Actual source code: ex11.c
1: static const char help[] = "Solves a Q1-P0 Stokes problem from Underworld.\n\
2: \n\
3: You can obtain a sample matrix from http://ftp.mcs.anl.gov/pub/petsc/Datafiles/matrices/underworld32.gz\n\
4: and run with -f underworld32.gz\n\n";
6: #include <petscksp.h>
7: #include <petscdmda.h>
9: static PetscErrorCode replace_submats(Mat A, IS isu, IS isp)
10: {
11: Mat A11, A22, A12, A21;
12: Mat nA11, nA22, nA12, nA21;
13: const char *prefix;
15: PetscFunctionBeginUser;
16: PetscCall(MatCreateSubMatrix(A, isu, isu, MAT_INITIAL_MATRIX, &A11));
17: PetscCall(MatCreateSubMatrix(A, isu, isp, MAT_INITIAL_MATRIX, &A12));
18: PetscCall(MatCreateSubMatrix(A, isp, isu, MAT_INITIAL_MATRIX, &A21));
19: PetscCall(MatCreateSubMatrix(A, isp, isp, MAT_INITIAL_MATRIX, &A22));
20: PetscCall(MatDuplicate(A11, MAT_COPY_VALUES, &nA11));
21: PetscCall(MatDuplicate(A12, MAT_COPY_VALUES, &nA12));
22: PetscCall(MatDuplicate(A21, MAT_COPY_VALUES, &nA21));
23: PetscCall(MatDuplicate(A22, MAT_COPY_VALUES, &nA22));
24: PetscCall(MatGetOptionsPrefix(A11, &prefix));
25: PetscCall(MatSetOptionsPrefix(nA11, prefix));
26: PetscCall(MatGetOptionsPrefix(A22, &prefix));
27: PetscCall(MatSetOptionsPrefix(nA22, prefix));
28: PetscCall(MatNestSetSubMat(A, 0, 0, nA11));
29: PetscCall(MatNestSetSubMat(A, 0, 1, nA12));
30: PetscCall(MatNestSetSubMat(A, 1, 0, nA21));
31: PetscCall(MatNestSetSubMat(A, 1, 1, nA22));
32: PetscCall(MatDestroy(&A11));
33: PetscCall(MatDestroy(&A12));
34: PetscCall(MatDestroy(&A21));
35: PetscCall(MatDestroy(&A22));
36: PetscCall(MatDestroy(&nA11));
37: PetscCall(MatDestroy(&nA12));
38: PetscCall(MatDestroy(&nA21));
39: PetscCall(MatDestroy(&nA22));
40: PetscFunctionReturn(PETSC_SUCCESS);
41: }
43: PetscErrorCode LSCLoadTestOperators(Mat *A11, Mat *A12, Mat *A21, Mat *A22, Vec *b1, Vec *b2)
44: {
45: PetscViewer viewer;
46: char filename[PETSC_MAX_PATH_LEN];
47: PetscBool flg;
49: PetscFunctionBeginUser;
50: PetscCall(MatCreate(PETSC_COMM_WORLD, A11));
51: PetscCall(MatCreate(PETSC_COMM_WORLD, A12));
52: PetscCall(MatCreate(PETSC_COMM_WORLD, A21));
53: PetscCall(MatCreate(PETSC_COMM_WORLD, A22));
54: PetscCall(MatSetOptionsPrefix(*A11, "a11_"));
55: PetscCall(MatSetOptionsPrefix(*A22, "a22_"));
56: PetscCall(MatSetFromOptions(*A11));
57: PetscCall(MatSetFromOptions(*A22));
58: PetscCall(VecCreate(PETSC_COMM_WORLD, b1));
59: PetscCall(VecCreate(PETSC_COMM_WORLD, b2));
60: /* Load matrices from a Q1-P0 discretisation of variable viscosity Stokes. The matrix blocks are packed into one file. */
61: PetscCall(PetscOptionsGetString(NULL, NULL, "-f", filename, sizeof(filename), &flg));
62: PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must provide a matrix file with -f");
63: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, filename, FILE_MODE_READ, &viewer));
64: PetscCall(MatLoad(*A11, viewer));
65: PetscCall(MatLoad(*A12, viewer));
66: PetscCall(MatLoad(*A21, viewer));
67: PetscCall(MatLoad(*A22, viewer));
68: PetscCall(VecLoad(*b1, viewer));
69: PetscCall(VecLoad(*b2, viewer));
70: PetscCall(PetscViewerDestroy(&viewer));
71: PetscFunctionReturn(PETSC_SUCCESS);
72: }
74: PetscErrorCode LoadTestMatrices(Mat *_A, Vec *_x, Vec *_b, IS *_isu, IS *_isp)
75: {
76: Vec f, h, x, b, bX[2];
77: Mat A, Auu, Aup, Apu, App, bA[2][2];
78: IS is_u, is_p, bis[2];
79: PetscInt lnu, lnp, nu, np, i, start_u, end_u, start_p, end_p;
80: VecScatter *vscat;
81: PetscMPIInt rank;
83: PetscFunctionBeginUser;
84: /* fetch test matrices and vectors */
85: PetscCall(LSCLoadTestOperators(&Auu, &Aup, &Apu, &App, &f, &h));
87: /* build the mat-nest */
88: PetscCall(VecGetSize(f, &nu));
89: PetscCall(VecGetSize(h, &np));
91: PetscCall(VecGetLocalSize(f, &lnu));
92: PetscCall(VecGetLocalSize(h, &lnp));
94: PetscCall(VecGetOwnershipRange(f, &start_u, &end_u));
95: PetscCall(VecGetOwnershipRange(h, &start_p, &end_p));
97: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
98: PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "[%d] lnu = %" PetscInt_FMT " | lnp = %" PetscInt_FMT " \n", rank, lnu, lnp));
99: PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "[%d] s_u = %" PetscInt_FMT " | e_u = %" PetscInt_FMT " \n", rank, start_u, end_u));
100: PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "[%d] s_p = %" PetscInt_FMT " | e_p = %" PetscInt_FMT " \n", rank, start_p, end_p));
101: PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "[%d] is_u (offset) = %" PetscInt_FMT " \n", rank, start_u + start_p));
102: PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "[%d] is_p (offset) = %" PetscInt_FMT " \n", rank, start_u + start_p + lnu));
103: PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));
105: PetscCall(ISCreateStride(PETSC_COMM_WORLD, lnu, start_u + start_p, 1, &is_u));
106: PetscCall(ISCreateStride(PETSC_COMM_WORLD, lnp, start_u + start_p + lnu, 1, &is_p));
108: bis[0] = is_u;
109: bis[1] = is_p;
110: bA[0][0] = Auu;
111: bA[0][1] = Aup;
112: bA[1][0] = Apu;
113: bA[1][1] = App;
114: PetscCall(MatCreateNest(PETSC_COMM_WORLD, 2, bis, 2, bis, &bA[0][0], &A));
115: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
116: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
118: /* Pull f,h into b */
119: PetscCall(MatCreateVecs(A, &b, &x));
120: bX[0] = f;
121: bX[1] = h;
122: PetscCall(PetscMalloc1(2, &vscat));
123: for (i = 0; i < 2; i++) {
124: PetscCall(VecScatterCreate(b, bis[i], bX[i], NULL, &vscat[i]));
125: PetscCall(VecScatterBegin(vscat[i], bX[i], b, INSERT_VALUES, SCATTER_REVERSE));
126: PetscCall(VecScatterEnd(vscat[i], bX[i], b, INSERT_VALUES, SCATTER_REVERSE));
127: PetscCall(VecScatterDestroy(&vscat[i]));
128: }
130: PetscCall(PetscFree(vscat));
131: PetscCall(MatDestroy(&Auu));
132: PetscCall(MatDestroy(&Aup));
133: PetscCall(MatDestroy(&Apu));
134: PetscCall(MatDestroy(&App));
135: PetscCall(VecDestroy(&f));
136: PetscCall(VecDestroy(&h));
138: *_isu = is_u;
139: *_isp = is_p;
140: *_A = A;
141: *_x = x;
142: *_b = b;
143: PetscFunctionReturn(PETSC_SUCCESS);
144: }
146: PetscErrorCode port_lsd_bfbt(void)
147: {
148: Mat A, P;
149: Vec x, b;
150: KSP ksp_A;
151: PC pc_A;
152: IS isu, isp;
153: PetscBool test_fs = PETSC_FALSE;
155: PetscFunctionBeginUser;
156: PetscCall(LoadTestMatrices(&A, &x, &b, &isu, &isp));
157: PetscCall(PetscOptionsGetBool(NULL, NULL, "-test_fs", &test_fs, NULL));
158: if (!test_fs) {
159: PetscCall(PetscObjectReference((PetscObject)A));
160: P = A;
161: } else {
162: PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &P));
163: }
164: PetscCall(KSPCreate(PETSC_COMM_WORLD, &ksp_A));
165: PetscCall(KSPSetOptionsPrefix(ksp_A, "fc_"));
166: PetscCall(KSPSetOperators(ksp_A, A, P));
168: PetscCall(KSPSetFromOptions(ksp_A));
169: PetscCall(KSPGetPC(ksp_A, &pc_A));
170: PetscCall(PetscObjectTypeCompare((PetscObject)pc_A, PCLU, &test_fs));
171: if (test_fs) {
172: PetscCall(MatDestroy(&P));
173: PetscCall(MatConvert(A, MATAIJ, MAT_INITIAL_MATRIX, &P));
174: PetscCall(KSPSetOperators(ksp_A, A, P));
175: PetscCall(KSPSetFromOptions(ksp_A));
176: PetscCall(KSPSolve(ksp_A, b, x));
177: } else {
178: PetscCall(PCFieldSplitSetBlockSize(pc_A, 2));
179: PetscCall(PCFieldSplitSetIS(pc_A, "velocity", isu));
180: PetscCall(PCFieldSplitSetIS(pc_A, "pressure", isp));
181: PetscCall(KSPSolve(ksp_A, b, x));
183: /* Pull u,p out of x */
184: {
185: PetscInt loc;
186: PetscReal max, norm;
187: PetscScalar sum;
188: Vec uvec, pvec;
189: VecScatter uscat, pscat;
190: Mat A11, A22;
192: /* grab matrices and create the compatible u,p vectors */
193: PetscCall(MatCreateSubMatrix(A, isu, isu, MAT_INITIAL_MATRIX, &A11));
194: PetscCall(MatCreateSubMatrix(A, isp, isp, MAT_INITIAL_MATRIX, &A22));
196: PetscCall(MatCreateVecs(A11, &uvec, NULL));
197: PetscCall(MatCreateVecs(A22, &pvec, NULL));
199: /* perform the scatter from x -> (u,p) */
200: PetscCall(VecScatterCreate(x, isu, uvec, NULL, &uscat));
201: PetscCall(VecScatterBegin(uscat, x, uvec, INSERT_VALUES, SCATTER_FORWARD));
202: PetscCall(VecScatterEnd(uscat, x, uvec, INSERT_VALUES, SCATTER_FORWARD));
204: PetscCall(VecScatterCreate(x, isp, pvec, NULL, &pscat));
205: PetscCall(VecScatterBegin(pscat, x, pvec, INSERT_VALUES, SCATTER_FORWARD));
206: PetscCall(VecScatterEnd(pscat, x, pvec, INSERT_VALUES, SCATTER_FORWARD));
208: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "-- vector vector values --\n"));
209: PetscCall(VecMin(uvec, &loc, &max));
210: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Min(u) = %1.6f [loc=%" PetscInt_FMT "]\n", (double)max, loc));
211: PetscCall(VecMax(uvec, &loc, &max));
212: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Max(u) = %1.6f [loc=%" PetscInt_FMT "]\n", (double)max, loc));
213: PetscCall(VecNorm(uvec, NORM_2, &norm));
214: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Norm(u) = %1.6f \n", (double)norm));
215: PetscCall(VecSum(uvec, &sum));
216: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Sum(u) = %1.6f \n", (double)PetscRealPart(sum)));
218: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "-- pressure vector values --\n"));
219: PetscCall(VecMin(pvec, &loc, &max));
220: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Min(p) = %1.6f [loc=%" PetscInt_FMT "]\n", (double)max, loc));
221: PetscCall(VecMax(pvec, &loc, &max));
222: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Max(p) = %1.6f [loc=%" PetscInt_FMT "]\n", (double)max, loc));
223: PetscCall(VecNorm(pvec, NORM_2, &norm));
224: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Norm(p) = %1.6f \n", (double)norm));
225: PetscCall(VecSum(pvec, &sum));
226: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Sum(p) = %1.6f \n", (double)PetscRealPart(sum)));
228: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "-- Full vector values --\n"));
229: PetscCall(VecMin(x, &loc, &max));
230: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Min(u,p) = %1.6f [loc=%" PetscInt_FMT "]\n", (double)max, loc));
231: PetscCall(VecMax(x, &loc, &max));
232: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Max(u,p) = %1.6f [loc=%" PetscInt_FMT "]\n", (double)max, loc));
233: PetscCall(VecNorm(x, NORM_2, &norm));
234: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Norm(u,p) = %1.6f \n", (double)norm));
235: PetscCall(VecSum(x, &sum));
236: PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Sum(u,p) = %1.6f \n", (double)PetscRealPart(sum)));
238: PetscCall(VecScatterDestroy(&uscat));
239: PetscCall(VecScatterDestroy(&pscat));
240: PetscCall(VecDestroy(&uvec));
241: PetscCall(VecDestroy(&pvec));
242: PetscCall(MatDestroy(&A11));
243: PetscCall(MatDestroy(&A22));
244: }
246: /* test second solve by changing the mat associated to the MATNEST blocks */
247: {
248: PetscCall(replace_submats(A, isu, isp));
249: PetscCall(replace_submats(P, isu, isp));
250: PetscCall(KSPSolve(ksp_A, b, x));
251: }
252: }
254: PetscCall(KSPDestroy(&ksp_A));
255: PetscCall(MatDestroy(&P));
256: PetscCall(MatDestroy(&A));
257: PetscCall(VecDestroy(&x));
258: PetscCall(VecDestroy(&b));
259: PetscCall(ISDestroy(&isu));
260: PetscCall(ISDestroy(&isp));
261: PetscFunctionReturn(PETSC_SUCCESS);
262: }
264: int main(int argc, char **argv)
265: {
266: PetscFunctionBeginUser;
267: PetscCall(PetscInitialize(&argc, &argv, 0, help));
268: PetscCall(port_lsd_bfbt());
269: PetscCall(PetscFinalize());
270: return 0;
271: }
273: /*TEST
275: test:
276: args: -f ${DATAFILESPATH}/matrices/underworld32.gz -fc_ksp_view -fc_ksp_monitor_short -fc_ksp_type fgmres -fc_ksp_max_it 4000 -fc_ksp_diagonal_scale -fc_pc_type fieldsplit -fc_pc_fieldsplit_type SCHUR -fc_pc_fieldsplit_schur_fact_type UPPER -fc_fieldsplit_velocity_ksp_type cg -fc_fieldsplit_velocity_pc_type cholesky -fc_fieldsplit_velocity_pc_factor_mat_ordering_type nd -fc_fieldsplit_pressure_ksp_max_it 100 -fc_fieldsplit_pressure_ksp_constant_null_space -fc_fieldsplit_pressure_ksp_monitor_short -fc_fieldsplit_pressure_pc_type lsc -fc_fieldsplit_pressure_lsc_ksp_type cg -fc_fieldsplit_pressure_lsc_ksp_max_it 100 -fc_fieldsplit_pressure_lsc_ksp_constant_null_space -fc_fieldsplit_pressure_lsc_ksp_converged_reason -fc_fieldsplit_pressure_lsc_pc_type icc -test_fs {{0 1}separate output} -fc_pc_fieldsplit_off_diag_use_amat {{0 1}separate output} -fc_pc_fieldsplit_diag_use_amat {{0 1}separate output}
277: requires: datafilespath double !complex !defined(PETSC_USE_64BIT_INDICES)
279: test:
280: suffix: 2
281: nsize: 4
282: args: -f ${DATAFILESPATH}/matrices/underworld32.gz -fc_ksp_view -fc_ksp_monitor_short -fc_ksp_type fgmres -fc_ksp_max_it 4000 -fc_ksp_diagonal_scale -fc_pc_type fieldsplit -fc_pc_fieldsplit_type SCHUR -fc_pc_fieldsplit_schur_fact_type UPPER -fc_fieldsplit_velocity_ksp_type cg -fc_fieldsplit_velocity_ksp_rtol 1.0e-6 -fc_fieldsplit_velocity_pc_type bjacobi -fc_fieldsplit_velocity_sub_pc_type cholesky -fc_fieldsplit_velocity_sub_pc_factor_mat_ordering_type nd -fc_fieldsplit_pressure_ksp_type fgmres -fc_fieldsplit_pressure_ksp_constant_null_space -fc_fieldsplit_pressure_ksp_monitor_short -fc_fieldsplit_pressure_pc_type lsc -fc_fieldsplit_pressure_lsc_ksp_type cg -fc_fieldsplit_pressure_lsc_ksp_rtol 1.0e-2 -fc_fieldsplit_pressure_lsc_ksp_constant_null_space -fc_fieldsplit_pressure_lsc_ksp_converged_reason -fc_fieldsplit_pressure_lsc_pc_type bjacobi -fc_fieldsplit_pressure_lsc_sub_pc_type icc -test_fs {{0 1}separate output} -fc_pc_fieldsplit_off_diag_use_amat {{0 1}separate output} -fc_pc_fieldsplit_diag_use_amat {{0 1}separate output}
283: requires: datafilespath double !complex !defined(PETSC_USE_64BIT_INDICES)
285: test:
286: suffix: 3
287: nsize: 2
288: args: -f ${DATAFILESPATH}/matrices/underworld32.gz -fc_ksp_view_pre -fc_pc_type lu
289: requires: datafilespath mumps double !complex !defined(PETSC_USE_64BIT_INDICES)
291: TEST*/