1 2 /* 3 Tools to help solve the coarse grid problem redundantly. 4 Provides two scatter contexts that (1) map from the usual global vector 5 to all processors the entire vector in NATURAL numbering and (2) 6 from the entire vector on each processor in natural numbering extracts 7 out this processors piece in GLOBAL numbering 8 */ 9 10 #include <petsc/private/dmdaimpl.h> /*I "petscdmda.h" I*/ 11 12 /*@ 13 DMDAGlobalToNaturalAllCreate - Creates a scatter context that maps from the 14 global vector the entire vector to each processor in natural numbering 15 16 Collective on da 17 18 Input Parameter: 19 . da - the distributed array context 20 21 Output Parameter: 22 . scatter - the scatter context 23 24 Level: advanced 25 26 .seealso: DMDAGlobalToNaturalEnd(), DMLocalToGlobalBegin(), DMDACreate2d(), 27 DMGlobalToLocalBegin(), DMGlobalToLocalEnd(), DMDACreateNaturalVector() 28 @*/ 29 PetscErrorCode DMDAGlobalToNaturalAllCreate(DM da,VecScatter *scatter) 30 { 31 PetscErrorCode ierr; 32 PetscInt N; 33 IS from,to; 34 Vec tmplocal,global; 35 AO ao; 36 DM_DA *dd = (DM_DA*)da->data; 37 38 PetscFunctionBegin; 39 PetscValidHeaderSpecificType(da,DM_CLASSID,1,DMDA); 40 PetscValidPointer(scatter,2); 41 ierr = DMDAGetAO(da,&ao);CHKERRQ(ierr); 42 43 /* create the scatter context */ 44 ierr = VecCreateMPIWithArray(PetscObjectComm((PetscObject)da),dd->w,dd->Nlocal,PETSC_DETERMINE,NULL,&global);CHKERRQ(ierr); 45 ierr = VecGetSize(global,&N);CHKERRQ(ierr); 46 ierr = ISCreateStride(PetscObjectComm((PetscObject)da),N,0,1,&to);CHKERRQ(ierr); 47 ierr = AOPetscToApplicationIS(ao,to);CHKERRQ(ierr); 48 ierr = ISCreateStride(PetscObjectComm((PetscObject)da),N,0,1,&from);CHKERRQ(ierr); 49 ierr = VecCreateSeqWithArray(PETSC_COMM_SELF,dd->w,N,NULL,&tmplocal);CHKERRQ(ierr); 50 ierr = VecScatterCreate(global,from,tmplocal,to,scatter);CHKERRQ(ierr); 51 ierr = VecDestroy(&tmplocal);CHKERRQ(ierr); 52 ierr = VecDestroy(&global);CHKERRQ(ierr); 53 ierr = ISDestroy(&from);CHKERRQ(ierr); 54 ierr = ISDestroy(&to);CHKERRQ(ierr); 55 PetscFunctionReturn(0); 56 } 57 58 /*@ 59 DMDANaturalAllToGlobalCreate - Creates a scatter context that maps from a copy 60 of the entire vector on each processor to its local part in the global vector. 61 62 Collective on da 63 64 Input Parameter: 65 . da - the distributed array context 66 67 Output Parameter: 68 . scatter - the scatter context 69 70 Level: advanced 71 72 .seealso: DMDAGlobalToNaturalEnd(), DMLocalToGlobalBegin(), DMDACreate2d(), 73 DMGlobalToLocalBegin(), DMGlobalToLocalEnd(), DMDACreateNaturalVector() 74 @*/ 75 PetscErrorCode DMDANaturalAllToGlobalCreate(DM da,VecScatter *scatter) 76 { 77 PetscErrorCode ierr; 78 DM_DA *dd = (DM_DA*)da->data; 79 PetscInt M,m = dd->Nlocal,start; 80 IS from,to; 81 Vec tmplocal,global; 82 AO ao; 83 84 PetscFunctionBegin; 85 PetscValidHeaderSpecificType(da,DM_CLASSID,1,DMDA); 86 PetscValidPointer(scatter,2); 87 ierr = DMDAGetAO(da,&ao);CHKERRQ(ierr); 88 89 /* create the scatter context */ 90 ierr = MPIU_Allreduce(&m,&M,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)da));CHKERRMPI(ierr); 91 ierr = VecCreateMPIWithArray(PetscObjectComm((PetscObject)da),dd->w,m,PETSC_DETERMINE,NULL,&global);CHKERRQ(ierr); 92 ierr = VecGetOwnershipRange(global,&start,NULL);CHKERRQ(ierr); 93 ierr = ISCreateStride(PetscObjectComm((PetscObject)da),m,start,1,&from);CHKERRQ(ierr); 94 ierr = AOPetscToApplicationIS(ao,from);CHKERRQ(ierr); 95 ierr = ISCreateStride(PetscObjectComm((PetscObject)da),m,start,1,&to);CHKERRQ(ierr); 96 ierr = VecCreateSeqWithArray(PETSC_COMM_SELF,dd->w,M,NULL,&tmplocal);CHKERRQ(ierr); 97 ierr = VecScatterCreate(tmplocal,from,global,to,scatter);CHKERRQ(ierr); 98 ierr = VecDestroy(&tmplocal);CHKERRQ(ierr); 99 ierr = VecDestroy(&global);CHKERRQ(ierr); 100 ierr = ISDestroy(&from);CHKERRQ(ierr); 101 ierr = ISDestroy(&to);CHKERRQ(ierr); 102 PetscFunctionReturn(0); 103 } 104 105