Actual source code: chwirut2f.F

petsc-3.5.2 2014-09-08
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  1: !  Program usage: mpirun -np 1 chwirut1f [-help] [all TAO options]
  2: !
  3: !  Description:  This example demonstrates use of the TAO package to solve a
  4: !  nonlinear least-squares problem on a single processor.  We minimize the
  5: !  Chwirut function:
  6: !       sum_{i=0}^{n/2-1} ( alpha*(x_{2i+1}-x_{2i}^2)^2 + (1-x_{2i})^2 )
  7: !
  8: !  The C version of this code is chwirut1.c
  9: !
 10: !/*T
 11: !  Concepts: TAO^Solving an unconstrained minimization problem
 12: !  Routines: TaoCreate();
 13: !  Routines: TaoSetType();
 14: !  Routines: TaoSetSeparableObjectiveRoutine();
 15: !  Routines: TaoSetInitialVector();
 16: !  Routines: TaoSetFromOptions();
 17: !  Routines: TaoSolve();
 18: !  Routines: TaoDestroy();
 19: !  Processors: n
 20: !T*/
 21: !
 22: ! ----------------------------------------------------------------------
 23: !
 24:       implicit none

 26: #include "chwirut2f.h"

 28: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 29: !                   Variable declarations
 30: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 31: !
 32: !  See additional variable declarations in the file chwirut2f.h

 34:       PetscErrorCode   ierr    ! used to check for functions returning nonzeros
 35:       Vec              x       ! solution vector
 36:       Vec              f       ! vector of functions
 37:       Tao        tao     ! Tao context
 38:       PetscInt         i




 43: !  Note: Any user-defined Fortran routines (such as FormGradient)
 44: !  MUST be declared as external.

 46:       external FormFunction

 48: !  Initialize TAO and PETSc
 49:       call PetscInitialize(PETSC_NULL_CHARACTER,ierr)

 51:       call MPI_Comm_size(PETSC_COMM_WORLD,size,ierr)
 52:       CHKERRQ(ierr)
 53:       call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr)
 54:       CHKERRQ(ierr)

 56: !  Initialize problem parameters
 57:       call InitializeData()

 59:       if (rank .eq. 0) then
 60: !  Allocate vectors for the solution and gradient
 61:          call VecCreateSeq(PETSC_COMM_SELF,n,x,ierr)
 62:          CHKERRQ(ierr)
 63:          call VecCreateSeq(PETSC_COMM_SELF,m,f,ierr)
 64:          CHKERRQ(ierr)


 67: !     The TAO code begins here

 69: !     Create TAO solver
 70:          call TaoCreate(PETSC_COMM_SELF,tao,ierr)
 71:          CHKERRQ(ierr)
 72:          call TaoSetType(tao,TAOPOUNDERS,ierr)
 73:          CHKERRQ(ierr)

 75: !     Set routines for function, gradient, and hessian evaluation
 76:          call TaoSetSeparableObjectiveRoutine(tao,f,                    &
 77:      &        FormFunction,PETSC_NULL_OBJECT,ierr)
 78:          CHKERRQ(ierr)

 80: !     Optional: Set initial guess
 81:          call FormStartingPoint(x)
 82:          call TaoSetInitialVector(tao, x, ierr)
 83:          CHKERRQ(ierr)


 86: !     Check for TAO command line options
 87:          call TaoSetFromOptions(tao,ierr)
 88:          CHKERRQ(ierr)
 89: !     SOLVE THE APPLICATION
 90:          call TaoSolve(tao,ierr)
 91:          CHKERRQ(ierr)

 93: !     Free TAO data structures
 94:          call TaoDestroy(tao,ierr)
 95:          CHKERRQ(ierr)

 97: !     Free PETSc data structures
 98:          call VecDestroy(x,ierr)
 99:          CHKERRQ(ierr)
100:          call VecDestroy(f,ierr)
101:          CHKERRQ(ierr)
102:          call StopWorkers(ierr)
103:          CHKERRQ(ierr)

105:       else
106:          call TaskWorker(ierr)
107:          CHKERRQ(ierr)
108:       endif

110:       call PetscFinalize(ierr)
111:       end


114: ! --------------------------------------------------------------------
115: !  FormFunction - Evaluates the function f(X) and gradient G(X)
116: !
117: !  Input Parameters:
118: !  tao - the Tao context
119: !  X   - input vector
120: !  dummy - not used
121: !
122: !  Output Parameters:
123: !  f - function vector

125:       subroutine FormFunction(tao, x, f, dummy, ierr)
126:       implicit none

128: ! n,alpha defined in chwirut2f.h
129: #include "chwirut2f.h"

131:       Tao        tao
132:       Vec              x,f
133:       PetscErrorCode   ierr
134:       PetscInt         dummy

136:       PetscInt         i,checkedin
137:       PetscInt         finished_tasks
138:       integer          next_task,status(MPI_STATUS_SIZE),tag,source

140: ! PETSc's VecGetArray acts differently in Fortran than it does in C.
141: ! Calling VecGetArray((Vec) X, (PetscReal) x_array(0:1), (PetscOffset) x_index, ierr)
142: ! will return an array of doubles referenced by x_array offset by x_index.
143: !  i.e.,  to reference the kth element of X, use x_array(k + x_index).
144: ! Notice that by declaring the arrays with range (0:1), we are using the C 0-indexing practice.
145:       PetscReal        f_v(0:1),x_v(0:1),fval
146:       PetscOffset      f_i,x_i

148:       0

150: !     Get pointers to vector data
151:       call VecGetArray(x,x_v,x_i,ierr)
152:       CHKERRQ(ierr)
153:       call VecGetArray(f,f_v,f_i,ierr)
154:       CHKERRQ(ierr)


157: !     Compute F(X)
158:       if (size .eq. 1) then
159:          ! Single processor
160:          do i=0,m-1
161:             call RunSimulation(x_v(x_i),i,f_v(i+f_i),ierr)
162:          enddo
163:       else
164:          ! Multiprocessor master
165:          next_task = 0
166:          finished_tasks = 0
167:          checkedin = 0

169:          do while (finished_tasks .lt. m .or. checkedin .lt. size-1)
170:             call MPI_Recv(fval,1,MPIU_SCALAR,MPI_ANY_SOURCE,               &
171:      &           MPI_ANY_TAG,PETSC_COMM_WORLD,status,ierr)
172:             tag = status(MPI_TAG)
173:             source = status(MPI_SOURCE)
174:             if (tag .eq. IDLE_TAG) then
175:                checkedin = checkedin + 1
176:             else
177:                f_v(f_i+tag) = fval
178:                finished_tasks = finished_tasks + 1
179:             endif
180:             if (next_task .lt. m) then
181:                ! Send task to worker
182:                call MPI_Send(x_v(x_i),n,MPIU_SCALAR,source,next_task,             &
183:      &              PETSC_COMM_WORLD,ierr)
184:                next_task = next_task + 1
185:             else
186:                ! Send idle message to worker
187:                call MPI_Send(x_v(x_i),n,MPIU_SCALAR,source,IDLE_TAG,              &
188:      &              PETSC_COMM_WORLD,ierr)
189:             end if
190:          enddo
191:       endif

193: !     Restore vectors
194:       call VecRestoreArray(x,x_v,x_i,ierr)
195:       CHKERRQ(ierr)
196:       call VecRestoreArray(F,f_v,f_i,ierr)
197:       CHKERRQ(ierr)
198:       return
199:       end





205:       subroutine FormStartingPoint(x)
206:       implicit none

208: ! n,alpha defined in chwirut2f.h
209: #include "chwirut2f.h"
210:       Vec             x
211:       PetscReal       x_v(0:1)
212:       PetscOffset     x_i
213:       PetscErrorCode  ierr

215:       call VecGetArray(x,x_v,x_i,ierr)
216:       CHKERRQ(ierr)
217:       x_v(x_i) = 0.15d0
218:       x_v(x_i+1) = 0.008d0
219:       x_v(x_i+2) = 0.01d0
220:       call VecRestoreArray(x,x_v,x_i,ierr)
221:       CHKERRQ(ierr)
222:       return
223:       end


226:       subroutine InitializeData()
227:       implicit none

229: ! n,alpha defined in chwirut2f.h
230: #include "chwirut2f.h"
231:       PetscInt i
232:       i=0
233:       y(i) =    92.9000;  t(i) =  0.5000; i=i+1
234:       y(i) =    78.7000;  t(i) =   0.6250; i=i+1
235:       y(i) =    64.2000;  t(i) =   0.7500; i=i+1
236:       y(i) =    64.9000;  t(i) =   0.8750; i=i+1
237:       y(i) =    57.1000;  t(i) =   1.0000; i=i+1
238:       y(i) =    43.3000;  t(i) =   1.2500; i=i+1
239:       y(i) =    31.1000;  t(i) =  1.7500; i=i+1
240:       y(i) =    23.6000;  t(i) =  2.2500; i=i+1
241:       y(i) =    31.0500;  t(i) =  1.7500; i=i+1
242:       y(i) =    23.7750;  t(i) =  2.2500; i=i+1
243:       y(i) =    17.7375;  t(i) =  2.7500; i=i+1
244:       y(i) =    13.8000;  t(i) =  3.2500; i=i+1
245:       y(i) =    11.5875;  t(i) =  3.7500; i=i+1
246:       y(i) =     9.4125;  t(i) =  4.2500; i=i+1
247:       y(i) =     7.7250;  t(i) =  4.7500; i=i+1
248:       y(i) =     7.3500;  t(i) =  5.2500; i=i+1
249:       y(i) =     8.0250;  t(i) =  5.7500; i=i+1
250:       y(i) =    90.6000;  t(i) =  0.5000; i=i+1
251:       y(i) =    76.9000;  t(i) =  0.6250; i=i+1
252:       y(i) =    71.6000;  t(i) = 0.7500; i=i+1
253:       y(i) =    63.6000;  t(i) =  0.8750; i=i+1
254:       y(i) =    54.0000;  t(i) =  1.0000; i=i+1
255:       y(i) =    39.2000;  t(i) =  1.2500; i=i+1
256:       y(i) =    29.3000;  t(i) = 1.7500; i=i+1
257:       y(i) =    21.4000;  t(i) =  2.2500; i=i+1
258:       y(i) =    29.1750;  t(i) =  1.7500; i=i+1
259:       y(i) =    22.1250;  t(i) =  2.2500; i=i+1
260:       y(i) =    17.5125;  t(i) =  2.7500; i=i+1
261:       y(i) =    14.2500;  t(i) =  3.2500; i=i+1
262:       y(i) =     9.4500;  t(i) =  3.7500; i=i+1
263:       y(i) =     9.1500;  t(i) =  4.2500; i=i+1
264:       y(i) =     7.9125;  t(i) =  4.7500; i=i+1
265:       y(i) =     8.4750;  t(i) =  5.2500; i=i+1
266:       y(i) =     6.1125;  t(i) =  5.7500; i=i+1
267:       y(i) =    80.0000;  t(i) =  0.5000; i=i+1
268:       y(i) =    79.0000;  t(i) =  0.6250; i=i+1
269:       y(i) =    63.8000;  t(i) =  0.7500; i=i+1
270:       y(i) =    57.2000;  t(i) =  0.8750; i=i+1
271:       y(i) =    53.2000;  t(i) =  1.0000; i=i+1
272:       y(i) =    42.5000;  t(i) =  1.2500; i=i+1
273:       y(i) =    26.8000;  t(i) =  1.7500; i=i+1
274:       y(i) =    20.4000;  t(i) =  2.2500; i=i+1
275:       y(i) =    26.8500;  t(i) =   1.7500; i=i+1
276:       y(i) =    21.0000;  t(i) =   2.2500; i=i+1
277:       y(i) =    16.4625;  t(i) =   2.7500; i=i+1
278:       y(i) =    12.5250;  t(i) =   3.2500; i=i+1
279:       y(i) =    10.5375;  t(i) =   3.7500; i=i+1
280:       y(i) =     8.5875;  t(i) =   4.2500; i=i+1
281:       y(i) =     7.1250;  t(i) =   4.7500; i=i+1
282:       y(i) =     6.1125;  t(i) =   5.2500; i=i+1
283:       y(i) =     5.9625;  t(i) =   5.7500; i=i+1
284:       y(i) =    74.1000;  t(i) =   0.5000; i=i+1
285:       y(i) =    67.3000;  t(i) =   0.6250; i=i+1
286:       y(i) =    60.8000;  t(i) =   0.7500; i=i+1
287:       y(i) =    55.5000;  t(i) =   0.8750; i=i+1
288:       y(i) =    50.3000;  t(i) =   1.0000; i=i+1
289:       y(i) =    41.0000;  t(i) =   1.2500; i=i+1
290:       y(i) =    29.4000;  t(i) =   1.7500; i=i+1
291:       y(i) =    20.4000;  t(i) =   2.2500; i=i+1
292:       y(i) =    29.3625;  t(i) =   1.7500; i=i+1
293:       y(i) =    21.1500;  t(i) =   2.2500; i=i+1
294:       y(i) =    16.7625;  t(i) =   2.7500; i=i+1
295:       y(i) =    13.2000;  t(i) =   3.2500; i=i+1
296:       y(i) =    10.8750;  t(i) =   3.7500; i=i+1
297:       y(i) =     8.1750;  t(i) =   4.2500; i=i+1
298:       y(i) =     7.3500;  t(i) =   4.7500; i=i+1
299:       y(i) =     5.9625;  t(i) =  5.2500; i=i+1
300:       y(i) =     5.6250;  t(i) =   5.7500; i=i+1
301:       y(i) =    81.5000;  t(i) =    .5000; i=i+1
302:       y(i) =    62.4000;  t(i) =    .7500; i=i+1
303:       y(i) =    32.5000;  t(i) =   1.5000; i=i+1
304:       y(i) =    12.4100;  t(i) =   3.0000; i=i+1
305:       y(i) =    13.1200;  t(i) =   3.0000; i=i+1
306:       y(i) =    15.5600;  t(i) =   3.0000; i=i+1
307:       y(i) =     5.6300;  t(i) =   6.0000; i=i+1
308:       y(i) =    78.0000;  t(i) =   .5000; i=i+1
309:       y(i) =    59.9000;  t(i) =    .7500; i=i+1
310:       y(i) =    33.2000;  t(i) =   1.5000; i=i+1
311:       y(i) =    13.8400;  t(i) =   3.0000; i=i+1
312:       y(i) =    12.7500;  t(i) =   3.0000; i=i+1
313:       y(i) =    14.6200;  t(i) =   3.0000; i=i+1
314:       y(i) =     3.9400;  t(i) =   6.0000; i=i+1
315:       y(i) =    76.8000;  t(i) =    .5000; i=i+1
316:       y(i) =    61.0000;  t(i) =    .7500; i=i+1
317:       y(i) =    32.9000;  t(i) =   1.5000; i=i+1
318:       y(i) =    13.8700;  t(i) = 3.0000; i=i+1
319:       y(i) =    11.8100;  t(i) =   3.0000; i=i+1
320:       y(i) =    13.3100;  t(i) =   3.0000; i=i+1
321:       y(i) =     5.4400;  t(i) =   6.0000; i=i+1
322:       y(i) =    78.0000;  t(i) =    .5000; i=i+1
323:       y(i) =    63.5000;  t(i) =    .7500; i=i+1
324:       y(i) =    33.8000;  t(i) =   1.5000; i=i+1
325:       y(i) =    12.5600;  t(i) =   3.0000; i=i+1
326:       y(i) =     5.6300;  t(i) =   6.0000; i=i+1
327:       y(i) =    12.7500;  t(i) =   3.0000; i=i+1
328:       y(i) =    13.1200;  t(i) =   3.0000; i=i+1
329:       y(i) =     5.4400;  t(i) =   6.0000; i=i+1
330:       y(i) =    76.8000;  t(i) =    .5000; i=i+1
331:       y(i) =    60.0000;  t(i) =    .7500; i=i+1
332:       y(i) =    47.8000;  t(i) =   1.0000; i=i+1
333:       y(i) =    32.0000;  t(i) =   1.5000; i=i+1
334:       y(i) =    22.2000;  t(i) =   2.0000; i=i+1
335:       y(i) =    22.5700;  t(i) =   2.0000; i=i+1
336:       y(i) =    18.8200;  t(i) =   2.5000; i=i+1
337:       y(i) =    13.9500;  t(i) =   3.0000; i=i+1
338:       y(i) =    11.2500;  t(i) =   4.0000; i=i+1
339:       y(i) =     9.0000;  t(i) =   5.0000; i=i+1
340:       y(i) =     6.6700;  t(i) =   6.0000; i=i+1
341:       y(i) =    75.8000;  t(i) =    .5000; i=i+1
342:       y(i) =    62.0000;  t(i) =    .7500; i=i+1
343:       y(i) =    48.8000;  t(i) =   1.0000; i=i+1
344:       y(i) =    35.2000;  t(i) =   1.5000; i=i+1
345:       y(i) =    20.0000;  t(i) =   2.0000; i=i+1
346:       y(i) =    20.3200;  t(i) =   2.0000; i=i+1
347:       y(i) =    19.3100;  t(i) =   2.5000; i=i+1
348:       y(i) =    12.7500;  t(i) =   3.0000; i=i+1
349:       y(i) =    10.4200;  t(i) =   4.0000; i=i+1
350:       y(i) =     7.3100;  t(i) =   5.0000; i=i+1
351:       y(i) =     7.4200;  t(i) =   6.0000; i=i+1
352:       y(i) =    70.5000;  t(i) =    .5000; i=i+1
353:       y(i) =    59.5000;  t(i) =    .7500; i=i+1
354:       y(i) =    48.5000;  t(i) =   1.0000; i=i+1
355:       y(i) =    35.8000;  t(i) =   1.5000; i=i+1
356:       y(i) =    21.0000;  t(i) =   2.0000; i=i+1
357:       y(i) =    21.6700;  t(i) =   2.0000; i=i+1
358:       y(i) =    21.0000;  t(i) =   2.5000; i=i+1
359:       y(i) =    15.6400;  t(i) =   3.0000; i=i+1
360:       y(i) =     8.1700;  t(i) =   4.0000; i=i+1
361:       y(i) =     8.5500;  t(i) =   5.0000; i=i+1
362:       y(i) =    10.1200;  t(i) =   6.0000; i=i+1
363:       y(i) =    78.0000;  t(i) =    .5000; i=i+1
364:       y(i) =    66.0000;  t(i) =    .6250; i=i+1
365:       y(i) =    62.0000;  t(i) =    .7500; i=i+1
366:       y(i) =    58.0000;  t(i) =    .8750; i=i+1
367:       y(i) =    47.7000;  t(i) =   1.0000; i=i+1
368:       y(i) =    37.8000;  t(i) =   1.2500; i=i+1
369:       y(i) =    20.2000;  t(i) =   2.2500; i=i+1
370:       y(i) =    21.0700;  t(i) =   2.2500; i=i+1
371:       y(i) =    13.8700;  t(i) =   2.7500; i=i+1
372:       y(i) =     9.6700;  t(i) =   3.2500; i=i+1
373:       y(i) =     7.7600;  t(i) =   3.7500; i=i+1
374:       y(i) =     5.4400;  t(i) =  4.2500; i=i+1
375:       y(i) =     4.8700;  t(i) =  4.7500; i=i+1
376:       y(i) =     4.0100;  t(i) =   5.2500; i=i+1
377:       y(i) =     3.7500;  t(i) =   5.7500; i=i+1
378:       y(i) =    24.1900;  t(i) =   3.0000; i=i+1
379:       y(i) =    25.7600;  t(i) =   3.0000; i=i+1
380:       y(i) =    18.0700;  t(i) =   3.0000; i=i+1
381:       y(i) =    11.8100;  t(i) =   3.0000; i=i+1
382:       y(i) =    12.0700;  t(i) =   3.0000; i=i+1
383:       y(i) =    16.1200;  t(i) =   3.0000; i=i+1
384:       y(i) =    70.8000;  t(i) =    .5000; i=i+1
385:       y(i) =    54.7000;  t(i) =    .7500; i=i+1
386:       y(i) =    48.0000;  t(i) =   1.0000; i=i+1
387:       y(i) =    39.8000;  t(i) =   1.5000; i=i+1
388:       y(i) =    29.8000;  t(i) =   2.0000; i=i+1
389:       y(i) =    23.7000;  t(i) =   2.5000; i=i+1
390:       y(i) =    29.6200;  t(i) =   2.0000; i=i+1
391:       y(i) =    23.8100;  t(i) =   2.5000; i=i+1
392:       y(i) =    17.7000;  t(i) =   3.0000; i=i+1
393:       y(i) =    11.5500;  t(i) =   4.0000; i=i+1
394:       y(i) =    12.0700;  t(i) =   5.0000; i=i+1
395:       y(i) =     8.7400;  t(i) =   6.0000; i=i+1
396:       y(i) =    80.7000;  t(i) =    .5000; i=i+1
397:       y(i) =    61.3000;  t(i) =    .7500; i=i+1
398:       y(i) =    47.5000;  t(i) =   1.0000; i=i+1
399:       y(i) =    29.0000;  t(i) =   1.5000; i=i+1
400:       y(i) =    24.0000;  t(i) =   2.0000; i=i+1
401:       y(i) =    17.7000;  t(i) =   2.5000; i=i+1
402:       y(i) =    24.5600;  t(i) =   2.0000; i=i+1
403:       y(i) =    18.6700;  t(i) =   2.5000; i=i+1
404:       y(i) =    16.2400;  t(i) =   3.0000; i=i+1
405:       y(i) =     8.7400;  t(i) =   4.0000; i=i+1
406:       y(i) =     7.8700;  t(i) =   5.0000; i=i+1
407:       y(i) =     8.5100;  t(i) =   6.0000; i=i+1
408:       y(i) =    66.7000;  t(i) =    .5000; i=i+1
409:       y(i) =    59.2000;  t(i) =    .7500; i=i+1
410:       y(i) =    40.8000;  t(i) =   1.0000; i=i+1
411:       y(i) =    30.7000;  t(i) =   1.5000; i=i+1
412:       y(i) =    25.7000;  t(i) =   2.0000; i=i+1
413:       y(i) =    16.3000;  t(i) =   2.5000; i=i+1
414:       y(i) =    25.9900;  t(i) =   2.0000; i=i+1
415:       y(i) =    16.9500;  t(i) =   2.5000; i=i+1
416:       y(i) =    13.3500;  t(i) =   3.0000; i=i+1
417:       y(i) =     8.6200;  t(i) =   4.0000; i=i+1
418:       y(i) =     7.2000;  t(i) =   5.0000; i=i+1
419:       y(i) =     6.6400;  t(i) =   6.0000; i=i+1
420:       y(i) =    13.6900;  t(i) =   3.0000; i=i+1
421:       y(i) =    81.0000;  t(i) =    .5000; i=i+1
422:       y(i) =    64.5000;  t(i) =    .7500; i=i+1
423:       y(i) =    35.5000;  t(i) =   1.5000; i=i+1
424:       y(i) =    13.3100;  t(i) =   3.0000; i=i+1
425:       y(i) =     4.8700;  t(i) =   6.0000; i=i+1
426:       y(i) =    12.9400;  t(i) =   3.0000; i=i+1
427:       y(i) =     5.0600;  t(i) =   6.0000; i=i+1
428:       y(i) =    15.1900;  t(i) =   3.0000; i=i+1
429:       y(i) =    14.6200;  t(i) =   3.0000; i=i+1
430:       y(i) =    15.6400;  t(i) =   3.0000; i=i+1
431:       y(i) =    25.5000;  t(i) =   1.7500; i=i+1
432:       y(i) =    25.9500;  t(i) =   1.7500; i=i+1
433:       y(i) =    81.7000;  t(i) =    .5000; i=i+1
434:       y(i) =    61.6000;  t(i) =    .7500; i=i+1
435:       y(i) =    29.8000;  t(i) =   1.7500; i=i+1
436:       y(i) =    29.8100;  t(i) =   1.7500; i=i+1
437:       y(i) =    17.1700;  t(i) =   2.7500; i=i+1
438:       y(i) =    10.3900;  t(i) =   3.7500; i=i+1
439:       y(i) =    28.4000;  t(i) =   1.7500; i=i+1
440:       y(i) =    28.6900;  t(i) =   1.7500; i=i+1
441:       y(i) =    81.3000;  t(i) =    .5000; i=i+1
442:       y(i) =    60.9000;  t(i) =    .7500; i=i+1
443:       y(i) =    16.6500;  t(i) =   2.7500; i=i+1
444:       y(i) =    10.0500;  t(i) =   3.7500; i=i+1
445:       y(i) =    28.9000;  t(i) =   1.7500; i=i+1
446:       y(i) =    28.9500;  t(i) =   1.7500; i=i+1

448:       return
449:       end



453:       subroutine TaskWorker(ierr)
454:       implicit none
455: #include "chwirut2f.h"
456:       PetscErrorCode ierr
457:       PetscReal x(n),f
458:       integer tag
459:       PetscInt index
460:       integer status(MPI_STATUS_SIZE)

462:       tag = IDLE_TAG
463:       f   = 0.0
464:       ! Send check-in message to master
465:       call MPI_Send(f,1,MPIU_SCALAR,0,IDLE_TAG,PETSC_COMM_WORLD,ierr)
466:       CHKERRQ(ierr)
467:       do while (tag .ne. DIE_TAG)
468:          call MPI_Recv(x,n,MPIU_SCALAR,0,MPI_ANY_TAG,PETSC_COMM_WORLD,     &
469:      &        status,ierr)
470:          CHKERRQ(ierr)
471:          tag = status(MPI_TAG)
472:          if (tag .eq. IDLE_TAG) then
473:             call MPI_Send(f,1,MPIU_SCALAR,0,IDLE_TAG,PETSC_COMM_WORLD,     &
474:      &           ierr)
475:             CHKERRQ(ierr)
476:          else if (tag .ne. DIE_TAG) then
477:             index = tag
478:             ! Compute local part of residual
479:             call RunSimulation(x,index,f,ierr)
480:             CHKERRQ(ierr)

482:             ! Return residual to master
483:             call MPI_Send(f,1,MPIU_SCALAR,0,tag,PETSC_COMM_WORLD,ierr)
484:             CHKERRQ(ierr)
485:          end if
486:       enddo
487:       0
488:       return
489:       end



493:       subroutine RunSimulation(x,i,f,ierr)
494:       implicit none
495: #include "chwirut2f.h"
496:       PetscReal x(n),f
497:       PetscInt i
498:       PetscErrorCode ierr
499:       f = y(i) - exp(-x(1)*t(i))/(x(2)+x(3)*t(i))
500:       0
501:       return
502:       end

504:       subroutine StopWorkers(ierr)
505:       implicit none
506: #include "chwirut2f.h"
507:       integer checkedin
508:       integer status(MPI_STATUS_SIZE)
509:       integer source
510:       PetscReal f,x(n)
511:       PetscErrorCode ierr
512:       PetscInt i

514:       checkedin=0
515:       do while (checkedin .lt. size-1)
516:          call MPI_Recv(f,1,MPIU_SCALAR,MPI_ANY_SOURCE,MPI_ANY_TAG,         &
517:      &        PETSC_COMM_WORLD,status,ierr)
518:          CHKERRQ(ierr)
519:          checkedin=checkedin+1
520:          source = status(MPI_SOURCE)
521:          do i=1,n
522:            x(i) = 0.0
523:          enddo
524:          call MPI_Send(x,n,MPIU_SCALAR,source,DIE_TAG,PETSC_COMM_WORLD,    &
525:      &        ierr)
526:          CHKERRQ(ierr)
527:       enddo
528:       ierr=0
529:       return
530:       end