1 2 /* 3 Code for manipulating distributed regular arrays in parallel. 4 */ 5 6 #include <private/daimpl.h> /*I "petscdmda.h" I*/ 7 8 #undef __FUNCT__ 9 #define __FUNCT__ "DMDAGetGlobalIndices" 10 /*@C 11 DMDAGetGlobalIndices - Returns the global node number of all local nodes, 12 including ghost nodes. 13 14 Not Collective 15 16 Input Parameter: 17 . da - the distributed array 18 19 Output Parameters: 20 + n - the number of local elements, including ghost nodes (or PETSC_NULL) 21 - idx - the global indices 22 23 Level: intermediate 24 25 Note: 26 For DMDA_STENCIL_STAR stencils the inactive corner ghost nodes are also included 27 in the list of local indices (even though those nodes are not updated 28 during calls to DMDAXXXToXXX(). 29 30 Essentially the same data is returned in the form of a local-to-global mapping 31 with the routine DMDAGetISLocalToGlobalMapping(); 32 33 Fortran Note: 34 This routine is used differently from Fortran 35 .vb 36 DM da 37 integer n,da_array(1) 38 PetscOffset i_da 39 integer ierr 40 call DMDAGetGlobalIndices(da,n,da_array,i_da,ierr) 41 42 C Access first local entry in list 43 value = da_array(i_da + 1) 44 .ve 45 46 See the <A href="../../docs/manual.pdf#nameddest=ch_fortran">Fortran chapter</A> of the users manual for details. 47 48 .keywords: distributed array, get, global, indices, local-to-global 49 50 .seealso: DMDACreate2d(), DMDAGetGhostCorners(), DMDAGetCorners(), DMLocalToGlobalBegin() 51 DMGlobalToLocalBegin(), DMGlobalToLocalEnd(), DMDALocalToLocalBegin(), DMDAGetAO(), DMDAGetGlobalIndicesF90() 52 DMDAGetISLocalToGlobalMapping(), DMDACreate3d(), DMDACreate1d(), DMDALocalToLocalEnd(), DMDAGetOwnershipRanges() 53 @*/ 54 PetscErrorCode DMDAGetGlobalIndices(DM da,PetscInt *n,PetscInt **idx) 55 { 56 DM_DA *dd = (DM_DA*)da->data; 57 58 PetscFunctionBegin; 59 PetscValidHeaderSpecific(da,DM_CLASSID,1); 60 if (n) *n = dd->Nl; 61 if (idx) *idx = dd->idx; 62 PetscFunctionReturn(0); 63 } 64 65 #undef __FUNCT__ 66 #define __FUNCT__ "DMDAGetNatural_Private" 67 /* 68 Gets the natural number for each global number on the process. 69 70 Used by DMDAGetAO() and DMDAGlobalToNatural_Create() 71 */ 72 PetscErrorCode DMDAGetNatural_Private(DM da,PetscInt *outNlocal,IS *isnatural) 73 { 74 PetscErrorCode ierr; 75 PetscInt Nlocal,i,j,k,*lidx,lict = 0; 76 DM_DA *dd = (DM_DA*)da->data; 77 78 PetscFunctionBegin; 79 Nlocal = (dd->xe-dd->xs); 80 if (dd->dim > 1) { 81 Nlocal *= (dd->ye-dd->ys); 82 } 83 if (dd->dim > 2) { 84 Nlocal *= (dd->ze-dd->zs); 85 } 86 87 ierr = PetscMalloc(Nlocal*sizeof(PetscInt),&lidx);CHKERRQ(ierr); 88 89 if (dd->dim == 1) { 90 for (i=dd->xs; i<dd->xe; i++) { 91 /* global number in natural ordering */ 92 lidx[lict++] = i; 93 } 94 } else if (dd->dim == 2) { 95 for (j=dd->ys; j<dd->ye; j++) { 96 for (i=dd->xs; i<dd->xe; i++) { 97 /* global number in natural ordering */ 98 lidx[lict++] = i + j*dd->M*dd->w; 99 } 100 } 101 } else if (dd->dim == 3) { 102 for (k=dd->zs; k<dd->ze; k++) { 103 for (j=dd->ys; j<dd->ye; j++) { 104 for (i=dd->xs; i<dd->xe; i++) { 105 lidx[lict++] = i + j*dd->M*dd->w + k*dd->M*dd->N*dd->w; 106 } 107 } 108 } 109 } 110 *outNlocal = Nlocal; 111 ierr = ISCreateGeneral(((PetscObject)da)->comm,Nlocal,lidx,PETSC_OWN_POINTER,isnatural);CHKERRQ(ierr); 112 PetscFunctionReturn(0); 113 } 114 115 #undef __FUNCT__ 116 #define __FUNCT__ "DMDAGetAO" 117 /*@ 118 DMDAGetAO - Gets the application ordering context for a distributed array. 119 120 Collective on DMDA 121 122 Input Parameter: 123 . da - the distributed array 124 125 Output Parameters: 126 . ao - the application ordering context for DMDAs 127 128 Level: intermediate 129 130 Notes: 131 In this case, the AO maps to the natural grid ordering that would be used 132 for the DMDA if only 1 processor were employed (ordering most rapidly in the 133 x-direction, then y, then z). Multiple degrees of freedom are numbered 134 for each node (rather than 1 component for the whole grid, then the next 135 component, etc.) 136 137 .keywords: distributed array, get, global, indices, local-to-global 138 139 .seealso: DMDACreate2d(), DMDAGetGhostCorners(), DMDAGetCorners(), DMDALocalToGlocal() 140 DMGlobalToLocalBegin(), DMGlobalToLocalEnd(), DMDALocalToLocalBegin(), DMDALocalToLocalEnd(), DMDAGetGlobalIndices(), DMDAGetOwnershipRanges(), 141 AO, AOPetscToApplication(), AOApplicationToPetsc() 142 @*/ 143 PetscErrorCode DMDAGetAO(DM da,AO *ao) 144 { 145 DM_DA *dd = (DM_DA*)da->data; 146 147 PetscFunctionBegin; 148 PetscValidHeaderSpecific(da,DM_CLASSID,1); 149 PetscValidPointer(ao,2); 150 151 /* 152 Build the natural ordering to PETSc ordering mappings. 153 */ 154 if (!dd->ao) { 155 IS ispetsc,isnatural; 156 PetscErrorCode ierr; 157 PetscInt Nlocal; 158 159 ierr = DMDAGetNatural_Private(da,&Nlocal,&isnatural);CHKERRQ(ierr); 160 ierr = ISCreateStride(((PetscObject)da)->comm,Nlocal,dd->base,1,&ispetsc);CHKERRQ(ierr); 161 ierr = AOCreateBasicIS(isnatural,ispetsc,&dd->ao);CHKERRQ(ierr); 162 ierr = PetscLogObjectParent(da,dd->ao);CHKERRQ(ierr); 163 ierr = ISDestroy(&ispetsc);CHKERRQ(ierr); 164 ierr = ISDestroy(&isnatural);CHKERRQ(ierr); 165 } 166 *ao = dd->ao; 167 PetscFunctionReturn(0); 168 } 169 170 /*MC 171 DMDAGetGlobalIndicesF90 - Returns a Fortran90 pointer to the list of 172 global indices (global node number of all local nodes, including 173 ghost nodes). 174 175 Synopsis: 176 DMDAGetGlobalIndicesF90(DM da,integer n,{integer, pointer :: idx(:)},integer ierr) 177 178 Not Collective 179 180 Input Parameter: 181 . da - the distributed array 182 183 Output Parameters: 184 + n - the number of local elements, including ghost nodes (or PETSC_NULL) 185 . idx - the Fortran90 pointer to the global indices 186 - ierr - error code 187 188 Level: intermediate 189 190 Notes: 191 Not yet supported for all F90 compilers 192 193 .keywords: distributed array, get, global, indices, local-to-global, f90 194 195 .seealso: DMDAGetGlobalIndices() 196 M*/ 197