Actual source code: dasub.c
petsc-3.7.5 2017-01-01
2: /*
3: Code for manipulating distributed regular arrays in parallel.
4: */
6: #include <petsc/private/dmdaimpl.h> /*I "petscdmda.h" I*/
10: /*@C
11: 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
13: Collective on DMDA
15: Input Parameters:
16: + da - the distributed array
17: - x,y,z - the physical coordinates
19: Output Parameters:
20: + II, JJ, KK - the logical coordinate (-1 on processes that do not contain that point)
21: - X, Y, Z, - (optional) the coordinates of the located grid point
23: Level: advanced
25: Notes:
26: All processors that share the DMDA must call this with the same coordinate value
28: .keywords: distributed array, get, processor subset
29: @*/
30: PetscErrorCode DMDAGetLogicalCoordinate(DM da,PetscScalar x,PetscScalar y,PetscScalar z,PetscInt *II,PetscInt *JJ,PetscInt *KK,PetscScalar *X,PetscScalar *Y,PetscScalar *Z)
31: {
33: Vec coors;
34: DM dacoors;
35: DMDACoor2d **c;
36: PetscInt i,j,xs,xm,ys,ym;
37: PetscReal d,D = PETSC_MAX_REAL,Dv;
38: PetscMPIInt rank,root;
41: if (da->dim == 1) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_SUP,"Cannot get point from 1d DMDA");
42: if (da->dim == 3) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_SUP,"Cannot get point from 3d DMDA");
44: *II = -1;
45: *JJ = -1;
47: DMGetCoordinateDM(da,&dacoors);
48: DMDAGetCorners(dacoors,&xs,&ys,NULL,&xm,&ym,NULL);
49: DMGetCoordinates(da,&coors);
50: DMDAVecGetArrayRead(dacoors,coors,&c);
51: for (j=ys; j<ys+ym; j++) {
52: for (i=xs; i<xs+xm; i++) {
53: d = PetscSqrtReal(PetscRealPart( (c[j][i].x - x)*(c[j][i].x - x) + (c[j][i].y - y)*(c[j][i].y - y) ));
54: if (d < D) {
55: D = d;
56: *II = i;
57: *JJ = j;
58: }
59: }
60: }
61: MPIU_Allreduce(&D,&Dv,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)da));
62: if (D != Dv) {
63: *II = -1;
64: *JJ = -1;
65: rank = 0;
66: } else {
67: *X = c[*JJ][*II].x;
68: *Y = c[*JJ][*II].y;
69: MPI_Comm_rank(PetscObjectComm((PetscObject)da),&rank);
70: rank++;
71: }
72: MPIU_Allreduce(&rank,&root,1,MPI_INT,MPI_SUM,PetscObjectComm((PetscObject)da));
73: root--;
74: MPI_Bcast(X,1,MPIU_SCALAR,root,PetscObjectComm((PetscObject)da));
75: MPI_Bcast(Y,1,MPIU_SCALAR,root,PetscObjectComm((PetscObject)da));
76: DMDAVecRestoreArrayRead(dacoors,coors,&c);
77: return(0);
78: }
82: /*@C
83: DMDAGetRay - Returns a vector on process zero that contains a row or column of the values in a DMDA vector
85: Collective on DMDA
87: Input Parameters:
88: + da - the distributed array
89: . vec - the vector
90: . dir - Cartesian direction, either DMDA_X, DMDA_Y, or DMDA_Z
91: - gp - global grid point number in this direction
93: Output Parameters:
94: + newvec - the new vector that can hold the values (size zero on all processes except process 0)
95: - scatter - the VecScatter that will map from the original vector to the slice
97: Level: advanced
99: Notes:
100: All processors that share the DMDA must call this with the same gp value
102: .keywords: distributed array, get, processor subset
103: @*/
104: PetscErrorCode DMDAGetRay(DM da,DMDADirection dir,PetscInt gp,Vec *newvec,VecScatter *scatter)
105: {
106: PetscMPIInt rank;
107: DM_DA *dd = (DM_DA*)da->data;
109: IS is;
110: AO ao;
111: Vec vec;
112: PetscInt *indices,i,j;
115: if (da->dim == 3) SETERRQ(PetscObjectComm((PetscObject) da), PETSC_ERR_SUP, "Cannot get slice from 3d DMDA");
116: MPI_Comm_rank(PetscObjectComm((PetscObject) da), &rank);
117: DMDAGetAO(da, &ao);
118: if (!rank) {
119: if (da->dim == 1) {
120: if (dir == DMDA_X) {
121: PetscMalloc1(dd->w, &indices);
122: indices[0] = dd->w*gp;
123: for (i = 1; i < dd->w; ++i) indices[i] = indices[i-1] + 1;
124: AOApplicationToPetsc(ao, dd->w, indices);
125: VecCreate(PETSC_COMM_SELF, newvec);
126: VecSetBlockSize(*newvec, dd->w);
127: VecSetSizes(*newvec, dd->w, PETSC_DETERMINE);
128: VecSetType(*newvec, VECSEQ);
129: ISCreateGeneral(PETSC_COMM_SELF, dd->w, indices, PETSC_OWN_POINTER, &is);
130: } else if (dir == DMDA_Y) SETERRQ(PetscObjectComm((PetscObject) da), PETSC_ERR_SUP, "Cannot get Y slice from 1d DMDA");
131: else SETERRQ(PetscObjectComm((PetscObject) da), PETSC_ERR_ARG_OUTOFRANGE, "Unknown DMDADirection");
132: } else {
133: if (dir == DMDA_Y) {
134: PetscMalloc1(dd->w*dd->M,&indices);
135: indices[0] = gp*dd->M*dd->w;
136: for (i=1; i<dd->M*dd->w; i++) indices[i] = indices[i-1] + 1;
138: AOApplicationToPetsc(ao,dd->M*dd->w,indices);
139: VecCreate(PETSC_COMM_SELF,newvec);
140: VecSetBlockSize(*newvec,dd->w);
141: VecSetSizes(*newvec,dd->M*dd->w,PETSC_DETERMINE);
142: VecSetType(*newvec,VECSEQ);
143: ISCreateGeneral(PETSC_COMM_SELF,dd->w*dd->M,indices,PETSC_OWN_POINTER,&is);
144: } else if (dir == DMDA_X) {
145: PetscMalloc1(dd->w*dd->N,&indices);
146: indices[0] = dd->w*gp;
147: for (j=1; j<dd->w; j++) indices[j] = indices[j-1] + 1;
148: for (i=1; i<dd->N; i++) {
149: indices[i*dd->w] = indices[i*dd->w-1] + dd->w*dd->M - dd->w + 1;
150: for (j=1; j<dd->w; j++) indices[i*dd->w + j] = indices[i*dd->w + j - 1] + 1;
151: }
152: AOApplicationToPetsc(ao,dd->w*dd->N,indices);
153: VecCreate(PETSC_COMM_SELF,newvec);
154: VecSetBlockSize(*newvec,dd->w);
155: VecSetSizes(*newvec,dd->N*dd->w,PETSC_DETERMINE);
156: VecSetType(*newvec,VECSEQ);
157: ISCreateGeneral(PETSC_COMM_SELF,dd->w*dd->N,indices,PETSC_OWN_POINTER,&is);
158: } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Unknown DMDADirection");
159: }
160: } else {
161: VecCreateSeq(PETSC_COMM_SELF, 0, newvec);
162: ISCreateGeneral(PETSC_COMM_SELF, 0, 0, PETSC_COPY_VALUES, &is);
163: }
164: DMGetGlobalVector(da, &vec);
165: VecScatterCreate(vec, is, *newvec, NULL, scatter);
166: DMRestoreGlobalVector(da, &vec);
167: ISDestroy(&is);
168: return(0);
169: }
173: /*@C
174: DMDAGetProcessorSubset - Returns a communicator consisting only of the
175: processors in a DMDA that own a particular global x, y, or z grid point
176: (corresponding to a logical plane in a 3D grid or a line in a 2D grid).
178: Collective on DMDA
180: Input Parameters:
181: + da - the distributed array
182: . dir - Cartesian direction, either DMDA_X, DMDA_Y, or DMDA_Z
183: - gp - global grid point number in this direction
185: Output Parameters:
186: . comm - new communicator
188: Level: advanced
190: Notes:
191: All processors that share the DMDA must call this with the same gp value
193: This routine is particularly useful to compute boundary conditions
194: or other application-specific calculations that require manipulating
195: sets of data throughout a logical plane of grid points.
197: .keywords: distributed array, get, processor subset
198: @*/
199: PetscErrorCode DMDAGetProcessorSubset(DM da,DMDADirection dir,PetscInt gp,MPI_Comm *comm)
200: {
201: MPI_Group group,subgroup;
203: PetscInt i,ict,flag,*owners,xs,xm,ys,ym,zs,zm;
204: PetscMPIInt size,*ranks = NULL;
205: DM_DA *dd = (DM_DA*)da->data;
209: flag = 0;
210: DMDAGetCorners(da,&xs,&ys,&zs,&xm,&ym,&zm);
211: MPI_Comm_size(PetscObjectComm((PetscObject)da),&size);
212: if (dir == DMDA_Z) {
213: if (da->dim < 3) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_OUTOFRANGE,"DMDA_Z invalid for DMDA dim < 3");
214: if (gp < 0 || gp > dd->P) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"invalid grid point");
215: if (gp >= zs && gp < zs+zm) flag = 1;
216: } else if (dir == DMDA_Y) {
217: if (da->dim == 1) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_OUTOFRANGE,"DMDA_Y invalid for DMDA dim = 1");
218: if (gp < 0 || gp > dd->N) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"invalid grid point");
219: if (gp >= ys && gp < ys+ym) flag = 1;
220: } else if (dir == DMDA_X) {
221: if (gp < 0 || gp > dd->M) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"invalid grid point");
222: if (gp >= xs && gp < xs+xm) flag = 1;
223: } else SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_OUTOFRANGE,"Invalid direction");
225: PetscMalloc2(size,&owners,size,&ranks);
226: MPI_Allgather(&flag,1,MPIU_INT,owners,1,MPIU_INT,PetscObjectComm((PetscObject)da));
227: ict = 0;
228: PetscInfo2(da,"DMDAGetProcessorSubset: dim=%D, direction=%d, procs: ",da->dim,(int)dir);
229: for (i=0; i<size; i++) {
230: if (owners[i]) {
231: ranks[ict] = i; ict++;
232: PetscInfo1(da,"%D ",i);
233: }
234: }
235: PetscInfo(da,"\n");
236: MPI_Comm_group(PetscObjectComm((PetscObject)da),&group);
237: MPI_Group_incl(group,ict,ranks,&subgroup);
238: MPI_Comm_create(PetscObjectComm((PetscObject)da),subgroup,comm);
239: MPI_Group_free(&subgroup);
240: MPI_Group_free(&group);
241: PetscFree2(owners,ranks);
242: return(0);
243: }
247: /*@C
248: DMDAGetProcessorSubsets - Returns communicators consisting only of the
249: processors in a DMDA adjacent in a particular dimension,
250: corresponding to a logical plane in a 3D grid or a line in a 2D grid.
252: Collective on DMDA
254: Input Parameters:
255: + da - the distributed array
256: - dir - Cartesian direction, either DMDA_X, DMDA_Y, or DMDA_Z
258: Output Parameters:
259: . subcomm - new communicator
261: Level: advanced
263: Notes:
264: This routine is useful for distributing one-dimensional data in a tensor product grid.
266: .keywords: distributed array, get, processor subset
267: @*/
268: PetscErrorCode DMDAGetProcessorSubsets(DM da, DMDADirection dir, MPI_Comm *subcomm)
269: {
270: MPI_Comm comm;
271: MPI_Group group, subgroup;
272: PetscInt subgroupSize = 0;
273: PetscInt *firstPoints;
274: PetscMPIInt size, *subgroupRanks = NULL;
275: PetscInt xs, xm, ys, ym, zs, zm, firstPoint, p;
280: PetscObjectGetComm((PetscObject)da,&comm);
281: DMDAGetCorners(da, &xs, &ys, &zs, &xm, &ym, &zm);
282: MPI_Comm_size(comm, &size);
283: if (dir == DMDA_Z) {
284: if (da->dim < 3) SETERRQ(comm,PETSC_ERR_ARG_OUTOFRANGE,"DMDA_Z invalid for DMDA dim < 3");
285: firstPoint = zs;
286: } else if (dir == DMDA_Y) {
287: if (da->dim == 1) SETERRQ(comm,PETSC_ERR_ARG_OUTOFRANGE,"DMDA_Y invalid for DMDA dim = 1");
288: firstPoint = ys;
289: } else if (dir == DMDA_X) {
290: firstPoint = xs;
291: } else SETERRQ(comm,PETSC_ERR_ARG_OUTOFRANGE,"Invalid direction");
293: PetscMalloc2(size, &firstPoints, size, &subgroupRanks);
294: MPI_Allgather(&firstPoint, 1, MPIU_INT, firstPoints, 1, MPIU_INT, comm);
295: PetscInfo2(da,"DMDAGetProcessorSubset: dim=%D, direction=%d, procs: ",da->dim,(int)dir);
296: for (p = 0; p < size; ++p) {
297: if (firstPoints[p] == firstPoint) {
298: subgroupRanks[subgroupSize++] = p;
299: PetscInfo1(da, "%D ", p);
300: }
301: }
302: PetscInfo(da, "\n");
303: MPI_Comm_group(comm, &group);
304: MPI_Group_incl(group, subgroupSize, subgroupRanks, &subgroup);
305: MPI_Comm_create(comm, subgroup, subcomm);
306: MPI_Group_free(&subgroup);
307: MPI_Group_free(&group);
308: PetscFree2(firstPoints, subgroupRanks);
309: return(0);
310: }