Actual source code: mscatter.c

petsc-3.5.2 2014-09-08
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  2: /*
  3:    This provides a matrix that applies a VecScatter to a vector.
  4: */

  6: #include <petsc-private/matimpl.h>        /*I "petscmat.h" I*/
  7: #include <petsc-private/vecimpl.h>

  9: typedef struct {
 10:   VecScatter scatter;
 11: } Mat_Scatter;

 15: /*@
 16:     MatScatterGetVecScatter - Returns the user-provided scatter set with MatScatterSetVecScatter()

 18:     Not Collective, but not cannot use scatter if not used collectively on Mat

 20:     Input Parameter:
 21: .   mat - the matrix, should have been created with MatCreateScatter() or have type MATSCATTER

 23:     Output Parameter:
 24: .   scatter - the scatter context

 26:     Level: intermediate

 28: .keywords: matrix, scatter, get

 30: .seealso: MatCreateScatter(), MatScatterSetVecScatter(), MATSCATTER
 31: @*/
 32: PetscErrorCode  MatScatterGetVecScatter(Mat mat,VecScatter *scatter)
 33: {
 34:   Mat_Scatter *mscatter;

 39:   mscatter = (Mat_Scatter*)mat->data;
 40:   *scatter = mscatter->scatter;
 41:   return(0);
 42: }

 46: PetscErrorCode MatDestroy_Scatter(Mat mat)
 47: {
 49:   Mat_Scatter    *scatter = (Mat_Scatter*)mat->data;

 52:   VecScatterDestroy(&scatter->scatter);
 53:   PetscFree(mat->data);
 54:   return(0);
 55: }

 59: PetscErrorCode MatMult_Scatter(Mat A,Vec x,Vec y)
 60: {
 61:   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;

 65:   if (!scatter->scatter) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
 66:   VecZeroEntries(y);
 67:   VecScatterBegin(scatter->scatter,x,y,ADD_VALUES,SCATTER_FORWARD);
 68:   VecScatterEnd(scatter->scatter,x,y,ADD_VALUES,SCATTER_FORWARD);
 69:   return(0);
 70: }

 74: PetscErrorCode MatMultAdd_Scatter(Mat A,Vec x,Vec y,Vec z)
 75: {
 76:   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;

 80:   if (!scatter->scatter) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
 81:   if (z != y) {VecCopy(y,z);}
 82:   VecScatterBegin(scatter->scatter,x,z,ADD_VALUES,SCATTER_FORWARD);
 83:   VecScatterEnd(scatter->scatter,x,z,ADD_VALUES,SCATTER_FORWARD);
 84:   return(0);
 85: }

 89: PetscErrorCode MatMultTranspose_Scatter(Mat A,Vec x,Vec y)
 90: {
 91:   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;

 95:   if (!scatter->scatter) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
 96:   VecZeroEntries(y);
 97:   VecScatterBegin(scatter->scatter,x,y,ADD_VALUES,SCATTER_REVERSE);
 98:   VecScatterEnd(scatter->scatter,x,y,ADD_VALUES,SCATTER_REVERSE);
 99:   return(0);
100: }

104: PetscErrorCode MatMultTransposeAdd_Scatter(Mat A,Vec x,Vec y,Vec z)
105: {
106:   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;

110:   if (!scatter->scatter) SETERRQ(PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
111:   if (z != y) {VecCopy(y,z);}
112:   VecScatterBegin(scatter->scatter,x,z,ADD_VALUES,SCATTER_REVERSE);
113:   VecScatterEnd(scatter->scatter,x,z,ADD_VALUES,SCATTER_REVERSE);
114:   return(0);
115: }

117: static struct _MatOps MatOps_Values = {0,
118:                                        0,
119:                                        0,
120:                                        MatMult_Scatter,
121:                                /*  4*/ MatMultAdd_Scatter,
122:                                        MatMultTranspose_Scatter,
123:                                        MatMultTransposeAdd_Scatter,
124:                                        0,
125:                                        0,
126:                                        0,
127:                                /* 10*/ 0,
128:                                        0,
129:                                        0,
130:                                        0,
131:                                        0,
132:                                /* 15*/ 0,
133:                                        0,
134:                                        0,
135:                                        0,
136:                                        0,
137:                                /* 20*/ 0,
138:                                        0,
139:                                        0,
140:                                        0,
141:                                /* 24*/ 0,
142:                                        0,
143:                                        0,
144:                                        0,
145:                                        0,
146:                                /* 29*/ 0,
147:                                        0,
148:                                        0,
149:                                        0,
150:                                        0,
151:                                /* 34*/ 0,
152:                                        0,
153:                                        0,
154:                                        0,
155:                                        0,
156:                                /* 39*/ 0,
157:                                        0,
158:                                        0,
159:                                        0,
160:                                        0,
161:                                /* 44*/ 0,
162:                                        0,
163:                                        0,
164:                                        0,
165:                                        0,
166:                                /* 49*/ 0,
167:                                        0,
168:                                        0,
169:                                        0,
170:                                        0,
171:                                /* 54*/ 0,
172:                                        0,
173:                                        0,
174:                                        0,
175:                                        0,
176:                                /* 59*/ 0,
177:                                        MatDestroy_Scatter,
178:                                        0,
179:                                        0,
180:                                        0,
181:                                /* 64*/ 0,
182:                                        0,
183:                                        0,
184:                                        0,
185:                                        0,
186:                                /* 69*/ 0,
187:                                        0,
188:                                        0,
189:                                        0,
190:                                        0,
191:                                /* 74*/ 0,
192:                                        0,
193:                                        0,
194:                                        0,
195:                                        0,
196:                                /* 79*/ 0,
197:                                        0,
198:                                        0,
199:                                        0,
200:                                        0,
201:                                /* 84*/ 0,
202:                                        0,
203:                                        0,
204:                                        0,
205:                                        0,
206:                                /* 89*/ 0,
207:                                        0,
208:                                        0,
209:                                        0,
210:                                        0,
211:                                /* 94*/ 0,
212:                                        0,
213:                                        0,
214:                                        0,
215:                                        0,
216:                                 /*99*/ 0,
217:                                        0,
218:                                        0,
219:                                        0,
220:                                        0,
221:                                /*104*/ 0,
222:                                        0,
223:                                        0,
224:                                        0,
225:                                        0,
226:                                /*109*/ 0,
227:                                        0,
228:                                        0,
229:                                        0,
230:                                        0,
231:                                /*114*/ 0,
232:                                        0,
233:                                        0,
234:                                        0,
235:                                        0,
236:                                /*119*/ 0,
237:                                        0,
238:                                        0,
239:                                        0,
240:                                        0,
241:                                /*124*/ 0,
242:                                        0,
243:                                        0,
244:                                        0,
245:                                        0,
246:                                /*129*/ 0,
247:                                        0,
248:                                        0,
249:                                        0,
250:                                        0,
251:                                /*134*/ 0,
252:                                        0,
253:                                        0,
254:                                        0,
255:                                        0,
256:                                /*139*/ 0,
257:                                        0,
258:                                        0
259: };

261: /*MC
262:    MATSCATTER - MATSCATTER = "scatter" - A matrix type that simply applies a VecScatterBegin/End()

264:   Level: advanced

266: .seealso: MatCreateScatter(), MatScatterSetVecScatter(), MatScatterGetVecScatter()

268: M*/

272: PETSC_EXTERN PetscErrorCode MatCreate_Scatter(Mat A)
273: {
274:   Mat_Scatter    *b;

278:   PetscMemcpy(A->ops,&MatOps_Values,sizeof(struct _MatOps));
279:   PetscNewLog(A,&b);

281:   A->data = (void*)b;

283:   PetscLayoutSetUp(A->rmap);
284:   PetscLayoutSetUp(A->cmap);

286:   A->assembled    = PETSC_TRUE;
287:   A->preallocated = PETSC_FALSE;

289:   PetscObjectChangeTypeName((PetscObject)A,MATSCATTER);
290:   return(0);
291: }

295: /*@C
296:    MatCreateScatter - Creates a new matrix based on a VecScatter

298:   Collective on MPI_Comm

300:    Input Parameters:
301: +  comm - MPI communicator
302: -  scatter - a VecScatterContext

304:    Output Parameter:
305: .  A - the matrix

307:    Level: intermediate

309:    PETSc requires that matrices and vectors being used for certain
310:    operations are partitioned accordingly.  For example, when
311:    creating a scatter matrix, A, that supports parallel matrix-vector
312:    products using MatMult(A,x,y) the user should set the number
313:    of local matrix rows to be the number of local elements of the
314:    corresponding result vector, y. Note that this is information is
315:    required for use of the matrix interface routines, even though
316:    the scatter matrix may not actually be physically partitioned.

318: .keywords: matrix, scatter, create

320: .seealso: MatScatterSetVecScatter(), MatScatterGetVecScatter(), MATSCATTER
321: @*/
322: PetscErrorCode  MatCreateScatter(MPI_Comm comm,VecScatter scatter,Mat *A)
323: {

327:   MatCreate(comm,A);
328:   MatSetSizes(*A,scatter->to_n,scatter->from_n,PETSC_DETERMINE,PETSC_DETERMINE);
329:   MatSetType(*A,MATSCATTER);
330:   MatScatterSetVecScatter(*A,scatter);
331:   MatSetUp(*A);
332:   return(0);
333: }

337: /*@
338:     MatScatterSetVecScatter - sets that scatter that the matrix is to apply as its linear operator

340:    Collective on Mat

342:     Input Parameters:
343: +   mat - the scatter matrix
344: -   scatter - the scatter context create with VecScatterCreate()

346:    Level: advanced


349: .seealso: MatCreateScatter(), MATSCATTER
350: @*/
351: PetscErrorCode  MatScatterSetVecScatter(Mat mat,VecScatter scatter)
352: {
353:   Mat_Scatter    *mscatter = (Mat_Scatter*)mat->data;

360:   if (mat->rmap->n != scatter->to_n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number of local rows in matrix %D not equal local scatter size %D",mat->rmap->n,scatter->to_n);
361:   if (mat->cmap->n != scatter->from_n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Number of local columns in matrix %D not equal local scatter size %D",mat->cmap->n,scatter->from_n);

363:   PetscObjectReference((PetscObject)scatter);
364:   VecScatterDestroy(&mscatter->scatter);

366:   mscatter->scatter = scatter;
367:   return(0);
368: }