FORWARD));
71   PetscFunctionReturn(0);
72 }
73 
74 PetscErrorCode MatMultTranspose_Scatter(Mat A,Vec x,Vec y)
75 {
76   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
77 
78   PetscFunctionBegin;
79   PetscCheck(scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
80   PetscCall(VecZeroEntries(y));
81   PetscCall(VecScatterBegin(scatter->scatter,x,y,ADD_VALUES,SCATTER_REVERSE));
82   PetscCall(VecScatterEnd(scatter->scatter,x,y,ADD_VALUES,SCATTER_REVERSE));
83   PetscFunctionReturn(0);
84 }
85 
86 PetscErrorCode MatMultTransposeAdd_Scatter(Mat A,Vec x,Vec y,Vec z)
87 {
88   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
89 
90   PetscFunctionBegin;
91   PetscCheck(scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
92   if (z != y) PetscCall(VecCopy(y,z));
93   PetscCall(VecScatterBegin(scatter->scatter,x,z,ADD_VALUES,SCATTER_REVERSE));
94   PetscCall(VecScatterEnd(scatter->scatter,x,z,ADD_VALUES,SCATTER_REVERSE));
95   PetscFunctionReturn(0);
96 }
97 
98 static struct _MatOps MatOps_Values = {NULL,
99                                        NULL,
100                                        NULL,
101                                        MatMult_Scatter,
102                                /*  4*/ MatMultAdd_Scatter,
103                                        MatMultTranspose_Scatter,
104                                        MatMultTransposeAdd_Scatter,
105                                        NULL,
106                                        NULL,
107                                        NULL,
108                                /* 10*/ NULL,
109                                        NULL,
110                                        NULL,
111                                        NULL,
112                                        NULL,
113                                /* 15*/ NULL,
114                                        NULL,
115                                        NULL,
116                                        NULL,
117                                        NULL,
118                                /* 20*/ NULL,
119                                        NULL,
120                                        NULL,
121                                        NULL,
122                                /* 24*/ NULL,
123                                        NULL,
124                                        NULL,
125                                        NULL,
126                                        NULL,
127                                /* 29*/ NULL,
128                                        NULL,
129                                        NULL,
130                                        NULL,
131                                        NULL,
132                                /* 34*/ NULL,
133                                        NULL,
134                                        NULL,
135                                        NULL,
136                                        NULL,
137                                /* 39*/ NULL,
138                                        NULL,
139                                        NULL,
140                                        NULL,
141                                        NULL,
142                                /* 44*/ NULL,
143                                        NULL,
144                                        MatShift_Basic,
145                                        NULL,
146                                        NULL,
147                                /* 49*/ NULL,
148                                        NULL,
149                                        NULL,
150                                        NULL,
151                                        NULL,
152                                /* 54*/ NULL,
153                                        NULL,
154                                        NULL,
155                                        NULL,
156                                        NULL,
157                                /* 59*/ NULL,
158                                        MatDestroy_Scatter,
159                                        NULL,
160                                        NULL,
161                                        NULL,
162                                /* 64*/ NULL,
163                                        NULL,
164                                        NULL,
165                                        NULL,
166                                        NULL,
167                                /* 69*/ NULL,
168                                        NULL,
169                                        NULL,
170                                        NULL,
171                                        NULL,
172                                /* 74*/ NULL,
173                                        NULL,
174                                        NULL,
175                                        NULL,
176                                        NULL,
177                                /* 79*/ NULL,
178                                        NULL,
179                                        NULL,
180                                        NULL,
181                                        NULL,
182                                /* 84*/ NULL,
183                                        NULL,
184                                        NULL,
185                                        NULL,
186                                        NULL,
187                                /* 89*/ NULL,
188                                        NULL,
189                                        NULL,
190                                        NULL,
191                                        NULL,
192                                /* 94*/ NULL,
193                                        NULL,
194                                        NULL,
195                                        NULL,
196                                        NULL,
197                                 /*99*/ NULL,
198                                        NULL,
199                                        NULL,
200                                        NULL,
201                                        NULL,
202                                /*104*/ NULL,
203                                        NULL,
204                                        NULL,
205                                        NULL,
206                                        NULL,
207                                /*109*/ NULL,
208                                        NULL,
209                                        NULL,
210                                        NULL,
211                                        NULL,
212                                /*114*/ NULL,
213                                        NULL,
214                                        NULL,
215                                        NULL,
216                                        NULL,
217                                /*119*/ NULL,
218                                        NULL,
219                                        NULL,
220                                        NULL,
221                                        NULL,
222                                /*124*/ NULL,
223                                        NULL,
224                                        NULL,
225                                        NULL,
226                                        NULL,
227                                /*129*/ NULL,
228                                        NULL,
229                                        NULL,
230                                        NULL,
231                                        NULL,
232                                /*134*/ NULL,
233                                        NULL,
234                                        NULL,
235                                        NULL,
236                                        NULL,
237                                 /*139*/NULL,
238                                        NULL,
239                                        NULL,
240                                        NULL,
241                                        NULL,
242                                 /*144*/NULL,
243                                        NULL,
244                                        NULL,
245                                        NULL
246 };
247 
248 /*MC
249    MATSCATTER - MATSCATTER = "scatter" - A matrix type that simply applies a VecScatterBegin/End()
250 
251   Level: advanced
252 
253 .seealso: `MatCreateScatter()`, `MatScatterSetVecScatter()`, `MatScatterGetVecScatter()`
254 
255 M*/
256 
257 PETSC_EXTERN PetscErrorCode MatCreate_Scatter(Mat A)
258 {
259   Mat_Scatter    *b;
260 
261   PetscFunctionBegin;
262   PetscCall(PetscMemcpy(A->ops,&MatOps_Values,sizeof(struct _MatOps)));
263   PetscCall(PetscNewLog(A,&b));
264 
265   A->data = (void*)b;
266 
267   PetscCall(PetscLayoutSetUp(A->rmap));
268   PetscCall(PetscLayoutSetUp(A->cmap));
269 
270   A->assembled    = PETSC_TRUE;
271   A->preallocated = PETSC_FALSE;
272 
273   PetscCall(PetscObjectChangeTypeName((PetscObject)A,MATSCATTER));
274   PetscFunctionReturn(0);
275 }
276 
277 #include <petsc/private/sfimpl.h>
278 /*@C
279    MatCreateScatter - Creates a new matrix based on a VecScatter
280 
281   Collective
282 
283    Input Parameters:
284 +  comm - MPI communicator
285 -  scatter - a VecScatterContext
286 
287    Output Parameter:
288 .  A - the matrix
289 
290    Level: intermediate
291 
292    PETSc requires that matrices and vectors being used for certain
293    operations are partitioned accordingly.  For example, when
294    creating a scatter matrix, A, that supports parallel matrix-vector
295    products using MatMult(A,x,y) the user should set the number
296    of local matrix rows to be the number of local elements of the
297    corresponding result vector, y. Note that this is information is
298    required for use of the matrix interface routines, even though
299    the scatter matrix may not actually be physically partitioned.
300 
301   Developer Notes: This directly accesses information inside the VecScatter associated with the matrix-vector product
302    for this matrix. This is not desirable..
303 
304 .seealso: `MatScatterSetVecScatter()`, `MatScatterGetVecScatter()`, `MATSCATTER`
305 @*/
306 PetscErrorCode  MatCreateScatter(MPI_Comm comm,VecScatter scatter,Mat *A)
307 {
308   PetscFunctionBegin;
309   PetscCall(MatCreate(comm,A));
310   PetscCall(MatSetSizes(*A,scatter->vscat.to_n,scatter->vscat.from_n,PETSC_DETERMINE,PETSC_DETERMINE));
311   PetscCall(MatSetType(*A,MATSCATTER));
312   PetscCall(MatScatterSetVecScatter(*A,scatter));
313   PetscCall(MatSetUp(*A));
314   PetscFunctionReturn(0);
315 }
316 
317 /*@
318     MatScatterSetVecScatter - sets that scatter that the matrix is to apply as its linear operator
319 
320    Collective on Mat
321 
322     Input Parameters:
323 +   mat - the scatter matrix
324 -   scatter - the scatter context create with VecScatterCreate()
325 
326    Level: advanced
327 
328 .seealso: `MatCreateScatter()`, `MATSCATTER`
329 @*/
330 PetscErrorCode  MatScatterSetVecScatter(Mat mat,VecScatter scatter)
331 {
332   Mat_Scatter    *mscatter = (Mat_Scatter*)mat->data;
333 
334   PetscFunctionBegin;
335   PetscValidHeaderSpecific(mat,MAT_CLASSID,1);
336   PetscValidHeaderSpecific(scatter,PETSCSF_CLASSID,2);
337   PetscCheckSameComm((PetscObject)scatter,2,(PetscObject)mat,1);
338   PetscCheck(mat->rmap->n == scatter->vscat.to_n,PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number of local rows in matrix %" PetscInt_FMT " not equal local scatter size %" PetscInt_FMT,mat->rmap->n,scatter->vscat.to_n);
339   PetscCheck(mat->cmap->n == scatter->vscat.from_n,PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number of local columns in matrix %" PetscInt_FMT " not equal local scatter size %" PetscInt_FMT,mat->cmap->n,scatter->vscat.from_n);
340 
341   PetscCall(PetscObjectReference((PetscObject)scatter));
342   PetscCall(VecScatterDestroy(&mscatter->scatter));
343 
344   mscatter->scatter = scatter;
345   PetscFunctionReturn(0);
346 }
347