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