Actual source code: ex5opt_ic.c
1: static char help[] = "Demonstrates adjoint sensitivity analysis for Reaction-Diffusion Equations.\n";
3: /*
4: See ex5.c for details on the equation.
5: This code demonestrates the TSAdjoint/TAO interface to solve an inverse initial value problem built on a system of
6: time-dependent partial differential equations.
7: In this problem, the initial value for the PDE is unknown, but the output (the final solution of the PDE) is known.
8: We want to determine the initial value that can produce the given output.
9: We formulate the problem as a nonlinear optimization problem that minimizes the discrepancy between the simulated
10: result and given reference solution, calculate the gradient of the objective function with the discrete adjoint
11: solver, and solve the optimization problem with TAO.
13: Runtime options:
14: -forwardonly - run only the forward simulation
15: -implicitform - provide IFunction and IJacobian to TS, if not set, RHSFunction and RHSJacobian will be used
16: */
18: #include "reaction_diffusion.h"
19: #include <petscdm.h>
20: #include <petscdmda.h>
21: #include <petsctao.h>
23: /* User-defined routines */
24: extern PetscErrorCode FormFunctionAndGradient(Tao, Vec, PetscReal *, Vec, void *);
26: /*
27: Set terminal condition for the adjoint variable
28: */
29: PetscErrorCode InitializeLambda(DM da, Vec lambda, Vec U, AppCtx *appctx)
30: {
31: char filename[PETSC_MAX_PATH_LEN] = "";
32: PetscViewer viewer;
33: Vec Uob;
35: PetscFunctionBegin;
36: PetscCall(VecDuplicate(U, &Uob));
37: PetscCall(PetscSNPrintf(filename, sizeof filename, "ex5opt.ob"));
38: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, filename, FILE_MODE_READ, &viewer));
39: PetscCall(VecLoad(Uob, viewer));
40: PetscCall(PetscViewerDestroy(&viewer));
41: PetscCall(VecAYPX(Uob, -1., U));
42: PetscCall(VecScale(Uob, 2.0));
43: PetscCall(VecAXPY(lambda, 1., Uob));
44: PetscCall(VecDestroy(&Uob));
45: PetscFunctionReturn(PETSC_SUCCESS);
46: }
48: /*
49: Set up a viewer that dumps data into a binary file
50: */
51: PetscErrorCode OutputBIN(DM da, const char *filename, PetscViewer *viewer)
52: {
53: PetscFunctionBegin;
54: PetscCall(PetscViewerCreate(PetscObjectComm((PetscObject)da), viewer));
55: PetscCall(PetscViewerSetType(*viewer, PETSCVIEWERBINARY));
56: PetscCall(PetscViewerFileSetMode(*viewer, FILE_MODE_WRITE));
57: PetscCall(PetscViewerFileSetName(*viewer, filename));
58: PetscFunctionReturn(PETSC_SUCCESS);
59: }
61: /*
62: Generate a reference solution and save it to a binary file
63: */
64: PetscErrorCode GenerateOBs(TS ts, Vec U, AppCtx *appctx)
65: {
66: char filename[PETSC_MAX_PATH_LEN] = "";
67: PetscViewer viewer;
68: DM da;
70: PetscFunctionBegin;
71: PetscCall(TSGetDM(ts, &da));
72: PetscCall(TSSolve(ts, U));
73: PetscCall(PetscSNPrintf(filename, sizeof filename, "ex5opt.ob"));
74: PetscCall(OutputBIN(da, filename, &viewer));
75: PetscCall(VecView(U, viewer));
76: PetscCall(PetscViewerDestroy(&viewer));
77: PetscFunctionReturn(PETSC_SUCCESS);
78: }
80: PetscErrorCode InitialConditions(DM da, Vec U)
81: {
82: PetscInt i, j, xs, ys, xm, ym, Mx, My;
83: Field **u;
84: PetscReal hx, hy, x, y;
86: PetscFunctionBegin;
87: PetscCall(DMDAGetInfo(da, PETSC_IGNORE, &Mx, &My, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE));
89: hx = 2.5 / (PetscReal)Mx;
90: hy = 2.5 / (PetscReal)My;
92: PetscCall(DMDAVecGetArray(da, U, &u));
93: /* Get local grid boundaries */
94: PetscCall(DMDAGetCorners(da, &xs, &ys, NULL, &xm, &ym, NULL));
96: /* Compute function over the locally owned part of the grid */
97: for (j = ys; j < ys + ym; j++) {
98: y = j * hy;
99: for (i = xs; i < xs + xm; i++) {
100: x = i * hx;
101: if ((1.0 <= x) && (x <= 1.5) && (1.0 <= y) && (y <= 1.5)) u[j][i].v = .25 * PetscPowReal(PetscSinReal(4.0 * PETSC_PI * x), 2.0) * PetscPowReal(PetscSinReal(4.0 * PETSC_PI * y), 2.0);
102: else u[j][i].v = 0.0;
104: u[j][i].u = 1.0 - 2.0 * u[j][i].v;
105: }
106: }
108: PetscCall(DMDAVecRestoreArray(da, U, &u));
109: PetscFunctionReturn(PETSC_SUCCESS);
110: }
112: PetscErrorCode PerturbedInitialConditions(DM da, Vec U)
113: {
114: PetscInt i, j, xs, ys, xm, ym, Mx, My;
115: Field **u;
116: PetscReal hx, hy, x, y;
118: PetscFunctionBegin;
119: PetscCall(DMDAGetInfo(da, PETSC_IGNORE, &Mx, &My, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE));
121: hx = 2.5 / (PetscReal)Mx;
122: hy = 2.5 / (PetscReal)My;
124: PetscCall(DMDAVecGetArray(da, U, &u));
125: /* Get local grid boundaries */
126: PetscCall(DMDAGetCorners(da, &xs, &ys, NULL, &xm, &ym, NULL));
128: /* Compute function over the locally owned part of the grid */
129: for (j = ys; j < ys + ym; j++) {
130: y = j * hy;
131: for (i = xs; i < xs + xm; i++) {
132: x = i * hx;
133: if ((1.0 <= x) && (x <= 1.5) && (1.0 <= y) && (y <= 1.5)) u[j][i].v = .25 * PetscPowReal(PetscSinReal(4.0 * PETSC_PI * 0.5 * x), 2.0) * PetscPowReal(PetscSinReal(4.0 * PETSC_PI * 0.5 * y), 2.0);
134: else u[j][i].v = 0.0;
136: u[j][i].u = 1.0 - 2.0 * u[j][i].v;
137: }
138: }
140: PetscCall(DMDAVecRestoreArray(da, U, &u));
141: PetscFunctionReturn(PETSC_SUCCESS);
142: }
144: PetscErrorCode PerturbedInitialConditions2(DM da, Vec U)
145: {
146: PetscInt i, j, xs, ys, xm, ym, Mx, My;
147: Field **u;
148: PetscReal hx, hy, x, y;
150: PetscFunctionBegin;
151: PetscCall(DMDAGetInfo(da, PETSC_IGNORE, &Mx, &My, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE));
153: hx = 2.5 / (PetscReal)Mx;
154: hy = 2.5 / (PetscReal)My;
156: PetscCall(DMDAVecGetArray(da, U, &u));
157: /* Get local grid boundaries */
158: PetscCall(DMDAGetCorners(da, &xs, &ys, NULL, &xm, &ym, NULL));
160: /* Compute function over the locally owned part of the grid */
161: for (j = ys; j < ys + ym; j++) {
162: y = j * hy;
163: for (i = xs; i < xs + xm; i++) {
164: x = i * hx;
165: if (PetscApproximateGTE(x, 1.0) && PetscApproximateLTE(x, 1.5) && PetscApproximateGTE(y, 1.0) && PetscApproximateLTE(y, 1.5))
166: u[j][i].v = PetscPowReal(PetscSinReal(4.0 * PETSC_PI * (x - 0.5)), 2.0) * PetscPowReal(PetscSinReal(4.0 * PETSC_PI * y), 2.0) / 4.0;
167: else u[j][i].v = 0.0;
169: u[j][i].u = 1.0 - 2.0 * u[j][i].v;
170: }
171: }
173: PetscCall(DMDAVecRestoreArray(da, U, &u));
174: PetscFunctionReturn(PETSC_SUCCESS);
175: }
177: PetscErrorCode PerturbedInitialConditions3(DM da, Vec U)
178: {
179: PetscInt i, j, xs, ys, xm, ym, Mx, My;
180: Field **u;
181: PetscReal hx, hy, x, y;
183: PetscFunctionBegin;
184: PetscCall(DMDAGetInfo(da, PETSC_IGNORE, &Mx, &My, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE, PETSC_IGNORE));
186: hx = 2.5 / (PetscReal)Mx;
187: hy = 2.5 / (PetscReal)My;
189: PetscCall(DMDAVecGetArray(da, U, &u));
190: /* Get local grid boundaries */
191: PetscCall(DMDAGetCorners(da, &xs, &ys, NULL, &xm, &ym, NULL));
193: /* Compute function over the locally owned part of the grid */
194: for (j = ys; j < ys + ym; j++) {
195: y = j * hy;
196: for (i = xs; i < xs + xm; i++) {
197: x = i * hx;
198: if ((0.5 <= x) && (x <= 2.0) && (0.5 <= y) && (y <= 2.0)) u[j][i].v = .25 * PetscPowReal(PetscSinReal(4.0 * PETSC_PI * x), 2.0) * PetscPowReal(PetscSinReal(4.0 * PETSC_PI * y), 2.0);
199: else u[j][i].v = 0.0;
201: u[j][i].u = 1.0 - 2.0 * u[j][i].v;
202: }
203: }
205: PetscCall(DMDAVecRestoreArray(da, U, &u));
206: PetscFunctionReturn(PETSC_SUCCESS);
207: }
209: int main(int argc, char **argv)
210: {
211: DM da;
212: AppCtx appctx;
213: PetscBool forwardonly = PETSC_FALSE, implicitform = PETSC_FALSE;
214: PetscInt perturbic = 1;
216: PetscFunctionBeginUser;
217: PetscCall(PetscInitialize(&argc, &argv, NULL, help));
218: PetscCall(PetscOptionsGetBool(NULL, NULL, "-forwardonly", &forwardonly, NULL));
219: PetscCall(PetscOptionsGetBool(NULL, NULL, "-implicitform", &implicitform, NULL));
220: PetscCall(PetscOptionsGetInt(NULL, NULL, "-perturbic", &perturbic, NULL));
222: appctx.D1 = 8.0e-5;
223: appctx.D2 = 4.0e-5;
224: appctx.gamma = .024;
225: appctx.kappa = .06;
226: appctx.aijpc = PETSC_FALSE;
228: /* Create distributed array (DMDA) to manage parallel grid and vectors */
229: PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_PERIODIC, DM_BOUNDARY_PERIODIC, DMDA_STENCIL_STAR, 64, 64, PETSC_DECIDE, PETSC_DECIDE, 2, 1, NULL, NULL, &da));
230: PetscCall(DMSetFromOptions(da));
231: PetscCall(DMSetUp(da));
232: PetscCall(DMDASetFieldName(da, 0, "u"));
233: PetscCall(DMDASetFieldName(da, 1, "v"));
235: /* Extract global vectors from DMDA; then duplicate for remaining
236: vectors that are the same types */
237: PetscCall(DMCreateGlobalVector(da, &appctx.U));
239: /* Create timestepping solver context */
240: PetscCall(TSCreate(PETSC_COMM_WORLD, &appctx.ts));
241: PetscCall(TSSetType(appctx.ts, TSCN));
242: PetscCall(TSSetDM(appctx.ts, da));
243: PetscCall(TSSetProblemType(appctx.ts, TS_NONLINEAR));
244: PetscCall(TSSetEquationType(appctx.ts, TS_EQ_ODE_EXPLICIT)); /* less Jacobian evaluations when adjoint BEuler is used, otherwise no effect */
245: if (!implicitform) {
246: PetscCall(TSSetRHSFunction(appctx.ts, NULL, RHSFunction, &appctx));
247: PetscCall(TSSetRHSJacobian(appctx.ts, NULL, NULL, RHSJacobian, &appctx));
248: } else {
249: PetscCall(TSSetIFunction(appctx.ts, NULL, IFunction, &appctx));
250: PetscCall(TSSetIJacobian(appctx.ts, NULL, NULL, IJacobian, &appctx));
251: }
253: /* Set initial conditions */
254: PetscCall(InitialConditions(da, appctx.U));
255: PetscCall(TSSetSolution(appctx.ts, appctx.U));
257: /* Set solver options */
258: PetscCall(TSSetMaxTime(appctx.ts, 2000.0));
259: PetscCall(TSSetTimeStep(appctx.ts, 0.5));
260: PetscCall(TSSetExactFinalTime(appctx.ts, TS_EXACTFINALTIME_MATCHSTEP));
261: PetscCall(TSSetFromOptions(appctx.ts));
263: PetscCall(GenerateOBs(appctx.ts, appctx.U, &appctx));
265: if (!forwardonly) {
266: Tao tao;
267: Vec P;
268: Vec lambda[1];
269: PetscLogStage opt_stage;
271: PetscCall(PetscLogStageRegister("Optimization", &opt_stage));
272: PetscCall(PetscLogStagePush(opt_stage));
273: if (perturbic == 1) {
274: PetscCall(PerturbedInitialConditions(da, appctx.U));
275: } else if (perturbic == 2) {
276: PetscCall(PerturbedInitialConditions2(da, appctx.U));
277: } else if (perturbic == 3) {
278: PetscCall(PerturbedInitialConditions3(da, appctx.U));
279: }
281: PetscCall(VecDuplicate(appctx.U, &lambda[0]));
282: PetscCall(TSSetCostGradients(appctx.ts, 1, lambda, NULL));
284: /* Have the TS save its trajectory needed by TSAdjointSolve() */
285: PetscCall(TSSetSaveTrajectory(appctx.ts));
287: /* Create TAO solver and set desired solution method */
288: PetscCall(TaoCreate(PETSC_COMM_WORLD, &tao));
289: PetscCall(TaoSetType(tao, TAOBLMVM));
291: /* Set initial guess for TAO */
292: PetscCall(VecDuplicate(appctx.U, &P));
293: PetscCall(VecCopy(appctx.U, P));
294: PetscCall(TaoSetSolution(tao, P));
296: /* Set routine for function and gradient evaluation */
297: PetscCall(TaoSetObjectiveAndGradient(tao, NULL, FormFunctionAndGradient, &appctx));
299: /* Check for any TAO command line options */
300: PetscCall(TaoSetFromOptions(tao));
302: PetscCall(TaoSolve(tao));
303: PetscCall(TaoDestroy(&tao));
304: PetscCall(VecDestroy(&lambda[0]));
305: PetscCall(VecDestroy(&P));
306: PetscCall(PetscLogStagePop());
307: }
309: /* Free work space. All PETSc objects should be destroyed when they
310: are no longer needed. */
311: PetscCall(VecDestroy(&appctx.U));
312: PetscCall(TSDestroy(&appctx.ts));
313: PetscCall(DMDestroy(&da));
314: PetscCall(PetscFinalize());
315: return 0;
316: }
318: /* ------------------------ TAO callbacks ---------------------------- */
320: /*
321: FormFunctionAndGradient - Evaluates the function and corresponding gradient.
323: Input Parameters:
324: tao - the Tao context
325: P - the input vector
326: ctx - optional user-defined context, as set by TaoSetObjectiveAndGradient()
328: Output Parameters:
329: f - the newly evaluated function
330: G - the newly evaluated gradient
331: */
332: PetscErrorCode FormFunctionAndGradient(Tao tao, Vec P, PetscReal *f, Vec G, void *ctx)
333: {
334: AppCtx *appctx = (AppCtx *)ctx;
335: PetscReal soberr, timestep;
336: Vec *lambda;
337: Vec SDiff;
338: DM da;
339: char filename[PETSC_MAX_PATH_LEN] = "";
340: PetscViewer viewer;
342: PetscFunctionBeginUser;
343: PetscCall(TSSetTime(appctx->ts, 0.0));
344: PetscCall(TSGetTimeStep(appctx->ts, ×tep));
345: if (timestep < 0) PetscCall(TSSetTimeStep(appctx->ts, -timestep));
346: PetscCall(TSSetStepNumber(appctx->ts, 0));
347: PetscCall(TSSetFromOptions(appctx->ts));
349: PetscCall(VecDuplicate(P, &SDiff));
350: PetscCall(VecCopy(P, appctx->U));
351: PetscCall(TSGetDM(appctx->ts, &da));
352: *f = 0;
354: PetscCall(TSSolve(appctx->ts, appctx->U));
355: PetscCall(PetscSNPrintf(filename, sizeof filename, "ex5opt.ob"));
356: PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, filename, FILE_MODE_READ, &viewer));
357: PetscCall(VecLoad(SDiff, viewer));
358: PetscCall(PetscViewerDestroy(&viewer));
359: PetscCall(VecAYPX(SDiff, -1., appctx->U));
360: PetscCall(VecDot(SDiff, SDiff, &soberr));
361: *f += soberr;
363: PetscCall(TSGetCostGradients(appctx->ts, NULL, &lambda, NULL));
364: PetscCall(VecSet(lambda[0], 0.0));
365: PetscCall(InitializeLambda(da, lambda[0], appctx->U, appctx));
366: PetscCall(TSAdjointSolve(appctx->ts));
368: PetscCall(VecCopy(lambda[0], G));
370: PetscCall(VecDestroy(&SDiff));
371: PetscFunctionReturn(PETSC_SUCCESS);
372: }
374: /*TEST
376: build:
377: depends: reaction_diffusion.c
378: requires: !complex !single
380: test:
381: args: -ts_max_steps 5 -ts_type rk -ts_rk_type 3 -ts_trajectory_type memory -tao_monitor -tao_view -tao_gatol 1e-6
382: output_file: output/ex5opt_ic_1.out
384: TEST*/