xref: /petsc/src/tao/tutorials/ex1.c (revision 6a5217c03994f2d95bb2e6dbd8bed42381aeb015)
1 static char help[] = "One-Shot Multigrid for Parameter Estimation Problem for the Poisson Equation.\n\
2 Using the Interior Point Method.\n\n\n";
3 
4 /*F
5   We are solving the parameter estimation problem for the Laplacian. We will ask to minimize a Lagrangian
6 function over $a$ and $u$, given by
7 \begin{align}
8   L(u, a, \lambda) = \frac{1}{2} || Qu - d ||^2 + \frac{1}{2} || L (a - a_r) ||^2 + \lambda F(u; a)
9 \end{align}
10 where $Q$ is a sampling operator, $L$ is a regularization operator, $F$ defines the PDE.
11 
12 Currently, we have perfect information, meaning $Q = I$, and then we need no regularization, $L = I$. We
13 also give the exact control for the reference $a_r$.
14 
15 The PDE will be the Laplace equation with homogeneous boundary conditions
16 \begin{align}
17   -nabla \cdot a \nabla u = f
18 \end{align}
19 
20 F*/
21 
22 #include <petsc.h>
23 #include <petscfe.h>
24 
25 typedef enum {RUN_FULL, RUN_TEST} RunType;
26 
27 typedef struct {
28   RunType runType;  /* Whether to run tests, or solve the full problem */
29 } AppCtx;
30 
31 static PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
32 {
33   const char    *runTypes[2] = {"full", "test"};
34   PetscInt       run;
35   PetscErrorCode ierr;
36 
37   PetscFunctionBeginUser;
38   options->runType = RUN_FULL;
39 
40   ierr = PetscOptionsBegin(comm, "", "Inverse Problem Options", "DMPLEX");PetscCall(ierr);
41   run  = options->runType;
42   PetscCall(PetscOptionsEList("-run_type", "The run type", "ex1.c", runTypes, 2, runTypes[options->runType], &run, NULL));
43   options->runType = (RunType) run;
44   ierr = PetscOptionsEnd();PetscCall(ierr);
45   PetscFunctionReturn(0);
46 }
47 
48 static PetscErrorCode CreateMesh(MPI_Comm comm, AppCtx *user, DM *dm)
49 {
50   PetscFunctionBeginUser;
51   PetscCall(DMCreate(comm, dm));
52   PetscCall(DMSetType(*dm, DMPLEX));
53   PetscCall(DMSetFromOptions(*dm));
54   PetscCall(DMViewFromOptions(*dm, NULL, "-dm_view"));
55   PetscFunctionReturn(0);
56 }
57 
58 /* u - (x^2 + y^2) */
59 void f0_u(PetscInt dim, PetscInt Nf, PetscInt NfAux,
60           const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
61           const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
62           PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
63 {
64   f0[0] = u[0] - (x[0]*x[0] + x[1]*x[1]);
65 }
66 /* a \nabla\lambda */
67 void f1_u(PetscInt dim, PetscInt Nf, PetscInt NfAux,
68           const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
69           const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
70           PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
71 {
72   PetscInt d;
73   for (d = 0; d < dim; ++d) f1[d] = u[1]*u_x[dim*2+d];
74 }
75 /* I */
76 void g0_uu(PetscInt dim, PetscInt Nf, PetscInt NfAux,
77            const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
78            const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
79            PetscReal t, PetscReal u_tShift, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar g0[])
80 {
81   g0[0] = 1.0;
82 }
83 /* \nabla */
84 void g2_ua(PetscInt dim, PetscInt Nf, PetscInt NfAux,
85            const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
86            const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
87            PetscReal t, PetscReal u_tShift, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar g2[])
88 {
89   PetscInt d;
90   for (d = 0; d < dim; ++d) g2[d] = u_x[dim*2+d];
91 }
92 /* a */
93 void g3_ul(PetscInt dim, PetscInt Nf, PetscInt NfAux,
94            const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
95            const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
96            PetscReal t, PetscReal u_tShift, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar g3[])
97 {
98   PetscInt d;
99   for (d = 0; d < dim; ++d) g3[d*dim+d] = u[1];
100 }
101 /* a - (x + y) */
102 void f0_a(PetscInt dim, PetscInt Nf, PetscInt NfAux,
103           const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
104           const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
105           PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
106 {
107   f0[0] = u[1] - (x[0] + x[1]);
108 }
109 /* \lambda \nabla u */
110 void f1_a(PetscInt dim, PetscInt Nf, PetscInt NfAux,
111           const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
112           const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
113           PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
114 {
115   PetscInt d;
116   for (d = 0; d < dim; ++d) f1[d] = u[2]*u_x[d];
117 }
118 /* I */
119 void g0_aa(PetscInt dim, PetscInt Nf, PetscInt NfAux,
120            const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
121            const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
122            PetscReal t, PetscReal u_tShift, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar g0[])
123 {
124   g0[0] = 1.0;
125 }
126 /* 6 (x + y) */
127 void f0_l(PetscInt dim, PetscInt Nf, PetscInt NfAux,
128           const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
129           const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
130           PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
131 {
132   f0[0] = 6.0*(x[0] + x[1]);
133 }
134 /* a \nabla u */
135 void f1_l(PetscInt dim, PetscInt Nf, PetscInt NfAux,
136           const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
137           const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
138           PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
139 {
140   PetscInt d;
141   for (d = 0; d < dim; ++d) f1[d] = u[1]*u_x[d];
142 }
143 /* \nabla u */
144 void g2_la(PetscInt dim, PetscInt Nf, PetscInt NfAux,
145            const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
146            const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
147            PetscReal t, PetscReal u_tShift, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar g2[])
148 {
149   PetscInt d;
150   for (d = 0; d < dim; ++d) g2[d] = u_x[d];
151 }
152 /* a */
153 void g3_lu(PetscInt dim, PetscInt Nf, PetscInt NfAux,
154            const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
155            const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
156            PetscReal t, PetscReal u_tShift, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar g3[])
157 {
158   PetscInt d;
159   for (d = 0; d < dim; ++d) g3[d*dim+d] = u[1];
160 }
161 
162 /*
163   In 2D for Dirichlet conditions with a variable coefficient, we use exact solution:
164 
165     u  = x^2 + y^2
166     f  = 6 (x + y)
167     kappa(a) = a = (x + y)
168 
169   so that
170 
171     -\div \kappa(a) \grad u + f = -6 (x + y) + 6 (x + y) = 0
172 */
173 PetscErrorCode quadratic_u_2d(PetscInt dim, PetscReal t, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
174 {
175   *u = x[0]*x[0] + x[1]*x[1];
176   return 0;
177 }
178 PetscErrorCode linear_a_2d(PetscInt dim, PetscReal t, const PetscReal x[], PetscInt Nf, PetscScalar *a, void *ctx)
179 {
180   *a = x[0] + x[1];
181   return 0;
182 }
183 PetscErrorCode zero(PetscInt dim, PetscReal t, const PetscReal x[], PetscInt Nf, PetscScalar *l, void *ctx)
184 {
185   *l = 0.0;
186   return 0;
187 }
188 
189 PetscErrorCode SetupProblem(DM dm, AppCtx *user)
190 {
191   PetscDS        ds;
192   DMLabel        label;
193   const PetscInt id = 1;
194 
195   PetscFunctionBeginUser;
196   PetscCall(DMGetDS(dm, &ds));
197   PetscCall(PetscDSSetResidual(ds, 0, f0_u, f1_u));
198   PetscCall(PetscDSSetResidual(ds, 1, f0_a, f1_a));
199   PetscCall(PetscDSSetResidual(ds, 2, f0_l, f1_l));
200   PetscCall(PetscDSSetJacobian(ds, 0, 0, g0_uu, NULL, NULL, NULL));
201   PetscCall(PetscDSSetJacobian(ds, 0, 1, NULL, NULL, g2_ua, NULL));
202   PetscCall(PetscDSSetJacobian(ds, 0, 2, NULL, NULL, NULL, g3_ul));
203   PetscCall(PetscDSSetJacobian(ds, 1, 1, g0_aa, NULL, NULL, NULL));
204   PetscCall(PetscDSSetJacobian(ds, 2, 1, NULL, NULL, g2_la, NULL));
205   PetscCall(PetscDSSetJacobian(ds, 2, 0, NULL, NULL, NULL, g3_lu));
206 
207   PetscCall(PetscDSSetExactSolution(ds, 0, quadratic_u_2d, NULL));
208   PetscCall(PetscDSSetExactSolution(ds, 1, linear_a_2d, NULL));
209   PetscCall(PetscDSSetExactSolution(ds, 2, zero, NULL));
210   PetscCall(DMGetLabel(dm, "marker", &label));
211   PetscCall(DMAddBoundary(dm, DM_BC_ESSENTIAL, "wall", label, 1, &id, 0, 0, NULL, (void (*)(void)) quadratic_u_2d, NULL, user, NULL));
212   PetscCall(DMAddBoundary(dm, DM_BC_ESSENTIAL, "wall", label, 1, &id, 1, 0, NULL, (void (*)(void)) linear_a_2d, NULL, user, NULL));
213   PetscCall(DMAddBoundary(dm, DM_BC_ESSENTIAL, "wall", label, 1, &id, 2, 0, NULL, (void (*)(void)) zero, NULL, user, NULL));
214   PetscFunctionReturn(0);
215 }
216 
217 PetscErrorCode SetupDiscretization(DM dm, AppCtx *user)
218 {
219   DM              cdm = dm;
220   const PetscInt  dim = 2;
221   PetscFE         fe[3];
222   PetscInt        f;
223   MPI_Comm        comm;
224 
225   PetscFunctionBeginUser;
226   /* Create finite element */
227   PetscCall(PetscObjectGetComm((PetscObject) dm, &comm));
228   PetscCall(PetscFECreateDefault(comm, dim, 1, PETSC_TRUE, "potential_", -1, &fe[0]));
229   PetscCall(PetscObjectSetName((PetscObject) fe[0], "potential"));
230   PetscCall(PetscFECreateDefault(comm, dim, 1, PETSC_TRUE, "conductivity_", -1, &fe[1]));
231   PetscCall(PetscObjectSetName((PetscObject) fe[1], "conductivity"));
232   PetscCall(PetscFECopyQuadrature(fe[0], fe[1]));
233   PetscCall(PetscFECreateDefault(comm, dim, 1, PETSC_TRUE, "multiplier_", -1, &fe[2]));
234   PetscCall(PetscObjectSetName((PetscObject) fe[2], "multiplier"));
235   PetscCall(PetscFECopyQuadrature(fe[0], fe[2]));
236   /* Set discretization and boundary conditions for each mesh */
237   for (f = 0; f < 3; ++f) PetscCall(DMSetField(dm, f, NULL, (PetscObject) fe[f]));
238   PetscCall(DMCreateDS(dm));
239   PetscCall(SetupProblem(dm, user));
240   while (cdm) {
241     PetscCall(DMCopyDisc(dm, cdm));
242     PetscCall(DMGetCoarseDM(cdm, &cdm));
243   }
244   for (f = 0; f < 3; ++f) PetscCall(PetscFEDestroy(&fe[f]));
245   PetscFunctionReturn(0);
246 }
247 
248 int main(int argc, char **argv)
249 {
250   DM             dm;
251   SNES           snes;
252   Vec            u, r;
253   AppCtx         user;
254 
255   PetscCall(PetscInitialize(&argc, &argv, NULL,help));
256   PetscCall(ProcessOptions(PETSC_COMM_WORLD, &user));
257   PetscCall(SNESCreate(PETSC_COMM_WORLD, &snes));
258   PetscCall(CreateMesh(PETSC_COMM_WORLD, &user, &dm));
259   PetscCall(SNESSetDM(snes, dm));
260   PetscCall(SetupDiscretization(dm, &user));
261 
262   PetscCall(DMCreateGlobalVector(dm, &u));
263   PetscCall(PetscObjectSetName((PetscObject) u, "solution"));
264   PetscCall(VecDuplicate(u, &r));
265   PetscCall(DMPlexSetSNESLocalFEM(dm,&user,&user,&user));
266   PetscCall(SNESSetFromOptions(snes));
267 
268   PetscCall(DMSNESCheckFromOptions(snes, u));
269   if (user.runType == RUN_FULL) {
270     PetscDS          ds;
271     PetscErrorCode (*exactFuncs[3])(PetscInt dim, PetscReal t, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx);
272     PetscErrorCode (*initialGuess[3])(PetscInt dim, PetscReal t, const PetscReal x[], PetscInt Nf, PetscScalar u[], void *ctx);
273     PetscReal        error;
274 
275     PetscCall(DMGetDS(dm, &ds));
276     PetscCall(PetscDSGetExactSolution(ds, 0, &exactFuncs[0], NULL));
277     PetscCall(PetscDSGetExactSolution(ds, 1, &exactFuncs[1], NULL));
278     PetscCall(PetscDSGetExactSolution(ds, 2, &exactFuncs[2], NULL));
279     initialGuess[0] = zero;
280     initialGuess[1] = zero;
281     initialGuess[2] = zero;
282     PetscCall(DMProjectFunction(dm, 0.0, initialGuess, NULL, INSERT_VALUES, u));
283     PetscCall(VecViewFromOptions(u, NULL, "-initial_vec_view"));
284     PetscCall(DMComputeL2Diff(dm, 0.0, exactFuncs, NULL, u, &error));
285     if (error < 1.0e-11) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Initial L_2 Error: < 1.0e-11\n"));
286     else                 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Initial L_2 Error: %g\n", error));
287     PetscCall(SNESSolve(snes, NULL, u));
288     PetscCall(DMComputeL2Diff(dm, 0.0, exactFuncs, NULL, u, &error));
289     if (error < 1.0e-11) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Final L_2 Error: < 1.0e-11\n"));
290     else                 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Final L_2 Error: %g\n", error));
291   }
292   PetscCall(VecViewFromOptions(u, NULL, "-sol_vec_view"));
293 
294   PetscCall(VecDestroy(&u));
295   PetscCall(VecDestroy(&r));
296   PetscCall(SNESDestroy(&snes));
297   PetscCall(DMDestroy(&dm));
298   PetscCall(PetscFinalize());
299   return 0;
300 }
301 
302 /*TEST
303 
304   build:
305     requires: !complex
306 
307   test:
308     suffix: 0
309     requires: triangle
310     args: -run_type test -dmsnes_check -potential_petscspace_degree 2 -conductivity_petscspace_degree 1 -multiplier_petscspace_degree 2
311 
312   test:
313     suffix: 1
314     requires: triangle
315     args: -potential_petscspace_degree 2 -conductivity_petscspace_degree 1 -multiplier_petscspace_degree 2 -snes_monitor -pc_type fieldsplit -pc_fieldsplit_0_fields 0,1 -pc_fieldsplit_1_fields 2 -pc_fieldsplit_type schur -pc_fieldsplit_schur_factorization_type full -pc_fieldsplit_schur_precondition selfp -fieldsplit_0_pc_type lu -fieldsplit_multiplier_ksp_rtol 1.0e-10 -fieldsplit_multiplier_pc_type lu -sol_vec_view
316 
317 TEST*/
318