xref: /petsc/src/tao/leastsquares/tutorials/chwirut2.c (revision ccb4e88a40f0b86eaeca07ff64c64e4de2fae686)
1 /*
2    Include "petsctao.h" so that we can use TAO solvers.  Note that this
3    file automatically includes libraries such as:
4      petsc.h       - base PETSc routines   petscvec.h - vectors
5      petscsys.h    - system routines        petscmat.h - matrices
6      petscis.h     - index sets            petscksp.h - Krylov subspace methods
7      petscviewer.h - viewers               petscpc.h  - preconditioners
8 
9 */
10 
11 #include <petsctao.h>
12 
13 /*
14 Description:   These data are the result of a NIST study involving
15                ultrasonic calibration.  The response variable is
16                ultrasonic response, and the predictor variable is
17                metal distance.
18 
19 Reference:     Chwirut, D., NIST (197?).
20                Ultrasonic Reference Block Study.
21 */
22 
23 static char help[]="Finds the nonlinear least-squares solution to the model \n\
24             y = exp[-b1*x]/(b2+b3*x)  +  e \n";
25 
26 /* T
27    Concepts: TAO^Solving a system of nonlinear equations, nonlinear least squares
28    Routines: TaoCreate();
29    Routines: TaoSetType();
30    Routines: TaoSetResidualRoutine();
31    Routines: TaoSetMonitor();
32    Routines: TaoSetInitialVector();
33    Routines: TaoSetFromOptions();
34    Routines: TaoSolve();
35    Routines: TaoDestroy();
36    Processors: n
37 T*/
38 
39 #define NOBSERVATIONS 214
40 #define NPARAMETERS 3
41 
42 #define DIE_TAG 2000
43 #define IDLE_TAG 1000
44 
45 /* User-defined application context */
46 typedef struct {
47   /* Working space */
48   PetscReal   t[NOBSERVATIONS];   /* array of independent variables of observation */
49   PetscReal   y[NOBSERVATIONS];   /* array of dependent variables */
50   PetscMPIInt size,rank;
51 } AppCtx;
52 
53 /* User provided Routines */
54 PetscErrorCode InitializeData(AppCtx *user);
55 PetscErrorCode FormStartingPoint(Vec);
56 PetscErrorCode EvaluateFunction(Tao, Vec, Vec, void *);
57 PetscErrorCode TaskWorker(AppCtx *user);
58 PetscErrorCode StopWorkers(AppCtx *user);
59 PetscErrorCode RunSimulation(PetscReal *x, PetscInt i, PetscReal*f, AppCtx *user);
60 
61 /*--------------------------------------------------------------------*/
62 int main(int argc,char **argv)
63 {
64   PetscErrorCode ierr;           /* used to check for functions returning nonzeros */
65   Vec            x, f;               /* solution, function */
66   Tao            tao;                /* Tao solver context */
67   AppCtx         user;               /* user-defined work context */
68 
69    /* Initialize TAO and PETSc */
70   ierr = PetscInitialize(&argc,&argv,(char *)0,help);if (ierr) return ierr;
71   MPI_Comm_size(MPI_COMM_WORLD,&user.size);
72   MPI_Comm_rank(MPI_COMM_WORLD,&user.rank);
73   ierr = InitializeData(&user);CHKERRQ(ierr);
74 
75   /* Run optimization on rank 0 */
76   if (user.rank == 0) {
77     /* Allocate vectors */
78     ierr = VecCreateSeq(PETSC_COMM_SELF,NPARAMETERS,&x);CHKERRQ(ierr);
79     ierr = VecCreateSeq(PETSC_COMM_SELF,NOBSERVATIONS,&f);CHKERRQ(ierr);
80 
81     /* TAO code begins here */
82 
83     /* Create TAO solver and set desired solution method */
84     ierr = TaoCreate(PETSC_COMM_SELF,&tao);CHKERRQ(ierr);
85     ierr = TaoSetType(tao,TAOPOUNDERS);CHKERRQ(ierr);
86 
87     /* Set the function and Jacobian routines. */
88     ierr = FormStartingPoint(x);CHKERRQ(ierr);
89     ierr = TaoSetInitialVector(tao,x);CHKERRQ(ierr);
90     ierr = TaoSetResidualRoutine(tao,f,EvaluateFunction,(void*)&user);CHKERRQ(ierr);
91 
92     /* Check for any TAO command line arguments */
93     ierr = TaoSetFromOptions(tao);CHKERRQ(ierr);
94 
95     /* Perform the Solve */
96     ierr = TaoSolve(tao);CHKERRQ(ierr);
97 
98     /* Free TAO data structures */
99     ierr = TaoDestroy(&tao);CHKERRQ(ierr);
100 
101     /* Free PETSc data structures */
102     ierr = VecDestroy(&x);CHKERRQ(ierr);
103     ierr = VecDestroy(&f);CHKERRQ(ierr);
104     StopWorkers(&user);
105   } else {
106     TaskWorker(&user);
107   }
108   ierr = PetscFinalize();
109   return ierr;
110 }
111 
112 /*--------------------------------------------------------------------*/
113 PetscErrorCode EvaluateFunction(Tao tao, Vec X, Vec F, void *ptr)
114 {
115   AppCtx         *user = (AppCtx *)ptr;
116   PetscInt       i;
117   PetscReal      *x,*f;
118   PetscErrorCode ierr;
119 
120   PetscFunctionBegin;
121   ierr = VecGetArray(X,&x);CHKERRQ(ierr);
122   ierr = VecGetArray(F,&f);CHKERRQ(ierr);
123   if (user->size == 1) {
124     /* Single processor */
125     for (i=0;i<NOBSERVATIONS;i++) {
126       ierr = RunSimulation(x,i,&f[i],user);CHKERRQ(ierr);
127     }
128   } else {
129     /* Multiprocessor main */
130     PetscMPIInt tag;
131     PetscInt    finishedtasks,next_task,checkedin;
132     PetscReal   f_i=0.0;
133     MPI_Status  status;
134 
135     next_task=0;
136     finishedtasks=0;
137     checkedin=0;
138 
139     while (finishedtasks < NOBSERVATIONS || checkedin < user->size-1) {
140       ierr = MPI_Recv(&f_i,1,MPIU_REAL,MPI_ANY_SOURCE,MPI_ANY_TAG,PETSC_COMM_WORLD,&status);CHKERRMPI(ierr);
141       if (status.MPI_TAG == IDLE_TAG) {
142         checkedin++;
143       } else {
144 
145         tag = status.MPI_TAG;
146         f[tag] = (PetscReal)f_i;
147         finishedtasks++;
148       }
149 
150       if (next_task<NOBSERVATIONS) {
151         ierr = MPI_Send(x,NPARAMETERS,MPIU_REAL,status.MPI_SOURCE,next_task,PETSC_COMM_WORLD);CHKERRMPI(ierr);
152         next_task++;
153 
154       } else {
155         /* Send idle message */
156         ierr = MPI_Send(x,NPARAMETERS,MPIU_REAL,status.MPI_SOURCE,IDLE_TAG,PETSC_COMM_WORLD);CHKERRMPI(ierr);
157       }
158     }
159   }
160   ierr = VecRestoreArray(X,&x);CHKERRQ(ierr);
161   ierr = VecRestoreArray(F,&f);CHKERRQ(ierr);
162   PetscLogFlops(6*NOBSERVATIONS);
163   PetscFunctionReturn(0);
164 }
165 
166 /* ------------------------------------------------------------ */
167 PetscErrorCode FormStartingPoint(Vec X)
168 {
169   PetscReal      *x;
170   PetscErrorCode ierr;
171 
172   PetscFunctionBegin;
173   ierr = VecGetArray(X,&x);CHKERRQ(ierr);
174   x[0] = 0.15;
175   x[1] = 0.008;
176   x[2] = 0.010;
177   ierr = VecRestoreArray(X,&x);CHKERRQ(ierr);
178   PetscFunctionReturn(0);
179 }
180 
181 /* ---------------------------------------------------------------------- */
182 PetscErrorCode InitializeData(AppCtx *user)
183 {
184   PetscReal *t=user->t,*y=user->y;
185   PetscInt  i=0;
186 
187   PetscFunctionBegin;
188   y[i] =   92.9000;   t[i++] =  0.5000;
189   y[i] =    78.7000;  t[i++] =   0.6250;
190   y[i] =    64.2000;  t[i++] =   0.7500;
191   y[i] =    64.9000;  t[i++] =   0.8750;
192   y[i] =    57.1000;  t[i++] =   1.0000;
193   y[i] =    43.3000;  t[i++] =   1.2500;
194   y[i] =    31.1000;   t[i++] =  1.7500;
195   y[i] =    23.6000;   t[i++] =  2.2500;
196   y[i] =    31.0500;   t[i++] =  1.7500;
197   y[i] =    23.7750;   t[i++] =  2.2500;
198   y[i] =    17.7375;   t[i++] =  2.7500;
199   y[i] =    13.8000;   t[i++] =  3.2500;
200   y[i] =    11.5875;   t[i++] =  3.7500;
201   y[i] =     9.4125;   t[i++] =  4.2500;
202   y[i] =     7.7250;   t[i++] =  4.7500;
203   y[i] =     7.3500;   t[i++] =  5.2500;
204   y[i] =     8.0250;   t[i++] =  5.7500;
205   y[i] =    90.6000;   t[i++] =  0.5000;
206   y[i] =    76.9000;   t[i++] =  0.6250;
207   y[i] =    71.6000;   t[i++] = 0.7500;
208   y[i] =    63.6000;   t[i++] =  0.8750;
209   y[i] =    54.0000;   t[i++] =  1.0000;
210   y[i] =    39.2000;   t[i++] =  1.2500;
211   y[i] =    29.3000;   t[i++] = 1.7500;
212   y[i] =    21.4000;   t[i++] =  2.2500;
213   y[i] =    29.1750;   t[i++] =  1.7500;
214   y[i] =    22.1250;   t[i++] =  2.2500;
215   y[i] =    17.5125;   t[i++] =  2.7500;
216   y[i] =    14.2500;   t[i++] =  3.2500;
217   y[i] =     9.4500;   t[i++] =  3.7500;
218   y[i] =     9.1500;   t[i++] =  4.2500;
219   y[i] =     7.9125;   t[i++] =  4.7500;
220   y[i] =     8.4750;   t[i++] =  5.2500;
221   y[i] =     6.1125;   t[i++] =  5.7500;
222   y[i] =    80.0000;   t[i++] =  0.5000;
223   y[i] =    79.0000;   t[i++] =  0.6250;
224   y[i] =    63.8000;   t[i++] =  0.7500;
225   y[i] =    57.2000;   t[i++] =  0.8750;
226   y[i] =    53.2000;   t[i++] =  1.0000;
227   y[i] =   42.5000;   t[i++] =  1.2500;
228   y[i] =   26.8000;   t[i++] =  1.7500;
229   y[i] =    20.4000;   t[i++] =  2.2500;
230   y[i] =    26.8500;  t[i++] =   1.7500;
231   y[i] =    21.0000;  t[i++] =   2.2500;
232   y[i] =    16.4625;  t[i++] =   2.7500;
233   y[i] =    12.5250;  t[i++] =   3.2500;
234   y[i] =    10.5375;  t[i++] =   3.7500;
235   y[i] =     8.5875;  t[i++] =   4.2500;
236   y[i] =     7.1250;  t[i++] =   4.7500;
237   y[i] =     6.1125;  t[i++] =   5.2500;
238   y[i] =     5.9625;  t[i++] =   5.7500;
239   y[i] =    74.1000;  t[i++] =   0.5000;
240   y[i] =    67.3000;  t[i++] =   0.6250;
241   y[i] =    60.8000;  t[i++] =   0.7500;
242   y[i] =    55.5000;  t[i++] =   0.8750;
243   y[i] =    50.3000;  t[i++] =   1.0000;
244   y[i] =    41.0000;  t[i++] =   1.2500;
245   y[i] =    29.4000;  t[i++] =   1.7500;
246   y[i] =    20.4000;  t[i++] =   2.2500;
247   y[i] =    29.3625;  t[i++] =   1.7500;
248   y[i] =    21.1500;  t[i++] =   2.2500;
249   y[i] =    16.7625;  t[i++] =   2.7500;
250   y[i] =    13.2000;  t[i++] =   3.2500;
251   y[i] =    10.8750;  t[i++] =   3.7500;
252   y[i] =     8.1750;  t[i++] =   4.2500;
253   y[i] =     7.3500;  t[i++] =   4.7500;
254   y[i] =     5.9625;  t[i++] =  5.2500;
255   y[i] =     5.6250;  t[i++] =   5.7500;
256   y[i] =    81.5000;  t[i++] =    .5000;
257   y[i] =    62.4000;  t[i++] =    .7500;
258   y[i] =    32.5000;  t[i++] =   1.5000;
259   y[i] =    12.4100;  t[i++] =   3.0000;
260   y[i] =    13.1200;  t[i++] =   3.0000;
261   y[i] =    15.5600;  t[i++] =   3.0000;
262   y[i] =     5.6300;  t[i++] =   6.0000;
263   y[i] =    78.0000;   t[i++] =   .5000;
264   y[i] =    59.9000;  t[i++] =    .7500;
265   y[i] =    33.2000;  t[i++] =   1.5000;
266   y[i] =    13.8400;  t[i++] =   3.0000;
267   y[i] =    12.7500;  t[i++] =   3.0000;
268   y[i] =    14.6200;  t[i++] =   3.0000;
269   y[i] =     3.9400;  t[i++] =   6.0000;
270   y[i] =    76.8000;  t[i++] =    .5000;
271   y[i] =    61.0000;  t[i++] =    .7500;
272   y[i] =    32.9000;  t[i++] =   1.5000;
273   y[i] =   13.8700;   t[i++] = 3.0000;
274   y[i] =    11.8100;  t[i++] =   3.0000;
275   y[i] =    13.3100;  t[i++] =   3.0000;
276   y[i] =     5.4400;  t[i++] =   6.0000;
277   y[i] =    78.0000;  t[i++] =    .5000;
278   y[i] =    63.5000;  t[i++] =    .7500;
279   y[i] =    33.8000;  t[i++] =   1.5000;
280   y[i] =    12.5600;  t[i++] =   3.0000;
281   y[i] =     5.6300;  t[i++] =   6.0000;
282   y[i] =    12.7500;  t[i++] =   3.0000;
283   y[i] =    13.1200;  t[i++] =   3.0000;
284   y[i] =     5.4400;  t[i++] =   6.0000;
285   y[i] =    76.8000;  t[i++] =    .5000;
286   y[i] =    60.0000;  t[i++] =    .7500;
287   y[i] =    47.8000;  t[i++] =   1.0000;
288   y[i] =    32.0000;  t[i++] =   1.5000;
289   y[i] =    22.2000;  t[i++] =   2.0000;
290   y[i] =    22.5700;  t[i++] =   2.0000;
291   y[i] =    18.8200;  t[i++] =   2.5000;
292   y[i] =    13.9500;  t[i++] =   3.0000;
293   y[i] =    11.2500;  t[i++] =   4.0000;
294   y[i] =     9.0000;  t[i++] =   5.0000;
295   y[i] =     6.6700;  t[i++] =   6.0000;
296   y[i] =    75.8000;  t[i++] =    .5000;
297   y[i] =    62.0000;  t[i++] =    .7500;
298   y[i] =    48.8000;  t[i++] =   1.0000;
299   y[i] =    35.2000;  t[i++] =   1.5000;
300   y[i] =    20.0000;  t[i++] =   2.0000;
301   y[i] =    20.3200;  t[i++] =   2.0000;
302   y[i] =    19.3100;  t[i++] =   2.5000;
303   y[i] =    12.7500;  t[i++] =   3.0000;
304   y[i] =    10.4200;  t[i++] =   4.0000;
305   y[i] =     7.3100;  t[i++] =   5.0000;
306   y[i] =     7.4200;  t[i++] =   6.0000;
307   y[i] =    70.5000;  t[i++] =    .5000;
308   y[i] =    59.5000;  t[i++] =    .7500;
309   y[i] =    48.5000;  t[i++] =   1.0000;
310   y[i] =    35.8000;  t[i++] =   1.5000;
311   y[i] =    21.0000;  t[i++] =   2.0000;
312   y[i] =    21.6700;  t[i++] =   2.0000;
313   y[i] =    21.0000;  t[i++] =   2.5000;
314   y[i] =    15.6400;  t[i++] =   3.0000;
315   y[i] =     8.1700;  t[i++] =   4.0000;
316   y[i] =     8.5500;  t[i++] =   5.0000;
317   y[i] =    10.1200;  t[i++] =   6.0000;
318   y[i] =    78.0000;  t[i++] =    .5000;
319   y[i] =    66.0000;  t[i++] =    .6250;
320   y[i] =    62.0000;  t[i++] =    .7500;
321   y[i] =    58.0000;  t[i++] =    .8750;
322   y[i] =    47.7000;  t[i++] =   1.0000;
323   y[i] =    37.8000;  t[i++] =   1.2500;
324   y[i] =    20.2000;  t[i++] =   2.2500;
325   y[i] =    21.0700;  t[i++] =   2.2500;
326   y[i] =    13.8700;  t[i++] =   2.7500;
327   y[i] =     9.6700;  t[i++] =   3.2500;
328   y[i] =     7.7600;  t[i++] =   3.7500;
329   y[i] =    5.4400;   t[i++] =  4.2500;
330   y[i] =    4.8700;   t[i++] =  4.7500;
331   y[i] =     4.0100;  t[i++] =   5.2500;
332   y[i] =     3.7500;  t[i++] =   5.7500;
333   y[i] =    24.1900;  t[i++] =   3.0000;
334   y[i] =    25.7600;  t[i++] =   3.0000;
335   y[i] =    18.0700;  t[i++] =   3.0000;
336   y[i] =    11.8100;  t[i++] =   3.0000;
337   y[i] =    12.0700;  t[i++] =   3.0000;
338   y[i] =    16.1200;  t[i++] =   3.0000;
339   y[i] =    70.8000;  t[i++] =    .5000;
340   y[i] =    54.7000;  t[i++] =    .7500;
341   y[i] =    48.0000;  t[i++] =   1.0000;
342   y[i] =    39.8000;  t[i++] =   1.5000;
343   y[i] =    29.8000;  t[i++] =   2.0000;
344   y[i] =    23.7000;  t[i++] =   2.5000;
345   y[i] =    29.6200;  t[i++] =   2.0000;
346   y[i] =    23.8100;  t[i++] =   2.5000;
347   y[i] =    17.7000;  t[i++] =   3.0000;
348   y[i] =    11.5500;  t[i++] =   4.0000;
349   y[i] =    12.0700;  t[i++] =   5.0000;
350   y[i] =     8.7400;  t[i++] =   6.0000;
351   y[i] =    80.7000;  t[i++] =    .5000;
352   y[i] =    61.3000;  t[i++] =    .7500;
353   y[i] =    47.5000;  t[i++] =   1.0000;
354    y[i] =   29.0000;  t[i++] =   1.5000;
355    y[i] =   24.0000;  t[i++] =   2.0000;
356   y[i] =    17.7000;  t[i++] =   2.5000;
357   y[i] =    24.5600;  t[i++] =   2.0000;
358   y[i] =    18.6700;  t[i++] =   2.5000;
359    y[i] =   16.2400;  t[i++] =   3.0000;
360   y[i] =     8.7400;  t[i++] =   4.0000;
361   y[i] =     7.8700;  t[i++] =   5.0000;
362   y[i] =     8.5100;  t[i++] =   6.0000;
363   y[i] =    66.7000;  t[i++] =    .5000;
364   y[i] =    59.2000;  t[i++] =    .7500;
365   y[i] =    40.8000;  t[i++] =   1.0000;
366   y[i] =    30.7000;  t[i++] =   1.5000;
367   y[i] =    25.7000;  t[i++] =   2.0000;
368   y[i] =    16.3000;  t[i++] =   2.5000;
369   y[i] =    25.9900;  t[i++] =   2.0000;
370   y[i] =    16.9500;  t[i++] =   2.5000;
371   y[i] =    13.3500;  t[i++] =   3.0000;
372   y[i] =     8.6200;  t[i++] =   4.0000;
373   y[i] =     7.2000;  t[i++] =   5.0000;
374   y[i] =     6.6400;  t[i++] =   6.0000;
375   y[i] =    13.6900;  t[i++] =   3.0000;
376   y[i] =    81.0000;  t[i++] =    .5000;
377   y[i] =    64.5000;  t[i++] =    .7500;
378   y[i] =    35.5000;  t[i++] =   1.5000;
379    y[i] =   13.3100;  t[i++] =   3.0000;
380   y[i] =     4.8700;  t[i++] =   6.0000;
381   y[i] =    12.9400;  t[i++] =   3.0000;
382   y[i] =     5.0600;  t[i++] =   6.0000;
383   y[i] =    15.1900;  t[i++] =   3.0000;
384   y[i] =    14.6200;  t[i++] =   3.0000;
385   y[i] =    15.6400;  t[i++] =   3.0000;
386   y[i] =    25.5000;  t[i++] =   1.7500;
387   y[i] =    25.9500;  t[i++] =   1.7500;
388   y[i] =    81.7000;  t[i++] =    .5000;
389   y[i] =    61.6000;  t[i++] =    .7500;
390   y[i] =    29.8000;  t[i++] =   1.7500;
391   y[i] =    29.8100;  t[i++] =   1.7500;
392   y[i] =    17.1700;  t[i++] =   2.7500;
393   y[i] =    10.3900;  t[i++] =   3.7500;
394   y[i] =    28.4000;  t[i++] =   1.7500;
395   y[i] =    28.6900;  t[i++] =   1.7500;
396   y[i] =    81.3000;  t[i++] =    .5000;
397   y[i] =    60.9000;  t[i++] =    .7500;
398   y[i] =    16.6500;  t[i++] =   2.7500;
399   y[i] =    10.0500;  t[i++] =   3.7500;
400   y[i] =    28.9000;  t[i++] =   1.7500;
401   y[i] =    28.9500;  t[i++] =   1.7500;
402   PetscFunctionReturn(0);
403 }
404 
405 PetscErrorCode TaskWorker(AppCtx *user)
406 {
407   PetscReal      x[NPARAMETERS],f = 0.0;
408   PetscMPIInt    tag=IDLE_TAG;
409   PetscInt       index;
410   MPI_Status     status;
411   PetscErrorCode ierr;
412 
413   PetscFunctionBegin;
414   /* Send check-in message to rank-0 */
415 
416   ierr = MPI_Send(&f,1,MPIU_REAL,0,IDLE_TAG,PETSC_COMM_WORLD);CHKERRMPI(ierr);
417   while (tag != DIE_TAG) {
418     ierr = MPI_Recv(x,NPARAMETERS,MPIU_REAL,0,MPI_ANY_TAG,PETSC_COMM_WORLD,&status);CHKERRMPI(ierr);
419     tag = status.MPI_TAG;
420     if (tag == IDLE_TAG) {
421       ierr = MPI_Send(&f,1,MPIU_REAL,0,IDLE_TAG,PETSC_COMM_WORLD);CHKERRMPI(ierr);
422     } else if (tag != DIE_TAG) {
423       index = (PetscInt)tag;
424       ierr = RunSimulation(x,index,&f,user);CHKERRQ(ierr);
425       ierr = MPI_Send(&f,1,MPIU_REAL,0,tag,PETSC_COMM_WORLD);CHKERRMPI(ierr);
426     }
427   }
428   PetscFunctionReturn(0);
429 }
430 
431 PetscErrorCode RunSimulation(PetscReal *x, PetscInt i, PetscReal*f, AppCtx *user)
432 {
433   PetscReal *t = user->t;
434   PetscReal *y = user->y;
435 #if defined(PETSC_USE_REAL_SINGLE)
436   *f = y[i] - exp(-x[0]*t[i])/(x[1] + x[2]*t[i]); /* expf() for single-precision breaks this example on freebsd, valgrind errors on linux */
437 #else
438   *f = y[i] - PetscExpScalar(-x[0]*t[i])/(x[1] + x[2]*t[i]);
439 #endif
440   return(0);
441 }
442 
443 PetscErrorCode StopWorkers(AppCtx *user)
444 {
445   PetscInt       checkedin;
446   MPI_Status     status;
447   PetscReal      f,x[NPARAMETERS];
448   PetscErrorCode ierr;
449 
450   PetscFunctionBegin;
451   checkedin=0;
452   while (checkedin < user->size-1) {
453     ierr = MPI_Recv(&f,1,MPIU_REAL,MPI_ANY_SOURCE,MPI_ANY_TAG,PETSC_COMM_WORLD,&status);CHKERRMPI(ierr);
454     checkedin++;
455     ierr = PetscArrayzero(x,NPARAMETERS);CHKERRQ(ierr);
456     ierr = MPI_Send(x,NPARAMETERS,MPIU_REAL,status.MPI_SOURCE,DIE_TAG,PETSC_COMM_WORLD);CHKERRMPI(ierr);
457   }
458   PetscFunctionReturn(0);
459 }
460 
461 /*TEST
462 
463    build:
464       requires: !complex
465 
466    test:
467       nsize: 3
468       requires: !single
469       args: -tao_smonitor -tao_max_it 100 -tao_type pounders -tao_gatol 1.e-5
470 
471 TEST*/
472