xref: /petsc/src/ts/tutorials/autodiff/ex16opt_ic.cxx (revision c3b5f7ba6bc5ce25a01a67bb37ba5d34b02bbbd7)
1 static char help[] = "Demonstrates automatic Jacobian generation using ADOL-C for an ODE-constrained optimization problem.\n\
2 Input parameters include:\n\
3       -mu : stiffness parameter\n\n";
4 
5 /*
6    REQUIRES configuration of PETSc with option --download-adolc.
7 
8    For documentation on ADOL-C, see
9      $PETSC_ARCH/externalpackages/ADOL-C-2.6.0/ADOL-C/doc/adolc-manual.pdf
10 */
11 /* ------------------------------------------------------------------------
12   See ex16opt_ic for a description of the problem being solved.
13   ------------------------------------------------------------------------- */
14 #include <petsctao.h>
15 #include <petscts.h>
16 #include <petscmat.h>
17 #include "adolc-utils/drivers.cxx"
18 #include <adolc/adolc.h>
19 
20 typedef struct _n_User *User;
21 struct _n_User {
22   PetscReal mu;
23   PetscReal next_output;
24   PetscInt  steps;
25 
26   /* Sensitivity analysis support */
27   PetscReal ftime,x_ob[2];
28   Mat       A;             /* Jacobian matrix */
29   Vec       x,lambda[2];   /* adjoint variables */
30 
31   /* Automatic differentiation support */
32   AdolcCtx  *adctx;
33 };
34 
35 PetscErrorCode FormFunctionGradient(Tao,Vec,PetscReal*,Vec,void*);
36 
37 /*
38   'Passive' RHS function, used in residual evaluations during the time integration.
39 */
40 static PetscErrorCode RHSFunctionPassive(TS ts,PetscReal t,Vec X,Vec F,void *ctx)
41 {
42   User              user = (User)ctx;
43   PetscScalar       *f;
44   const PetscScalar *x;
45 
46   PetscFunctionBeginUser;
47   PetscCall(VecGetArrayRead(X,&x));
48   PetscCall(VecGetArray(F,&f));
49   f[0] = x[1];
50   f[1] = user->mu*(1.-x[0]*x[0])*x[1]-x[0];
51   PetscCall(VecRestoreArrayRead(X,&x));
52   PetscCall(VecRestoreArray(F,&f));
53   PetscFunctionReturn(0);
54 }
55 
56 /*
57   Trace RHS to mark on tape 1 the dependence of f upon x. This tape is used in generating the
58   Jacobian transform.
59 */
60 static PetscErrorCode RHSFunctionActive(TS ts,PetscReal t,Vec X,Vec F,void *ctx)
61 {
62   User              user = (User)ctx;
63   PetscReal         mu   = user->mu;
64   PetscScalar       *f;
65   const PetscScalar *x;
66 
67   adouble           f_a[2];                     /* adouble for dependent variables */
68   adouble           x_a[2];                     /* adouble for independent variables */
69 
70   PetscFunctionBeginUser;
71   PetscCall(VecGetArrayRead(X,&x));
72   PetscCall(VecGetArray(F,&f));
73 
74   trace_on(1);                                  /* Start of active section */
75   x_a[0] <<= x[0]; x_a[1] <<= x[1];             /* Mark as independent */
76   f_a[0] = x_a[1];
77   f_a[1] = mu*(1.-x_a[0]*x_a[0])*x_a[1]-x_a[0];
78   f_a[0] >>= f[0]; f_a[1] >>= f[1];             /* Mark as dependent */
79   trace_off(1);                                 /* End of active section */
80 
81   PetscCall(VecRestoreArrayRead(X,&x));
82   PetscCall(VecRestoreArray(F,&f));
83   PetscFunctionReturn(0);
84 }
85 
86 /*
87   Compute the Jacobian w.r.t. x using PETSc-ADOL-C driver.
88 */
89 static PetscErrorCode RHSJacobian(TS ts,PetscReal t,Vec X,Mat A,Mat B,void *ctx)
90 {
91   User              user=(User)ctx;
92   const PetscScalar *x;
93 
94   PetscFunctionBeginUser;
95   PetscCall(VecGetArrayRead(X,&x));
96   PetscCall(PetscAdolcComputeRHSJacobian(1,A,x,user->adctx));
97   PetscCall(VecRestoreArrayRead(X,&x));
98   PetscFunctionReturn(0);
99 }
100 
101 /*
102   Monitor timesteps and use interpolation to output at integer multiples of 0.1
103 */
104 static PetscErrorCode Monitor(TS ts,PetscInt step,PetscReal t,Vec X,void *ctx)
105 {
106   const PetscScalar *x;
107   PetscReal         tfinal, dt, tprev;
108   User              user = (User)ctx;
109 
110   PetscFunctionBeginUser;
111   PetscCall(TSGetTimeStep(ts,&dt));
112   PetscCall(TSGetMaxTime(ts,&tfinal));
113   PetscCall(TSGetPrevTime(ts,&tprev));
114   PetscCall(VecGetArrayRead(X,&x));
115   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"[%.1f] %D TS %.6f (dt = %.6f) X % 12.6e % 12.6e\n",(double)user->next_output,step,(double)t,(double)dt,(double)PetscRealPart(x[0]),(double)PetscRealPart(x[1])));
116   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"t %.6f (tprev = %.6f) \n",(double)t,(double)tprev));
117   PetscCall(VecGetArrayRead(X,&x));
118   PetscFunctionReturn(0);
119 }
120 
121 int main(int argc,char **argv)
122 {
123   TS                 ts = NULL;          /* nonlinear solver */
124   Vec                ic,r;
125   PetscBool          monitor = PETSC_FALSE;
126   PetscScalar        *x_ptr;
127   PetscMPIInt        size;
128   struct _n_User     user;
129   AdolcCtx           *adctx;
130   Tao                tao;
131   KSP                ksp;
132   PC                 pc;
133 
134   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
135      Initialize program
136      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
137   PetscCall(PetscInitialize(&argc,&argv,NULL,help));
138   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
139   PetscCheckFalse(size != 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!");
140 
141   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
142     Set runtime options and create AdolcCtx
143     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
144   PetscCall(PetscNew(&adctx));
145   user.mu          = 1.0;
146   user.next_output = 0.0;
147   user.steps       = 0;
148   user.ftime       = 0.5;
149   adctx->m = 2;adctx->n = 2;adctx->p = 2;
150   user.adctx = adctx;
151 
152   PetscCall(PetscOptionsGetReal(NULL,NULL,"-mu",&user.mu,NULL));
153   PetscCall(PetscOptionsGetBool(NULL,NULL,"-monitor",&monitor,NULL));
154 
155   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
156     Create necessary matrix and vectors, solve same ODE on every process
157     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
158   PetscCall(MatCreate(PETSC_COMM_WORLD,&user.A));
159   PetscCall(MatSetSizes(user.A,PETSC_DECIDE,PETSC_DECIDE,2,2));
160   PetscCall(MatSetFromOptions(user.A));
161   PetscCall(MatSetUp(user.A));
162   PetscCall(MatCreateVecs(user.A,&user.x,NULL));
163 
164   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
165      Set initial conditions
166    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
167   PetscCall(VecGetArray(user.x,&x_ptr));
168   x_ptr[0] = 2.0;   x_ptr[1] = 0.66666654321;
169   PetscCall(VecRestoreArray(user.x,&x_ptr));
170 
171   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
172      Trace just once on each tape and put zeros on Jacobian diagonal
173      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
174   PetscCall(VecDuplicate(user.x,&r));
175   PetscCall(RHSFunctionActive(ts,0.,user.x,r,&user));
176   PetscCall(VecSet(r,0));
177   PetscCall(MatDiagonalSet(user.A,r,INSERT_VALUES));
178   PetscCall(VecDestroy(&r));
179 
180   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
181      Create timestepping solver context
182      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
183   PetscCall(TSCreate(PETSC_COMM_WORLD,&ts));
184   PetscCall(TSSetType(ts,TSRK));
185   PetscCall(TSSetRHSFunction(ts,NULL,RHSFunctionPassive,&user));
186   PetscCall(TSSetRHSJacobian(ts,user.A,user.A,RHSJacobian,&user));
187   PetscCall(TSSetMaxTime(ts,user.ftime));
188   PetscCall(TSSetExactFinalTime(ts,TS_EXACTFINALTIME_MATCHSTEP));
189   if (monitor) {
190     PetscCall(TSMonitorSet(ts,Monitor,&user,NULL));
191   }
192 
193   PetscCall(TSSetTime(ts,0.0));
194   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"mu %g, steps %D, ftime %g\n",(double)user.mu,user.steps,(double)(user.ftime)));
195 
196   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
197     Save trajectory of solution so that TSAdjointSolve() may be used
198    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
199   PetscCall(TSSetSaveTrajectory(ts));
200 
201   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
202      Set runtime options
203    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
204   PetscCall(TSSetFromOptions(ts));
205 
206   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
207      Solve nonlinear system
208      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
209   PetscCall(TSSolve(ts,user.x));
210   PetscCall(TSGetSolveTime(ts,&(user.ftime)));
211   PetscCall(TSGetStepNumber(ts,&user.steps));
212   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"mu %g, steps %D, ftime %g\n",(double)user.mu,user.steps,(double)user.ftime));
213 
214   PetscCall(VecGetArray(user.x,&x_ptr));
215   user.x_ob[0] = x_ptr[0];
216   user.x_ob[1] = x_ptr[1];
217   PetscCall(VecRestoreArray(user.x,&x_ptr));
218 
219   PetscCall(MatCreateVecs(user.A,&user.lambda[0],NULL));
220 
221   /* Create TAO solver and set desired solution method */
222   PetscCall(TaoCreate(PETSC_COMM_WORLD,&tao));
223   PetscCall(TaoSetType(tao,TAOCG));
224 
225   /* Set initial solution guess */
226   PetscCall(MatCreateVecs(user.A,&ic,NULL));
227   PetscCall(VecGetArray(ic,&x_ptr));
228   x_ptr[0]  = 2.1;
229   x_ptr[1]  = 0.7;
230   PetscCall(VecRestoreArray(ic,&x_ptr));
231 
232   PetscCall(TaoSetSolution(tao,ic));
233 
234   /* Set routine for function and gradient evaluation */
235   PetscCall(TaoSetObjectiveAndGradient(tao,NULL,FormFunctionGradient,(void *)&user));
236 
237   /* Check for any TAO command line options */
238   PetscCall(TaoSetFromOptions(tao));
239   PetscCall(TaoGetKSP(tao,&ksp));
240   if (ksp) {
241     PetscCall(KSPGetPC(ksp,&pc));
242     PetscCall(PCSetType(pc,PCNONE));
243   }
244 
245   PetscCall(TaoSetTolerances(tao,1e-10,PETSC_DEFAULT,PETSC_DEFAULT));
246 
247   /* SOLVE THE APPLICATION */
248   PetscCall(TaoSolve(tao));
249 
250   /* Free TAO data structures */
251   PetscCall(TaoDestroy(&tao));
252 
253   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
254      Free work space.  All PETSc objects should be destroyed when they
255      are no longer needed.
256    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
257   PetscCall(MatDestroy(&user.A));
258   PetscCall(VecDestroy(&user.x));
259   PetscCall(VecDestroy(&user.lambda[0]));
260   PetscCall(TSDestroy(&ts));
261   PetscCall(VecDestroy(&ic));
262   PetscCall(PetscFree(adctx));
263   PetscCall(PetscFinalize());
264   return 0;
265 }
266 
267 /* ------------------------------------------------------------------ */
268 /*
269    FormFunctionGradient - Evaluates the function and corresponding gradient.
270 
271    Input Parameters:
272    tao - the Tao context
273    X   - the input vector
274    ptr - optional user-defined context, as set by TaoSetObjectiveAndGradient()
275 
276    Output Parameters:
277    f   - the newly evaluated function
278    G   - the newly evaluated gradient
279 */
280 PetscErrorCode FormFunctionGradient(Tao tao,Vec IC,PetscReal *f,Vec G,void *ctx)
281 {
282   User              user = (User)ctx;
283   TS                ts;
284   PetscScalar       *x_ptr,*y_ptr;
285 
286   PetscFunctionBeginUser;
287   PetscCall(VecCopy(IC,user->x));
288 
289   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
290      Create timestepping solver context
291      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
292   PetscCall(TSCreate(PETSC_COMM_WORLD,&ts));
293   PetscCall(TSSetType(ts,TSRK));
294   PetscCall(TSSetRHSFunction(ts,NULL,RHSFunctionPassive,user));
295   /*   Set RHS Jacobian  for the adjoint integration */
296   PetscCall(TSSetRHSJacobian(ts,user->A,user->A,RHSJacobian,user));
297 
298   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
299      Set time
300    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
301   PetscCall(TSSetTime(ts,0.0));
302   PetscCall(TSSetTimeStep(ts,.001));
303   PetscCall(TSSetMaxTime(ts,0.5));
304   PetscCall(TSSetExactFinalTime(ts,TS_EXACTFINALTIME_MATCHSTEP));
305 
306   PetscCall(TSSetTolerances(ts,1e-7,NULL,1e-7,NULL));
307 
308   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
309     Save trajectory of solution so that TSAdjointSolve() may be used
310    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
311   PetscCall(TSSetSaveTrajectory(ts));
312 
313   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
314      Set runtime options
315    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
316   PetscCall(TSSetFromOptions(ts));
317 
318   PetscCall(TSSolve(ts,user->x));
319   PetscCall(TSGetSolveTime(ts,&user->ftime));
320   PetscCall(TSGetStepNumber(ts,&user->steps));
321   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"mu %.6f, steps %D, ftime %g\n",(double)user->mu,user->steps,(double)user->ftime));
322 
323   PetscCall(VecGetArray(user->x,&x_ptr));
324   *f   = (x_ptr[0]-user->x_ob[0])*(x_ptr[0]-user->x_ob[0])+(x_ptr[1]-user->x_ob[1])*(x_ptr[1]-user->x_ob[1]);
325   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Observed value y_ob=[%f; %f], ODE solution y=[%f;%f], Cost function f=%f\n",(double)user->x_ob[0],(double)user->x_ob[1],(double)x_ptr[0],(double)x_ptr[1],(double)(*f)));
326 
327   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
328      Adjoint model starts here
329      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
330   /*   Redet initial conditions for the adjoint integration */
331   PetscCall(VecGetArray(user->lambda[0],&y_ptr));
332   y_ptr[0] = 2.*(x_ptr[0]-user->x_ob[0]);
333   y_ptr[1] = 2.*(x_ptr[1]-user->x_ob[1]);
334   PetscCall(VecRestoreArray(user->lambda[0],&y_ptr));
335   PetscCall(VecRestoreArray(user->x,&x_ptr));
336   PetscCall(TSSetCostGradients(ts,1,user->lambda,NULL));
337 
338   PetscCall(TSAdjointSolve(ts));
339 
340   PetscCall(VecCopy(user->lambda[0],G));
341 
342   PetscCall(TSDestroy(&ts));
343   PetscFunctionReturn(0);
344 }
345 
346 /*TEST
347 
348   build:
349     requires: double !complex adolc
350 
351   test:
352     suffix: 1
353     args: -ts_rhs_jacobian_test_mult_transpose FALSE -tao_max_it 2 -ts_rhs_jacobian_test_mult FALSE
354     output_file: output/ex16opt_ic_1.out
355 
356 TEST*/
357