Actual source code: ex37.c
1: static char help[] = "Test MatGetMultiProcBlock() and MatCreateRedundantMatrix() \n\
2: Reads a PETSc matrix and vector from a file and solves a linear system.\n\n";
3: /*
4: Example:
5: mpiexec -n 4 ./ex37 -f <input_file> -nsubcomm 2 -psubcomm_view -subcomm_type <1 or 2>
6: */
8: #include <petscksp.h>
9: #include <petscsys.h>
11: int main(int argc, char **args)
12: {
13: KSP subksp;
14: Mat A, subA;
15: Vec x, b, u, subb, subx, subu;
16: PetscViewer fd;
17: char file[PETSC_MAX_PATH_LEN];
18: PetscBool flg;
19: PetscInt i, m, n, its;
20: PetscReal norm;
21: PetscMPIInt rank, size;
22: MPI_Comm comm, subcomm;
23: PetscSubcomm psubcomm;
24: PetscInt nsubcomm = 1, id;
25: PetscScalar *barray, *xarray, *uarray, *array, one = 1.0;
26: PetscInt type = 1;
28: PetscFunctionBeginUser;
29: PetscCall(PetscInitialize(&argc, &args, NULL, help));
30: /* Load the matrix */
31: PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg));
32: PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER_INPUT, "Must indicate binary file with the -f option");
33: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
35: /* Load the matrix; then destroy the viewer.*/
36: PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
37: PetscCall(MatLoad(A, fd));
38: PetscCall(PetscViewerDestroy(&fd));
40: PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
41: PetscCallMPI(MPI_Comm_size(comm, &size));
42: PetscCallMPI(MPI_Comm_rank(comm, &rank));
44: /* Create rhs vector b */
45: PetscCall(MatGetLocalSize(A, &m, NULL));
46: PetscCall(VecCreate(PETSC_COMM_WORLD, &b));
47: PetscCall(VecSetSizes(b, m, PETSC_DECIDE));
48: PetscCall(VecSetFromOptions(b));
49: PetscCall(VecSet(b, one));
51: PetscCall(VecDuplicate(b, &x));
52: PetscCall(VecDuplicate(b, &u));
54: /* Test MatGetMultiProcBlock() */
55: PetscCall(PetscOptionsGetInt(NULL, NULL, "-nsubcomm", &nsubcomm, NULL));
56: PetscCall(PetscOptionsGetInt(NULL, NULL, "-subcomm_type", &type, NULL));
58: PetscCall(PetscSubcommCreate(comm, &psubcomm));
59: PetscCall(PetscSubcommSetNumber(psubcomm, nsubcomm));
60: if (type == PETSC_SUBCOMM_GENERAL) { /* user provides color, subrank and duprank */
61: PetscMPIInt color, subrank, duprank, subsize;
62: duprank = size - 1 - rank;
63: subsize = size / nsubcomm;
64: PetscCheck(subsize * nsubcomm == size, comm, PETSC_ERR_SUP, "This example requires nsubcomm %" PetscInt_FMT " divides size %d", nsubcomm, size);
65: color = duprank / subsize;
66: subrank = duprank - color * subsize;
67: PetscCall(PetscSubcommSetTypeGeneral(psubcomm, color, subrank));
68: } else if (type == PETSC_SUBCOMM_CONTIGUOUS) {
69: PetscCall(PetscSubcommSetType(psubcomm, PETSC_SUBCOMM_CONTIGUOUS));
70: } else if (type == PETSC_SUBCOMM_INTERLACED) {
71: PetscCall(PetscSubcommSetType(psubcomm, PETSC_SUBCOMM_INTERLACED));
72: } else SETERRQ(psubcomm->parent, PETSC_ERR_SUP, "PetscSubcommType %" PetscInt_FMT " is not supported yet", type);
73: PetscCall(PetscSubcommSetFromOptions(psubcomm));
74: subcomm = PetscSubcommChild(psubcomm);
76: /* Test MatCreateRedundantMatrix() */
77: if (size > 1) {
78: PetscMPIInt subrank = -1, color = -1;
79: MPI_Comm dcomm;
81: if (rank == 0) {
82: color = 0;
83: subrank = 0;
84: } else if (rank == 1) {
85: color = 0;
86: subrank = 1;
87: } else {
88: color = 1;
89: subrank = 0;
90: }
92: PetscCall(PetscCommDuplicate(PETSC_COMM_WORLD, &dcomm, NULL));
93: PetscCallMPI(MPI_Comm_split(dcomm, color, subrank, &subcomm));
95: PetscCall(MatCreate(subcomm, &subA));
96: PetscCall(MatSetSizes(subA, PETSC_DECIDE, PETSC_DECIDE, 10, 10));
97: PetscCall(MatSetFromOptions(subA));
98: PetscCall(MatSetUp(subA));
99: PetscCall(MatAssemblyBegin(subA, MAT_FINAL_ASSEMBLY));
100: PetscCall(MatAssemblyEnd(subA, MAT_FINAL_ASSEMBLY));
101: PetscCall(MatZeroEntries(subA));
103: /* Test MatMult() */
104: PetscCall(MatCreateVecs(subA, &subx, &subb));
105: PetscCall(VecSet(subx, 1.0));
106: PetscCall(MatMult(subA, subx, subb));
108: PetscCall(VecDestroy(&subx));
109: PetscCall(VecDestroy(&subb));
110: PetscCall(MatDestroy(&subA));
111: PetscCall(PetscCommDestroy(&dcomm));
112: }
114: /* Create subA */
115: PetscCall(MatGetMultiProcBlock(A, subcomm, MAT_INITIAL_MATRIX, &subA));
116: PetscCall(MatGetMultiProcBlock(A, subcomm, MAT_REUSE_MATRIX, &subA));
118: /* Create sub vectors without arrays. Place b's and x's local arrays into subb and subx */
119: PetscCall(MatGetLocalSize(subA, &m, &n));
120: PetscCall(VecCreateMPIWithArray(subcomm, 1, m, PETSC_DECIDE, NULL, &subb));
121: PetscCall(VecCreateMPIWithArray(subcomm, 1, n, PETSC_DECIDE, NULL, &subx));
122: PetscCall(VecCreateMPIWithArray(subcomm, 1, n, PETSC_DECIDE, NULL, &subu));
124: PetscCall(VecGetArray(b, &barray));
125: PetscCall(VecGetArray(x, &xarray));
126: PetscCall(VecGetArray(u, &uarray));
127: PetscCall(VecPlaceArray(subb, barray));
128: PetscCall(VecPlaceArray(subx, xarray));
129: PetscCall(VecPlaceArray(subu, uarray));
131: /* Create linear solvers associated with subA */
132: PetscCall(KSPCreate(subcomm, &subksp));
133: PetscCall(KSPSetOperators(subksp, subA, subA));
134: PetscCall(KSPSetFromOptions(subksp));
136: /* Solve sub systems */
137: PetscCall(KSPSolve(subksp, subb, subx));
138: PetscCall(KSPGetIterationNumber(subksp, &its));
140: /* check residual */
141: PetscCall(MatMult(subA, subx, subu));
142: PetscCall(VecAXPY(subu, -1.0, subb));
143: PetscCall(VecNorm(u, NORM_2, &norm));
144: if (norm > 1.e-4 && rank == 0) {
145: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "[%d] Number of iterations = %3" PetscInt_FMT "\n", rank, its));
146: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Error: Residual norm of each block |subb - subA*subx |= %g\n", (double)norm));
147: }
148: PetscCall(VecResetArray(subb));
149: PetscCall(VecResetArray(subx));
150: PetscCall(VecResetArray(subu));
152: PetscCall(PetscOptionsGetInt(NULL, NULL, "-subvec_view", &id, &flg));
153: if (flg && rank == id) {
154: PetscCall(PetscPrintf(PETSC_COMM_SELF, "[%d] subb:\n", rank));
155: PetscCall(VecGetArray(subb, &array));
156: for (i = 0; i < m; i++) PetscCall(PetscPrintf(PETSC_COMM_SELF, "%g\n", (double)PetscRealPart(array[i])));
157: PetscCall(VecRestoreArray(subb, &array));
158: PetscCall(PetscPrintf(PETSC_COMM_SELF, "[%d] subx:\n", rank));
159: PetscCall(VecGetArray(subx, &array));
160: for (i = 0; i < m; i++) PetscCall(PetscPrintf(PETSC_COMM_SELF, "%g\n", (double)PetscRealPart(array[i])));
161: PetscCall(VecRestoreArray(subx, &array));
162: }
164: PetscCall(VecRestoreArray(x, &xarray));
165: PetscCall(VecRestoreArray(b, &barray));
166: PetscCall(VecRestoreArray(u, &uarray));
167: PetscCall(MatDestroy(&subA));
168: PetscCall(VecDestroy(&subb));
169: PetscCall(VecDestroy(&subx));
170: PetscCall(VecDestroy(&subu));
171: PetscCall(KSPDestroy(&subksp));
172: PetscCall(PetscSubcommDestroy(&psubcomm));
173: if (size > 1) PetscCallMPI(MPI_Comm_free(&subcomm));
174: PetscCall(MatDestroy(&A));
175: PetscCall(VecDestroy(&b));
176: PetscCall(VecDestroy(&u));
177: PetscCall(VecDestroy(&x));
179: PetscCall(PetscFinalize());
180: return 0;
181: }
183: /*TEST
185: test:
186: args: -f ${DATAFILESPATH}/matrices/small -nsubcomm 1
187: requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
188: output_file: output/empty.out
190: test:
191: suffix: 2
192: args: -f ${DATAFILESPATH}/matrices/small -nsubcomm 2
193: requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
194: nsize: 4
195: output_file: output/empty.out
197: test:
198: suffix: mumps
199: args: -f ${DATAFILESPATH}/matrices/small -nsubcomm 2 -pc_factor_mat_solver_type mumps -pc_type lu
200: requires: datafilespath mumps !complex double !defined(PETSC_USE_64BIT_INDICES)
201: nsize: 4
202: output_file: output/empty.out
204: test:
205: suffix: 3
206: nsize: 4
207: args: -f ${DATAFILESPATH}/matrices/small -nsubcomm 2 -subcomm_type 0
208: requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
209: output_file: output/empty.out
211: test:
212: suffix: 4
213: nsize: 4
214: args: -f ${DATAFILESPATH}/matrices/small -nsubcomm 2 -subcomm_type 1
215: requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
216: output_file: output/empty.out
218: test:
219: suffix: 5
220: nsize: 4
221: args: -f ${DATAFILESPATH}/matrices/small -nsubcomm 2 -subcomm_type 2
222: requires: datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
223: output_file: output/empty.out
225: TEST*/