Actual source code: ts.c

petsc-3.5.2 2014-09-08
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  2: #include <petsc-private/tsimpl.h>        /*I "petscts.h"  I*/
  3: #include <petscdmshell.h>
  4: #include <petscdmda.h>
  5: #include <petscviewer.h>
  6: #include <petscdraw.h>

  8: /* Logging support */
  9: PetscClassId  TS_CLASSID, DMTS_CLASSID;
 10: PetscLogEvent TS_Step, TS_PseudoComputeTimeStep, TS_FunctionEval, TS_JacobianEval;

 12: const char *const TSExactFinalTimeOptions[] = {"STEPOVER","INTERPOLATE","MATCHSTEP","TSExactFinalTimeOption","TS_EXACTFINALTIME_",0};

 16: /*
 17:   TSSetTypeFromOptions - Sets the type of ts from user options.

 19:   Collective on TS

 21:   Input Parameter:
 22: . ts - The ts

 24:   Level: intermediate

 26: .keywords: TS, set, options, database, type
 27: .seealso: TSSetFromOptions(), TSSetType()
 28: */
 29: static PetscErrorCode TSSetTypeFromOptions(TS ts)
 30: {
 31:   PetscBool      opt;
 32:   const char     *defaultType;
 33:   char           typeName[256];

 37:   if (((PetscObject)ts)->type_name) defaultType = ((PetscObject)ts)->type_name;
 38:   else defaultType = TSEULER;

 40:   if (!TSRegisterAllCalled) {TSRegisterAll();}
 41:   PetscOptionsFList("-ts_type", "TS method"," TSSetType", TSList, defaultType, typeName, 256, &opt);
 42:   if (opt) {
 43:     TSSetType(ts, typeName);
 44:   } else {
 45:     TSSetType(ts, defaultType);
 46:   }
 47:   return(0);
 48: }

 50: struct _n_TSMonitorDrawCtx {
 51:   PetscViewer   viewer;
 52:   PetscDrawAxis axis;
 53:   Vec           initialsolution;
 54:   PetscBool     showinitial;
 55:   PetscInt      howoften;  /* when > 0 uses step % howoften, when negative only final solution plotted */
 56:   PetscBool     showtimestepandtime;
 57:   int           color;
 58: };

 62: /*@
 63:    TSSetFromOptions - Sets various TS parameters from user options.

 65:    Collective on TS

 67:    Input Parameter:
 68: .  ts - the TS context obtained from TSCreate()

 70:    Options Database Keys:
 71: +  -ts_type <type> - TSEULER, TSBEULER, TSSUNDIALS, TSPSEUDO, TSCN, TSRK, TSTHETA, TSGL, TSSSP
 72: .  -ts_max_steps maxsteps - maximum number of time-steps to take
 73: .  -ts_final_time time - maximum time to compute to
 74: .  -ts_dt dt - initial time step
 75: .  -ts_monitor - print information at each timestep
 76: .  -ts_monitor_lg_timestep - Monitor timestep size graphically
 77: .  -ts_monitor_lg_solution - Monitor solution graphically
 78: .  -ts_monitor_lg_error - Monitor error graphically
 79: .  -ts_monitor_lg_snes_iterations - Monitor number nonlinear iterations for each timestep graphically
 80: .  -ts_monitor_lg_ksp_iterations - Monitor number nonlinear iterations for each timestep graphically
 81: .  -ts_monitor_sp_eig - Monitor eigenvalues of linearized operator graphically
 82: .  -ts_monitor_draw_solution - Monitor solution graphically
 83: .  -ts_monitor_draw_solution_phase - Monitor solution graphically with phase diagram
 84: .  -ts_monitor_draw_error - Monitor error graphically
 85: .  -ts_monitor_solution_binary <filename> - Save each solution to a binary file
 86: -  -ts_monitor_solution_vtk <filename.vts> - Save each time step to a binary file, use filename-%%03D.vts

 88:    Developer Note: We should unify all the -ts_monitor options in the way that -xxx_view has been unified

 90:    Level: beginner

 92: .keywords: TS, timestep, set, options, database

 94: .seealso: TSGetType()
 95: @*/
 96: PetscErrorCode  TSSetFromOptions(TS ts)
 97: {
 98:   PetscBool              opt,flg;
 99:   PetscErrorCode         ierr;
100:   PetscViewer            monviewer;
101:   char                   monfilename[PETSC_MAX_PATH_LEN];
102:   SNES                   snes;
103:   TSAdapt                adapt;
104:   PetscReal              time_step;
105:   TSExactFinalTimeOption eftopt;
106:   char                   dir[16];

110:   PetscObjectOptionsBegin((PetscObject)ts);
111:   /* Handle TS type options */
112:   TSSetTypeFromOptions(ts);

114:   /* Handle generic TS options */
115:   PetscOptionsInt("-ts_max_steps","Maximum number of time steps","TSSetDuration",ts->max_steps,&ts->max_steps,NULL);
116:   PetscOptionsReal("-ts_final_time","Time to run to","TSSetDuration",ts->max_time,&ts->max_time,NULL);
117:   PetscOptionsReal("-ts_init_time","Initial time","TSSetTime",ts->ptime,&ts->ptime,NULL);
118:   PetscOptionsReal("-ts_dt","Initial time step","TSSetTimeStep",ts->time_step,&time_step,&flg);
119:   if (flg) {
120:     TSSetTimeStep(ts,time_step);
121:   }
122:   PetscOptionsEnum("-ts_exact_final_time","Option for handling of final time step","TSSetExactFinalTime",TSExactFinalTimeOptions,(PetscEnum)ts->exact_final_time,(PetscEnum*)&eftopt,&flg);
123:   if (flg) {TSSetExactFinalTime(ts,eftopt);}
124:   PetscOptionsInt("-ts_max_snes_failures","Maximum number of nonlinear solve failures","TSSetMaxSNESFailures",ts->max_snes_failures,&ts->max_snes_failures,NULL);
125:   PetscOptionsInt("-ts_max_reject","Maximum number of step rejections before step fails","TSSetMaxStepRejections",ts->max_reject,&ts->max_reject,NULL);
126:   PetscOptionsBool("-ts_error_if_step_fails","Error if no step succeeds","TSSetErrorIfStepFails",ts->errorifstepfailed,&ts->errorifstepfailed,NULL);
127:   PetscOptionsReal("-ts_rtol","Relative tolerance for local truncation error","TSSetTolerances",ts->rtol,&ts->rtol,NULL);
128:   PetscOptionsReal("-ts_atol","Absolute tolerance for local truncation error","TSSetTolerances",ts->atol,&ts->atol,NULL);

130: #if defined(PETSC_HAVE_SAWS)
131:   {
132:   PetscBool set;
133:   flg  = PETSC_FALSE;
134:   PetscOptionsBool("-ts_saws_block","Block for SAWs memory snooper at end of TSSolve","PetscObjectSAWsBlock",((PetscObject)ts)->amspublishblock,&flg,&set);
135:   if (set) {
136:     PetscObjectSAWsSetBlock((PetscObject)ts,flg);
137:   }
138:   }
139: #endif

141:   /* Monitor options */
142:   PetscOptionsString("-ts_monitor","Monitor timestep size","TSMonitorDefault","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);
143:   if (flg) {
144:     PetscViewerASCIIOpen(PetscObjectComm((PetscObject)ts),monfilename,&monviewer);
145:     TSMonitorSet(ts,TSMonitorDefault,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);
146:   }
147:   PetscOptionsString("-ts_monitor_python","Use Python function","TSMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
148:   if (flg) {PetscPythonMonitorSet((PetscObject)ts,monfilename);}

150:   PetscOptionsName("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",&opt);
151:   if (opt) {
152:     TSMonitorLGCtx ctx;
153:     PetscInt       howoften = 1;

155:     PetscOptionsInt("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",howoften,&howoften,NULL);
156:     TSMonitorLGCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);
157:     TSMonitorSet(ts,TSMonitorLGTimeStep,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);
158:   }
159:   PetscOptionsName("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",&opt);
160:   if (opt) {
161:     TSMonitorLGCtx ctx;
162:     PetscInt       howoften = 1;

164:     PetscOptionsInt("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",howoften,&howoften,NULL);
165:     TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
166:     TSMonitorSet(ts,TSMonitorLGSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);
167:   }
168:   PetscOptionsName("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",&opt);
169:   if (opt) {
170:     TSMonitorLGCtx ctx;
171:     PetscInt       howoften = 1;

173:     PetscOptionsInt("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",howoften,&howoften,NULL);
174:     TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
175:     TSMonitorSet(ts,TSMonitorLGError,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);
176:   }
177:   PetscOptionsName("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",&opt);
178:   if (opt) {
179:     TSMonitorLGCtx ctx;
180:     PetscInt       howoften = 1;

182:     PetscOptionsInt("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",howoften,&howoften,NULL);
183:     TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);
184:     TSMonitorSet(ts,TSMonitorLGSNESIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);
185:   }
186:   PetscOptionsName("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",&opt);
187:   if (opt) {
188:     TSMonitorLGCtx ctx;
189:     PetscInt       howoften = 1;

191:     PetscOptionsInt("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",howoften,&howoften,NULL);
192:     TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);
193:     TSMonitorSet(ts,TSMonitorLGKSPIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);
194:   }
195:   PetscOptionsName("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",&opt);
196:   if (opt) {
197:     TSMonitorSPEigCtx ctx;
198:     PetscInt          howoften = 1;

200:     PetscOptionsInt("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",howoften,&howoften,NULL);
201:     TSMonitorSPEigCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
202:     TSMonitorSet(ts,TSMonitorSPEig,ctx,(PetscErrorCode (*)(void**))TSMonitorSPEigCtxDestroy);
203:   }
204:   opt  = PETSC_FALSE;
205:   PetscOptionsName("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",&opt);
206:   if (opt) {
207:     TSMonitorDrawCtx ctx;
208:     PetscInt         howoften = 1;

210:     PetscOptionsInt("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",howoften,&howoften,NULL);
211:     TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
212:     TSMonitorSet(ts,TSMonitorDrawSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);
213:   }
214:   opt  = PETSC_FALSE;
215:   PetscOptionsName("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",&opt);
216:   if (opt) {
217:     TSMonitorDrawCtx ctx;
218:     PetscReal        bounds[4];
219:     PetscInt         n = 4;
220:     PetscDraw        draw;

222:     PetscOptionsRealArray("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",bounds,&n,NULL);
223:     if (n != 4) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Must provide bounding box of phase field");
224:     TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,1,&ctx);
225:     PetscViewerDrawGetDraw(ctx->viewer,0,&draw);
226:     PetscDrawClear(draw);
227:     PetscDrawAxisCreate(draw,&ctx->axis);
228:     PetscDrawAxisSetLimits(ctx->axis,bounds[0],bounds[2],bounds[1],bounds[3]);
229:     PetscDrawAxisSetLabels(ctx->axis,"Phase Diagram","Variable 1","Variable 2");
230:     PetscDrawAxisDraw(ctx->axis);
231:     /* PetscDrawSetCoordinates(draw,bounds[0],bounds[1],bounds[2],bounds[3]); */
232:     TSMonitorSet(ts,TSMonitorDrawSolutionPhase,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);
233:   }
234:   opt  = PETSC_FALSE;
235:   PetscOptionsName("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",&opt);
236:   if (opt) {
237:     TSMonitorDrawCtx ctx;
238:     PetscInt         howoften = 1;

240:     PetscOptionsInt("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",howoften,&howoften,NULL);
241:     TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
242:     TSMonitorSet(ts,TSMonitorDrawError,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);
243:   }
244:   opt  = PETSC_FALSE;
245:   PetscOptionsString("-ts_monitor_solution_binary","Save each solution to a binary file","TSMonitorSolutionBinary",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
246:   if (flg) {
247:     PetscViewer ctx;
248:     if (monfilename[0]) {
249:       PetscViewerBinaryOpen(PetscObjectComm((PetscObject)ts),monfilename,FILE_MODE_WRITE,&ctx);
250:       TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);
251:     } else {
252:       ctx = PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)ts));
253:       TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))NULL);
254:     }
255:   }
256:   opt  = PETSC_FALSE;
257:   PetscOptionsString("-ts_monitor_solution_vtk","Save each time step to a binary file, use filename-%%03D.vts","TSMonitorSolutionVTK",0,monfilename,PETSC_MAX_PATH_LEN,&flg);
258:   if (flg) {
259:     const char *ptr,*ptr2;
260:     char       *filetemplate;
261:     if (!monfilename[0]) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
262:     /* Do some cursory validation of the input. */
263:     PetscStrstr(monfilename,"%",(char**)&ptr);
264:     if (!ptr) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
265:     for (ptr++; ptr && *ptr; ptr++) {
266:       PetscStrchr("DdiouxX",*ptr,(char**)&ptr2);
267:       if (!ptr2 && (*ptr < '0' || '9' < *ptr)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Invalid file template argument to -ts_monitor_solution_vtk, should look like filename-%%03D.vts");
268:       if (ptr2) break;
269:     }
270:     PetscStrallocpy(monfilename,&filetemplate);
271:     TSMonitorSet(ts,TSMonitorSolutionVTK,filetemplate,(PetscErrorCode (*)(void**))TSMonitorSolutionVTKDestroy);
272:   }

274:   PetscOptionsString("-ts_monitor_dmda_ray","Display a ray of the solution","None","y=0",dir,16,&flg);
275:   if (flg) {
276:     TSMonitorDMDARayCtx *rayctx;
277:     int                  ray = 0;
278:     DMDADirection        ddir;
279:     DM                   da;
280:     PetscMPIInt          rank;

282:     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
283:     if (dir[0] == 'x') ddir = DMDA_X;
284:     else if (dir[0] == 'y') ddir = DMDA_Y;
285:     else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
286:     sscanf(dir+2,"%d",&ray);

288:     PetscInfo2(((PetscObject)ts),"Displaying DMDA ray %c = %D\n",dir[0],ray);
289:     PetscNew(&rayctx);
290:     TSGetDM(ts,&da);
291:     DMDAGetRay(da,ddir,ray,&rayctx->ray,&rayctx->scatter);
292:     MPI_Comm_rank(PetscObjectComm((PetscObject)ts),&rank);
293:     if (!rank) {
294:       PetscViewerDrawOpen(PETSC_COMM_SELF,0,0,0,0,600,300,&rayctx->viewer);
295:     }
296:     rayctx->lgctx = NULL;
297:     TSMonitorSet(ts,TSMonitorDMDARay,rayctx,TSMonitorDMDARayDestroy);
298:   }
299:   PetscOptionsString("-ts_monitor_lg_dmda_ray","Display a ray of the solution","None","x=0",dir,16,&flg);
300:   if (flg) {
301:     TSMonitorDMDARayCtx *rayctx;
302:     int                 ray = 0;
303:     DMDADirection       ddir;
304:     DM                  da;
305:     PetscInt            howoften = 1;

307:     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Malformed ray %s", dir);
308:     if      (dir[0] == 'x') ddir = DMDA_X;
309:     else if (dir[0] == 'y') ddir = DMDA_Y;
310:     else SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Unknown ray direction %s", dir);
311:     sscanf(dir+2, "%d", &ray);

313:     PetscInfo2(((PetscObject) ts),"Displaying LG DMDA ray %c = %D\n", dir[0], ray);
314:     PetscNew(&rayctx);
315:     TSGetDM(ts, &da);
316:     DMDAGetRay(da, ddir, ray, &rayctx->ray, &rayctx->scatter);
317:     TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&rayctx->lgctx);
318:     TSMonitorSet(ts, TSMonitorLGDMDARay, rayctx, TSMonitorDMDARayDestroy);
319:   }

321:   /*
322:      This code is all wrong. One is creating objects inside the TSSetFromOptions() so if run with the options gui
323:      will bleed memory. Also one is using a PetscOptionsBegin() inside a PetscOptionsBegin()
324:   */
325:   TSGetAdapt(ts,&adapt);
326:   TSAdaptSetFromOptions(adapt);

328:   TSGetSNES(ts,&snes);
329:   if (ts->problem_type == TS_LINEAR) {SNESSetType(snes,SNESKSPONLY);}

331:   /* Handle specific TS options */
332:   if (ts->ops->setfromoptions) {
333:     (*ts->ops->setfromoptions)(ts);
334:   }

336:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
337:   PetscObjectProcessOptionsHandlers((PetscObject)ts);
338:   PetscOptionsEnd();
339:   return(0);
340: }

345: /*@
346:    TSComputeRHSJacobian - Computes the Jacobian matrix that has been
347:       set with TSSetRHSJacobian().

349:    Collective on TS and Vec

351:    Input Parameters:
352: +  ts - the TS context
353: .  t - current timestep
354: -  U - input vector

356:    Output Parameters:
357: +  A - Jacobian matrix
358: .  B - optional preconditioning matrix
359: -  flag - flag indicating matrix structure

361:    Notes:
362:    Most users should not need to explicitly call this routine, as it
363:    is used internally within the nonlinear solvers.

365:    See KSPSetOperators() for important information about setting the
366:    flag parameter.

368:    Level: developer

370: .keywords: SNES, compute, Jacobian, matrix

372: .seealso:  TSSetRHSJacobian(), KSPSetOperators()
373: @*/
374: PetscErrorCode  TSComputeRHSJacobian(TS ts,PetscReal t,Vec U,Mat A,Mat B)
375: {
377:   PetscObjectState Ustate;
378:   DM             dm;
379:   DMTS           tsdm;
380:   TSRHSJacobian  rhsjacobianfunc;
381:   void           *ctx;
382:   TSIJacobian    ijacobianfunc;

388:   TSGetDM(ts,&dm);
389:   DMGetDMTS(dm,&tsdm);
390:   DMTSGetRHSJacobian(dm,&rhsjacobianfunc,&ctx);
391:   DMTSGetIJacobian(dm,&ijacobianfunc,NULL);
392:   PetscObjectStateGet((PetscObject)U,&Ustate);
393:   if (ts->rhsjacobian.time == t && (ts->problem_type == TS_LINEAR || (ts->rhsjacobian.X == U && ts->rhsjacobian.Xstate == Ustate))) {
394:     return(0);
395:   }

397:   if (!rhsjacobianfunc && !ijacobianfunc) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");

399:   if (ts->rhsjacobian.reuse) {
400:     MatShift(A,-ts->rhsjacobian.shift);
401:     MatScale(A,1./ts->rhsjacobian.scale);
402:     if (A != B) {
403:       MatShift(B,-ts->rhsjacobian.shift);
404:       MatScale(B,1./ts->rhsjacobian.scale);
405:     }
406:     ts->rhsjacobian.shift = 0;
407:     ts->rhsjacobian.scale = 1.;
408:   }

410:   if (rhsjacobianfunc) {
411:     PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);
412:     PetscStackPush("TS user Jacobian function");
413:     (*rhsjacobianfunc)(ts,t,U,A,B,ctx);
414:     PetscStackPop;
415:     PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);
416:     /* make sure user returned a correct Jacobian and preconditioner */
419:   } else {
420:     MatZeroEntries(A);
421:     if (A != B) {MatZeroEntries(B);}
422:   }
423:   ts->rhsjacobian.time       = t;
424:   ts->rhsjacobian.X          = U;
425:   PetscObjectStateGet((PetscObject)U,&ts->rhsjacobian.Xstate);
426:   return(0);
427: }

431: /*@
432:    TSComputeRHSFunction - Evaluates the right-hand-side function.

434:    Collective on TS and Vec

436:    Input Parameters:
437: +  ts - the TS context
438: .  t - current time
439: -  U - state vector

441:    Output Parameter:
442: .  y - right hand side

444:    Note:
445:    Most users should not need to explicitly call this routine, as it
446:    is used internally within the nonlinear solvers.

448:    Level: developer

450: .keywords: TS, compute

452: .seealso: TSSetRHSFunction(), TSComputeIFunction()
453: @*/
454: PetscErrorCode TSComputeRHSFunction(TS ts,PetscReal t,Vec U,Vec y)
455: {
457:   TSRHSFunction  rhsfunction;
458:   TSIFunction    ifunction;
459:   void           *ctx;
460:   DM             dm;

466:   TSGetDM(ts,&dm);
467:   DMTSGetRHSFunction(dm,&rhsfunction,&ctx);
468:   DMTSGetIFunction(dm,&ifunction,NULL);

470:   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");

472:   PetscLogEventBegin(TS_FunctionEval,ts,U,y,0);
473:   if (rhsfunction) {
474:     PetscStackPush("TS user right-hand-side function");
475:     (*rhsfunction)(ts,t,U,y,ctx);
476:     PetscStackPop;
477:   } else {
478:     VecZeroEntries(y);
479:   }

481:   PetscLogEventEnd(TS_FunctionEval,ts,U,y,0);
482:   return(0);
483: }

487: /*@
488:    TSComputeSolutionFunction - Evaluates the solution function.

490:    Collective on TS and Vec

492:    Input Parameters:
493: +  ts - the TS context
494: -  t - current time

496:    Output Parameter:
497: .  U - the solution

499:    Note:
500:    Most users should not need to explicitly call this routine, as it
501:    is used internally within the nonlinear solvers.

503:    Level: developer

505: .keywords: TS, compute

507: .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
508: @*/
509: PetscErrorCode TSComputeSolutionFunction(TS ts,PetscReal t,Vec U)
510: {
511:   PetscErrorCode     ierr;
512:   TSSolutionFunction solutionfunction;
513:   void               *ctx;
514:   DM                 dm;

519:   TSGetDM(ts,&dm);
520:   DMTSGetSolutionFunction(dm,&solutionfunction,&ctx);

522:   if (solutionfunction) {
523:     PetscStackPush("TS user solution function");
524:     (*solutionfunction)(ts,t,U,ctx);
525:     PetscStackPop;
526:   }
527:   return(0);
528: }
531: /*@
532:    TSComputeForcingFunction - Evaluates the forcing function.

534:    Collective on TS and Vec

536:    Input Parameters:
537: +  ts - the TS context
538: -  t - current time

540:    Output Parameter:
541: .  U - the function value

543:    Note:
544:    Most users should not need to explicitly call this routine, as it
545:    is used internally within the nonlinear solvers.

547:    Level: developer

549: .keywords: TS, compute

551: .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
552: @*/
553: PetscErrorCode TSComputeForcingFunction(TS ts,PetscReal t,Vec U)
554: {
555:   PetscErrorCode     ierr, (*forcing)(TS,PetscReal,Vec,void*);
556:   void               *ctx;
557:   DM                 dm;

562:   TSGetDM(ts,&dm);
563:   DMTSGetForcingFunction(dm,&forcing,&ctx);

565:   if (forcing) {
566:     PetscStackPush("TS user forcing function");
567:     (*forcing)(ts,t,U,ctx);
568:     PetscStackPop;
569:   }
570:   return(0);
571: }

575: static PetscErrorCode TSGetRHSVec_Private(TS ts,Vec *Frhs)
576: {
577:   Vec            F;

581:   *Frhs = NULL;
582:   TSGetIFunction(ts,&F,NULL,NULL);
583:   if (!ts->Frhs) {
584:     VecDuplicate(F,&ts->Frhs);
585:   }
586:   *Frhs = ts->Frhs;
587:   return(0);
588: }

592: static PetscErrorCode TSGetRHSMats_Private(TS ts,Mat *Arhs,Mat *Brhs)
593: {
594:   Mat            A,B;

598:   if (Arhs) *Arhs = NULL;
599:   if (Brhs) *Brhs = NULL;
600:   TSGetIJacobian(ts,&A,&B,NULL,NULL);
601:   if (Arhs) {
602:     if (!ts->Arhs) {
603:       MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&ts->Arhs);
604:     }
605:     *Arhs = ts->Arhs;
606:   }
607:   if (Brhs) {
608:     if (!ts->Brhs) {
609:       if (A != B) {
610:         MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&ts->Brhs);
611:       } else {
612:         ts->Brhs = ts->Arhs;
613:         PetscObjectReference((PetscObject)ts->Arhs);
614:       }
615:     }
616:     *Brhs = ts->Brhs;
617:   }
618:   return(0);
619: }

623: /*@
624:    TSComputeIFunction - Evaluates the DAE residual written in implicit form F(t,U,Udot)=0

626:    Collective on TS and Vec

628:    Input Parameters:
629: +  ts - the TS context
630: .  t - current time
631: .  U - state vector
632: .  Udot - time derivative of state vector
633: -  imex - flag indicates if the method is IMEX so that the RHSFunction should be kept separate

635:    Output Parameter:
636: .  Y - right hand side

638:    Note:
639:    Most users should not need to explicitly call this routine, as it
640:    is used internally within the nonlinear solvers.

642:    If the user did did not write their equations in implicit form, this
643:    function recasts them in implicit form.

645:    Level: developer

647: .keywords: TS, compute

649: .seealso: TSSetIFunction(), TSComputeRHSFunction()
650: @*/
651: PetscErrorCode TSComputeIFunction(TS ts,PetscReal t,Vec U,Vec Udot,Vec Y,PetscBool imex)
652: {
654:   TSIFunction    ifunction;
655:   TSRHSFunction  rhsfunction;
656:   void           *ctx;
657:   DM             dm;


665:   TSGetDM(ts,&dm);
666:   DMTSGetIFunction(dm,&ifunction,&ctx);
667:   DMTSGetRHSFunction(dm,&rhsfunction,NULL);

669:   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");

671:   PetscLogEventBegin(TS_FunctionEval,ts,U,Udot,Y);
672:   if (ifunction) {
673:     PetscStackPush("TS user implicit function");
674:     (*ifunction)(ts,t,U,Udot,Y,ctx);
675:     PetscStackPop;
676:   }
677:   if (imex) {
678:     if (!ifunction) {
679:       VecCopy(Udot,Y);
680:     }
681:   } else if (rhsfunction) {
682:     if (ifunction) {
683:       Vec Frhs;
684:       TSGetRHSVec_Private(ts,&Frhs);
685:       TSComputeRHSFunction(ts,t,U,Frhs);
686:       VecAXPY(Y,-1,Frhs);
687:     } else {
688:       TSComputeRHSFunction(ts,t,U,Y);
689:       VecAYPX(Y,-1,Udot);
690:     }
691:   }
692:   PetscLogEventEnd(TS_FunctionEval,ts,U,Udot,Y);
693:   return(0);
694: }

698: /*@
699:    TSComputeIJacobian - Evaluates the Jacobian of the DAE

701:    Collective on TS and Vec

703:    Input
704:       Input Parameters:
705: +  ts - the TS context
706: .  t - current timestep
707: .  U - state vector
708: .  Udot - time derivative of state vector
709: .  shift - shift to apply, see note below
710: -  imex - flag indicates if the method is IMEX so that the RHSJacobian should be kept separate

712:    Output Parameters:
713: +  A - Jacobian matrix
714: .  B - optional preconditioning matrix
715: -  flag - flag indicating matrix structure

717:    Notes:
718:    If F(t,U,Udot)=0 is the DAE, the required Jacobian is

720:    dF/dU + shift*dF/dUdot

722:    Most users should not need to explicitly call this routine, as it
723:    is used internally within the nonlinear solvers.

725:    Level: developer

727: .keywords: TS, compute, Jacobian, matrix

729: .seealso:  TSSetIJacobian()
730: @*/
731: PetscErrorCode TSComputeIJacobian(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,PetscBool imex)
732: {
734:   TSIJacobian    ijacobian;
735:   TSRHSJacobian  rhsjacobian;
736:   DM             dm;
737:   void           *ctx;


748:   TSGetDM(ts,&dm);
749:   DMTSGetIJacobian(dm,&ijacobian,&ctx);
750:   DMTSGetRHSJacobian(dm,&rhsjacobian,NULL);

752:   if (!rhsjacobian && !ijacobian) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");

754:   PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);
755:   if (ijacobian) {
756:     PetscStackPush("TS user implicit Jacobian");
757:     (*ijacobian)(ts,t,U,Udot,shift,A,B,ctx);
758:     PetscStackPop;
759:     /* make sure user returned a correct Jacobian and preconditioner */
762:   }
763:   if (imex) {
764:     if (!ijacobian) {  /* system was written as Udot = G(t,U) */
765:       MatZeroEntries(A);
766:       MatShift(A,shift);
767:       if (A != B) {
768:         MatZeroEntries(B);
769:         MatShift(B,shift);
770:       }
771:     }
772:   } else {
773:     Mat Arhs = NULL,Brhs = NULL;
774:     if (rhsjacobian) {
775:       if (ijacobian) {
776:         TSGetRHSMats_Private(ts,&Arhs,&Brhs);
777:       } else {
778:         TSGetIJacobian(ts,&Arhs,&Brhs,NULL,NULL);
779:       }
780:       TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);
781:     }
782:     if (Arhs == A) {           /* No IJacobian, so we only have the RHS matrix */
783:       ts->rhsjacobian.scale = -1;
784:       ts->rhsjacobian.shift = shift;
785:       MatScale(A,-1);
786:       MatShift(A,shift);
787:       if (A != B) {
788:         MatScale(B,-1);
789:         MatShift(B,shift);
790:       }
791:     } else if (Arhs) {          /* Both IJacobian and RHSJacobian */
792:       MatStructure axpy = DIFFERENT_NONZERO_PATTERN;
793:       if (!ijacobian) {         /* No IJacobian provided, but we have a separate RHS matrix */
794:         MatZeroEntries(A);
795:         MatShift(A,shift);
796:         if (A != B) {
797:           MatZeroEntries(B);
798:           MatShift(B,shift);
799:         }
800:       }
801:       MatAXPY(A,-1,Arhs,axpy);
802:       if (A != B) {
803:         MatAXPY(B,-1,Brhs,axpy);
804:       }
805:     }
806:   }
807:   PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);
808:   return(0);
809: }

813: /*@C
814:     TSSetRHSFunction - Sets the routine for evaluating the function,
815:     where U_t = G(t,u).

817:     Logically Collective on TS

819:     Input Parameters:
820: +   ts - the TS context obtained from TSCreate()
821: .   r - vector to put the computed right hand side (or NULL to have it created)
822: .   f - routine for evaluating the right-hand-side function
823: -   ctx - [optional] user-defined context for private data for the
824:           function evaluation routine (may be NULL)

826:     Calling sequence of func:
827: $     func (TS ts,PetscReal t,Vec u,Vec F,void *ctx);

829: +   t - current timestep
830: .   u - input vector
831: .   F - function vector
832: -   ctx - [optional] user-defined function context

834:     Level: beginner

836: .keywords: TS, timestep, set, right-hand-side, function

838: .seealso: TSSetRHSJacobian(), TSSetIJacobian()
839: @*/
840: PetscErrorCode  TSSetRHSFunction(TS ts,Vec r,PetscErrorCode (*f)(TS,PetscReal,Vec,Vec,void*),void *ctx)
841: {
843:   SNES           snes;
844:   Vec            ralloc = NULL;
845:   DM             dm;


851:   TSGetDM(ts,&dm);
852:   DMTSSetRHSFunction(dm,f,ctx);
853:   TSGetSNES(ts,&snes);
854:   if (!r && !ts->dm && ts->vec_sol) {
855:     VecDuplicate(ts->vec_sol,&ralloc);
856:     r    = ralloc;
857:   }
858:   SNESSetFunction(snes,r,SNESTSFormFunction,ts);
859:   VecDestroy(&ralloc);
860:   return(0);
861: }

865: /*@C
866:     TSSetSolutionFunction - Provide a function that computes the solution of the ODE or DAE

868:     Logically Collective on TS

870:     Input Parameters:
871: +   ts - the TS context obtained from TSCreate()
872: .   f - routine for evaluating the solution
873: -   ctx - [optional] user-defined context for private data for the
874:           function evaluation routine (may be NULL)

876:     Calling sequence of func:
877: $     func (TS ts,PetscReal t,Vec u,void *ctx);

879: +   t - current timestep
880: .   u - output vector
881: -   ctx - [optional] user-defined function context

883:     Notes:
884:     This routine is used for testing accuracy of time integration schemes when you already know the solution.
885:     If analytic solutions are not known for your system, consider using the Method of Manufactured Solutions to
886:     create closed-form solutions with non-physical forcing terms.

888:     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.

890:     Level: beginner

892: .keywords: TS, timestep, set, right-hand-side, function

894: .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetForcingFunction()
895: @*/
896: PetscErrorCode  TSSetSolutionFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
897: {
899:   DM             dm;

903:   TSGetDM(ts,&dm);
904:   DMTSSetSolutionFunction(dm,f,ctx);
905:   return(0);
906: }

910: /*@C
911:     TSSetForcingFunction - Provide a function that computes a forcing term for a ODE or PDE

913:     Logically Collective on TS

915:     Input Parameters:
916: +   ts - the TS context obtained from TSCreate()
917: .   f - routine for evaluating the forcing function
918: -   ctx - [optional] user-defined context for private data for the
919:           function evaluation routine (may be NULL)

921:     Calling sequence of func:
922: $     func (TS ts,PetscReal t,Vec u,void *ctx);

924: +   t - current timestep
925: .   u - output vector
926: -   ctx - [optional] user-defined function context

928:     Notes:
929:     This routine is useful for testing accuracy of time integration schemes when using the Method of Manufactured Solutions to
930:     create closed-form solutions with a non-physical forcing term.

932:     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.

934:     Level: beginner

936: .keywords: TS, timestep, set, right-hand-side, function

938: .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetSolutionFunction()
939: @*/
940: PetscErrorCode  TSSetForcingFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
941: {
943:   DM             dm;

947:   TSGetDM(ts,&dm);
948:   DMTSSetForcingFunction(dm,f,ctx);
949:   return(0);
950: }

954: /*@C
955:    TSSetRHSJacobian - Sets the function to compute the Jacobian of F,
956:    where U_t = G(U,t), as well as the location to store the matrix.

958:    Logically Collective on TS

960:    Input Parameters:
961: +  ts  - the TS context obtained from TSCreate()
962: .  Amat - (approximate) Jacobian matrix
963: .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
964: .  f   - the Jacobian evaluation routine
965: -  ctx - [optional] user-defined context for private data for the
966:          Jacobian evaluation routine (may be NULL)

968:    Calling sequence of func:
969: $     func (TS ts,PetscReal t,Vec u,Mat *A,Mat *B,MatStructure *flag,void *ctx);

971: +  t - current timestep
972: .  u - input vector
973: .  Amat - (approximate) Jacobian matrix
974: .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
975: .  flag - flag indicating information about the preconditioner matrix
976:           structure (same as flag in KSPSetOperators())
977: -  ctx - [optional] user-defined context for matrix evaluation routine

979:    Notes:
980:    See KSPSetOperators() for important information about setting the flag
981:    output parameter in the routine func().  Be sure to read this information!

983:    The routine func() takes Mat * as the matrix arguments rather than Mat.
984:    This allows the matrix evaluation routine to replace A and/or B with a
985:    completely new matrix structure (not just different matrix elements)
986:    when appropriate, for instance, if the nonzero structure is changing
987:    throughout the global iterations.

989:    Level: beginner

991: .keywords: TS, timestep, set, right-hand-side, Jacobian

993: .seealso: SNESComputeJacobianDefaultColor(), TSSetRHSFunction(), TSRHSJacobianSetReuse()

995: @*/
996: PetscErrorCode  TSSetRHSJacobian(TS ts,Mat Amat,Mat Pmat,TSRHSJacobian f,void *ctx)
997: {
999:   SNES           snes;
1000:   DM             dm;
1001:   TSIJacobian    ijacobian;


1010:   TSGetDM(ts,&dm);
1011:   DMTSSetRHSJacobian(dm,f,ctx);
1012:   if (f == TSComputeRHSJacobianConstant) {
1013:     /* Handle this case automatically for the user; otherwise user should call themselves. */
1014:     TSRHSJacobianSetReuse(ts,PETSC_TRUE);
1015:   }
1016:   DMTSGetIJacobian(dm,&ijacobian,NULL);
1017:   TSGetSNES(ts,&snes);
1018:   if (!ijacobian) {
1019:     SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);
1020:   }
1021:   if (Amat) {
1022:     PetscObjectReference((PetscObject)Amat);
1023:     MatDestroy(&ts->Arhs);

1025:     ts->Arhs = Amat;
1026:   }
1027:   if (Pmat) {
1028:     PetscObjectReference((PetscObject)Pmat);
1029:     MatDestroy(&ts->Brhs);

1031:     ts->Brhs = Pmat;
1032:   }
1033:   return(0);
1034: }


1039: /*@C
1040:    TSSetIFunction - Set the function to compute F(t,U,U_t) where F() = 0 is the DAE to be solved.

1042:    Logically Collective on TS

1044:    Input Parameters:
1045: +  ts  - the TS context obtained from TSCreate()
1046: .  r   - vector to hold the residual (or NULL to have it created internally)
1047: .  f   - the function evaluation routine
1048: -  ctx - user-defined context for private data for the function evaluation routine (may be NULL)

1050:    Calling sequence of f:
1051: $  f(TS ts,PetscReal t,Vec u,Vec u_t,Vec F,ctx);

1053: +  t   - time at step/stage being solved
1054: .  u   - state vector
1055: .  u_t - time derivative of state vector
1056: .  F   - function vector
1057: -  ctx - [optional] user-defined context for matrix evaluation routine

1059:    Important:
1060:    The user MUST call either this routine, TSSetRHSFunction().  This routine must be used when not solving an ODE, for example a DAE.

1062:    Level: beginner

1064: .keywords: TS, timestep, set, DAE, Jacobian

1066: .seealso: TSSetRHSJacobian(), TSSetRHSFunction(), TSSetIJacobian()
1067: @*/
1068: PetscErrorCode  TSSetIFunction(TS ts,Vec res,TSIFunction f,void *ctx)
1069: {
1071:   SNES           snes;
1072:   Vec            resalloc = NULL;
1073:   DM             dm;


1079:   TSGetDM(ts,&dm);
1080:   DMTSSetIFunction(dm,f,ctx);

1082:   TSGetSNES(ts,&snes);
1083:   if (!res && !ts->dm && ts->vec_sol) {
1084:     VecDuplicate(ts->vec_sol,&resalloc);
1085:     res  = resalloc;
1086:   }
1087:   SNESSetFunction(snes,res,SNESTSFormFunction,ts);
1088:   VecDestroy(&resalloc);
1089:   return(0);
1090: }

1094: /*@C
1095:    TSGetIFunction - Returns the vector where the implicit residual is stored and the function/contex to compute it.

1097:    Not Collective

1099:    Input Parameter:
1100: .  ts - the TS context

1102:    Output Parameter:
1103: +  r - vector to hold residual (or NULL)
1104: .  func - the function to compute residual (or NULL)
1105: -  ctx - the function context (or NULL)

1107:    Level: advanced

1109: .keywords: TS, nonlinear, get, function

1111: .seealso: TSSetIFunction(), SNESGetFunction()
1112: @*/
1113: PetscErrorCode TSGetIFunction(TS ts,Vec *r,TSIFunction *func,void **ctx)
1114: {
1116:   SNES           snes;
1117:   DM             dm;

1121:   TSGetSNES(ts,&snes);
1122:   SNESGetFunction(snes,r,NULL,NULL);
1123:   TSGetDM(ts,&dm);
1124:   DMTSGetIFunction(dm,func,ctx);
1125:   return(0);
1126: }

1130: /*@C
1131:    TSGetRHSFunction - Returns the vector where the right hand side is stored and the function/context to compute it.

1133:    Not Collective

1135:    Input Parameter:
1136: .  ts - the TS context

1138:    Output Parameter:
1139: +  r - vector to hold computed right hand side (or NULL)
1140: .  func - the function to compute right hand side (or NULL)
1141: -  ctx - the function context (or NULL)

1143:    Level: advanced

1145: .keywords: TS, nonlinear, get, function

1147: .seealso: TSSetRhsfunction(), SNESGetFunction()
1148: @*/
1149: PetscErrorCode TSGetRHSFunction(TS ts,Vec *r,TSRHSFunction *func,void **ctx)
1150: {
1152:   SNES           snes;
1153:   DM             dm;

1157:   TSGetSNES(ts,&snes);
1158:   SNESGetFunction(snes,r,NULL,NULL);
1159:   TSGetDM(ts,&dm);
1160:   DMTSGetRHSFunction(dm,func,ctx);
1161:   return(0);
1162: }

1166: /*@C
1167:    TSSetIJacobian - Set the function to compute the matrix dF/dU + a*dF/dU_t where F(t,U,U_t) is the function
1168:         you provided with TSSetIFunction().

1170:    Logically Collective on TS

1172:    Input Parameters:
1173: +  ts  - the TS context obtained from TSCreate()
1174: .  Amat - (approximate) Jacobian matrix
1175: .  Pmat - matrix used to compute preconditioner (usually the same as Amat)
1176: .  f   - the Jacobian evaluation routine
1177: -  ctx - user-defined context for private data for the Jacobian evaluation routine (may be NULL)

1179:    Calling sequence of f:
1180: $  f(TS ts,PetscReal t,Vec U,Vec U_t,PetscReal a,Mat *Amat,Mat *Pmat,MatStructure *flag,void *ctx);

1182: +  t    - time at step/stage being solved
1183: .  U    - state vector
1184: .  U_t  - time derivative of state vector
1185: .  a    - shift
1186: .  Amat - (approximate) Jacobian of F(t,U,W+a*U), equivalent to dF/dU + a*dF/dU_t
1187: .  Pmat - matrix used for constructing preconditioner, usually the same as Amat
1188: .  flag - flag indicating information about the preconditioner matrix
1189:           structure (same as flag in KSPSetOperators())
1190: -  ctx  - [optional] user-defined context for matrix evaluation routine

1192:    Notes:
1193:    The matrices Amat and Pmat are exactly the matrices that are used by SNES for the nonlinear solve.

1195:    The matrix dF/dU + a*dF/dU_t you provide turns out to be
1196:    the Jacobian of F(t,U,W+a*U) where F(t,U,U_t) = 0 is the DAE to be solved.
1197:    The time integrator internally approximates U_t by W+a*U where the positive "shift"
1198:    a and vector W depend on the integration method, step size, and past states. For example with
1199:    the backward Euler method a = 1/dt and W = -a*U(previous timestep) so
1200:    W + a*U = a*(U - U(previous timestep)) = (U - U(previous timestep))/dt

1202:    Level: beginner

1204: .keywords: TS, timestep, DAE, Jacobian

1206: .seealso: TSSetIFunction(), TSSetRHSJacobian(), SNESComputeJacobianDefaultColor(), SNESComputeJacobianDefault()

1208: @*/
1209: PetscErrorCode  TSSetIJacobian(TS ts,Mat Amat,Mat Pmat,TSIJacobian f,void *ctx)
1210: {
1212:   SNES           snes;
1213:   DM             dm;


1222:   TSGetDM(ts,&dm);
1223:   DMTSSetIJacobian(dm,f,ctx);

1225:   TSGetSNES(ts,&snes);
1226:   SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);
1227:   return(0);
1228: }

1232: /*@
1233:    TSRHSJacobianSetReuse - restore RHS Jacobian before re-evaluating.  Without this flag, TS will change the sign and
1234:    shift the RHS Jacobian for a finite-time-step implicit solve, in which case the user function will need to recompute
1235:    the entire Jacobian.  The reuse flag must be set if the evaluation function will assume that the matrix entries have
1236:    not been changed by the TS.

1238:    Logically Collective

1240:    Input Arguments:
1241: +  ts - TS context obtained from TSCreate()
1242: -  reuse - PETSC_TRUE if the RHS Jacobian

1244:    Level: intermediate

1246: .seealso: TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
1247: @*/
1248: PetscErrorCode TSRHSJacobianSetReuse(TS ts,PetscBool reuse)
1249: {
1251:   ts->rhsjacobian.reuse = reuse;
1252:   return(0);
1253: }

1257: /*@C
1258:   TSLoad - Loads a KSP that has been stored in binary  with KSPView().

1260:   Collective on PetscViewer

1262:   Input Parameters:
1263: + newdm - the newly loaded TS, this needs to have been created with TSCreate() or
1264:            some related function before a call to TSLoad().
1265: - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()

1267:    Level: intermediate

1269:   Notes:
1270:    The type is determined by the data in the file, any type set into the TS before this call is ignored.

1272:   Notes for advanced users:
1273:   Most users should not need to know the details of the binary storage
1274:   format, since TSLoad() and TSView() completely hide these details.
1275:   But for anyone who's interested, the standard binary matrix storage
1276:   format is
1277: .vb
1278:      has not yet been determined
1279: .ve

1281: .seealso: PetscViewerBinaryOpen(), TSView(), MatLoad(), VecLoad()
1282: @*/
1283: PetscErrorCode  TSLoad(TS ts, PetscViewer viewer)
1284: {
1286:   PetscBool      isbinary;
1287:   PetscInt       classid;
1288:   char           type[256];
1289:   DMTS           sdm;
1290:   DM             dm;

1295:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
1296:   if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");

1298:   PetscViewerBinaryRead(viewer,&classid,1,PETSC_INT);
1299:   if (classid != TS_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Not TS next in file");
1300:   PetscViewerBinaryRead(viewer,type,256,PETSC_CHAR);
1301:   TSSetType(ts, type);
1302:   if (ts->ops->load) {
1303:     (*ts->ops->load)(ts,viewer);
1304:   }
1305:   DMCreate(PetscObjectComm((PetscObject)ts),&dm);
1306:   DMLoad(dm,viewer);
1307:   TSSetDM(ts,dm);
1308:   DMCreateGlobalVector(ts->dm,&ts->vec_sol);
1309:   VecLoad(ts->vec_sol,viewer);
1310:   DMGetDMTS(ts->dm,&sdm);
1311:   DMTSLoad(sdm,viewer);
1312:   return(0);
1313: }

1315: #include <petscdraw.h>
1316: #if defined(PETSC_HAVE_SAWS)
1317: #include <petscviewersaws.h>
1318: #endif
1321: /*@C
1322:     TSView - Prints the TS data structure.

1324:     Collective on TS

1326:     Input Parameters:
1327: +   ts - the TS context obtained from TSCreate()
1328: -   viewer - visualization context

1330:     Options Database Key:
1331: .   -ts_view - calls TSView() at end of TSStep()

1333:     Notes:
1334:     The available visualization contexts include
1335: +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
1336: -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
1337:          output where only the first processor opens
1338:          the file.  All other processors send their
1339:          data to the first processor to print.

1341:     The user can open an alternative visualization context with
1342:     PetscViewerASCIIOpen() - output to a specified file.

1344:     Level: beginner

1346: .keywords: TS, timestep, view

1348: .seealso: PetscViewerASCIIOpen()
1349: @*/
1350: PetscErrorCode  TSView(TS ts,PetscViewer viewer)
1351: {
1353:   TSType         type;
1354:   PetscBool      iascii,isstring,isundials,isbinary,isdraw;
1355:   DMTS           sdm;
1356: #if defined(PETSC_HAVE_SAWS)
1357:   PetscBool      isams;
1358: #endif

1362:   if (!viewer) {
1363:     PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ts),&viewer);
1364:   }

1368:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
1369:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);
1370:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);
1371:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
1372: #if defined(PETSC_HAVE_SAWS)
1373:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&isams);
1374: #endif
1375:   if (iascii) {
1376:     PetscObjectPrintClassNamePrefixType((PetscObject)ts,viewer);
1377:     PetscViewerASCIIPrintf(viewer,"  maximum steps=%D\n",ts->max_steps);
1378:     PetscViewerASCIIPrintf(viewer,"  maximum time=%g\n",(double)ts->max_time);
1379:     if (ts->problem_type == TS_NONLINEAR) {
1380:       PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solver iterations=%D\n",ts->snes_its);
1381:       PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solve failures=%D\n",ts->num_snes_failures);
1382:     }
1383:     PetscViewerASCIIPrintf(viewer,"  total number of linear solver iterations=%D\n",ts->ksp_its);
1384:     PetscViewerASCIIPrintf(viewer,"  total number of rejected steps=%D\n",ts->reject);
1385:     DMGetDMTS(ts->dm,&sdm);
1386:     DMTSView(sdm,viewer);
1387:     if (ts->ops->view) {
1388:       PetscViewerASCIIPushTab(viewer);
1389:       (*ts->ops->view)(ts,viewer);
1390:       PetscViewerASCIIPopTab(viewer);
1391:     }
1392:   } else if (isstring) {
1393:     TSGetType(ts,&type);
1394:     PetscViewerStringSPrintf(viewer," %-7.7s",type);
1395:   } else if (isbinary) {
1396:     PetscInt    classid = TS_FILE_CLASSID;
1397:     MPI_Comm    comm;
1398:     PetscMPIInt rank;
1399:     char        type[256];

1401:     PetscObjectGetComm((PetscObject)ts,&comm);
1402:     MPI_Comm_rank(comm,&rank);
1403:     if (!rank) {
1404:       PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);
1405:       PetscStrncpy(type,((PetscObject)ts)->type_name,256);
1406:       PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);
1407:     }
1408:     if (ts->ops->view) {
1409:       (*ts->ops->view)(ts,viewer);
1410:     }
1411:     DMView(ts->dm,viewer);
1412:     VecView(ts->vec_sol,viewer);
1413:     DMGetDMTS(ts->dm,&sdm);
1414:     DMTSView(sdm,viewer);
1415:   } else if (isdraw) {
1416:     PetscDraw draw;
1417:     char      str[36];
1418:     PetscReal x,y,bottom,h;

1420:     PetscViewerDrawGetDraw(viewer,0,&draw);
1421:     PetscDrawGetCurrentPoint(draw,&x,&y);
1422:     PetscStrcpy(str,"TS: ");
1423:     PetscStrcat(str,((PetscObject)ts)->type_name);
1424:     PetscDrawBoxedString(draw,x,y,PETSC_DRAW_BLACK,PETSC_DRAW_BLACK,str,NULL,&h);
1425:     bottom = y - h;
1426:     PetscDrawPushCurrentPoint(draw,x,bottom);
1427:     if (ts->ops->view) {
1428:       (*ts->ops->view)(ts,viewer);
1429:     }
1430:     PetscDrawPopCurrentPoint(draw);
1431: #if defined(PETSC_HAVE_SAWS)
1432:   } else if (isams) {
1433:     PetscMPIInt rank;
1434:     const char  *name;

1436:     PetscObjectGetName((PetscObject)ts,&name);
1437:     MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
1438:     if (!((PetscObject)ts)->amsmem && !rank) {
1439:       char       dir[1024];

1441:       PetscObjectViewSAWs((PetscObject)ts,viewer);
1442:       PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time_step",name);
1443:       PetscStackCallSAWs(SAWs_Register,(dir,&ts->steps,1,SAWs_READ,SAWs_INT));
1444:       PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time",name);
1445:       PetscStackCallSAWs(SAWs_Register,(dir,&ts->ptime,1,SAWs_READ,SAWs_DOUBLE));
1446:     }
1447:     if (ts->ops->view) {
1448:       (*ts->ops->view)(ts,viewer);
1449:     }
1450: #endif
1451:   }

1453:   PetscViewerASCIIPushTab(viewer);
1454:   PetscObjectTypeCompare((PetscObject)ts,TSSUNDIALS,&isundials);
1455:   PetscViewerASCIIPopTab(viewer);
1456:   return(0);
1457: }


1462: /*@
1463:    TSSetApplicationContext - Sets an optional user-defined context for
1464:    the timesteppers.

1466:    Logically Collective on TS

1468:    Input Parameters:
1469: +  ts - the TS context obtained from TSCreate()
1470: -  usrP - optional user context

1472:    Level: intermediate

1474: .keywords: TS, timestep, set, application, context

1476: .seealso: TSGetApplicationContext()
1477: @*/
1478: PetscErrorCode  TSSetApplicationContext(TS ts,void *usrP)
1479: {
1482:   ts->user = usrP;
1483:   return(0);
1484: }

1488: /*@
1489:     TSGetApplicationContext - Gets the user-defined context for the
1490:     timestepper.

1492:     Not Collective

1494:     Input Parameter:
1495: .   ts - the TS context obtained from TSCreate()

1497:     Output Parameter:
1498: .   usrP - user context

1500:     Level: intermediate

1502: .keywords: TS, timestep, get, application, context

1504: .seealso: TSSetApplicationContext()
1505: @*/
1506: PetscErrorCode  TSGetApplicationContext(TS ts,void *usrP)
1507: {
1510:   *(void**)usrP = ts->user;
1511:   return(0);
1512: }

1516: /*@
1517:    TSGetTimeStepNumber - Gets the number of time steps completed.

1519:    Not Collective

1521:    Input Parameter:
1522: .  ts - the TS context obtained from TSCreate()

1524:    Output Parameter:
1525: .  iter - number of steps completed so far

1527:    Level: intermediate

1529: .keywords: TS, timestep, get, iteration, number
1530: .seealso: TSGetTime(), TSGetTimeStep(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSSetPostStep()
1531: @*/
1532: PetscErrorCode  TSGetTimeStepNumber(TS ts,PetscInt *iter)
1533: {
1537:   *iter = ts->steps;
1538:   return(0);
1539: }

1543: /*@
1544:    TSSetInitialTimeStep - Sets the initial timestep to be used,
1545:    as well as the initial time.

1547:    Logically Collective on TS

1549:    Input Parameters:
1550: +  ts - the TS context obtained from TSCreate()
1551: .  initial_time - the initial time
1552: -  time_step - the size of the timestep

1554:    Level: intermediate

1556: .seealso: TSSetTimeStep(), TSGetTimeStep()

1558: .keywords: TS, set, initial, timestep
1559: @*/
1560: PetscErrorCode  TSSetInitialTimeStep(TS ts,PetscReal initial_time,PetscReal time_step)
1561: {

1566:   TSSetTimeStep(ts,time_step);
1567:   TSSetTime(ts,initial_time);
1568:   return(0);
1569: }

1573: /*@
1574:    TSSetTimeStep - Allows one to reset the timestep at any time,
1575:    useful for simple pseudo-timestepping codes.

1577:    Logically Collective on TS

1579:    Input Parameters:
1580: +  ts - the TS context obtained from TSCreate()
1581: -  time_step - the size of the timestep

1583:    Level: intermediate

1585: .seealso: TSSetInitialTimeStep(), TSGetTimeStep()

1587: .keywords: TS, set, timestep
1588: @*/
1589: PetscErrorCode  TSSetTimeStep(TS ts,PetscReal time_step)
1590: {
1594:   ts->time_step      = time_step;
1595:   ts->time_step_orig = time_step;
1596:   return(0);
1597: }

1601: /*@
1602:    TSSetExactFinalTime - Determines whether to adapt the final time step to
1603:      match the exact final time, interpolate solution to the exact final time,
1604:      or just return at the final time TS computed.

1606:   Logically Collective on TS

1608:    Input Parameter:
1609: +   ts - the time-step context
1610: -   eftopt - exact final time option

1612:    Level: beginner

1614: .seealso: TSExactFinalTimeOption
1615: @*/
1616: PetscErrorCode  TSSetExactFinalTime(TS ts,TSExactFinalTimeOption eftopt)
1617: {
1621:   ts->exact_final_time = eftopt;
1622:   return(0);
1623: }

1627: /*@
1628:    TSGetTimeStep - Gets the current timestep size.

1630:    Not Collective

1632:    Input Parameter:
1633: .  ts - the TS context obtained from TSCreate()

1635:    Output Parameter:
1636: .  dt - the current timestep size

1638:    Level: intermediate

1640: .seealso: TSSetInitialTimeStep(), TSGetTimeStep()

1642: .keywords: TS, get, timestep
1643: @*/
1644: PetscErrorCode  TSGetTimeStep(TS ts,PetscReal *dt)
1645: {
1649:   *dt = ts->time_step;
1650:   return(0);
1651: }

1655: /*@
1656:    TSGetSolution - Returns the solution at the present timestep. It
1657:    is valid to call this routine inside the function that you are evaluating
1658:    in order to move to the new timestep. This vector not changed until
1659:    the solution at the next timestep has been calculated.

1661:    Not Collective, but Vec returned is parallel if TS is parallel

1663:    Input Parameter:
1664: .  ts - the TS context obtained from TSCreate()

1666:    Output Parameter:
1667: .  v - the vector containing the solution

1669:    Level: intermediate

1671: .seealso: TSGetTimeStep()

1673: .keywords: TS, timestep, get, solution
1674: @*/
1675: PetscErrorCode  TSGetSolution(TS ts,Vec *v)
1676: {
1680:   *v = ts->vec_sol;
1681:   return(0);
1682: }

1684: /* ----- Routines to initialize and destroy a timestepper ---- */
1687: /*@
1688:   TSSetProblemType - Sets the type of problem to be solved.

1690:   Not collective

1692:   Input Parameters:
1693: + ts   - The TS
1694: - type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1695: .vb
1696:          U_t - A U = 0      (linear)
1697:          U_t - A(t) U = 0   (linear)
1698:          F(t,U,U_t) = 0     (nonlinear)
1699: .ve

1701:    Level: beginner

1703: .keywords: TS, problem type
1704: .seealso: TSSetUp(), TSProblemType, TS
1705: @*/
1706: PetscErrorCode  TSSetProblemType(TS ts, TSProblemType type)
1707: {

1712:   ts->problem_type = type;
1713:   if (type == TS_LINEAR) {
1714:     SNES snes;
1715:     TSGetSNES(ts,&snes);
1716:     SNESSetType(snes,SNESKSPONLY);
1717:   }
1718:   return(0);
1719: }

1723: /*@C
1724:   TSGetProblemType - Gets the type of problem to be solved.

1726:   Not collective

1728:   Input Parameter:
1729: . ts   - The TS

1731:   Output Parameter:
1732: . type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1733: .vb
1734:          M U_t = A U
1735:          M(t) U_t = A(t) U
1736:          F(t,U,U_t)
1737: .ve

1739:    Level: beginner

1741: .keywords: TS, problem type
1742: .seealso: TSSetUp(), TSProblemType, TS
1743: @*/
1744: PetscErrorCode  TSGetProblemType(TS ts, TSProblemType *type)
1745: {
1749:   *type = ts->problem_type;
1750:   return(0);
1751: }

1755: /*@
1756:    TSSetUp - Sets up the internal data structures for the later use
1757:    of a timestepper.

1759:    Collective on TS

1761:    Input Parameter:
1762: .  ts - the TS context obtained from TSCreate()

1764:    Notes:
1765:    For basic use of the TS solvers the user need not explicitly call
1766:    TSSetUp(), since these actions will automatically occur during
1767:    the call to TSStep().  However, if one wishes to control this
1768:    phase separately, TSSetUp() should be called after TSCreate()
1769:    and optional routines of the form TSSetXXX(), but before TSStep().

1771:    Level: advanced

1773: .keywords: TS, timestep, setup

1775: .seealso: TSCreate(), TSStep(), TSDestroy()
1776: @*/
1777: PetscErrorCode  TSSetUp(TS ts)
1778: {
1780:   DM             dm;
1781:   PetscErrorCode (*func)(SNES,Vec,Vec,void*);
1782:   PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
1783:   TSIJacobian    ijac;
1784:   TSRHSJacobian  rhsjac;

1788:   if (ts->setupcalled) return(0);

1790:   if (!((PetscObject)ts)->type_name) {
1791:     TSSetType(ts,TSEULER);
1792:   }

1794:   if (!ts->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call TSSetSolution() first");

1796:   TSGetAdapt(ts,&ts->adapt);

1798:   if (ts->rhsjacobian.reuse) {
1799:     Mat Amat,Pmat;
1800:     SNES snes;
1801:     TSGetSNES(ts,&snes);
1802:     SNESGetJacobian(snes,&Amat,&Pmat,NULL,NULL);
1803:     /* Matching matrices implies that an IJacobian is NOT set, because if it had been set, the IJacobian's matrix would
1804:      * have displaced the RHS matrix */
1805:     if (Amat == ts->Arhs) {
1806:       MatDuplicate(ts->Arhs,MAT_DO_NOT_COPY_VALUES,&Amat);
1807:       SNESSetJacobian(snes,Amat,NULL,NULL,NULL);
1808:       MatDestroy(&Amat);
1809:     }
1810:     if (Pmat == ts->Brhs) {
1811:       MatDuplicate(ts->Brhs,MAT_DO_NOT_COPY_VALUES,&Pmat);
1812:       SNESSetJacobian(snes,NULL,Pmat,NULL,NULL);
1813:       MatDestroy(&Pmat);
1814:     }
1815:   }

1817:   if (ts->ops->setup) {
1818:     (*ts->ops->setup)(ts);
1819:   }

1821:   /* in the case where we've set a DMTSFunction or what have you, we need the default SNESFunction
1822:    to be set right but can't do it elsewhere due to the overreliance on ctx=ts.
1823:    */
1824:   TSGetDM(ts,&dm);
1825:   DMSNESGetFunction(dm,&func,NULL);
1826:   if (!func) {
1827:     ierr =DMSNESSetFunction(dm,SNESTSFormFunction,ts);
1828:   }
1829:   /* if the SNES doesn't have a jacobian set and the TS has an ijacobian or rhsjacobian set, set the SNES to use it.
1830:      Otherwise, the SNES will use coloring internally to form the Jacobian.
1831:    */
1832:   DMSNESGetJacobian(dm,&jac,NULL);
1833:   DMTSGetIJacobian(dm,&ijac,NULL);
1834:   DMTSGetRHSJacobian(dm,&rhsjac,NULL);
1835:   if (!jac && (ijac || rhsjac)) {
1836:     DMSNESSetJacobian(dm,SNESTSFormJacobian,ts);
1837:   }
1838:   ts->setupcalled = PETSC_TRUE;
1839:   return(0);
1840: }

1844: /*@
1845:    TSReset - Resets a TS context and removes any allocated Vecs and Mats.

1847:    Collective on TS

1849:    Input Parameter:
1850: .  ts - the TS context obtained from TSCreate()

1852:    Level: beginner

1854: .keywords: TS, timestep, reset

1856: .seealso: TSCreate(), TSSetup(), TSDestroy()
1857: @*/
1858: PetscErrorCode  TSReset(TS ts)
1859: {

1864:   if (ts->ops->reset) {
1865:     (*ts->ops->reset)(ts);
1866:   }
1867:   if (ts->snes) {SNESReset(ts->snes);}

1869:   MatDestroy(&ts->Arhs);
1870:   MatDestroy(&ts->Brhs);
1871:   VecDestroy(&ts->Frhs);
1872:   VecDestroy(&ts->vec_sol);
1873:   VecDestroy(&ts->vatol);
1874:   VecDestroy(&ts->vrtol);
1875:   VecDestroyVecs(ts->nwork,&ts->work);

1877:   ts->setupcalled = PETSC_FALSE;
1878:   return(0);
1879: }

1883: /*@
1884:    TSDestroy - Destroys the timestepper context that was created
1885:    with TSCreate().

1887:    Collective on TS

1889:    Input Parameter:
1890: .  ts - the TS context obtained from TSCreate()

1892:    Level: beginner

1894: .keywords: TS, timestepper, destroy

1896: .seealso: TSCreate(), TSSetUp(), TSSolve()
1897: @*/
1898: PetscErrorCode  TSDestroy(TS *ts)
1899: {

1903:   if (!*ts) return(0);
1905:   if (--((PetscObject)(*ts))->refct > 0) {*ts = 0; return(0);}

1907:   TSReset((*ts));

1909:   /* if memory was published with SAWs then destroy it */
1910:   PetscObjectSAWsViewOff((PetscObject)*ts);
1911:   if ((*ts)->ops->destroy) {(*(*ts)->ops->destroy)((*ts));}

1913:   TSAdaptDestroy(&(*ts)->adapt);
1914:   if ((*ts)->event) {
1915:     TSEventMonitorDestroy(&(*ts)->event);
1916:   }
1917:   SNESDestroy(&(*ts)->snes);
1918:   DMDestroy(&(*ts)->dm);
1919:   TSMonitorCancel((*ts));

1921:   PetscHeaderDestroy(ts);
1922:   return(0);
1923: }

1927: /*@
1928:    TSGetSNES - Returns the SNES (nonlinear solver) associated with
1929:    a TS (timestepper) context. Valid only for nonlinear problems.

1931:    Not Collective, but SNES is parallel if TS is parallel

1933:    Input Parameter:
1934: .  ts - the TS context obtained from TSCreate()

1936:    Output Parameter:
1937: .  snes - the nonlinear solver context

1939:    Notes:
1940:    The user can then directly manipulate the SNES context to set various
1941:    options, etc.  Likewise, the user can then extract and manipulate the
1942:    KSP, KSP, and PC contexts as well.

1944:    TSGetSNES() does not work for integrators that do not use SNES; in
1945:    this case TSGetSNES() returns NULL in snes.

1947:    Level: beginner

1949: .keywords: timestep, get, SNES
1950: @*/
1951: PetscErrorCode  TSGetSNES(TS ts,SNES *snes)
1952: {

1958:   if (!ts->snes) {
1959:     SNESCreate(PetscObjectComm((PetscObject)ts),&ts->snes);
1960:     SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);
1961:     PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->snes);
1962:     PetscObjectIncrementTabLevel((PetscObject)ts->snes,(PetscObject)ts,1);
1963:     if (ts->dm) {SNESSetDM(ts->snes,ts->dm);}
1964:     if (ts->problem_type == TS_LINEAR) {
1965:       SNESSetType(ts->snes,SNESKSPONLY);
1966:     }
1967:   }
1968:   *snes = ts->snes;
1969:   return(0);
1970: }

1974: /*@
1975:    TSSetSNES - Set the SNES (nonlinear solver) to be used by the timestepping context

1977:    Collective

1979:    Input Parameter:
1980: +  ts - the TS context obtained from TSCreate()
1981: -  snes - the nonlinear solver context

1983:    Notes:
1984:    Most users should have the TS created by calling TSGetSNES()

1986:    Level: developer

1988: .keywords: timestep, set, SNES
1989: @*/
1990: PetscErrorCode TSSetSNES(TS ts,SNES snes)
1991: {
1993:   PetscErrorCode (*func)(SNES,Vec,Mat,Mat,void*);

1998:   PetscObjectReference((PetscObject)snes);
1999:   SNESDestroy(&ts->snes);

2001:   ts->snes = snes;

2003:   SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);
2004:   SNESGetJacobian(ts->snes,NULL,NULL,&func,NULL);
2005:   if (func == SNESTSFormJacobian) {
2006:     SNESSetJacobian(ts->snes,NULL,NULL,SNESTSFormJacobian,ts);
2007:   }
2008:   return(0);
2009: }

2013: /*@
2014:    TSGetKSP - Returns the KSP (linear solver) associated with
2015:    a TS (timestepper) context.

2017:    Not Collective, but KSP is parallel if TS is parallel

2019:    Input Parameter:
2020: .  ts - the TS context obtained from TSCreate()

2022:    Output Parameter:
2023: .  ksp - the nonlinear solver context

2025:    Notes:
2026:    The user can then directly manipulate the KSP context to set various
2027:    options, etc.  Likewise, the user can then extract and manipulate the
2028:    KSP and PC contexts as well.

2030:    TSGetKSP() does not work for integrators that do not use KSP;
2031:    in this case TSGetKSP() returns NULL in ksp.

2033:    Level: beginner

2035: .keywords: timestep, get, KSP
2036: @*/
2037: PetscErrorCode  TSGetKSP(TS ts,KSP *ksp)
2038: {
2040:   SNES           snes;

2045:   if (!((PetscObject)ts)->type_name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"KSP is not created yet. Call TSSetType() first");
2046:   if (ts->problem_type != TS_LINEAR) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Linear only; use TSGetSNES()");
2047:   TSGetSNES(ts,&snes);
2048:   SNESGetKSP(snes,ksp);
2049:   return(0);
2050: }

2052: /* ----------- Routines to set solver parameters ---------- */

2056: /*@
2057:    TSGetDuration - Gets the maximum number of timesteps to use and
2058:    maximum time for iteration.

2060:    Not Collective

2062:    Input Parameters:
2063: +  ts       - the TS context obtained from TSCreate()
2064: .  maxsteps - maximum number of iterations to use, or NULL
2065: -  maxtime  - final time to iterate to, or NULL

2067:    Level: intermediate

2069: .keywords: TS, timestep, get, maximum, iterations, time
2070: @*/
2071: PetscErrorCode  TSGetDuration(TS ts, PetscInt *maxsteps, PetscReal *maxtime)
2072: {
2075:   if (maxsteps) {
2077:     *maxsteps = ts->max_steps;
2078:   }
2079:   if (maxtime) {
2081:     *maxtime = ts->max_time;
2082:   }
2083:   return(0);
2084: }

2088: /*@
2089:    TSSetDuration - Sets the maximum number of timesteps to use and
2090:    maximum time for iteration.

2092:    Logically Collective on TS

2094:    Input Parameters:
2095: +  ts - the TS context obtained from TSCreate()
2096: .  maxsteps - maximum number of iterations to use
2097: -  maxtime - final time to iterate to

2099:    Options Database Keys:
2100: .  -ts_max_steps <maxsteps> - Sets maxsteps
2101: .  -ts_final_time <maxtime> - Sets maxtime

2103:    Notes:
2104:    The default maximum number of iterations is 5000. Default time is 5.0

2106:    Level: intermediate

2108: .keywords: TS, timestep, set, maximum, iterations

2110: .seealso: TSSetExactFinalTime()
2111: @*/
2112: PetscErrorCode  TSSetDuration(TS ts,PetscInt maxsteps,PetscReal maxtime)
2113: {
2118:   if (maxsteps >= 0) ts->max_steps = maxsteps;
2119:   if (maxtime != PETSC_DEFAULT) ts->max_time = maxtime;
2120:   return(0);
2121: }

2125: /*@
2126:    TSSetSolution - Sets the initial solution vector
2127:    for use by the TS routines.

2129:    Logically Collective on TS and Vec

2131:    Input Parameters:
2132: +  ts - the TS context obtained from TSCreate()
2133: -  u - the solution vector

2135:    Level: beginner

2137: .keywords: TS, timestep, set, solution, initial conditions
2138: @*/
2139: PetscErrorCode  TSSetSolution(TS ts,Vec u)
2140: {
2142:   DM             dm;

2147:   PetscObjectReference((PetscObject)u);
2148:   VecDestroy(&ts->vec_sol);

2150:   ts->vec_sol = u;

2152:   TSGetDM(ts,&dm);
2153:   DMShellSetGlobalVector(dm,u);
2154:   return(0);
2155: }

2159: /*@C
2160:   TSSetPreStep - Sets the general-purpose function
2161:   called once at the beginning of each time step.

2163:   Logically Collective on TS

2165:   Input Parameters:
2166: + ts   - The TS context obtained from TSCreate()
2167: - func - The function

2169:   Calling sequence of func:
2170: . func (TS ts);

2172:   Level: intermediate

2174:   Note:
2175:   If a step is rejected, TSStep() will call this routine again before each attempt.
2176:   The last completed time step number can be queried using TSGetTimeStepNumber(), the
2177:   size of the step being attempted can be obtained using TSGetTimeStep().

2179: .keywords: TS, timestep
2180: .seealso: TSSetPreStage(), TSSetPostStage(), TSSetPostStep(), TSStep()
2181: @*/
2182: PetscErrorCode  TSSetPreStep(TS ts, PetscErrorCode (*func)(TS))
2183: {
2186:   ts->prestep = func;
2187:   return(0);
2188: }

2192: /*@
2193:   TSPreStep - Runs the user-defined pre-step function.

2195:   Collective on TS

2197:   Input Parameters:
2198: . ts   - The TS context obtained from TSCreate()

2200:   Notes:
2201:   TSPreStep() is typically used within time stepping implementations,
2202:   so most users would not generally call this routine themselves.

2204:   Level: developer

2206: .keywords: TS, timestep
2207: .seealso: TSSetPreStep(), TSPreStage(), TSPostStage(), TSPostStep()
2208: @*/
2209: PetscErrorCode  TSPreStep(TS ts)
2210: {

2215:   if (ts->prestep) {
2216:     PetscStackCallStandard((*ts->prestep),(ts));
2217:   }
2218:   return(0);
2219: }

2223: /*@C
2224:   TSSetPreStage - Sets the general-purpose function
2225:   called once at the beginning of each stage.

2227:   Logically Collective on TS

2229:   Input Parameters:
2230: + ts   - The TS context obtained from TSCreate()
2231: - func - The function

2233:   Calling sequence of func:
2234: . PetscErrorCode func(TS ts, PetscReal stagetime);

2236:   Level: intermediate

2238:   Note:
2239:   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2240:   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2241:   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().

2243: .keywords: TS, timestep
2244: .seealso: TSSetPostStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2245: @*/
2246: PetscErrorCode  TSSetPreStage(TS ts, PetscErrorCode (*func)(TS,PetscReal))
2247: {
2250:   ts->prestage = func;
2251:   return(0);
2252: }

2256: /*@C
2257:   TSSetPostStage - Sets the general-purpose function
2258:   called once at the end of each stage.

2260:   Logically Collective on TS

2262:   Input Parameters:
2263: + ts   - The TS context obtained from TSCreate()
2264: - func - The function

2266:   Calling sequence of func:
2267: . PetscErrorCode func(TS ts, PetscReal stagetime, PetscInt stageindex, Vec* Y);

2269:   Level: intermediate

2271:   Note:
2272:   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2273:   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2274:   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().

2276: .keywords: TS, timestep
2277: .seealso: TSSetPreStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2278: @*/
2279: PetscErrorCode  TSSetPostStage(TS ts, PetscErrorCode (*func)(TS,PetscReal,PetscInt,Vec*))
2280: {
2283:   ts->poststage = func;
2284:   return(0);
2285: }

2289: /*@
2290:   TSPreStage - Runs the user-defined pre-stage function set using TSSetPreStage()

2292:   Collective on TS

2294:   Input Parameters:
2295: . ts          - The TS context obtained from TSCreate()
2296:   stagetime   - The absolute time of the current stage

2298:   Notes:
2299:   TSPreStage() is typically used within time stepping implementations,
2300:   most users would not generally call this routine themselves.

2302:   Level: developer

2304: .keywords: TS, timestep
2305: .seealso: TSPostStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2306: @*/
2307: PetscErrorCode  TSPreStage(TS ts, PetscReal stagetime)
2308: {

2313:   if (ts->prestage) {
2314:     PetscStackCallStandard((*ts->prestage),(ts,stagetime));
2315:   }
2316:   return(0);
2317: }

2321: /*@
2322:   TSPostStage - Runs the user-defined post-stage function set using TSSetPostStage()

2324:   Collective on TS

2326:   Input Parameters:
2327: . ts          - The TS context obtained from TSCreate()
2328:   stagetime   - The absolute time of the current stage
2329:   stageindex  - Stage number
2330:   Y           - Array of vectors (of size = total number
2331:                 of stages) with the stage solutions

2333:   Notes:
2334:   TSPostStage() is typically used within time stepping implementations,
2335:   most users would not generally call this routine themselves.

2337:   Level: developer

2339: .keywords: TS, timestep
2340: .seealso: TSPreStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2341: @*/
2342: PetscErrorCode  TSPostStage(TS ts, PetscReal stagetime, PetscInt stageindex, Vec *Y)
2343: {

2348:   if (ts->prestage) {
2349:     PetscStackCallStandard((*ts->poststage),(ts,stagetime,stageindex,Y));
2350:   }
2351:   return(0);
2352: }

2356: /*@C
2357:   TSSetPostStep - Sets the general-purpose function
2358:   called once at the end of each time step.

2360:   Logically Collective on TS

2362:   Input Parameters:
2363: + ts   - The TS context obtained from TSCreate()
2364: - func - The function

2366:   Calling sequence of func:
2367: $ func (TS ts);

2369:   Level: intermediate

2371: .keywords: TS, timestep
2372: .seealso: TSSetPreStep(), TSSetPreStage(), TSGetTimeStep(), TSGetTimeStepNumber(), TSGetTime()
2373: @*/
2374: PetscErrorCode  TSSetPostStep(TS ts, PetscErrorCode (*func)(TS))
2375: {
2378:   ts->poststep = func;
2379:   return(0);
2380: }

2384: /*@
2385:   TSPostStep - Runs the user-defined post-step function.

2387:   Collective on TS

2389:   Input Parameters:
2390: . ts   - The TS context obtained from TSCreate()

2392:   Notes:
2393:   TSPostStep() is typically used within time stepping implementations,
2394:   so most users would not generally call this routine themselves.

2396:   Level: developer

2398: .keywords: TS, timestep
2399: @*/
2400: PetscErrorCode  TSPostStep(TS ts)
2401: {

2406:   if (ts->poststep) {
2407:     PetscStackCallStandard((*ts->poststep),(ts));
2408:   }
2409:   return(0);
2410: }

2412: /* ------------ Routines to set performance monitoring options ----------- */

2416: /*@C
2417:    TSMonitorSet - Sets an ADDITIONAL function that is to be used at every
2418:    timestep to display the iteration's  progress.

2420:    Logically Collective on TS

2422:    Input Parameters:
2423: +  ts - the TS context obtained from TSCreate()
2424: .  monitor - monitoring routine
2425: .  mctx - [optional] user-defined context for private data for the
2426:              monitor routine (use NULL if no context is desired)
2427: -  monitordestroy - [optional] routine that frees monitor context
2428:           (may be NULL)

2430:    Calling sequence of monitor:
2431: $    int monitor(TS ts,PetscInt steps,PetscReal time,Vec u,void *mctx)

2433: +    ts - the TS context
2434: .    steps - iteration number (after the final time step the monitor routine is called with a step of -1, this is at the final time which may have
2435:                                been interpolated to)
2436: .    time - current time
2437: .    u - current iterate
2438: -    mctx - [optional] monitoring context

2440:    Notes:
2441:    This routine adds an additional monitor to the list of monitors that
2442:    already has been loaded.

2444:    Fortran notes: Only a single monitor function can be set for each TS object

2446:    Level: intermediate

2448: .keywords: TS, timestep, set, monitor

2450: .seealso: TSMonitorDefault(), TSMonitorCancel()
2451: @*/
2452: PetscErrorCode  TSMonitorSet(TS ts,PetscErrorCode (*monitor)(TS,PetscInt,PetscReal,Vec,void*),void *mctx,PetscErrorCode (*mdestroy)(void**))
2453: {
2456:   if (ts->numbermonitors >= MAXTSMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
2457:   ts->monitor[ts->numbermonitors]          = monitor;
2458:   ts->monitordestroy[ts->numbermonitors]   = mdestroy;
2459:   ts->monitorcontext[ts->numbermonitors++] = (void*)mctx;
2460:   return(0);
2461: }

2465: /*@C
2466:    TSMonitorCancel - Clears all the monitors that have been set on a time-step object.

2468:    Logically Collective on TS

2470:    Input Parameters:
2471: .  ts - the TS context obtained from TSCreate()

2473:    Notes:
2474:    There is no way to remove a single, specific monitor.

2476:    Level: intermediate

2478: .keywords: TS, timestep, set, monitor

2480: .seealso: TSMonitorDefault(), TSMonitorSet()
2481: @*/
2482: PetscErrorCode  TSMonitorCancel(TS ts)
2483: {
2485:   PetscInt       i;

2489:   for (i=0; i<ts->numbermonitors; i++) {
2490:     if (ts->monitordestroy[i]) {
2491:       (*ts->monitordestroy[i])(&ts->monitorcontext[i]);
2492:     }
2493:   }
2494:   ts->numbermonitors = 0;
2495:   return(0);
2496: }

2500: /*@
2501:    TSMonitorDefault - Sets the Default monitor

2503:    Level: intermediate

2505: .keywords: TS, set, monitor

2507: .seealso: TSMonitorDefault(), TSMonitorSet()
2508: @*/
2509: PetscErrorCode TSMonitorDefault(TS ts,PetscInt step,PetscReal ptime,Vec v,void *dummy)
2510: {
2512:   PetscViewer    viewer = dummy ? (PetscViewer) dummy : PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)ts));

2515:   PetscViewerASCIIAddTab(viewer,((PetscObject)ts)->tablevel);
2516:   PetscViewerASCIIPrintf(viewer,"%D TS dt %g time %g\n",step,(double)ts->time_step,(double)ptime);
2517:   PetscViewerASCIISubtractTab(viewer,((PetscObject)ts)->tablevel);
2518:   return(0);
2519: }

2523: /*@
2524:    TSSetRetainStages - Request that all stages in the upcoming step be stored so that interpolation will be available.

2526:    Logically Collective on TS

2528:    Input Argument:
2529: .  ts - time stepping context

2531:    Output Argument:
2532: .  flg - PETSC_TRUE or PETSC_FALSE

2534:    Level: intermediate

2536: .keywords: TS, set

2538: .seealso: TSInterpolate(), TSSetPostStep()
2539: @*/
2540: PetscErrorCode TSSetRetainStages(TS ts,PetscBool flg)
2541: {
2544:   ts->retain_stages = flg;
2545:   return(0);
2546: }

2550: /*@
2551:    TSInterpolate - Interpolate the solution computed during the previous step to an arbitrary location in the interval

2553:    Collective on TS

2555:    Input Argument:
2556: +  ts - time stepping context
2557: -  t - time to interpolate to

2559:    Output Argument:
2560: .  U - state at given time

2562:    Notes:
2563:    The user should call TSSetRetainStages() before taking a step in which interpolation will be requested.

2565:    Level: intermediate

2567:    Developer Notes:
2568:    TSInterpolate() and the storing of previous steps/stages should be generalized to support delay differential equations and continuous adjoints.

2570: .keywords: TS, set

2572: .seealso: TSSetRetainStages(), TSSetPostStep()
2573: @*/
2574: PetscErrorCode TSInterpolate(TS ts,PetscReal t,Vec U)
2575: {

2581:   if (t < ts->ptime - ts->time_step_prev || t > ts->ptime) SETERRQ3(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_OUTOFRANGE,"Requested time %g not in last time steps [%g,%g]",t,(double)(ts->ptime-ts->time_step_prev),(double)ts->ptime);
2582:   if (!ts->ops->interpolate) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"%s does not provide interpolation",((PetscObject)ts)->type_name);
2583:   (*ts->ops->interpolate)(ts,t,U);
2584:   return(0);
2585: }

2589: /*@
2590:    TSStep - Steps one time step

2592:    Collective on TS

2594:    Input Parameter:
2595: .  ts - the TS context obtained from TSCreate()

2597:    Level: intermediate

2599:    Notes:
2600:    The hook set using TSSetPreStep() is called before each attempt to take the step. In general, the time step size may
2601:    be changed due to adaptive error controller or solve failures. Note that steps may contain multiple stages.

2603:    This may over-step the final time provided in TSSetDuration() depending on the time-step used. TSSolve() interpolates to exactly the
2604:    time provided in TSSetDuration(). One can use TSInterpolate() to determine an interpolated solution within the final timestep.

2606: .keywords: TS, timestep, solve

2608: .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSInterpolate()
2609: @*/
2610: PetscErrorCode  TSStep(TS ts)
2611: {
2612:   DM               dm;
2613:   PetscErrorCode   ierr;
2614:   static PetscBool cite = PETSC_FALSE;

2618:   PetscCitationsRegister("@techreport{tspaper,\n"
2619:                                 "  title       = {{PETSc/TS}: A Modern Scalable {DAE/ODE} Solver Library},\n"
2620:                                 "  author      = {Shrirang Abhyankar and Jed Brown and Emil Constantinescu and Debojyoti Ghosh and Barry F. Smith},\n"
2621:                                 "  type        = {Preprint},\n"
2622:                                 "  number      = {ANL/MCS-P5061-0114},\n"
2623:                                 "  institution = {Argonne National Laboratory},\n"
2624:                                 "  year        = {2014}\n}\n",&cite);

2626:   TSGetDM(ts, &dm);
2627:   TSSetUp(ts);

2629:   ts->reason = TS_CONVERGED_ITERATING;
2630:   ts->ptime_prev = ts->ptime;
2631:   DMSetOutputSequenceNumber(dm, ts->steps, ts->ptime);
2632:   VecViewFromOptions(ts->vec_sol, ((PetscObject) ts)->prefix, "-ts_view_solution");

2634:   PetscLogEventBegin(TS_Step,ts,0,0,0);
2635:   (*ts->ops->step)(ts);
2636:   PetscLogEventEnd(TS_Step,ts,0,0,0);

2638:   ts->time_step_prev = ts->ptime - ts->ptime_prev;
2639:   DMSetOutputSequenceNumber(dm, ts->steps, ts->ptime);

2641:   if (ts->reason < 0) {
2642:     if (ts->errorifstepfailed) {
2643:       if (ts->reason == TS_DIVERGED_NONLINEAR_SOLVE) {
2644:         SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s, increase -ts_max_snes_failures or make negative to attempt recovery",TSConvergedReasons[ts->reason]);
2645:       } else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s",TSConvergedReasons[ts->reason]);
2646:     }
2647:   } else if (!ts->reason) {
2648:     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2649:     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2650:   }
2651:   return(0);
2652: }

2656: /*@
2657:    TSEvaluateStep - Evaluate the solution at the end of a time step with a given order of accuracy.

2659:    Collective on TS

2661:    Input Arguments:
2662: +  ts - time stepping context
2663: .  order - desired order of accuracy
2664: -  done - whether the step was evaluated at this order (pass NULL to generate an error if not available)

2666:    Output Arguments:
2667: .  U - state at the end of the current step

2669:    Level: advanced

2671:    Notes:
2672:    This function cannot be called until all stages have been evaluated.
2673:    It is normally called by adaptive controllers before a step has been accepted and may also be called by the user after TSStep() has returned.

2675: .seealso: TSStep(), TSAdapt
2676: @*/
2677: PetscErrorCode TSEvaluateStep(TS ts,PetscInt order,Vec U,PetscBool *done)
2678: {

2685:   if (!ts->ops->evaluatestep) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSEvaluateStep not implemented for type '%s'",((PetscObject)ts)->type_name);
2686:   (*ts->ops->evaluatestep)(ts,order,U,done);
2687:   return(0);
2688: }

2692: /*@
2693:    TSSolve - Steps the requested number of timesteps.

2695:    Collective on TS

2697:    Input Parameter:
2698: +  ts - the TS context obtained from TSCreate()
2699: -  u - the solution vector  (can be null if TSSetSolution() was used, otherwise must contain the initial conditions)

2701:    Level: beginner

2703:    Notes:
2704:    The final time returned by this function may be different from the time of the internally
2705:    held state accessible by TSGetSolution() and TSGetTime() because the method may have
2706:    stepped over the final time.

2708: .keywords: TS, timestep, solve

2710: .seealso: TSCreate(), TSSetSolution(), TSStep()
2711: @*/
2712: PetscErrorCode TSSolve(TS ts,Vec u)
2713: {
2714:   Vec               solution;
2715:   PetscErrorCode    ierr;

2720:   if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE) {   /* Need ts->vec_sol to be distinct so it is not overwritten when we interpolate at the end */
2722:     if (!ts->vec_sol || u == ts->vec_sol) {
2723:       VecDuplicate(u,&solution);
2724:       TSSetSolution(ts,solution);
2725:       VecDestroy(&solution); /* grant ownership */
2726:     }
2727:     VecCopy(u,ts->vec_sol);
2728:   } else if (u) {
2729:     TSSetSolution(ts,u);
2730:   }
2731:   TSSetUp(ts);
2732:   /* reset time step and iteration counters */
2733:   ts->steps             = 0;
2734:   ts->ksp_its           = 0;
2735:   ts->snes_its          = 0;
2736:   ts->num_snes_failures = 0;
2737:   ts->reject            = 0;
2738:   ts->reason            = TS_CONVERGED_ITERATING;

2740:   TSViewFromOptions(ts,NULL,"-ts_view_pre");

2742:   if (ts->ops->solve) {         /* This private interface is transitional and should be removed when all implementations are updated. */
2743:     (*ts->ops->solve)(ts);
2744:     VecCopy(ts->vec_sol,u);
2745:     ts->solvetime = ts->ptime;
2746:   } else {
2747:     /* steps the requested number of timesteps. */
2748:     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2749:     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2750:     while (!ts->reason) {
2751:       TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);
2752:       TSStep(ts);
2753:       if (ts->event) {
2754:         TSEventMonitor(ts);
2755:         if (ts->event->status != TSEVENT_PROCESSING) {
2756:           TSPostStep(ts);
2757:         }
2758:       } else {
2759:         TSPostStep(ts);
2760:       }
2761:     }
2762:     if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE && ts->ptime > ts->max_time) {
2763:       TSInterpolate(ts,ts->max_time,u);
2764:       ts->solvetime = ts->max_time;
2765:       solution = u;
2766:     } else {
2767:       if (u) {VecCopy(ts->vec_sol,u);}
2768:       ts->solvetime = ts->ptime;
2769:       solution = ts->vec_sol;
2770:     }
2771:     TSMonitor(ts,ts->steps,ts->solvetime,solution);
2772:     VecViewFromOptions(u, ((PetscObject) ts)->prefix, "-ts_view_solution");
2773:   }
2774:   TSViewFromOptions(ts,NULL,"-ts_view");
2775:   PetscObjectSAWsBlock((PetscObject)ts);
2776:   return(0);
2777: }

2781: /*@
2782:    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()

2784:    Collective on TS

2786:    Input Parameters:
2787: +  ts - time stepping context obtained from TSCreate()
2788: .  step - step number that has just completed
2789: .  ptime - model time of the state
2790: -  u - state at the current model time

2792:    Notes:
2793:    TSMonitor() is typically used within the time stepping implementations.
2794:    Users might call this function when using the TSStep() interface instead of TSSolve().

2796:    Level: advanced

2798: .keywords: TS, timestep
2799: @*/
2800: PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
2801: {
2803:   PetscInt       i,n = ts->numbermonitors;

2808:   for (i=0; i<n; i++) {
2809:     (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);
2810:   }
2811:   return(0);
2812: }

2814: /* ------------------------------------------------------------------------*/
2817: /*@C
2818:    TSMonitorLGCtxCreate - Creates a line graph context for use with
2819:    TS to monitor the solution process graphically in various ways

2821:    Collective on TS

2823:    Input Parameters:
2824: +  host - the X display to open, or null for the local machine
2825: .  label - the title to put in the title bar
2826: .  x, y - the screen coordinates of the upper left coordinate of the window
2827: .  m, n - the screen width and height in pixels
2828: -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time

2830:    Output Parameter:
2831: .  ctx - the context

2833:    Options Database Key:
2834: +  -ts_monitor_lg_timestep - automatically sets line graph monitor
2835: .  -ts_monitor_lg_solution -
2836: .  -ts_monitor_lg_error -
2837: .  -ts_monitor_lg_ksp_iterations -
2838: .  -ts_monitor_lg_snes_iterations -
2839: -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true

2841:    Notes:
2842:    Use TSMonitorLGCtxDestroy() to destroy.

2844:    Level: intermediate

2846: .keywords: TS, monitor, line graph, residual, seealso

2848: .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()

2850: @*/
2851: PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
2852: {
2853:   PetscDraw      win;

2857:   PetscNew(ctx);
2858:   PetscDrawCreate(comm,host,label,x,y,m,n,&win);
2859:   PetscDrawSetFromOptions(win);
2860:   PetscDrawLGCreate(win,1,&(*ctx)->lg);
2861:   PetscLogObjectParent((PetscObject)(*ctx)->lg,(PetscObject)win);
2862:   PetscDrawLGIndicateDataPoints((*ctx)->lg,PETSC_TRUE);
2863:   PetscDrawLGSetFromOptions((*ctx)->lg);
2864:   (*ctx)->howoften = howoften;
2865:   return(0);
2866: }

2870: PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx)
2871: {
2872:   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
2873:   PetscReal      x   = ptime,y;

2877:   if (!step) {
2878:     PetscDrawAxis axis;
2879:     PetscDrawLGGetAxis(ctx->lg,&axis);
2880:     PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");
2881:     PetscDrawLGReset(ctx->lg);
2882:     PetscDrawLGIndicateDataPoints(ctx->lg,PETSC_TRUE);
2883:   }
2884:   TSGetTimeStep(ts,&y);
2885:   PetscDrawLGAddPoint(ctx->lg,&x,&y);
2886:   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
2887:     PetscDrawLGDraw(ctx->lg);
2888:   }
2889:   return(0);
2890: }

2894: /*@C
2895:    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
2896:    with TSMonitorLGCtxCreate().

2898:    Collective on TSMonitorLGCtx

2900:    Input Parameter:
2901: .  ctx - the monitor context

2903:    Level: intermediate

2905: .keywords: TS, monitor, line graph, destroy

2907: .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
2908: @*/
2909: PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
2910: {
2911:   PetscDraw      draw;

2915:   PetscDrawLGGetDraw((*ctx)->lg,&draw);
2916:   PetscDrawDestroy(&draw);
2917:   PetscDrawLGDestroy(&(*ctx)->lg);
2918:   PetscFree(*ctx);
2919:   return(0);
2920: }

2924: /*@
2925:    TSGetTime - Gets the time of the most recently completed step.

2927:    Not Collective

2929:    Input Parameter:
2930: .  ts - the TS context obtained from TSCreate()

2932:    Output Parameter:
2933: .  t  - the current time

2935:    Level: beginner

2937:    Note:
2938:    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
2939:    TSSetPreStage(), TSSetPostStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.

2941: .seealso: TSSetInitialTimeStep(), TSGetTimeStep()

2943: .keywords: TS, get, time
2944: @*/
2945: PetscErrorCode  TSGetTime(TS ts,PetscReal *t)
2946: {
2950:   *t = ts->ptime;
2951:   return(0);
2952: }

2956: /*@
2957:    TSSetTime - Allows one to reset the time.

2959:    Logically Collective on TS

2961:    Input Parameters:
2962: +  ts - the TS context obtained from TSCreate()
2963: -  time - the time

2965:    Level: intermediate

2967: .seealso: TSGetTime(), TSSetDuration()

2969: .keywords: TS, set, time
2970: @*/
2971: PetscErrorCode  TSSetTime(TS ts, PetscReal t)
2972: {
2976:   ts->ptime = t;
2977:   return(0);
2978: }

2982: /*@C
2983:    TSSetOptionsPrefix - Sets the prefix used for searching for all
2984:    TS options in the database.

2986:    Logically Collective on TS

2988:    Input Parameter:
2989: +  ts     - The TS context
2990: -  prefix - The prefix to prepend to all option names

2992:    Notes:
2993:    A hyphen (-) must NOT be given at the beginning of the prefix name.
2994:    The first character of all runtime options is AUTOMATICALLY the
2995:    hyphen.

2997:    Level: advanced

2999: .keywords: TS, set, options, prefix, database

3001: .seealso: TSSetFromOptions()

3003: @*/
3004: PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
3005: {
3007:   SNES           snes;

3011:   PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);
3012:   TSGetSNES(ts,&snes);
3013:   SNESSetOptionsPrefix(snes,prefix);
3014:   return(0);
3015: }


3020: /*@C
3021:    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
3022:    TS options in the database.

3024:    Logically Collective on TS

3026:    Input Parameter:
3027: +  ts     - The TS context
3028: -  prefix - The prefix to prepend to all option names

3030:    Notes:
3031:    A hyphen (-) must NOT be given at the beginning of the prefix name.
3032:    The first character of all runtime options is AUTOMATICALLY the
3033:    hyphen.

3035:    Level: advanced

3037: .keywords: TS, append, options, prefix, database

3039: .seealso: TSGetOptionsPrefix()

3041: @*/
3042: PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
3043: {
3045:   SNES           snes;

3049:   PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);
3050:   TSGetSNES(ts,&snes);
3051:   SNESAppendOptionsPrefix(snes,prefix);
3052:   return(0);
3053: }

3057: /*@C
3058:    TSGetOptionsPrefix - Sets the prefix used for searching for all
3059:    TS options in the database.

3061:    Not Collective

3063:    Input Parameter:
3064: .  ts - The TS context

3066:    Output Parameter:
3067: .  prefix - A pointer to the prefix string used

3069:    Notes: On the fortran side, the user should pass in a string 'prifix' of
3070:    sufficient length to hold the prefix.

3072:    Level: intermediate

3074: .keywords: TS, get, options, prefix, database

3076: .seealso: TSAppendOptionsPrefix()
3077: @*/
3078: PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
3079: {

3085:   PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);
3086:   return(0);
3087: }

3091: /*@C
3092:    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.

3094:    Not Collective, but parallel objects are returned if TS is parallel

3096:    Input Parameter:
3097: .  ts  - The TS context obtained from TSCreate()

3099:    Output Parameters:
3100: +  Amat - The (approximate) Jacobian J of G, where U_t = G(U,t)  (or NULL)
3101: .  Pmat - The matrix from which the preconditioner is constructed, usually the same as Amat  (or NULL)
3102: .  func - Function to compute the Jacobian of the RHS  (or NULL)
3103: -  ctx - User-defined context for Jacobian evaluation routine  (or NULL)

3105:    Notes: You can pass in NULL for any return argument you do not need.

3107:    Level: intermediate

3109: .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()

3111: .keywords: TS, timestep, get, matrix, Jacobian
3112: @*/
3113: PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *Amat,Mat *Pmat,TSRHSJacobian *func,void **ctx)
3114: {
3116:   SNES           snes;
3117:   DM             dm;

3120:   TSGetSNES(ts,&snes);
3121:   SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
3122:   TSGetDM(ts,&dm);
3123:   DMTSGetRHSJacobian(dm,func,ctx);
3124:   return(0);
3125: }

3129: /*@C
3130:    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.

3132:    Not Collective, but parallel objects are returned if TS is parallel

3134:    Input Parameter:
3135: .  ts  - The TS context obtained from TSCreate()

3137:    Output Parameters:
3138: +  Amat  - The (approximate) Jacobian of F(t,U,U_t)
3139: .  Pmat - The matrix from which the preconditioner is constructed, often the same as Amat
3140: .  f   - The function to compute the matrices
3141: - ctx - User-defined context for Jacobian evaluation routine

3143:    Notes: You can pass in NULL for any return argument you do not need.

3145:    Level: advanced

3147: .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()

3149: .keywords: TS, timestep, get, matrix, Jacobian
3150: @*/
3151: PetscErrorCode  TSGetIJacobian(TS ts,Mat *Amat,Mat *Pmat,TSIJacobian *f,void **ctx)
3152: {
3154:   SNES           snes;
3155:   DM             dm;

3158:   TSGetSNES(ts,&snes);
3159:   SNESSetUpMatrices(snes);
3160:   SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);
3161:   TSGetDM(ts,&dm);
3162:   DMTSGetIJacobian(dm,f,ctx);
3163:   return(0);
3164: }


3169: /*@C
3170:    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
3171:    VecView() for the solution at each timestep

3173:    Collective on TS

3175:    Input Parameters:
3176: +  ts - the TS context
3177: .  step - current time-step
3178: .  ptime - current time
3179: -  dummy - either a viewer or NULL

3181:    Options Database:
3182: .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution

3184:    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
3185:        will look bad

3187:    Level: intermediate

3189: .keywords: TS,  vector, monitor, view

3191: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3192: @*/
3193: PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3194: {
3195:   PetscErrorCode   ierr;
3196:   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
3197:   PetscDraw        draw;

3200:   if (!step && ictx->showinitial) {
3201:     if (!ictx->initialsolution) {
3202:       VecDuplicate(u,&ictx->initialsolution);
3203:     }
3204:     VecCopy(u,ictx->initialsolution);
3205:   }
3206:   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften))) || ((ictx->howoften == -1) && ts->reason))) return(0);

3208:   if (ictx->showinitial) {
3209:     PetscReal pause;
3210:     PetscViewerDrawGetPause(ictx->viewer,&pause);
3211:     PetscViewerDrawSetPause(ictx->viewer,0.0);
3212:     VecView(ictx->initialsolution,ictx->viewer);
3213:     PetscViewerDrawSetPause(ictx->viewer,pause);
3214:     PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);
3215:   }
3216:   VecView(u,ictx->viewer);
3217:   if (ictx->showtimestepandtime) {
3218:     PetscReal xl,yl,xr,yr,tw,w,h;
3219:     char      time[32];
3220:     size_t    len;

3222:     PetscViewerDrawGetDraw(ictx->viewer,0,&draw);
3223:     PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);
3224:     PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);
3225:      PetscStrlen(time,&len);
3226:     PetscDrawStringGetSize(draw,&tw,NULL);
3227:     w    = xl + .5*(xr - xl) - .5*len*tw;
3228:     h    = yl + .95*(yr - yl);
3229:     PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);
3230:     PetscDrawFlush(draw);
3231:   }

3233:   if (ictx->showinitial) {
3234:     PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);
3235:   }
3236:   return(0);
3237: }

3241: /*@C
3242:    TSMonitorDrawSolutionPhase - Monitors progress of the TS solvers by plotting the solution as a phase diagram

3244:    Collective on TS

3246:    Input Parameters:
3247: +  ts - the TS context
3248: .  step - current time-step
3249: .  ptime - current time
3250: -  dummy - either a viewer or NULL

3252:    Level: intermediate

3254: .keywords: TS,  vector, monitor, view

3256: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3257: @*/
3258: PetscErrorCode  TSMonitorDrawSolutionPhase(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3259: {
3260:   PetscErrorCode    ierr;
3261:   TSMonitorDrawCtx  ictx = (TSMonitorDrawCtx)dummy;
3262:   PetscDraw         draw;
3263:   MPI_Comm          comm;
3264:   PetscInt          n;
3265:   PetscMPIInt       size;
3266:   PetscReal         xl,yl,xr,yr,tw,w,h;
3267:   char              time[32];
3268:   size_t            len;
3269:   const PetscScalar *U;

3272:   PetscObjectGetComm((PetscObject)ts,&comm);
3273:   MPI_Comm_size(comm,&size);
3274:   if (size != 1) SETERRQ(comm,PETSC_ERR_SUP,"Only allowed for sequential runs");
3275:   VecGetSize(u,&n);
3276:   if (n != 2) SETERRQ(comm,PETSC_ERR_SUP,"Only for ODEs with two unknowns");

3278:   PetscViewerDrawGetDraw(ictx->viewer,0,&draw);

3280:   VecGetArrayRead(u,&U);
3281:   PetscDrawAxisGetLimits(ictx->axis,&xl,&xr,&yl,&yr);
3282:   if ((PetscRealPart(U[0]) < xl) || (PetscRealPart(U[1]) < yl) || (PetscRealPart(U[0]) > xr) || (PetscRealPart(U[1]) > yr)) {
3283:       VecRestoreArrayRead(u,&U);
3284:       return(0);
3285:   }
3286:   if (!step) ictx->color++;
3287:   PetscDrawPoint(draw,PetscRealPart(U[0]),PetscRealPart(U[1]),ictx->color);
3288:   VecRestoreArrayRead(u,&U);

3290:   if (ictx->showtimestepandtime) {
3291:     PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);
3292:     PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);
3293:     PetscStrlen(time,&len);
3294:     PetscDrawStringGetSize(draw,&tw,NULL);
3295:     w    = xl + .5*(xr - xl) - .5*len*tw;
3296:     h    = yl + .95*(yr - yl);
3297:     PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);
3298:   }
3299:   PetscDrawFlush(draw);
3300:   return(0);
3301: }


3306: /*@C
3307:    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()

3309:    Collective on TS

3311:    Input Parameters:
3312: .    ctx - the monitor context

3314:    Level: intermediate

3316: .keywords: TS,  vector, monitor, view

3318: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
3319: @*/
3320: PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
3321: {

3325:   PetscDrawAxisDestroy(&(*ictx)->axis);
3326:   PetscViewerDestroy(&(*ictx)->viewer);
3327:   VecDestroy(&(*ictx)->initialsolution);
3328:   PetscFree(*ictx);
3329:   return(0);
3330: }

3334: /*@C
3335:    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx

3337:    Collective on TS

3339:    Input Parameter:
3340: .    ts - time-step context

3342:    Output Patameter:
3343: .    ctx - the monitor context

3345:    Options Database:
3346: .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution

3348:    Level: intermediate

3350: .keywords: TS,  vector, monitor, view

3352: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
3353: @*/
3354: PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
3355: {
3356:   PetscErrorCode   ierr;

3359:   PetscNew(ctx);
3360:   PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);
3361:   PetscViewerSetFromOptions((*ctx)->viewer);

3363:   (*ctx)->howoften    = howoften;
3364:   (*ctx)->showinitial = PETSC_FALSE;
3365:   PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,NULL);

3367:   (*ctx)->showtimestepandtime = PETSC_FALSE;
3368:   PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_show_time",&(*ctx)->showtimestepandtime,NULL);
3369:   (*ctx)->color = PETSC_DRAW_WHITE;
3370:   return(0);
3371: }

3375: /*@C
3376:    TSMonitorDrawError - Monitors progress of the TS solvers by calling
3377:    VecView() for the error at each timestep

3379:    Collective on TS

3381:    Input Parameters:
3382: +  ts - the TS context
3383: .  step - current time-step
3384: .  ptime - current time
3385: -  dummy - either a viewer or NULL

3387:    Level: intermediate

3389: .keywords: TS,  vector, monitor, view

3391: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3392: @*/
3393: PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3394: {
3395:   PetscErrorCode   ierr;
3396:   TSMonitorDrawCtx ctx    = (TSMonitorDrawCtx)dummy;
3397:   PetscViewer      viewer = ctx->viewer;
3398:   Vec              work;

3401:   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason))) return(0);
3402:   VecDuplicate(u,&work);
3403:   TSComputeSolutionFunction(ts,ptime,work);
3404:   VecAXPY(work,-1.0,u);
3405:   VecView(work,viewer);
3406:   VecDestroy(&work);
3407:   return(0);
3408: }

3410: #include <petsc-private/dmimpl.h>
3413: /*@
3414:    TSSetDM - Sets the DM that may be used by some preconditioners

3416:    Logically Collective on TS and DM

3418:    Input Parameters:
3419: +  ts - the preconditioner context
3420: -  dm - the dm

3422:    Level: intermediate


3425: .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
3426: @*/
3427: PetscErrorCode  TSSetDM(TS ts,DM dm)
3428: {
3430:   SNES           snes;
3431:   DMTS           tsdm;

3435:   PetscObjectReference((PetscObject)dm);
3436:   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
3437:     if (ts->dm->dmts && !dm->dmts) {
3438:       DMCopyDMTS(ts->dm,dm);
3439:       DMGetDMTS(ts->dm,&tsdm);
3440:       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
3441:         tsdm->originaldm = dm;
3442:       }
3443:     }
3444:     DMDestroy(&ts->dm);
3445:   }
3446:   ts->dm = dm;

3448:   TSGetSNES(ts,&snes);
3449:   SNESSetDM(snes,dm);
3450:   return(0);
3451: }

3455: /*@
3456:    TSGetDM - Gets the DM that may be used by some preconditioners

3458:    Not Collective

3460:    Input Parameter:
3461: . ts - the preconditioner context

3463:    Output Parameter:
3464: .  dm - the dm

3466:    Level: intermediate


3469: .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
3470: @*/
3471: PetscErrorCode  TSGetDM(TS ts,DM *dm)
3472: {

3477:   if (!ts->dm) {
3478:     DMShellCreate(PetscObjectComm((PetscObject)ts),&ts->dm);
3479:     if (ts->snes) {SNESSetDM(ts->snes,ts->dm);}
3480:   }
3481:   *dm = ts->dm;
3482:   return(0);
3483: }

3487: /*@
3488:    SNESTSFormFunction - Function to evaluate nonlinear residual

3490:    Logically Collective on SNES

3492:    Input Parameter:
3493: + snes - nonlinear solver
3494: . U - the current state at which to evaluate the residual
3495: - ctx - user context, must be a TS

3497:    Output Parameter:
3498: . F - the nonlinear residual

3500:    Notes:
3501:    This function is not normally called by users and is automatically registered with the SNES used by TS.
3502:    It is most frequently passed to MatFDColoringSetFunction().

3504:    Level: advanced

3506: .seealso: SNESSetFunction(), MatFDColoringSetFunction()
3507: @*/
3508: PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
3509: {
3510:   TS             ts = (TS)ctx;

3518:   (ts->ops->snesfunction)(snes,U,F,ts);
3519:   return(0);
3520: }

3524: /*@
3525:    SNESTSFormJacobian - Function to evaluate the Jacobian

3527:    Collective on SNES

3529:    Input Parameter:
3530: + snes - nonlinear solver
3531: . U - the current state at which to evaluate the residual
3532: - ctx - user context, must be a TS

3534:    Output Parameter:
3535: + A - the Jacobian
3536: . B - the preconditioning matrix (may be the same as A)
3537: - flag - indicates any structure change in the matrix

3539:    Notes:
3540:    This function is not normally called by users and is automatically registered with the SNES used by TS.

3542:    Level: developer

3544: .seealso: SNESSetJacobian()
3545: @*/
3546: PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat A,Mat B,void *ctx)
3547: {
3548:   TS             ts = (TS)ctx;

3559:   (ts->ops->snesjacobian)(snes,U,A,B,ts);
3560:   return(0);
3561: }

3565: /*@C
3566:    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only

3568:    Collective on TS

3570:    Input Arguments:
3571: +  ts - time stepping context
3572: .  t - time at which to evaluate
3573: .  U - state at which to evaluate
3574: -  ctx - context

3576:    Output Arguments:
3577: .  F - right hand side

3579:    Level: intermediate

3581:    Notes:
3582:    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
3583:    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().

3585: .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
3586: @*/
3587: PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
3588: {
3590:   Mat            Arhs,Brhs;

3593:   TSGetRHSMats_Private(ts,&Arhs,&Brhs);
3594:   TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);
3595:   MatMult(Arhs,U,F);
3596:   return(0);
3597: }

3601: /*@C
3602:    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.

3604:    Collective on TS

3606:    Input Arguments:
3607: +  ts - time stepping context
3608: .  t - time at which to evaluate
3609: .  U - state at which to evaluate
3610: -  ctx - context

3612:    Output Arguments:
3613: +  A - pointer to operator
3614: .  B - pointer to preconditioning matrix
3615: -  flg - matrix structure flag

3617:    Level: intermediate

3619:    Notes:
3620:    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.

3622: .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
3623: @*/
3624: PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat A,Mat B,void *ctx)
3625: {
3627:   return(0);
3628: }

3632: /*@C
3633:    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only

3635:    Collective on TS

3637:    Input Arguments:
3638: +  ts - time stepping context
3639: .  t - time at which to evaluate
3640: .  U - state at which to evaluate
3641: .  Udot - time derivative of state vector
3642: -  ctx - context

3644:    Output Arguments:
3645: .  F - left hand side

3647:    Level: intermediate

3649:    Notes:
3650:    The assumption here is that the left hand side is of the form A*Udot (and not A*Udot + B*U). For other cases, the
3651:    user is required to write their own TSComputeIFunction.
3652:    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
3653:    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().

3655: .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
3656: @*/
3657: PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
3658: {
3660:   Mat            A,B;

3663:   TSGetIJacobian(ts,&A,&B,NULL,NULL);
3664:   TSComputeIJacobian(ts,t,U,Udot,1.0,A,B,PETSC_TRUE);
3665:   MatMult(A,Udot,F);
3666:   return(0);
3667: }

3671: /*@C
3672:    TSComputeIJacobianConstant - Reuses a time-independent for a semi-implicit DAE or ODE

3674:    Collective on TS

3676:    Input Arguments:
3677: +  ts - time stepping context
3678: .  t - time at which to evaluate
3679: .  U - state at which to evaluate
3680: .  Udot - time derivative of state vector
3681: .  shift - shift to apply
3682: -  ctx - context

3684:    Output Arguments:
3685: +  A - pointer to operator
3686: .  B - pointer to preconditioning matrix
3687: -  flg - matrix structure flag

3689:    Level: advanced

3691:    Notes:
3692:    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.

3694:    It is only appropriate for problems of the form

3696: $     M Udot = F(U,t)

3698:   where M is constant and F is non-stiff.  The user must pass M to TSSetIJacobian().  The current implementation only
3699:   works with IMEX time integration methods such as TSROSW and TSARKIMEX, since there is no support for de-constructing
3700:   an implicit operator of the form

3702: $    shift*M + J

3704:   where J is the Jacobian of -F(U).  Support may be added in a future version of PETSc, but for now, the user must store
3705:   a copy of M or reassemble it when requested.

3707: .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
3708: @*/
3709: PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,void *ctx)
3710: {

3714:   MatScale(A, shift / ts->ijacobian.shift);
3715:   ts->ijacobian.shift = shift;
3716:   return(0);
3717: }

3721: /*@
3722:    TSGetEquationType - Gets the type of the equation that TS is solving.

3724:    Not Collective

3726:    Input Parameter:
3727: .  ts - the TS context

3729:    Output Parameter:
3730: .  equation_type - see TSEquationType

3732:    Level: beginner

3734: .keywords: TS, equation type

3736: .seealso: TSSetEquationType(), TSEquationType
3737: @*/
3738: PetscErrorCode  TSGetEquationType(TS ts,TSEquationType *equation_type)
3739: {
3743:   *equation_type = ts->equation_type;
3744:   return(0);
3745: }

3749: /*@
3750:    TSSetEquationType - Sets the type of the equation that TS is solving.

3752:    Not Collective

3754:    Input Parameter:
3755: +  ts - the TS context
3756: .  equation_type - see TSEquationType

3758:    Level: advanced

3760: .keywords: TS, equation type

3762: .seealso: TSGetEquationType(), TSEquationType
3763: @*/
3764: PetscErrorCode  TSSetEquationType(TS ts,TSEquationType equation_type)
3765: {
3768:   ts->equation_type = equation_type;
3769:   return(0);
3770: }

3774: /*@
3775:    TSGetConvergedReason - Gets the reason the TS iteration was stopped.

3777:    Not Collective

3779:    Input Parameter:
3780: .  ts - the TS context

3782:    Output Parameter:
3783: .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3784:             manual pages for the individual convergence tests for complete lists

3786:    Level: beginner

3788:    Notes:
3789:    Can only be called after the call to TSSolve() is complete.

3791: .keywords: TS, nonlinear, set, convergence, test

3793: .seealso: TSSetConvergenceTest(), TSConvergedReason
3794: @*/
3795: PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
3796: {
3800:   *reason = ts->reason;
3801:   return(0);
3802: }

3806: /*@
3807:    TSSetConvergedReason - Sets the reason for handling the convergence of TSSolve.

3809:    Not Collective

3811:    Input Parameter:
3812: +  ts - the TS context
3813: .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3814:             manual pages for the individual convergence tests for complete lists

3816:    Level: advanced

3818:    Notes:
3819:    Can only be called during TSSolve() is active.

3821: .keywords: TS, nonlinear, set, convergence, test

3823: .seealso: TSConvergedReason
3824: @*/
3825: PetscErrorCode  TSSetConvergedReason(TS ts,TSConvergedReason reason)
3826: {
3829:   ts->reason = reason;
3830:   return(0);
3831: }

3835: /*@
3836:    TSGetSolveTime - Gets the time after a call to TSSolve()

3838:    Not Collective

3840:    Input Parameter:
3841: .  ts - the TS context

3843:    Output Parameter:
3844: .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()

3846:    Level: beginner

3848:    Notes:
3849:    Can only be called after the call to TSSolve() is complete.

3851: .keywords: TS, nonlinear, set, convergence, test

3853: .seealso: TSSetConvergenceTest(), TSConvergedReason
3854: @*/
3855: PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
3856: {
3860:   *ftime = ts->solvetime;
3861:   return(0);
3862: }

3866: /*@
3867:    TSGetSNESIterations - Gets the total number of nonlinear iterations
3868:    used by the time integrator.

3870:    Not Collective

3872:    Input Parameter:
3873: .  ts - TS context

3875:    Output Parameter:
3876: .  nits - number of nonlinear iterations

3878:    Notes:
3879:    This counter is reset to zero for each successive call to TSSolve().

3881:    Level: intermediate

3883: .keywords: TS, get, number, nonlinear, iterations

3885: .seealso:  TSGetKSPIterations()
3886: @*/
3887: PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
3888: {
3892:   *nits = ts->snes_its;
3893:   return(0);
3894: }

3898: /*@
3899:    TSGetKSPIterations - Gets the total number of linear iterations
3900:    used by the time integrator.

3902:    Not Collective

3904:    Input Parameter:
3905: .  ts - TS context

3907:    Output Parameter:
3908: .  lits - number of linear iterations

3910:    Notes:
3911:    This counter is reset to zero for each successive call to TSSolve().

3913:    Level: intermediate

3915: .keywords: TS, get, number, linear, iterations

3917: .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
3918: @*/
3919: PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
3920: {
3924:   *lits = ts->ksp_its;
3925:   return(0);
3926: }

3930: /*@
3931:    TSGetStepRejections - Gets the total number of rejected steps.

3933:    Not Collective

3935:    Input Parameter:
3936: .  ts - TS context

3938:    Output Parameter:
3939: .  rejects - number of steps rejected

3941:    Notes:
3942:    This counter is reset to zero for each successive call to TSSolve().

3944:    Level: intermediate

3946: .keywords: TS, get, number

3948: .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
3949: @*/
3950: PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
3951: {
3955:   *rejects = ts->reject;
3956:   return(0);
3957: }

3961: /*@
3962:    TSGetSNESFailures - Gets the total number of failed SNES solves

3964:    Not Collective

3966:    Input Parameter:
3967: .  ts - TS context

3969:    Output Parameter:
3970: .  fails - number of failed nonlinear solves

3972:    Notes:
3973:    This counter is reset to zero for each successive call to TSSolve().

3975:    Level: intermediate

3977: .keywords: TS, get, number

3979: .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
3980: @*/
3981: PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
3982: {
3986:   *fails = ts->num_snes_failures;
3987:   return(0);
3988: }

3992: /*@
3993:    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails

3995:    Not Collective

3997:    Input Parameter:
3998: +  ts - TS context
3999: -  rejects - maximum number of rejected steps, pass -1 for unlimited

4001:    Notes:
4002:    The counter is reset to zero for each step

4004:    Options Database Key:
4005:  .  -ts_max_reject - Maximum number of step rejections before a step fails

4007:    Level: intermediate

4009: .keywords: TS, set, maximum, number

4011: .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4012: @*/
4013: PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
4014: {
4017:   ts->max_reject = rejects;
4018:   return(0);
4019: }

4023: /*@
4024:    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves

4026:    Not Collective

4028:    Input Parameter:
4029: +  ts - TS context
4030: -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited

4032:    Notes:
4033:    The counter is reset to zero for each successive call to TSSolve().

4035:    Options Database Key:
4036:  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures

4038:    Level: intermediate

4040: .keywords: TS, set, maximum, number

4042: .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
4043: @*/
4044: PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
4045: {
4048:   ts->max_snes_failures = fails;
4049:   return(0);
4050: }

4054: /*@
4055:    TSSetErrorIfStepFails - Error if no step succeeds

4057:    Not Collective

4059:    Input Parameter:
4060: +  ts - TS context
4061: -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure

4063:    Options Database Key:
4064:  .  -ts_error_if_step_fails - Error if no step succeeds

4066:    Level: intermediate

4068: .keywords: TS, set, error

4070: .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4071: @*/
4072: PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
4073: {
4076:   ts->errorifstepfailed = err;
4077:   return(0);
4078: }

4082: /*@C
4083:    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file

4085:    Collective on TS

4087:    Input Parameters:
4088: +  ts - the TS context
4089: .  step - current time-step
4090: .  ptime - current time
4091: .  u - current state
4092: -  viewer - binary viewer

4094:    Level: intermediate

4096: .keywords: TS,  vector, monitor, view

4098: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4099: @*/
4100: PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
4101: {
4103:   PetscViewer    v = (PetscViewer)viewer;

4106:   VecView(u,v);
4107:   return(0);
4108: }

4112: /*@C
4113:    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.

4115:    Collective on TS

4117:    Input Parameters:
4118: +  ts - the TS context
4119: .  step - current time-step
4120: .  ptime - current time
4121: .  u - current state
4122: -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)

4124:    Level: intermediate

4126:    Notes:
4127:    The VTK format does not allow writing multiple time steps in the same file, therefore a different file will be written for each time step.
4128:    These are named according to the file name template.

4130:    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().

4132: .keywords: TS,  vector, monitor, view

4134: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4135: @*/
4136: PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
4137: {
4139:   char           filename[PETSC_MAX_PATH_LEN];
4140:   PetscViewer    viewer;

4143:   PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);
4144:   PetscViewerVTKOpen(PetscObjectComm((PetscObject)ts),filename,FILE_MODE_WRITE,&viewer);
4145:   VecView(u,viewer);
4146:   PetscViewerDestroy(&viewer);
4147:   return(0);
4148: }

4152: /*@C
4153:    TSMonitorSolutionVTKDestroy - Destroy context for monitoring

4155:    Collective on TS

4157:    Input Parameters:
4158: .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)

4160:    Level: intermediate

4162:    Note:
4163:    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().

4165: .keywords: TS,  vector, monitor, view

4167: .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
4168: @*/
4169: PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
4170: {

4174:   PetscFree(*(char**)filenametemplate);
4175:   return(0);
4176: }

4180: /*@
4181:    TSGetAdapt - Get the adaptive controller context for the current method

4183:    Collective on TS if controller has not been created yet

4185:    Input Arguments:
4186: .  ts - time stepping context

4188:    Output Arguments:
4189: .  adapt - adaptive controller

4191:    Level: intermediate

4193: .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
4194: @*/
4195: PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
4196: {

4202:   if (!ts->adapt) {
4203:     TSAdaptCreate(PetscObjectComm((PetscObject)ts),&ts->adapt);
4204:     PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->adapt);
4205:     PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);
4206:   }
4207:   *adapt = ts->adapt;
4208:   return(0);
4209: }

4213: /*@
4214:    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller

4216:    Logically Collective

4218:    Input Arguments:
4219: +  ts - time integration context
4220: .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
4221: .  vatol - vector of absolute tolerances or NULL, used in preference to atol if present
4222: .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
4223: -  vrtol - vector of relative tolerances or NULL, used in preference to atol if present

4225:    Level: beginner

4227: .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
4228: @*/
4229: PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
4230: {

4234:   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
4235:   if (vatol) {
4236:     PetscObjectReference((PetscObject)vatol);
4237:     VecDestroy(&ts->vatol);

4239:     ts->vatol = vatol;
4240:   }
4241:   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
4242:   if (vrtol) {
4243:     PetscObjectReference((PetscObject)vrtol);
4244:     VecDestroy(&ts->vrtol);

4246:     ts->vrtol = vrtol;
4247:   }
4248:   return(0);
4249: }

4253: /*@
4254:    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller

4256:    Logically Collective

4258:    Input Arguments:
4259: .  ts - time integration context

4261:    Output Arguments:
4262: +  atol - scalar absolute tolerances, NULL to ignore
4263: .  vatol - vector of absolute tolerances, NULL to ignore
4264: .  rtol - scalar relative tolerances, NULL to ignore
4265: -  vrtol - vector of relative tolerances, NULL to ignore

4267:    Level: beginner

4269: .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
4270: @*/
4271: PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
4272: {
4274:   if (atol)  *atol  = ts->atol;
4275:   if (vatol) *vatol = ts->vatol;
4276:   if (rtol)  *rtol  = ts->rtol;
4277:   if (vrtol) *vrtol = ts->vrtol;
4278:   return(0);
4279: }

4283: /*@
4284:    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state

4286:    Collective on TS

4288:    Input Arguments:
4289: +  ts - time stepping context
4290: -  Y - state vector to be compared to ts->vec_sol

4292:    Output Arguments:
4293: .  norm - weighted norm, a value of 1.0 is considered small

4295:    Level: developer

4297: .seealso: TSSetTolerances()
4298: @*/
4299: PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
4300: {
4301:   PetscErrorCode    ierr;
4302:   PetscInt          i,n,N;
4303:   const PetscScalar *u,*y;
4304:   Vec               U;
4305:   PetscReal         sum,gsum;

4311:   U = ts->vec_sol;
4313:   if (U == Y) SETERRQ(PetscObjectComm((PetscObject)U),PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");

4315:   VecGetSize(U,&N);
4316:   VecGetLocalSize(U,&n);
4317:   VecGetArrayRead(U,&u);
4318:   VecGetArrayRead(Y,&y);
4319:   sum  = 0.;
4320:   if (ts->vatol && ts->vrtol) {
4321:     const PetscScalar *atol,*rtol;
4322:     VecGetArrayRead(ts->vatol,&atol);
4323:     VecGetArrayRead(ts->vrtol,&rtol);
4324:     for (i=0; i<n; i++) {
4325:       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4326:       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4327:     }
4328:     VecRestoreArrayRead(ts->vatol,&atol);
4329:     VecRestoreArrayRead(ts->vrtol,&rtol);
4330:   } else if (ts->vatol) {       /* vector atol, scalar rtol */
4331:     const PetscScalar *atol;
4332:     VecGetArrayRead(ts->vatol,&atol);
4333:     for (i=0; i<n; i++) {
4334:       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4335:       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4336:     }
4337:     VecRestoreArrayRead(ts->vatol,&atol);
4338:   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
4339:     const PetscScalar *rtol;
4340:     VecGetArrayRead(ts->vrtol,&rtol);
4341:     for (i=0; i<n; i++) {
4342:       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4343:       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4344:     }
4345:     VecRestoreArrayRead(ts->vrtol,&rtol);
4346:   } else {                      /* scalar atol, scalar rtol */
4347:     for (i=0; i<n; i++) {
4348:       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4349:       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4350:     }
4351:   }
4352:   VecRestoreArrayRead(U,&u);
4353:   VecRestoreArrayRead(Y,&y);

4355:   MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)ts));
4356:   *norm = PetscSqrtReal(gsum / N);
4357:   if (PetscIsInfOrNanScalar(*norm)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
4358:   return(0);
4359: }

4363: /*@
4364:    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler

4366:    Logically Collective on TS

4368:    Input Arguments:
4369: +  ts - time stepping context
4370: -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)

4372:    Note:
4373:    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()

4375:    Level: intermediate

4377: .seealso: TSGetCFLTime(), TSADAPTCFL
4378: @*/
4379: PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
4380: {
4383:   ts->cfltime_local = cfltime;
4384:   ts->cfltime       = -1.;
4385:   return(0);
4386: }

4390: /*@
4391:    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler

4393:    Collective on TS

4395:    Input Arguments:
4396: .  ts - time stepping context

4398:    Output Arguments:
4399: .  cfltime - maximum stable time step for forward Euler

4401:    Level: advanced

4403: .seealso: TSSetCFLTimeLocal()
4404: @*/
4405: PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
4406: {

4410:   if (ts->cfltime < 0) {
4411:     MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));
4412:   }
4413:   *cfltime = ts->cfltime;
4414:   return(0);
4415: }

4419: /*@
4420:    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu

4422:    Input Parameters:
4423: .  ts   - the TS context.
4424: .  xl   - lower bound.
4425: .  xu   - upper bound.

4427:    Notes:
4428:    If this routine is not called then the lower and upper bounds are set to
4429:    PETSC_NINFINITY and PETSC_INFINITY respectively during SNESSetUp().

4431:    Level: advanced

4433: @*/
4434: PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
4435: {
4437:   SNES           snes;

4440:   TSGetSNES(ts,&snes);
4441:   SNESVISetVariableBounds(snes,xl,xu);
4442:   return(0);
4443: }

4445: #if defined(PETSC_HAVE_MATLAB_ENGINE)
4446: #include <mex.h>

4448: typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;

4452: /*
4453:    TSComputeFunction_Matlab - Calls the function that has been set with
4454:                          TSSetFunctionMatlab().

4456:    Collective on TS

4458:    Input Parameters:
4459: +  snes - the TS context
4460: -  u - input vector

4462:    Output Parameter:
4463: .  y - function vector, as set by TSSetFunction()

4465:    Notes:
4466:    TSComputeFunction() is typically used within nonlinear solvers
4467:    implementations, so most users would not generally call this routine
4468:    themselves.

4470:    Level: developer

4472: .keywords: TS, nonlinear, compute, function

4474: .seealso: TSSetFunction(), TSGetFunction()
4475: */
4476: PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
4477: {
4478:   PetscErrorCode  ierr;
4479:   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4480:   int             nlhs  = 1,nrhs = 7;
4481:   mxArray         *plhs[1],*prhs[7];
4482:   long long int   lx = 0,lxdot = 0,ly = 0,ls = 0;


4492:   PetscMemcpy(&ls,&snes,sizeof(snes));
4493:   PetscMemcpy(&lx,&u,sizeof(u));
4494:   PetscMemcpy(&lxdot,&udot,sizeof(udot));
4495:   PetscMemcpy(&ly,&y,sizeof(u));

4497:   prhs[0] =  mxCreateDoubleScalar((double)ls);
4498:   prhs[1] =  mxCreateDoubleScalar(time);
4499:   prhs[2] =  mxCreateDoubleScalar((double)lx);
4500:   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4501:   prhs[4] =  mxCreateDoubleScalar((double)ly);
4502:   prhs[5] =  mxCreateString(sctx->funcname);
4503:   prhs[6] =  sctx->ctx;
4504:    mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");
4505:    mxGetScalar(plhs[0]);
4506:   mxDestroyArray(prhs[0]);
4507:   mxDestroyArray(prhs[1]);
4508:   mxDestroyArray(prhs[2]);
4509:   mxDestroyArray(prhs[3]);
4510:   mxDestroyArray(prhs[4]);
4511:   mxDestroyArray(prhs[5]);
4512:   mxDestroyArray(plhs[0]);
4513:   return(0);
4514: }


4519: /*
4520:    TSSetFunctionMatlab - Sets the function evaluation routine and function
4521:    vector for use by the TS routines in solving ODEs
4522:    equations from MATLAB. Here the function is a string containing the name of a MATLAB function

4524:    Logically Collective on TS

4526:    Input Parameters:
4527: +  ts - the TS context
4528: -  func - function evaluation routine

4530:    Calling sequence of func:
4531: $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);

4533:    Level: beginner

4535: .keywords: TS, nonlinear, set, function

4537: .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4538: */
4539: PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
4540: {
4541:   PetscErrorCode  ierr;
4542:   TSMatlabContext *sctx;

4545:   /* currently sctx is memory bleed */
4546:   PetscMalloc(sizeof(TSMatlabContext),&sctx);
4547:   PetscStrallocpy(func,&sctx->funcname);
4548:   /*
4549:      This should work, but it doesn't
4550:   sctx->ctx = ctx;
4551:   mexMakeArrayPersistent(sctx->ctx);
4552:   */
4553:   sctx->ctx = mxDuplicateArray(ctx);

4555:   TSSetIFunction(ts,NULL,TSComputeFunction_Matlab,sctx);
4556:   return(0);
4557: }

4561: /*
4562:    TSComputeJacobian_Matlab - Calls the function that has been set with
4563:                          TSSetJacobianMatlab().

4565:    Collective on TS

4567:    Input Parameters:
4568: +  ts - the TS context
4569: .  u - input vector
4570: .  A, B - the matrices
4571: -  ctx - user context

4573:    Level: developer

4575: .keywords: TS, nonlinear, compute, function

4577: .seealso: TSSetFunction(), TSGetFunction()
4578: @*/
4579: PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat A,Mat B,void *ctx)
4580: {
4581:   PetscErrorCode  ierr;
4582:   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4583:   int             nlhs  = 2,nrhs = 9;
4584:   mxArray         *plhs[2],*prhs[9];
4585:   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;


4591:   /* call Matlab function in ctx with arguments u and y */

4593:   PetscMemcpy(&ls,&ts,sizeof(ts));
4594:   PetscMemcpy(&lx,&u,sizeof(u));
4595:   PetscMemcpy(&lxdot,&udot,sizeof(u));
4596:   PetscMemcpy(&lA,A,sizeof(u));
4597:   PetscMemcpy(&lB,B,sizeof(u));

4599:   prhs[0] =  mxCreateDoubleScalar((double)ls);
4600:   prhs[1] =  mxCreateDoubleScalar((double)time);
4601:   prhs[2] =  mxCreateDoubleScalar((double)lx);
4602:   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4603:   prhs[4] =  mxCreateDoubleScalar((double)shift);
4604:   prhs[5] =  mxCreateDoubleScalar((double)lA);
4605:   prhs[6] =  mxCreateDoubleScalar((double)lB);
4606:   prhs[7] =  mxCreateString(sctx->funcname);
4607:   prhs[8] =  sctx->ctx;
4608:    mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");
4609:    mxGetScalar(plhs[0]);
4610:   mxDestroyArray(prhs[0]);
4611:   mxDestroyArray(prhs[1]);
4612:   mxDestroyArray(prhs[2]);
4613:   mxDestroyArray(prhs[3]);
4614:   mxDestroyArray(prhs[4]);
4615:   mxDestroyArray(prhs[5]);
4616:   mxDestroyArray(prhs[6]);
4617:   mxDestroyArray(prhs[7]);
4618:   mxDestroyArray(plhs[0]);
4619:   mxDestroyArray(plhs[1]);
4620:   return(0);
4621: }


4626: /*
4627:    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
4628:    vector for use by the TS routines in solving ODEs from MATLAB. Here the function is a string containing the name of a MATLAB function

4630:    Logically Collective on TS

4632:    Input Parameters:
4633: +  ts - the TS context
4634: .  A,B - Jacobian matrices
4635: .  func - function evaluation routine
4636: -  ctx - user context

4638:    Calling sequence of func:
4639: $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);


4642:    Level: developer

4644: .keywords: TS, nonlinear, set, function

4646: .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4647: */
4648: PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
4649: {
4650:   PetscErrorCode  ierr;
4651:   TSMatlabContext *sctx;

4654:   /* currently sctx is memory bleed */
4655:   PetscMalloc(sizeof(TSMatlabContext),&sctx);
4656:   PetscStrallocpy(func,&sctx->funcname);
4657:   /*
4658:      This should work, but it doesn't
4659:   sctx->ctx = ctx;
4660:   mexMakeArrayPersistent(sctx->ctx);
4661:   */
4662:   sctx->ctx = mxDuplicateArray(ctx);

4664:   TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);
4665:   return(0);
4666: }

4670: /*
4671:    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().

4673:    Collective on TS

4675: .seealso: TSSetFunction(), TSGetFunction()
4676: @*/
4677: PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
4678: {
4679:   PetscErrorCode  ierr;
4680:   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4681:   int             nlhs  = 1,nrhs = 6;
4682:   mxArray         *plhs[1],*prhs[6];
4683:   long long int   lx = 0,ls = 0;


4689:   PetscMemcpy(&ls,&ts,sizeof(ts));
4690:   PetscMemcpy(&lx,&u,sizeof(u));

4692:   prhs[0] =  mxCreateDoubleScalar((double)ls);
4693:   prhs[1] =  mxCreateDoubleScalar((double)it);
4694:   prhs[2] =  mxCreateDoubleScalar((double)time);
4695:   prhs[3] =  mxCreateDoubleScalar((double)lx);
4696:   prhs[4] =  mxCreateString(sctx->funcname);
4697:   prhs[5] =  sctx->ctx;
4698:    mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");
4699:    mxGetScalar(plhs[0]);
4700:   mxDestroyArray(prhs[0]);
4701:   mxDestroyArray(prhs[1]);
4702:   mxDestroyArray(prhs[2]);
4703:   mxDestroyArray(prhs[3]);
4704:   mxDestroyArray(prhs[4]);
4705:   mxDestroyArray(plhs[0]);
4706:   return(0);
4707: }


4712: /*
4713:    TSMonitorSetMatlab - Sets the monitor function from Matlab

4715:    Level: developer

4717: .keywords: TS, nonlinear, set, function

4719: .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4720: */
4721: PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
4722: {
4723:   PetscErrorCode  ierr;
4724:   TSMatlabContext *sctx;

4727:   /* currently sctx is memory bleed */
4728:   PetscMalloc(sizeof(TSMatlabContext),&sctx);
4729:   PetscStrallocpy(func,&sctx->funcname);
4730:   /*
4731:      This should work, but it doesn't
4732:   sctx->ctx = ctx;
4733:   mexMakeArrayPersistent(sctx->ctx);
4734:   */
4735:   sctx->ctx = mxDuplicateArray(ctx);

4737:   TSMonitorSet(ts,TSMonitor_Matlab,sctx,NULL);
4738:   return(0);
4739: }
4740: #endif



4746: /*@C
4747:    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
4748:        in a time based line graph

4750:    Collective on TS

4752:    Input Parameters:
4753: +  ts - the TS context
4754: .  step - current time-step
4755: .  ptime - current time
4756: -  lg - a line graph object

4758:    Level: intermediate

4760:     Notes: each process in a parallel run displays its component solutions in a separate window

4762: .keywords: TS,  vector, monitor, view

4764: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4765: @*/
4766: PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4767: {
4768:   PetscErrorCode    ierr;
4769:   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4770:   const PetscScalar *yy;
4771:   PetscInt          dim;

4774:   if (!step) {
4775:     PetscDrawAxis axis;
4776:     PetscDrawLGGetAxis(ctx->lg,&axis);
4777:     PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");
4778:     VecGetLocalSize(u,&dim);
4779:     PetscDrawLGSetDimension(ctx->lg,dim);
4780:     PetscDrawLGReset(ctx->lg);
4781:   }
4782:   VecGetArrayRead(u,&yy);
4783: #if defined(PETSC_USE_COMPLEX)
4784:   {
4785:     PetscReal *yreal;
4786:     PetscInt  i,n;
4787:     VecGetLocalSize(u,&n);
4788:     PetscMalloc1(n,&yreal);
4789:     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4790:     PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);
4791:     PetscFree(yreal);
4792:   }
4793: #else
4794:   PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);
4795: #endif
4796:   VecRestoreArrayRead(u,&yy);
4797:   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4798:     PetscDrawLGDraw(ctx->lg);
4799:   }
4800:   return(0);
4801: }

4805: /*@C
4806:    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
4807:        in a time based line graph

4809:    Collective on TS

4811:    Input Parameters:
4812: +  ts - the TS context
4813: .  step - current time-step
4814: .  ptime - current time
4815: -  lg - a line graph object

4817:    Level: intermediate

4819:    Notes:
4820:    Only for sequential solves.

4822:    The user must provide the solution using TSSetSolutionFunction() to use this monitor.

4824:    Options Database Keys:
4825: .  -ts_monitor_lg_error - create a graphical monitor of error history

4827: .keywords: TS,  vector, monitor, view

4829: .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
4830: @*/
4831: PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4832: {
4833:   PetscErrorCode    ierr;
4834:   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4835:   const PetscScalar *yy;
4836:   Vec               y;
4837:   PetscInt          dim;

4840:   if (!step) {
4841:     PetscDrawAxis axis;
4842:     PetscDrawLGGetAxis(ctx->lg,&axis);
4843:     PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");
4844:     VecGetLocalSize(u,&dim);
4845:     PetscDrawLGSetDimension(ctx->lg,dim);
4846:     PetscDrawLGReset(ctx->lg);
4847:   }
4848:   VecDuplicate(u,&y);
4849:   TSComputeSolutionFunction(ts,ptime,y);
4850:   VecAXPY(y,-1.0,u);
4851:   VecGetArrayRead(y,&yy);
4852: #if defined(PETSC_USE_COMPLEX)
4853:   {
4854:     PetscReal *yreal;
4855:     PetscInt  i,n;
4856:     VecGetLocalSize(y,&n);
4857:     PetscMalloc1(n,&yreal);
4858:     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4859:     PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);
4860:     PetscFree(yreal);
4861:   }
4862: #else
4863:   PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);
4864: #endif
4865:   VecRestoreArrayRead(y,&yy);
4866:   VecDestroy(&y);
4867:   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4868:     PetscDrawLGDraw(ctx->lg);
4869:   }
4870:   return(0);
4871: }

4875: PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4876: {
4877:   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4878:   PetscReal      x   = ptime,y;
4880:   PetscInt       its;

4883:   if (!n) {
4884:     PetscDrawAxis axis;

4886:     PetscDrawLGGetAxis(ctx->lg,&axis);
4887:     PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");
4888:     PetscDrawLGReset(ctx->lg);

4890:     ctx->snes_its = 0;
4891:   }
4892:   TSGetSNESIterations(ts,&its);
4893:   y    = its - ctx->snes_its;
4894:   PetscDrawLGAddPoint(ctx->lg,&x,&y);
4895:   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4896:     PetscDrawLGDraw(ctx->lg);
4897:   }
4898:   ctx->snes_its = its;
4899:   return(0);
4900: }

4904: PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4905: {
4906:   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4907:   PetscReal      x   = ptime,y;
4909:   PetscInt       its;

4912:   if (!n) {
4913:     PetscDrawAxis axis;

4915:     PetscDrawLGGetAxis(ctx->lg,&axis);
4916:     PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");
4917:     PetscDrawLGReset(ctx->lg);

4919:     ctx->ksp_its = 0;
4920:   }
4921:   TSGetKSPIterations(ts,&its);
4922:   y    = its - ctx->ksp_its;
4923:   PetscDrawLGAddPoint(ctx->lg,&x,&y);
4924:   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4925:     PetscDrawLGDraw(ctx->lg);
4926:   }
4927:   ctx->ksp_its = its;
4928:   return(0);
4929: }

4933: /*@
4934:    TSComputeLinearStability - computes the linear stability function at a point

4936:    Collective on TS and Vec

4938:    Input Parameters:
4939: +  ts - the TS context
4940: -  xr,xi - real and imaginary part of input arguments

4942:    Output Parameters:
4943: .  yr,yi - real and imaginary part of function value

4945:    Level: developer

4947: .keywords: TS, compute

4949: .seealso: TSSetRHSFunction(), TSComputeIFunction()
4950: @*/
4951: PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
4952: {

4957:   if (!ts->ops->linearstability) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"Linearized stability function not provided for this method");
4958:   (*ts->ops->linearstability)(ts,xr,xi,yr,yi);
4959:   return(0);
4960: }

4964: /*@
4965:    TSRollBack - Rolls back one time step

4967:    Collective on TS

4969:    Input Parameter:
4970: .  ts - the TS context obtained from TSCreate()

4972:    Level: advanced

4974: .keywords: TS, timestep, rollback

4976: .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSInterpolate()
4977: @*/
4978: PetscErrorCode  TSRollBack(TS ts)
4979: {


4985:   if (!ts->ops->rollback) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSRollBack not implemented for type '%s'",((PetscObject)ts)->type_name);
4986:   (*ts->ops->rollback)(ts);
4987:   ts->time_step = ts->ptime - ts->ptime_prev;
4988:   ts->ptime = ts->ptime_prev;
4989:   return(0);
4990: }