1 2 /* 3 Code for manipulating distributed regular arrays in parallel. 4 */ 5 6 #include <petsc/private/dmdaimpl.h> /*I "petscdmda.h" I*/ 7 8 /*@ 9 DMDAGetLogicalCoordinate - Returns a the i,j,k logical coordinate for the closest mesh point to a x,y,z point in the coordinates of the DMDA 10 11 Collective on da 12 13 Input Parameters: 14 + da - the distributed array 15 . x - the first physical coordinate 16 . y - the second physical coordinate 17 - z - the third physical coordinate 18 19 Output Parameters: 20 + II - the first logical coordinate (-1 on processes that do not contain that point) 21 . JJ - the second logical coordinate (-1 on processes that do not contain that point) 22 . KK - the third logical coordinate (-1 on processes that do not contain that point) 23 . X - (optional) the first coordinate of the located grid point 24 . Y - (optional) the second coordinate of the located grid point 25 - Z - (optional) the third coordinate of the located grid point 26 27 Level: advanced 28 29 Notes: 30 All processors that share the DMDA must call this with the same coordinate value 31 32 @*/ 33 PetscErrorCode DMDAGetLogicalCoordinate(DM da, PetscScalar x, PetscScalar y, PetscScalar z, PetscInt *II, PetscInt *JJ, PetscInt *KK, PetscScalar *X, PetscScalar *Y, PetscScalar *Z) 34 { 35 Vec coors; 36 DM dacoors; 37 DMDACoor2d **c; 38 PetscInt i, j, xs, xm, ys, ym; 39 PetscReal d, D = PETSC_MAX_REAL, Dv; 40 PetscMPIInt rank, root; 41 42 PetscFunctionBegin; 43 PetscCheck(da->dim != 1, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Cannot get point from 1d DMDA"); 44 PetscCheck(da->dim != 3, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Cannot get point from 3d DMDA"); 45 46 *II = -1; 47 *JJ = -1; 48 49 PetscCall(DMGetCoordinateDM(da, &dacoors)); 50 PetscCall(DMDAGetCorners(dacoors, &xs, &ys, NULL, &xm, &ym, NULL)); 51 PetscCall(DMGetCoordinates(da, &coors)); 52 PetscCall(DMDAVecGetArrayRead(dacoors, coors, &c)); 53 for (j = ys; j < ys + ym; j++) { 54 for (i = xs; i < xs + xm; i++) { 55 d = PetscSqrtReal(PetscRealPart((c[j][i].x - x) * (c[j][i].x - x) + (c[j][i].y - y) * (c[j][i].y - y))); 56 if (d < D) { 57 D = d; 58 *II = i; 59 *JJ = j; 60 } 61 } 62 } 63 PetscCall(MPIU_Allreduce(&D, &Dv, 1, MPIU_REAL, MPIU_MIN, PetscObjectComm((PetscObject)da))); 64 if (D != Dv) { 65 *II = -1; 66 *JJ = -1; 67 rank = 0; 68 } else { 69 *X = c[*JJ][*II].x; 70 *Y = c[*JJ][*II].y; 71 PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)da), &rank)); 72 rank++; 73 } 74 PetscCall(MPIU_Allreduce(&rank, &root, 1, MPI_INT, MPI_SUM, PetscObjectComm((PetscObject)da))); 75 root--; 76 PetscCallMPI(MPI_Bcast(X, 1, MPIU_SCALAR, root, PetscObjectComm((PetscObject)da))); 77 PetscCallMPI(MPI_Bcast(Y, 1, MPIU_SCALAR, root, PetscObjectComm((PetscObject)da))); 78 PetscCall(DMDAVecRestoreArrayRead(dacoors, coors, &c)); 79 PetscFunctionReturn(0); 80 } 81 82 /*@ 83 DMDAGetRay - Returns a vector on process zero that contains a row or column of the values in a DMDA vector 84 85 Collective on DMDA 86 87 Input Parameters: 88 + da - the distributed array 89 . dir - Cartesian direction, either DM_X, DM_Y, or DM_Z 90 - gp - global grid point number in this direction 91 92 Output Parameters: 93 + newvec - the new vector that can hold the values (size zero on all processes except process 0) 94 - scatter - the VecScatter that will map from the original vector to the slice 95 96 Level: advanced 97 98 Notes: 99 All processors that share the DMDA must call this with the same gp value 100 101 @*/ 102 PetscErrorCode DMDAGetRay(DM da, DMDirection dir, PetscInt gp, Vec *newvec, VecScatter *scatter) 103 { 104 PetscMPIInt rank; 105 DM_DA *dd = (DM_DA *)da->data; 106 IS is; 107 AO ao; 108 Vec vec; 109 PetscInt *indices, i, j; 110 111 PetscFunctionBegin; 112 PetscCheck(da->dim != 3, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Cannot get slice from 3d DMDA"); 113 PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)da), &rank)); 114 PetscCall(DMDAGetAO(da, &ao)); 115 if (rank == 0) { 116 if (da->dim == 1) { 117 if (dir == DM_X) { 118 PetscCall(PetscMalloc1(dd->w, &indices)); 119 indices[0] = dd->w * gp; 120 for (i = 1; i < dd->w; ++i) indices[i] = indices[i - 1] + 1; 121 PetscCall(AOApplicationToPetsc(ao, dd->w, indices)); 122 PetscCall(VecCreate(PETSC_COMM_SELF, newvec)); 123 PetscCall(VecSetBlockSize(*newvec, dd->w)); 124 PetscCall(VecSetSizes(*newvec, dd->w, PETSC_DETERMINE)); 125 PetscCall(VecSetType(*newvec, VECSEQ)); 126 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, dd->w, indices, PETSC_OWN_POINTER, &is)); 127 } else { 128 PetscCheck(dir != DM_Y, PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Cannot get Y slice from 1d DMDA"); 129 SETERRQ(PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Unknown DMDirection"); 130 } 131 } else { 132 if (dir == DM_Y) { 133 PetscCall(PetscMalloc1(dd->w * dd->M, &indices)); 134 indices[0] = gp * dd->M * dd->w; 135 for (i = 1; i < dd->M * dd->w; i++) indices[i] = indices[i - 1] + 1; 136 137 PetscCall(AOApplicationToPetsc(ao, dd->M * dd->w, indices)); 138 PetscCall(VecCreate(PETSC_COMM_SELF, newvec)); 139 PetscCall(VecSetBlockSize(*newvec, dd->w)); 140 PetscCall(VecSetSizes(*newvec, dd->M * dd->w, PETSC_DETERMINE)); 141 PetscCall(VecSetType(*newvec, VECSEQ)); 142 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, dd->w * dd->M, indices, PETSC_OWN_POINTER, &is)); 143 } else if (dir == DM_X) { 144 PetscCall(PetscMalloc1(dd->w * dd->N, &indices)); 145 indices[0] = dd->w * gp; 146 for (j = 1; j < dd->w; j++) indices[j] = indices[j - 1] + 1; 147 for (i = 1; i < dd->N; i++) { 148 indices[i * dd->w] = indices[i * dd->w - 1] + dd->w * dd->M - dd->w + 1; 149 for (j = 1; j < dd->w; j++) indices[i * dd->w + j] = indices[i * dd->w + j - 1] + 1; 150 } 151 PetscCall(AOApplicationToPetsc(ao, dd->w * dd->N, indices)); 152 PetscCall(VecCreate(PETSC_COMM_SELF, newvec)); 153 PetscCall(VecSetBlockSize(*newvec, dd->w)); 154 PetscCall(VecSetSizes(*newvec, dd->N * dd->w, PETSC_DETERMINE)); 155 PetscCall(VecSetType(*newvec, VECSEQ)); 156 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, dd->w * dd->N, indices, PETSC_OWN_POINTER, &is)); 157 } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Unknown DMDirection"); 158 } 159 } else { 160 PetscCall(VecCreateSeq(PETSC_COMM_SELF, 0, newvec)); 161 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, 0, NULL, PETSC_COPY_VALUES, &is)); 162 } 163 PetscCall(DMGetGlobalVector(da, &vec)); 164 PetscCall(VecScatterCreate(vec, is, *newvec, NULL, scatter)); 165 PetscCall(DMRestoreGlobalVector(da, &vec)); 166 PetscCall(ISDestroy(&is)); 167 PetscFunctionReturn(0); 168 } 169 170 /*@C 171 DMDAGetProcessorSubset - Returns a communicator consisting only of the 172 processors in a DMDA that own a particular global x, y, or z grid point 173 (corresponding to a logical plane in a 3D grid or a line in a 2D grid). 174 175 Collective on da 176 177 Input Parameters: 178 + da - the distributed array 179 . dir - Cartesian direction, either DM_X, DM_Y, or DM_Z 180 - gp - global grid point number in this direction 181 182 Output Parameter: 183 . comm - new communicator 184 185 Level: advanced 186 187 Notes: 188 All processors that share the DMDA must call this with the same gp value 189 190 After use, comm should be freed with MPI_Comm_free() 191 192 This routine is particularly useful to compute boundary conditions 193 or other application-specific calculations that require manipulating 194 sets of data throughout a logical plane of grid points. 195 196 Not supported from Fortran 197 198 @*/ 199 PetscErrorCode DMDAGetProcessorSubset(DM da, DMDirection dir, PetscInt gp, MPI_Comm *comm) 200 { 201 MPI_Group group, subgroup; 202 PetscInt i, ict, flag, *owners, xs, xm, ys, ym, zs, zm; 203 PetscMPIInt size, *ranks = NULL; 204 DM_DA *dd = (DM_DA *)da->data; 205 206 PetscFunctionBegin; 207 PetscValidHeaderSpecificType(da, DM_CLASSID, 1, DMDA); 208 flag = 0; 209 PetscCall(DMDAGetCorners(da, &xs, &ys, &zs, &xm, &ym, &zm)); 210 PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)da), &size)); 211 if (dir == DM_Z) { 212 PetscCheck(da->dim >= 3, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "DM_Z invalid for DMDA dim < 3"); 213 PetscCheck(gp >= 0 && gp <= dd->P, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "invalid grid point"); 214 if (gp >= zs && gp < zs + zm) flag = 1; 215 } else if (dir == DM_Y) { 216 PetscCheck(da->dim != 1, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "DM_Y invalid for DMDA dim = 1"); 217 PetscCheck(gp >= 0 && gp <= dd->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "invalid grid point"); 218 if (gp >= ys && gp < ys + ym) flag = 1; 219 } else if (dir == DM_X) { 220 PetscCheck(gp >= 0 && gp <= dd->M, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "invalid grid point"); 221 if (gp >= xs && gp < xs + xm) flag = 1; 222 } else SETERRQ(PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Invalid direction"); 223 224 PetscCall(PetscMalloc2(size, &owners, size, &ranks)); 225 PetscCallMPI(MPI_Allgather(&flag, 1, MPIU_INT, owners, 1, MPIU_INT, PetscObjectComm((PetscObject)da))); 226 ict = 0; 227 PetscCall(PetscInfo(da, "DMDAGetProcessorSubset: dim=%" PetscInt_FMT ", direction=%d, procs: ", da->dim, (int)dir)); 228 for (i = 0; i < size; i++) { 229 if (owners[i]) { 230 ranks[ict] = i; 231 ict++; 232 PetscCall(PetscInfo(da, "%" PetscInt_FMT " ", i)); 233 } 234 } 235 PetscCall(PetscInfo(da, "\n")); 236 PetscCallMPI(MPI_Comm_group(PetscObjectComm((PetscObject)da), &group)); 237 PetscCallMPI(MPI_Group_incl(group, ict, ranks, &subgroup)); 238 PetscCallMPI(MPI_Comm_create(PetscObjectComm((PetscObject)da), subgroup, comm)); 239 PetscCallMPI(MPI_Group_free(&subgroup)); 240 PetscCallMPI(MPI_Group_free(&group)); 241 PetscCall(PetscFree2(owners, ranks)); 242 PetscFunctionReturn(0); 243 } 244 245 /*@C 246 DMDAGetProcessorSubsets - Returns communicators consisting only of the 247 processors in a DMDA adjacent in a particular dimension, 248 corresponding to a logical plane in a 3D grid or a line in a 2D grid. 249 250 Collective on da 251 252 Input Parameters: 253 + da - the distributed array 254 - dir - Cartesian direction, either DM_X, DM_Y, or DM_Z 255 256 Output Parameter: 257 . subcomm - new communicator 258 259 Level: advanced 260 261 Notes: 262 This routine is useful for distributing one-dimensional data in a tensor product grid. 263 264 After use, comm should be freed with MPI_Comm_free() 265 266 Not supported from Fortran 267 268 @*/ 269 PetscErrorCode DMDAGetProcessorSubsets(DM da, DMDirection dir, MPI_Comm *subcomm) 270 { 271 MPI_Comm comm; 272 MPI_Group group, subgroup; 273 PetscInt subgroupSize = 0; 274 PetscInt *firstPoints; 275 PetscMPIInt size, *subgroupRanks = NULL; 276 PetscInt xs, xm, ys, ym, zs, zm, firstPoint, p; 277 278 PetscFunctionBegin; 279 PetscValidHeaderSpecificType(da, DM_CLASSID, 1, DMDA); 280 PetscCall(PetscObjectGetComm((PetscObject)da, &comm)); 281 PetscCall(DMDAGetCorners(da, &xs, &ys, &zs, &xm, &ym, &zm)); 282 PetscCallMPI(MPI_Comm_size(comm, &size)); 283 if (dir == DM_Z) { 284 PetscCheck(da->dim >= 3, comm, PETSC_ERR_ARG_OUTOFRANGE, "DM_Z invalid for DMDA dim < 3"); 285 firstPoint = zs; 286 } else if (dir == DM_Y) { 287 PetscCheck(da->dim != 1, comm, PETSC_ERR_ARG_OUTOFRANGE, "DM_Y invalid for DMDA dim = 1"); 288 firstPoint = ys; 289 } else if (dir == DM_X) { 290 firstPoint = xs; 291 } else SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Invalid direction"); 292 293 PetscCall(PetscMalloc2(size, &firstPoints, size, &subgroupRanks)); 294 PetscCallMPI(MPI_Allgather(&firstPoint, 1, MPIU_INT, firstPoints, 1, MPIU_INT, comm)); 295 PetscCall(PetscInfo(da, "DMDAGetProcessorSubset: dim=%" PetscInt_FMT ", direction=%d, procs: ", da->dim, (int)dir)); 296 for (p = 0; p < size; ++p) { 297 if (firstPoints[p] == firstPoint) { 298 subgroupRanks[subgroupSize++] = p; 299 PetscCall(PetscInfo(da, "%" PetscInt_FMT " ", p)); 300 } 301 } 302 PetscCall(PetscInfo(da, "\n")); 303 PetscCallMPI(MPI_Comm_group(comm, &group)); 304 PetscCallMPI(MPI_Group_incl(group, subgroupSize, subgroupRanks, &subgroup)); 305 PetscCallMPI(MPI_Comm_create(comm, subgroup, subcomm)); 306 PetscCallMPI(MPI_Group_free(&subgroup)); 307 PetscCallMPI(MPI_Group_free(&group)); 308 PetscCall(PetscFree2(firstPoints, subgroupRanks)); 309 PetscFunctionReturn(0); 310 } 311