xref: /petsc/src/mat/impls/scatter/mscatter.c (revision 2c71b3e237ead271e4f3aa1505f92bf476e3413d)
12a6744ebSBarry Smith 
22a6744ebSBarry Smith /*
32a6744ebSBarry Smith    This provides a matrix that applies a VecScatter to a vector.
42a6744ebSBarry Smith */
52a6744ebSBarry Smith 
6af0996ceSBarry Smith #include <petsc/private/matimpl.h>        /*I "petscmat.h" I*/
7af0996ceSBarry Smith #include <petsc/private/vecimpl.h>
82a6744ebSBarry Smith 
92a6744ebSBarry Smith typedef struct {
102a6744ebSBarry Smith   VecScatter scatter;
112a6744ebSBarry Smith } Mat_Scatter;
122a6744ebSBarry Smith 
132a6744ebSBarry Smith /*@
142a6744ebSBarry Smith     MatScatterGetVecScatter - Returns the user-provided scatter set with MatScatterSetVecScatter()
152a6744ebSBarry Smith 
162a6744ebSBarry Smith     Not Collective, but not cannot use scatter if not used collectively on Mat
172a6744ebSBarry Smith 
182a6744ebSBarry Smith     Input Parameter:
192a6744ebSBarry Smith .   mat - the matrix, should have been created with MatCreateScatter() or have type MATSCATTER
202a6744ebSBarry Smith 
212a6744ebSBarry Smith     Output Parameter:
222a6744ebSBarry Smith .   scatter - the scatter context
232a6744ebSBarry Smith 
242a6744ebSBarry Smith     Level: intermediate
252a6744ebSBarry Smith 
262a6744ebSBarry Smith .seealso: MatCreateScatter(), MatScatterSetVecScatter(), MATSCATTER
272a6744ebSBarry Smith @*/
287087cfbeSBarry Smith PetscErrorCode  MatScatterGetVecScatter(Mat mat,VecScatter *scatter)
292a6744ebSBarry Smith {
302a6744ebSBarry Smith   Mat_Scatter *mscatter;
312a6744ebSBarry Smith 
322a6744ebSBarry Smith   PetscFunctionBegin;
330700a824SBarry Smith   PetscValidHeaderSpecific(mat,MAT_CLASSID,1);
342a6744ebSBarry Smith   PetscValidPointer(scatter,2);
352a6744ebSBarry Smith   mscatter = (Mat_Scatter*)mat->data;
362a6744ebSBarry Smith   *scatter = mscatter->scatter;
372a6744ebSBarry Smith   PetscFunctionReturn(0);
382a6744ebSBarry Smith }
392a6744ebSBarry Smith 
402a6744ebSBarry Smith PetscErrorCode MatDestroy_Scatter(Mat mat)
412a6744ebSBarry Smith {
422a6744ebSBarry Smith   PetscErrorCode ierr;
432a6744ebSBarry Smith   Mat_Scatter    *scatter = (Mat_Scatter*)mat->data;
442a6744ebSBarry Smith 
452a6744ebSBarry Smith   PetscFunctionBegin;
466bf464f9SBarry Smith   ierr = VecScatterDestroy(&scatter->scatter);CHKERRQ(ierr);
476bf464f9SBarry Smith   ierr = PetscFree(mat->data);CHKERRQ(ierr);
482a6744ebSBarry Smith   PetscFunctionReturn(0);
492a6744ebSBarry Smith }
502a6744ebSBarry Smith 
512a6744ebSBarry Smith PetscErrorCode MatMult_Scatter(Mat A,Vec x,Vec y)
522a6744ebSBarry Smith {
532a6744ebSBarry Smith   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
542a6744ebSBarry Smith   PetscErrorCode ierr;
552a6744ebSBarry Smith 
562a6744ebSBarry Smith   PetscFunctionBegin;
57*2c71b3e2SJacob Faibussowitsch   PetscCheckFalse(!scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
5874d95942SJed Brown   ierr = VecZeroEntries(y);CHKERRQ(ierr);
5974d95942SJed Brown   ierr = VecScatterBegin(scatter->scatter,x,y,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
6074d95942SJed Brown   ierr = VecScatterEnd(scatter->scatter,x,y,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
612a6744ebSBarry Smith   PetscFunctionReturn(0);
622a6744ebSBarry Smith }
632a6744ebSBarry Smith 
642a6744ebSBarry Smith PetscErrorCode MatMultAdd_Scatter(Mat A,Vec x,Vec y,Vec z)
652a6744ebSBarry Smith {
662a6744ebSBarry Smith   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
672a6744ebSBarry Smith   PetscErrorCode ierr;
682a6744ebSBarry Smith 
692a6744ebSBarry Smith   PetscFunctionBegin;
70*2c71b3e2SJacob Faibussowitsch   PetscCheckFalse(!scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
712a6744ebSBarry Smith   if (z != y) {ierr = VecCopy(y,z);CHKERRQ(ierr);}
72ca9f406cSSatish Balay   ierr = VecScatterBegin(scatter->scatter,x,z,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
73ca9f406cSSatish Balay   ierr = VecScatterEnd(scatter->scatter,x,z,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
742a6744ebSBarry Smith   PetscFunctionReturn(0);
752a6744ebSBarry Smith }
762a6744ebSBarry Smith 
772a6744ebSBarry Smith PetscErrorCode MatMultTranspose_Scatter(Mat A,Vec x,Vec y)
782a6744ebSBarry Smith {
792a6744ebSBarry Smith   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
802a6744ebSBarry Smith   PetscErrorCode ierr;
812a6744ebSBarry Smith 
822a6744ebSBarry Smith   PetscFunctionBegin;
83*2c71b3e2SJacob Faibussowitsch   PetscCheckFalse(!scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
8474d95942SJed Brown   ierr = VecZeroEntries(y);CHKERRQ(ierr);
8574d95942SJed Brown   ierr = VecScatterBegin(scatter->scatter,x,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
8674d95942SJed Brown   ierr = VecScatterEnd(scatter->scatter,x,y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
872a6744ebSBarry Smith   PetscFunctionReturn(0);
882a6744ebSBarry Smith }
892a6744ebSBarry Smith 
902a6744ebSBarry Smith PetscErrorCode MatMultTransposeAdd_Scatter(Mat A,Vec x,Vec y,Vec z)
912a6744ebSBarry Smith {
922a6744ebSBarry Smith   Mat_Scatter    *scatter = (Mat_Scatter*)A->data;
932a6744ebSBarry Smith   PetscErrorCode ierr;
942a6744ebSBarry Smith 
952a6744ebSBarry Smith   PetscFunctionBegin;
96*2c71b3e2SJacob Faibussowitsch   PetscCheckFalse(!scatter->scatter,PetscObjectComm((PetscObject)A),PETSC_ERR_ARG_WRONGSTATE,"Need to first call MatScatterSetScatter()");
972a6744ebSBarry Smith   if (z != y) {ierr = VecCopy(y,z);CHKERRQ(ierr);}
98ca9f406cSSatish Balay   ierr = VecScatterBegin(scatter->scatter,x,z,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
99ca9f406cSSatish Balay   ierr = VecScatterEnd(scatter->scatter,x,z,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
1002a6744ebSBarry Smith   PetscFunctionReturn(0);
1012a6744ebSBarry Smith }
1022a6744ebSBarry Smith 
103f4259b30SLisandro Dalcin static struct _MatOps MatOps_Values = {NULL,
104f4259b30SLisandro Dalcin                                        NULL,
105f4259b30SLisandro Dalcin                                        NULL,
1062a6744ebSBarry Smith                                        MatMult_Scatter,
1072a6744ebSBarry Smith                                /*  4*/ MatMultAdd_Scatter,
1082a6744ebSBarry Smith                                        MatMultTranspose_Scatter,
1092a6744ebSBarry Smith                                        MatMultTransposeAdd_Scatter,
110f4259b30SLisandro Dalcin                                        NULL,
111f4259b30SLisandro Dalcin                                        NULL,
112f4259b30SLisandro Dalcin                                        NULL,
113f4259b30SLisandro Dalcin                                /* 10*/ NULL,
114f4259b30SLisandro Dalcin                                        NULL,
115f4259b30SLisandro Dalcin                                        NULL,
116f4259b30SLisandro Dalcin                                        NULL,
117f4259b30SLisandro Dalcin                                        NULL,
118f4259b30SLisandro Dalcin                                /* 15*/ NULL,
119f4259b30SLisandro Dalcin                                        NULL,
120f4259b30SLisandro Dalcin                                        NULL,
121f4259b30SLisandro Dalcin                                        NULL,
122f4259b30SLisandro Dalcin                                        NULL,
123f4259b30SLisandro Dalcin                                /* 20*/ NULL,
124f4259b30SLisandro Dalcin                                        NULL,
125f4259b30SLisandro Dalcin                                        NULL,
126f4259b30SLisandro Dalcin                                        NULL,
127f4259b30SLisandro Dalcin                                /* 24*/ NULL,
128f4259b30SLisandro Dalcin                                        NULL,
129f4259b30SLisandro Dalcin                                        NULL,
130f4259b30SLisandro Dalcin                                        NULL,
131f4259b30SLisandro Dalcin                                        NULL,
132f4259b30SLisandro Dalcin                                /* 29*/ NULL,
133f4259b30SLisandro Dalcin                                        NULL,
134f4259b30SLisandro Dalcin                                        NULL,
135f4259b30SLisandro Dalcin                                        NULL,
136f4259b30SLisandro Dalcin                                        NULL,
137f4259b30SLisandro Dalcin                                /* 34*/ NULL,
138f4259b30SLisandro Dalcin                                        NULL,
139f4259b30SLisandro Dalcin                                        NULL,
140f4259b30SLisandro Dalcin                                        NULL,
141f4259b30SLisandro Dalcin                                        NULL,
142f4259b30SLisandro Dalcin                                /* 39*/ NULL,
143f4259b30SLisandro Dalcin                                        NULL,
144f4259b30SLisandro Dalcin                                        NULL,
145f4259b30SLisandro Dalcin                                        NULL,
146f4259b30SLisandro Dalcin                                        NULL,
147f4259b30SLisandro Dalcin                                /* 44*/ NULL,
148f4259b30SLisandro Dalcin                                        NULL,
1497d68702bSBarry Smith                                        MatShift_Basic,
150f4259b30SLisandro Dalcin                                        NULL,
151f4259b30SLisandro Dalcin                                        NULL,
152f4259b30SLisandro Dalcin                                /* 49*/ NULL,
153f4259b30SLisandro Dalcin                                        NULL,
154f4259b30SLisandro Dalcin                                        NULL,
155f4259b30SLisandro Dalcin                                        NULL,
156f4259b30SLisandro Dalcin                                        NULL,
157f4259b30SLisandro Dalcin                                /* 54*/ NULL,
158f4259b30SLisandro Dalcin                                        NULL,
159f4259b30SLisandro Dalcin                                        NULL,
160f4259b30SLisandro Dalcin                                        NULL,
161f4259b30SLisandro Dalcin                                        NULL,
162f4259b30SLisandro Dalcin                                /* 59*/ NULL,
1632a6744ebSBarry Smith                                        MatDestroy_Scatter,
164f4259b30SLisandro Dalcin                                        NULL,
165f4259b30SLisandro Dalcin                                        NULL,
166f4259b30SLisandro Dalcin                                        NULL,
167f4259b30SLisandro Dalcin                                /* 64*/ NULL,
168f4259b30SLisandro Dalcin                                        NULL,
169f4259b30SLisandro Dalcin                                        NULL,
170f4259b30SLisandro Dalcin                                        NULL,
171f4259b30SLisandro Dalcin                                        NULL,
172f4259b30SLisandro Dalcin                                /* 69*/ NULL,
173f4259b30SLisandro Dalcin                                        NULL,
174f4259b30SLisandro Dalcin                                        NULL,
175f4259b30SLisandro Dalcin                                        NULL,
176f4259b30SLisandro Dalcin                                        NULL,
177f4259b30SLisandro Dalcin                                /* 74*/ NULL,
178f4259b30SLisandro Dalcin                                        NULL,
179f4259b30SLisandro Dalcin                                        NULL,
180f4259b30SLisandro Dalcin                                        NULL,
181f4259b30SLisandro Dalcin                                        NULL,
182f4259b30SLisandro Dalcin                                /* 79*/ NULL,
183f4259b30SLisandro Dalcin                                        NULL,
184f4259b30SLisandro Dalcin                                        NULL,
185f4259b30SLisandro Dalcin                                        NULL,
186f4259b30SLisandro Dalcin                                        NULL,
187f4259b30SLisandro Dalcin                                /* 84*/ NULL,
188f4259b30SLisandro Dalcin                                        NULL,
189f4259b30SLisandro Dalcin                                        NULL,
190f4259b30SLisandro Dalcin                                        NULL,
191f4259b30SLisandro Dalcin                                        NULL,
192f4259b30SLisandro Dalcin                                /* 89*/ NULL,
193f4259b30SLisandro Dalcin                                        NULL,
194f4259b30SLisandro Dalcin                                        NULL,
195f4259b30SLisandro Dalcin                                        NULL,
196f4259b30SLisandro Dalcin                                        NULL,
197f4259b30SLisandro Dalcin                                /* 94*/ NULL,
198f4259b30SLisandro Dalcin                                        NULL,
199f4259b30SLisandro Dalcin                                        NULL,
200f4259b30SLisandro Dalcin                                        NULL,
201f4259b30SLisandro Dalcin                                        NULL,
202f4259b30SLisandro Dalcin                                 /*99*/ NULL,
203f4259b30SLisandro Dalcin                                        NULL,
204f4259b30SLisandro Dalcin                                        NULL,
205f4259b30SLisandro Dalcin                                        NULL,
206f4259b30SLisandro Dalcin                                        NULL,
207f4259b30SLisandro Dalcin                                /*104*/ NULL,
208f4259b30SLisandro Dalcin                                        NULL,
209f4259b30SLisandro Dalcin                                        NULL,
210f4259b30SLisandro Dalcin                                        NULL,
211f4259b30SLisandro Dalcin                                        NULL,
212f4259b30SLisandro Dalcin                                /*109*/ NULL,
213f4259b30SLisandro Dalcin                                        NULL,
214f4259b30SLisandro Dalcin                                        NULL,
215f4259b30SLisandro Dalcin                                        NULL,
216f4259b30SLisandro Dalcin                                        NULL,
217f4259b30SLisandro Dalcin                                /*114*/ NULL,
218f4259b30SLisandro Dalcin                                        NULL,
219f4259b30SLisandro Dalcin                                        NULL,
220f4259b30SLisandro Dalcin                                        NULL,
221f4259b30SLisandro Dalcin                                        NULL,
222f4259b30SLisandro Dalcin                                /*119*/ NULL,
223f4259b30SLisandro Dalcin                                        NULL,
224f4259b30SLisandro Dalcin                                        NULL,
225f4259b30SLisandro Dalcin                                        NULL,
226f4259b30SLisandro Dalcin                                        NULL,
227f4259b30SLisandro Dalcin                                /*124*/ NULL,
228f4259b30SLisandro Dalcin                                        NULL,
229f4259b30SLisandro Dalcin                                        NULL,
230f4259b30SLisandro Dalcin                                        NULL,
231f4259b30SLisandro Dalcin                                        NULL,
232f4259b30SLisandro Dalcin                                /*129*/ NULL,
233f4259b30SLisandro Dalcin                                        NULL,
234f4259b30SLisandro Dalcin                                        NULL,
235f4259b30SLisandro Dalcin                                        NULL,
236f4259b30SLisandro Dalcin                                        NULL,
237f4259b30SLisandro Dalcin                                /*134*/ NULL,
238f4259b30SLisandro Dalcin                                        NULL,
239f4259b30SLisandro Dalcin                                        NULL,
240f4259b30SLisandro Dalcin                                        NULL,
241f4259b30SLisandro Dalcin                                        NULL,
242f4259b30SLisandro Dalcin                                /*139*/ NULL,
243f4259b30SLisandro Dalcin                                        NULL,
244f4259b30SLisandro Dalcin                                        NULL
2453964eb88SJed Brown };
2462a6744ebSBarry Smith 
2472a6744ebSBarry Smith /*MC
2484a440b9bSBarry Smith    MATSCATTER - MATSCATTER = "scatter" - A matrix type that simply applies a VecScatterBegin/End()
2492a6744ebSBarry Smith 
2502a6744ebSBarry Smith   Level: advanced
2512a6744ebSBarry Smith 
2522a6744ebSBarry Smith .seealso: MatCreateScatter(), MatScatterSetVecScatter(), MatScatterGetVecScatter()
2532a6744ebSBarry Smith 
2542a6744ebSBarry Smith M*/
2552a6744ebSBarry Smith 
2568cc058d9SJed Brown PETSC_EXTERN PetscErrorCode MatCreate_Scatter(Mat A)
2572a6744ebSBarry Smith {
2582a6744ebSBarry Smith   Mat_Scatter    *b;
2592a6744ebSBarry Smith   PetscErrorCode ierr;
2602a6744ebSBarry Smith 
2612a6744ebSBarry Smith   PetscFunctionBegin;
2622a6744ebSBarry Smith   ierr = PetscMemcpy(A->ops,&MatOps_Values,sizeof(struct _MatOps));CHKERRQ(ierr);
263b00a9115SJed Brown   ierr = PetscNewLog(A,&b);CHKERRQ(ierr);
2642a6744ebSBarry Smith 
2652a6744ebSBarry Smith   A->data = (void*)b;
2662a6744ebSBarry Smith 
26726283091SBarry Smith   ierr = PetscLayoutSetUp(A->rmap);CHKERRQ(ierr);
26826283091SBarry Smith   ierr = PetscLayoutSetUp(A->cmap);CHKERRQ(ierr);
2692a6744ebSBarry Smith 
2702a6744ebSBarry Smith   A->assembled    = PETSC_TRUE;
2712a6744ebSBarry Smith   A->preallocated = PETSC_FALSE;
27274d95942SJed Brown 
27374d95942SJed Brown   ierr = PetscObjectChangeTypeName((PetscObject)A,MATSCATTER);CHKERRQ(ierr);
2742a6744ebSBarry Smith   PetscFunctionReturn(0);
2752a6744ebSBarry Smith }
2762a6744ebSBarry Smith 
27797929ea7SJunchao Zhang #include <petsc/private/sfimpl.h>
2782a6744ebSBarry Smith /*@C
2792a6744ebSBarry Smith    MatCreateScatter - Creates a new matrix based on a VecScatter
2802a6744ebSBarry Smith 
281d083f849SBarry Smith   Collective
2822a6744ebSBarry Smith 
2832a6744ebSBarry Smith    Input Parameters:
2842a6744ebSBarry Smith +  comm - MPI communicator
2852a6744ebSBarry Smith -  scatter - a VecScatterContext
2862a6744ebSBarry Smith 
2872a6744ebSBarry Smith    Output Parameter:
2882a6744ebSBarry Smith .  A - the matrix
2892a6744ebSBarry Smith 
2902a6744ebSBarry Smith    Level: intermediate
2912a6744ebSBarry Smith 
2922a6744ebSBarry Smith    PETSc requires that matrices and vectors being used for certain
2932a6744ebSBarry Smith    operations are partitioned accordingly.  For example, when
2942a6744ebSBarry Smith    creating a scatter matrix, A, that supports parallel matrix-vector
2952a6744ebSBarry Smith    products using MatMult(A,x,y) the user should set the number
2962a6744ebSBarry Smith    of local matrix rows to be the number of local elements of the
2972a6744ebSBarry Smith    corresponding result vector, y. Note that this is information is
2982a6744ebSBarry Smith    required for use of the matrix interface routines, even though
2992a6744ebSBarry Smith    the scatter matrix may not actually be physically partitioned.
3002a6744ebSBarry Smith 
3016eb45d04SBarry Smith   Developer Notes: This directly accesses information inside the VecScatter associated with the matrix-vector product
3026eb45d04SBarry Smith    for this matrix. This is not desirable..
3036eb45d04SBarry Smith 
3042a6744ebSBarry Smith .seealso: MatScatterSetVecScatter(), MatScatterGetVecScatter(), MATSCATTER
3052a6744ebSBarry Smith @*/
3067087cfbeSBarry Smith PetscErrorCode  MatCreateScatter(MPI_Comm comm,VecScatter scatter,Mat *A)
3072a6744ebSBarry Smith {
3082a6744ebSBarry Smith   PetscErrorCode ierr;
3092a6744ebSBarry Smith 
3102a6744ebSBarry Smith   PetscFunctionBegin;
3112a6744ebSBarry Smith   ierr = MatCreate(comm,A);CHKERRQ(ierr);
31297929ea7SJunchao Zhang   ierr = MatSetSizes(*A,scatter->vscat.to_n,scatter->vscat.from_n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
3132a6744ebSBarry Smith   ierr = MatSetType(*A,MATSCATTER);CHKERRQ(ierr);
3142a6744ebSBarry Smith   ierr = MatScatterSetVecScatter(*A,scatter);CHKERRQ(ierr);
31537e1895aSJed Brown   ierr = MatSetUp(*A);CHKERRQ(ierr);
3162a6744ebSBarry Smith   PetscFunctionReturn(0);
3172a6744ebSBarry Smith }
3182a6744ebSBarry Smith 
3192a6744ebSBarry Smith /*@
3202a6744ebSBarry Smith     MatScatterSetVecScatter - sets that scatter that the matrix is to apply as its linear operator
3212a6744ebSBarry Smith 
3222a6744ebSBarry Smith    Collective on Mat
3232a6744ebSBarry Smith 
3242a6744ebSBarry Smith     Input Parameters:
3252a6744ebSBarry Smith +   mat - the scatter matrix
3269448b7f1SJunchao Zhang -   scatter - the scatter context create with VecScatterCreate()
3272a6744ebSBarry Smith 
3282a6744ebSBarry Smith    Level: advanced
3292a6744ebSBarry Smith 
3302a6744ebSBarry Smith .seealso: MatCreateScatter(), MATSCATTER
3312a6744ebSBarry Smith @*/
3327087cfbeSBarry Smith PetscErrorCode  MatScatterSetVecScatter(Mat mat,VecScatter scatter)
3332a6744ebSBarry Smith {
3342a6744ebSBarry Smith   Mat_Scatter    *mscatter = (Mat_Scatter*)mat->data;
3352a6744ebSBarry Smith   PetscErrorCode ierr;
3362a6744ebSBarry Smith 
3372a6744ebSBarry Smith   PetscFunctionBegin;
3380700a824SBarry Smith   PetscValidHeaderSpecific(mat,MAT_CLASSID,1);
33997929ea7SJunchao Zhang   PetscValidHeaderSpecific(scatter,PETSCSF_CLASSID,2);
340064a246eSJacob Faibussowitsch   PetscCheckSameComm((PetscObject)scatter,2,(PetscObject)mat,1);
341*2c71b3e2SJacob Faibussowitsch   PetscCheckFalse(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);
342*2c71b3e2SJacob Faibussowitsch   PetscCheckFalse(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);
3432a6744ebSBarry Smith 
344c3122656SLisandro Dalcin   ierr = PetscObjectReference((PetscObject)scatter);CHKERRQ(ierr);
3456bf464f9SBarry Smith   ierr = VecScatterDestroy(&mscatter->scatter);CHKERRQ(ierr);
34626fbe8dcSKarl Rupp 
3472a6744ebSBarry Smith   mscatter->scatter = scatter;
3482a6744ebSBarry Smith   PetscFunctionReturn(0);
3492a6744ebSBarry Smith }
3502a6744ebSBarry Smith 
351