xref: /petsc/src/ts/interface/ts.c (revision 2b0a91c039c5de967a4765bca8336441f2b55a7b)
1 
2 #include <petsc-private/tsimpl.h>        /*I "petscts.h"  I*/
3 #include <petscdmshell.h>
4 
5 /* Logging support */
6 PetscClassId  TS_CLASSID, DMTS_CLASSID;
7 PetscLogEvent  TS_Step, TS_PseudoComputeTimeStep, TS_FunctionEval, TS_JacobianEval;
8 
9 #undef __FUNCT__
10 #define __FUNCT__ "TSSetTypeFromOptions"
11 /*
12   TSSetTypeFromOptions - Sets the type of ts from user options.
13 
14   Collective on TS
15 
16   Input Parameter:
17 . ts - The ts
18 
19   Level: intermediate
20 
21 .keywords: TS, set, options, database, type
22 .seealso: TSSetFromOptions(), TSSetType()
23 */
24 static PetscErrorCode TSSetTypeFromOptions(TS ts)
25 {
26   PetscBool      opt;
27   const char     *defaultType;
28   char           typeName[256];
29   PetscErrorCode ierr;
30 
31   PetscFunctionBegin;
32   if (((PetscObject)ts)->type_name) {
33     defaultType = ((PetscObject)ts)->type_name;
34   } else {
35     defaultType = TSEULER;
36   }
37 
38   if (!TSRegisterAllCalled) {ierr = TSRegisterAll(PETSC_NULL);CHKERRQ(ierr);}
39   ierr = PetscOptionsList("-ts_type", "TS method"," TSSetType", TSList, defaultType, typeName, 256, &opt);CHKERRQ(ierr);
40   if (opt) {
41     ierr = TSSetType(ts, typeName);CHKERRQ(ierr);
42   } else {
43     ierr = TSSetType(ts, defaultType);CHKERRQ(ierr);
44   }
45   PetscFunctionReturn(0);
46 }
47 
48 #undef __FUNCT__
49 #define __FUNCT__ "TSSetFromOptions"
50 /*@
51    TSSetFromOptions - Sets various TS parameters from user options.
52 
53    Collective on TS
54 
55    Input Parameter:
56 .  ts - the TS context obtained from TSCreate()
57 
58    Options Database Keys:
59 +  -ts_type <type> - TSEULER, TSBEULER, TSSUNDIALS, TSPSEUDO, TSCN, TSRK, TSTHETA, TSGL, TSSSP
60 .  -ts_max_steps maxsteps - maximum number of time-steps to take
61 .  -ts_final_time time - maximum time to compute to
62 .  -ts_dt dt - initial time step
63 .  -ts_monitor - print information at each timestep
64 .  -ts_monitor_lg_timestep - Monitor timestep size graphically
65 .  -ts_monitor_lg_solution - Monitor solution graphically
66 .  -ts_monitor_lg_error - Monitor error graphically
67 .  -ts_monitor_lg_snes_iterations - Monitor number nonlinear iterations for each timestep graphically
68 .  -ts_monitor_lg_ksp_iterations - Monitor number nonlinear iterations for each timestep graphically
69 .  -ts_monitor_sp_eig - Monitor eigenvalues of linearized operator graphically
70 .  -ts_monitor_draw_solution - Monitor solution graphically
71 .  -ts_monitor_draw_solution - Monitor solution graphically
72 .  -ts_monitor_draw_error - Monitor error graphically
73 .  -ts_monitor_draw_solution_binary <filename> - Save each solution to a binary file
74 -  -ts_monitor_draw_solution_vtk <filename.vts> - Save each time step to a binary file, use filename-%%03D.vts
75 
76    Level: beginner
77 
78 .keywords: TS, timestep, set, options, database
79 
80 .seealso: TSGetType()
81 @*/
82 PetscErrorCode  TSSetFromOptions(TS ts)
83 {
84   PetscBool      opt,flg;
85   PetscErrorCode ierr;
86   PetscViewer    monviewer;
87   char           monfilename[PETSC_MAX_PATH_LEN];
88   SNES           snes;
89   TSAdapt        adapt;
90   PetscReal      time_step;
91 
92   PetscFunctionBegin;
93   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
94   ierr = PetscObjectOptionsBegin((PetscObject)ts);CHKERRQ(ierr);
95     /* Handle TS type options */
96     ierr = TSSetTypeFromOptions(ts);CHKERRQ(ierr);
97 
98     /* Handle generic TS options */
99     ierr = PetscOptionsInt("-ts_max_steps","Maximum number of time steps","TSSetDuration",ts->max_steps,&ts->max_steps,PETSC_NULL);CHKERRQ(ierr);
100     ierr = PetscOptionsReal("-ts_final_time","Time to run to","TSSetDuration",ts->max_time,&ts->max_time,PETSC_NULL);CHKERRQ(ierr);
101     ierr = PetscOptionsReal("-ts_init_time","Initial time","TSSetTime",ts->ptime,&ts->ptime,PETSC_NULL);CHKERRQ(ierr);
102     ierr = PetscOptionsReal("-ts_dt","Initial time step","TSSetTimeStep",ts->time_step,&time_step,&flg);CHKERRQ(ierr);
103     if (flg) {
104       ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
105     }
106     opt = ts->exact_final_time == PETSC_DECIDE ? PETSC_FALSE : (PetscBool)ts->exact_final_time;
107     ierr = PetscOptionsBool("-ts_exact_final_time","Interpolate output to stop exactly at the final time","TSSetExactFinalTime",opt,&opt,&flg);CHKERRQ(ierr);
108     if (flg) {ierr = TSSetExactFinalTime(ts,opt);CHKERRQ(ierr);}
109     ierr = PetscOptionsInt("-ts_max_snes_failures","Maximum number of nonlinear solve failures","TSSetMaxSNESFailures",ts->max_snes_failures,&ts->max_snes_failures,PETSC_NULL);CHKERRQ(ierr);
110     ierr = PetscOptionsInt("-ts_max_reject","Maximum number of step rejections before step fails","TSSetMaxStepRejections",ts->max_reject,&ts->max_reject,PETSC_NULL);CHKERRQ(ierr);
111     ierr = PetscOptionsBool("-ts_error_if_step_fails","Error if no step succeeds","TSSetErrorIfStepFails",ts->errorifstepfailed,&ts->errorifstepfailed,PETSC_NULL);CHKERRQ(ierr);
112     ierr = PetscOptionsReal("-ts_rtol","Relative tolerance for local truncation error","TSSetTolerances",ts->rtol,&ts->rtol,PETSC_NULL);CHKERRQ(ierr);
113     ierr = PetscOptionsReal("-ts_atol","Absolute tolerance for local truncation error","TSSetTolerances",ts->atol,&ts->atol,PETSC_NULL);CHKERRQ(ierr);
114 
115     /* Monitor options */
116     ierr = PetscOptionsString("-ts_monitor","Monitor timestep size","TSMonitorDefault","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
117     if (flg) {
118       ierr = PetscViewerASCIIOpen(((PetscObject)ts)->comm,monfilename,&monviewer);CHKERRQ(ierr);
119       ierr = TSMonitorSet(ts,TSMonitorDefault,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
120     }
121     ierr = PetscOptionsString("-ts_monitor_python","Use Python function","TSMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
122     if (flg) {ierr = PetscPythonMonitorSet((PetscObject)ts,monfilename);CHKERRQ(ierr);}
123 
124     ierr = PetscOptionsName("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",&opt);CHKERRQ(ierr);
125     if (opt) {
126       TSMonitorLGCtx ctx;
127       PetscInt       howoften = 1;
128 
129       ierr = PetscOptionsInt("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
130       ierr = TSMonitorLGCtxCreate(((PetscObject)ts)->comm,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
131       ierr = TSMonitorSet(ts,TSMonitorLGTimeStep,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
132     }
133     ierr = PetscOptionsName("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",&opt);CHKERRQ(ierr);
134     if (opt) {
135       TSMonitorLGCtx ctx;
136       PetscInt       howoften = 1;
137 
138       ierr = PetscOptionsInt("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
139       ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
140       ierr = TSMonitorSet(ts,TSMonitorLGSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
141     }
142     ierr = PetscOptionsName("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",&opt);CHKERRQ(ierr);
143     if (opt) {
144       TSMonitorLGCtx ctx;
145       PetscInt       howoften = 1;
146 
147       ierr = PetscOptionsInt("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
148       ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
149       ierr = TSMonitorSet(ts,TSMonitorLGError,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
150     }
151     ierr = PetscOptionsName("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",&opt);CHKERRQ(ierr);
152     if (opt) {
153       TSMonitorLGCtx ctx;
154       PetscInt       howoften = 1;
155 
156       ierr = PetscOptionsInt("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
157       ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);
158       ierr = TSMonitorSet(ts,TSMonitorLGSNESIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
159     }
160     ierr = PetscOptionsName("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",&opt);CHKERRQ(ierr);
161     if (opt) {
162       TSMonitorLGCtx ctx;
163       PetscInt       howoften = 1;
164 
165       ierr = PetscOptionsInt("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
166       ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);
167       ierr = TSMonitorSet(ts,TSMonitorLGKSPIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
168     }
169     ierr = PetscOptionsName("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",&opt);CHKERRQ(ierr);
170     if (opt) {
171       TSMonitorSPEigCtx ctx;
172       PetscInt          howoften = 1;
173 
174       ierr = PetscOptionsInt("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
175       ierr = TSMonitorSPEigCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
176       ierr = TSMonitorSet(ts,TSMonitorSPEig,ctx,(PetscErrorCode (*)(void**))TSMonitorSPEigCtxDestroy);CHKERRQ(ierr);
177     }
178     opt  = PETSC_FALSE;
179     ierr = PetscOptionsName("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",&opt);CHKERRQ(ierr);
180     if (opt) {
181       TSMonitorDrawCtx ctx;
182       PetscInt         howoften = 1;
183 
184       ierr = PetscOptionsInt("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
185       ierr = TSMonitorDrawCtxCreate(((PetscObject)ts)->comm,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
186       ierr = TSMonitorSet(ts,TSMonitorDrawSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
187     }
188     opt  = PETSC_FALSE;
189     ierr = PetscOptionsName("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",&opt);CHKERRQ(ierr);
190     if (opt) {
191       TSMonitorDrawCtx ctx;
192       PetscInt         howoften = 1;
193 
194       ierr = PetscOptionsInt("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",howoften,&howoften,PETSC_NULL);CHKERRQ(ierr);
195       ierr = TSMonitorDrawCtxCreate(((PetscObject)ts)->comm,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);
196       ierr = TSMonitorSet(ts,TSMonitorDrawError,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
197     }
198     opt  = PETSC_FALSE;
199     ierr = PetscOptionsString("-ts_monitor_draw_solution_binary","Save each solution to a binary file","TSMonitorSolutionBinary",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
200     if (flg) {
201       PetscViewer ctx;
202       if (monfilename[0]) {
203         ierr = PetscViewerBinaryOpen(((PetscObject)ts)->comm,monfilename,FILE_MODE_WRITE,&ctx);CHKERRQ(ierr);
204       } else {
205         ctx = PETSC_VIEWER_BINARY_(((PetscObject)ts)->comm);
206       }
207       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
208     }
209     opt  = PETSC_FALSE;
210     ierr = PetscOptionsString("-ts_monitor_draw_solution_vtk","Save each time step to a binary file, use filename-%%03D.vts","TSMonitorSolutionVTK",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
211     if (flg) {
212       const char *ptr,*ptr2;
213       char *filetemplate;
214       if (!monfilename[0]) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_USER,"-ts_monitor_draw_solution_vtk requires a file template, e.g. filename-%%03D.vts");
215       /* Do some cursory validation of the input. */
216       ierr = PetscStrstr(monfilename,"%",(char**)&ptr);CHKERRQ(ierr);
217       if (!ptr) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_USER,"-ts_monitor_draw_solution_vtk requires a file template, e.g. filename-%%03D.vts");
218       for (ptr++ ; ptr && *ptr; ptr++) {
219         ierr = PetscStrchr("DdiouxX",*ptr,(char**)&ptr2);CHKERRQ(ierr);
220         if (!ptr2 && (*ptr < '0' || '9' < *ptr)) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_USER,"Invalid file template argument to -ts_monitor_draw_solution_vtk, should look like filename-%%03D.vts");
221         if (ptr2) break;
222       }
223       ierr = PetscStrallocpy(monfilename,&filetemplate);CHKERRQ(ierr);
224       ierr = TSMonitorSet(ts,TSMonitorSolutionVTK,filetemplate,(PetscErrorCode (*)(void**))TSMonitorSolutionVTKDestroy);CHKERRQ(ierr);
225     }
226 
227     ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
228     ierr = TSAdaptSetFromOptions(adapt);CHKERRQ(ierr);
229 
230     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
231     if (ts->problem_type == TS_LINEAR) {ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);}
232 
233     /* Handle specific TS options */
234     if (ts->ops->setfromoptions) {
235       ierr = (*ts->ops->setfromoptions)(ts);CHKERRQ(ierr);
236     }
237 
238     /* process any options handlers added with PetscObjectAddOptionsHandler() */
239     ierr = PetscObjectProcessOptionsHandlers((PetscObject)ts);CHKERRQ(ierr);
240   ierr = PetscOptionsEnd();CHKERRQ(ierr);
241   PetscFunctionReturn(0);
242 }
243 
244 #undef __FUNCT__
245 #undef __FUNCT__
246 #define __FUNCT__ "TSComputeRHSJacobian"
247 /*@
248    TSComputeRHSJacobian - Computes the Jacobian matrix that has been
249       set with TSSetRHSJacobian().
250 
251    Collective on TS and Vec
252 
253    Input Parameters:
254 +  ts - the TS context
255 .  t - current timestep
256 -  U - input vector
257 
258    Output Parameters:
259 +  A - Jacobian matrix
260 .  B - optional preconditioning matrix
261 -  flag - flag indicating matrix structure
262 
263    Notes:
264    Most users should not need to explicitly call this routine, as it
265    is used internally within the nonlinear solvers.
266 
267    See KSPSetOperators() for important information about setting the
268    flag parameter.
269 
270    Level: developer
271 
272 .keywords: SNES, compute, Jacobian, matrix
273 
274 .seealso:  TSSetRHSJacobian(), KSPSetOperators()
275 @*/
276 PetscErrorCode  TSComputeRHSJacobian(TS ts,PetscReal t,Vec U,Mat *A,Mat *B,MatStructure *flg)
277 {
278   PetscErrorCode ierr;
279   PetscInt       Ustate;
280   DM             dm;
281   DMTS           tsdm;
282   TSRHSJacobian  rhsjacobianfunc;
283   void           *ctx;
284   TSIJacobian    ijacobianfunc;
285 
286   PetscFunctionBegin;
287   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
288   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
289   PetscCheckSameComm(ts,1,U,3);
290   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
291   ierr = DMGetDMTS(dm,&tsdm);CHKERRQ(ierr);
292   ierr = DMTSGetRHSJacobian(dm,&rhsjacobianfunc,&ctx);CHKERRQ(ierr);
293   ierr = DMTSGetIJacobian(dm,&ijacobianfunc,PETSC_NULL);CHKERRQ(ierr);
294   ierr = PetscObjectStateQuery((PetscObject)U,&Ustate);CHKERRQ(ierr);
295   if (ts->rhsjacobian.time == t && (ts->problem_type == TS_LINEAR || (ts->rhsjacobian.X == U && ts->rhsjacobian.Xstate == Ustate))) {
296     *flg = ts->rhsjacobian.mstructure;
297     PetscFunctionReturn(0);
298   }
299 
300   if (!rhsjacobianfunc && !ijacobianfunc) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
301 
302   if (rhsjacobianfunc) {
303     ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
304     *flg = DIFFERENT_NONZERO_PATTERN;
305     PetscStackPush("TS user Jacobian function");
306     ierr = (*rhsjacobianfunc)(ts,t,U,A,B,flg,ctx);CHKERRQ(ierr);
307     PetscStackPop;
308     ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
309     /* make sure user returned a correct Jacobian and preconditioner */
310     PetscValidHeaderSpecific(*A,MAT_CLASSID,4);
311     PetscValidHeaderSpecific(*B,MAT_CLASSID,5);
312   } else {
313     ierr = MatZeroEntries(*A);CHKERRQ(ierr);
314     if (*A != *B) {ierr = MatZeroEntries(*B);CHKERRQ(ierr);}
315     *flg = SAME_NONZERO_PATTERN;
316   }
317   ts->rhsjacobian.time = t;
318   ts->rhsjacobian.X = U;
319   ierr = PetscObjectStateQuery((PetscObject)U,&ts->rhsjacobian.Xstate);CHKERRQ(ierr);
320   ts->rhsjacobian.mstructure = *flg;
321   PetscFunctionReturn(0);
322 }
323 
324 #undef __FUNCT__
325 #define __FUNCT__ "TSComputeRHSFunction"
326 /*@
327    TSComputeRHSFunction - Evaluates the right-hand-side function.
328 
329    Collective on TS and Vec
330 
331    Input Parameters:
332 +  ts - the TS context
333 .  t - current time
334 -  U - state vector
335 
336    Output Parameter:
337 .  y - right hand side
338 
339    Note:
340    Most users should not need to explicitly call this routine, as it
341    is used internally within the nonlinear solvers.
342 
343    Level: developer
344 
345 .keywords: TS, compute
346 
347 .seealso: TSSetRHSFunction(), TSComputeIFunction()
348 @*/
349 PetscErrorCode TSComputeRHSFunction(TS ts,PetscReal t,Vec U,Vec y)
350 {
351   PetscErrorCode ierr;
352   TSRHSFunction  rhsfunction;
353   TSIFunction    ifunction;
354   void           *ctx;
355   DM             dm;
356 
357   PetscFunctionBegin;
358   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
359   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
360   PetscValidHeaderSpecific(y,VEC_CLASSID,4);
361   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
362   ierr = DMTSGetRHSFunction(dm,&rhsfunction,&ctx);CHKERRQ(ierr);
363   ierr = DMTSGetIFunction(dm,&ifunction,PETSC_NULL);CHKERRQ(ierr);
364 
365   if (!rhsfunction && !ifunction) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
366 
367   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
368   if (rhsfunction) {
369     PetscStackPush("TS user right-hand-side function");
370     ierr = (*rhsfunction)(ts,t,U,y,ctx);CHKERRQ(ierr);
371     PetscStackPop;
372   } else {
373     ierr = VecZeroEntries(y);CHKERRQ(ierr);
374   }
375 
376   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
377   PetscFunctionReturn(0);
378 }
379 
380 #undef __FUNCT__
381 #define __FUNCT__ "TSComputeSolutionFunction"
382 /*@
383    TSComputeSolutionFunction - Evaluates the solution function.
384 
385    Collective on TS and Vec
386 
387    Input Parameters:
388 +  ts - the TS context
389 -  t - current time
390 
391    Output Parameter:
392 .  U - the solution
393 
394    Note:
395    Most users should not need to explicitly call this routine, as it
396    is used internally within the nonlinear solvers.
397 
398    Level: developer
399 
400 .keywords: TS, compute
401 
402 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
403 @*/
404 PetscErrorCode TSComputeSolutionFunction(TS ts,PetscReal t,Vec U)
405 {
406   PetscErrorCode     ierr;
407   TSSolutionFunction solutionfunction;
408   void               *ctx;
409   DM                 dm;
410 
411   PetscFunctionBegin;
412   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
413   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
414   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
415   ierr = DMTSGetSolutionFunction(dm,&solutionfunction,&ctx);CHKERRQ(ierr);
416 
417   if (solutionfunction) {
418     PetscStackPush("TS user right-hand-side function");
419     ierr = (*solutionfunction)(ts,t,U,ctx);CHKERRQ(ierr);
420     PetscStackPop;
421   }
422   PetscFunctionReturn(0);
423 }
424 
425 #undef __FUNCT__
426 #define __FUNCT__ "TSGetRHSVec_Private"
427 static PetscErrorCode TSGetRHSVec_Private(TS ts,Vec *Frhs)
428 {
429   Vec            F;
430   PetscErrorCode ierr;
431 
432   PetscFunctionBegin;
433   *Frhs = PETSC_NULL;
434   ierr = TSGetIFunction(ts,&F,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
435   if (!ts->Frhs) {
436     ierr = VecDuplicate(F,&ts->Frhs);CHKERRQ(ierr);
437   }
438   *Frhs = ts->Frhs;
439   PetscFunctionReturn(0);
440 }
441 
442 #undef __FUNCT__
443 #define __FUNCT__ "TSGetRHSMats_Private"
444 static PetscErrorCode TSGetRHSMats_Private(TS ts,Mat *Arhs,Mat *Brhs)
445 {
446   Mat            A,B;
447   PetscErrorCode ierr;
448 
449   PetscFunctionBegin;
450   ierr = TSGetIJacobian(ts,&A,&B,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
451   if (Arhs) {
452     if (!ts->Arhs) {
453       ierr = MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&ts->Arhs);CHKERRQ(ierr);
454     }
455     *Arhs = ts->Arhs;
456   }
457   if (Brhs) {
458     if (!ts->Brhs) {
459       ierr = MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&ts->Brhs);CHKERRQ(ierr);
460     }
461     *Brhs = ts->Brhs;
462   }
463   PetscFunctionReturn(0);
464 }
465 
466 #undef __FUNCT__
467 #define __FUNCT__ "TSComputeIFunction"
468 /*@
469    TSComputeIFunction - Evaluates the DAE residual written in implicit form F(t,U,Udot)=0
470 
471    Collective on TS and Vec
472 
473    Input Parameters:
474 +  ts - the TS context
475 .  t - current time
476 .  U - state vector
477 .  Udot - time derivative of state vector
478 -  imex - flag indicates if the method is IMEX so that the RHSFunction should be kept separate
479 
480    Output Parameter:
481 .  Y - right hand side
482 
483    Note:
484    Most users should not need to explicitly call this routine, as it
485    is used internally within the nonlinear solvers.
486 
487    If the user did did not write their equations in implicit form, this
488    function recasts them in implicit form.
489 
490    Level: developer
491 
492 .keywords: TS, compute
493 
494 .seealso: TSSetIFunction(), TSComputeRHSFunction()
495 @*/
496 PetscErrorCode TSComputeIFunction(TS ts,PetscReal t,Vec U,Vec Udot,Vec Y,PetscBool imex)
497 {
498   PetscErrorCode ierr;
499   TSIFunction    ifunction;
500   TSRHSFunction  rhsfunction;
501   void           *ctx;
502   DM             dm;
503 
504   PetscFunctionBegin;
505   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
506   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
507   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
508   PetscValidHeaderSpecific(Y,VEC_CLASSID,5);
509 
510   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
511   ierr = DMTSGetIFunction(dm,&ifunction,&ctx);CHKERRQ(ierr);
512   ierr = DMTSGetRHSFunction(dm,&rhsfunction,PETSC_NULL);CHKERRQ(ierr);
513 
514   if (!rhsfunction && !ifunction) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
515 
516   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
517   if (ifunction) {
518     PetscStackPush("TS user implicit function");
519     ierr = (*ifunction)(ts,t,U,Udot,Y,ctx);CHKERRQ(ierr);
520     PetscStackPop;
521   }
522   if (imex) {
523     if (!ifunction) {
524       ierr = VecCopy(Udot,Y);CHKERRQ(ierr);
525     }
526   } else if (rhsfunction) {
527     if (ifunction) {
528       Vec Frhs;
529       ierr = TSGetRHSVec_Private(ts,&Frhs);CHKERRQ(ierr);
530       ierr = TSComputeRHSFunction(ts,t,U,Frhs);CHKERRQ(ierr);
531       ierr = VecAXPY(Y,-1,Frhs);CHKERRQ(ierr);
532     } else {
533       ierr = TSComputeRHSFunction(ts,t,U,Y);CHKERRQ(ierr);
534       ierr = VecAYPX(Y,-1,Udot);CHKERRQ(ierr);
535     }
536   }
537   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
538   PetscFunctionReturn(0);
539 }
540 
541 #undef __FUNCT__
542 #define __FUNCT__ "TSComputeIJacobian"
543 /*@
544    TSComputeIJacobian - Evaluates the Jacobian of the DAE
545 
546    Collective on TS and Vec
547 
548    Input
549       Input Parameters:
550 +  ts - the TS context
551 .  t - current timestep
552 .  U - state vector
553 .  Udot - time derivative of state vector
554 .  shift - shift to apply, see note below
555 -  imex - flag indicates if the method is IMEX so that the RHSJacobian should be kept separate
556 
557    Output Parameters:
558 +  A - Jacobian matrix
559 .  B - optional preconditioning matrix
560 -  flag - flag indicating matrix structure
561 
562    Notes:
563    If F(t,U,Udot)=0 is the DAE, the required Jacobian is
564 
565    dF/dU + shift*dF/dUdot
566 
567    Most users should not need to explicitly call this routine, as it
568    is used internally within the nonlinear solvers.
569 
570    Level: developer
571 
572 .keywords: TS, compute, Jacobian, matrix
573 
574 .seealso:  TSSetIJacobian()
575 @*/
576 PetscErrorCode TSComputeIJacobian(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flg,PetscBool imex)
577 {
578   PetscInt       Ustate, Udotstate;
579   PetscErrorCode ierr;
580   TSIJacobian    ijacobian;
581   TSRHSJacobian  rhsjacobian;
582   DM             dm;
583   void           *ctx;
584 
585   PetscFunctionBegin;
586 
587   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
588   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
589   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
590   PetscValidPointer(A,6);
591   PetscValidHeaderSpecific(*A,MAT_CLASSID,6);
592   PetscValidPointer(B,7);
593   PetscValidHeaderSpecific(*B,MAT_CLASSID,7);
594   PetscValidPointer(flg,8);
595 
596   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
597   ierr = DMTSGetIJacobian(dm,&ijacobian,&ctx);CHKERRQ(ierr);
598   ierr = DMTSGetRHSJacobian(dm,&rhsjacobian,PETSC_NULL);CHKERRQ(ierr);
599 
600   ierr = PetscObjectStateQuery((PetscObject)U,&Ustate);CHKERRQ(ierr);
601   ierr = PetscObjectStateQuery((PetscObject)Udot,&Udotstate);CHKERRQ(ierr);
602   if (ts->ijacobian.time == t && (ts->problem_type == TS_LINEAR || (ts->ijacobian.X == U && ts->ijacobian.Xstate == Ustate && ts->ijacobian.Xdot == Udot && ts->ijacobian.Xdotstate == Udotstate && ts->ijacobian.imex == imex))) {
603     *flg = ts->ijacobian.mstructure;
604     ierr = MatScale(*A, shift / ts->ijacobian.shift);CHKERRQ(ierr);
605     PetscFunctionReturn(0);
606   }
607 
608   if (!rhsjacobian && !ijacobian) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
609 
610   *flg = SAME_NONZERO_PATTERN;  /* In case we're solving a linear problem in which case it wouldn't get initialized below. */
611   ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
612   if (ijacobian) {
613     *flg = DIFFERENT_NONZERO_PATTERN;
614     PetscStackPush("TS user implicit Jacobian");
615     ierr = (*ijacobian)(ts,t,U,Udot,shift,A,B,flg,ctx);CHKERRQ(ierr);
616     PetscStackPop;
617     /* make sure user returned a correct Jacobian and preconditioner */
618     PetscValidHeaderSpecific(*A,MAT_CLASSID,4);
619     PetscValidHeaderSpecific(*B,MAT_CLASSID,5);
620   }
621   if (imex) {
622     if (!ijacobian) {  /* system was written as Udot = G(t,U) */
623       ierr = MatZeroEntries(*A);CHKERRQ(ierr);
624       ierr = MatShift(*A,shift);CHKERRQ(ierr);
625       if (*A != *B) {
626         ierr = MatZeroEntries(*B);CHKERRQ(ierr);
627         ierr = MatShift(*B,shift);CHKERRQ(ierr);
628       }
629       *flg = SAME_PRECONDITIONER;
630     }
631   } else {
632     if (!ijacobian) {
633       ierr = TSComputeRHSJacobian(ts,t,U,A,B,flg);CHKERRQ(ierr);
634       ierr = MatScale(*A,-1);CHKERRQ(ierr);
635       ierr = MatShift(*A,shift);CHKERRQ(ierr);
636       if (*A != *B) {
637         ierr = MatScale(*B,-1);CHKERRQ(ierr);
638         ierr = MatShift(*B,shift);CHKERRQ(ierr);
639       }
640     } else if (rhsjacobian) {
641       Mat Arhs,Brhs;
642       MatStructure axpy,flg2 = DIFFERENT_NONZERO_PATTERN;
643       ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
644       ierr = TSComputeRHSJacobian(ts,t,U,&Arhs,&Brhs,&flg2);CHKERRQ(ierr);
645       axpy = (*flg == flg2) ? SAME_NONZERO_PATTERN : DIFFERENT_NONZERO_PATTERN;
646       ierr = MatAXPY(*A,-1,Arhs,axpy);CHKERRQ(ierr);
647       if (*A != *B) {
648         ierr = MatAXPY(*B,-1,Brhs,axpy);CHKERRQ(ierr);
649       }
650       *flg = PetscMin(*flg,flg2);
651     }
652   }
653 
654   ts->ijacobian.time = t;
655   ts->ijacobian.X = U;
656   ts->ijacobian.Xdot = Udot;
657   ierr = PetscObjectStateQuery((PetscObject)U,&ts->ijacobian.Xstate);CHKERRQ(ierr);
658   ierr = PetscObjectStateQuery((PetscObject)Udot,&ts->ijacobian.Xdotstate);CHKERRQ(ierr);
659   ts->ijacobian.shift = shift;
660   ts->ijacobian.imex = imex;
661   ts->ijacobian.mstructure = *flg;
662   ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,*A,*B);CHKERRQ(ierr);
663   PetscFunctionReturn(0);
664 }
665 
666 #undef __FUNCT__
667 #define __FUNCT__ "TSSetRHSFunction"
668 /*@C
669     TSSetRHSFunction - Sets the routine for evaluating the function,
670     where U_t = G(t,u).
671 
672     Logically Collective on TS
673 
674     Input Parameters:
675 +   ts - the TS context obtained from TSCreate()
676 .   r - vector to put the computed right hand side (or PETSC_NULL to have it created)
677 .   f - routine for evaluating the right-hand-side function
678 -   ctx - [optional] user-defined context for private data for the
679           function evaluation routine (may be PETSC_NULL)
680 
681     Calling sequence of func:
682 $     func (TS ts,PetscReal t,Vec u,Vec F,void *ctx);
683 
684 +   t - current timestep
685 .   u - input vector
686 .   F - function vector
687 -   ctx - [optional] user-defined function context
688 
689     Level: beginner
690 
691 .keywords: TS, timestep, set, right-hand-side, function
692 
693 .seealso: TSSetRHSJacobian(), TSSetIJacobian()
694 @*/
695 PetscErrorCode  TSSetRHSFunction(TS ts,Vec r,PetscErrorCode (*f)(TS,PetscReal,Vec,Vec,void*),void *ctx)
696 {
697   PetscErrorCode ierr;
698   SNES           snes;
699   Vec            ralloc = PETSC_NULL;
700   DM             dm;
701 
702   PetscFunctionBegin;
703   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
704   if (r) PetscValidHeaderSpecific(r,VEC_CLASSID,2);
705 
706   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
707   ierr = DMTSSetRHSFunction(dm,f,ctx);CHKERRQ(ierr);
708   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
709   if (!r && !ts->dm && ts->vec_sol) {
710     ierr = VecDuplicate(ts->vec_sol,&ralloc);CHKERRQ(ierr);
711     r = ralloc;
712   }
713   ierr = SNESSetFunction(snes,r,SNESTSFormFunction,ts);CHKERRQ(ierr);
714   ierr = VecDestroy(&ralloc);CHKERRQ(ierr);
715   PetscFunctionReturn(0);
716 }
717 
718 #undef __FUNCT__
719 #define __FUNCT__ "TSSetSolutionFunction"
720 /*@C
721     TSSetSolutionFunction - Provide a function that computes the solution of the ODE or DAE
722 
723     Logically Collective on TS
724 
725     Input Parameters:
726 +   ts - the TS context obtained from TSCreate()
727 .   f - routine for evaluating the solution
728 -   ctx - [optional] user-defined context for private data for the
729           function evaluation routine (may be PETSC_NULL)
730 
731     Calling sequence of func:
732 $     func (TS ts,PetscReal t,Vec u,void *ctx);
733 
734 +   t - current timestep
735 .   u - output vector
736 -   ctx - [optional] user-defined function context
737 
738     Notes:
739     This routine is used for testing accuracy of time integration schemes when you already know the solution.
740     If analytic solutions are not known for your system, consider using the Method of Manufactured Solutions to
741     create closed-form solutions with non-physical forcing terms.
742 
743     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
744 
745     Level: beginner
746 
747 .keywords: TS, timestep, set, right-hand-side, function
748 
749 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction()
750 @*/
751 PetscErrorCode  TSSetSolutionFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
752 {
753   PetscErrorCode ierr;
754   DM             dm;
755 
756   PetscFunctionBegin;
757   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
758   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
759   ierr = DMTSSetSolutionFunction(dm,f,ctx);CHKERRQ(ierr);
760   PetscFunctionReturn(0);
761 }
762 
763 #undef __FUNCT__
764 #define __FUNCT__ "TSSetRHSJacobian"
765 /*@C
766    TSSetRHSJacobian - Sets the function to compute the Jacobian of F,
767    where U_t = G(U,t), as well as the location to store the matrix.
768 
769    Logically Collective on TS
770 
771    Input Parameters:
772 +  ts  - the TS context obtained from TSCreate()
773 .  A   - Jacobian matrix
774 .  B   - preconditioner matrix (usually same as A)
775 .  f   - the Jacobian evaluation routine
776 -  ctx - [optional] user-defined context for private data for the
777          Jacobian evaluation routine (may be PETSC_NULL)
778 
779    Calling sequence of func:
780 $     func (TS ts,PetscReal t,Vec u,Mat *A,Mat *B,MatStructure *flag,void *ctx);
781 
782 +  t - current timestep
783 .  u - input vector
784 .  A - matrix A, where U_t = A(t)u
785 .  B - preconditioner matrix, usually the same as A
786 .  flag - flag indicating information about the preconditioner matrix
787           structure (same as flag in KSPSetOperators())
788 -  ctx - [optional] user-defined context for matrix evaluation routine
789 
790    Notes:
791    See KSPSetOperators() for important information about setting the flag
792    output parameter in the routine func().  Be sure to read this information!
793 
794    The routine func() takes Mat * as the matrix arguments rather than Mat.
795    This allows the matrix evaluation routine to replace A and/or B with a
796    completely new matrix structure (not just different matrix elements)
797    when appropriate, for instance, if the nonzero structure is changing
798    throughout the global iterations.
799 
800    Level: beginner
801 
802 .keywords: TS, timestep, set, right-hand-side, Jacobian
803 
804 .seealso: SNESDefaultComputeJacobianColor(), TSSetRHSFunction()
805 
806 @*/
807 PetscErrorCode  TSSetRHSJacobian(TS ts,Mat A,Mat B,TSRHSJacobian f,void *ctx)
808 {
809   PetscErrorCode ierr;
810   SNES           snes;
811   DM             dm;
812   TSIJacobian    ijacobian;
813 
814   PetscFunctionBegin;
815   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
816   if (A) PetscValidHeaderSpecific(A,MAT_CLASSID,2);
817   if (B) PetscValidHeaderSpecific(B,MAT_CLASSID,3);
818   if (A) PetscCheckSameComm(ts,1,A,2);
819   if (B) PetscCheckSameComm(ts,1,B,3);
820 
821   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
822   ierr = DMTSSetRHSJacobian(dm,f,ctx);CHKERRQ(ierr);
823   ierr = DMTSGetIJacobian(dm,&ijacobian,PETSC_NULL);CHKERRQ(ierr);
824 
825   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
826   if (!ijacobian) {
827     ierr = SNESSetJacobian(snes,A,B,SNESTSFormJacobian,ts);CHKERRQ(ierr);
828   }
829   if (A) {
830     ierr = PetscObjectReference((PetscObject)A);CHKERRQ(ierr);
831     ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
832     ts->Arhs = A;
833   }
834   if (B) {
835     ierr = PetscObjectReference((PetscObject)B);CHKERRQ(ierr);
836     ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
837     ts->Brhs = B;
838   }
839   PetscFunctionReturn(0);
840 }
841 
842 
843 #undef __FUNCT__
844 #define __FUNCT__ "TSSetIFunction"
845 /*@C
846    TSSetIFunction - Set the function to compute F(t,U,U_t) where F() = 0 is the DAE to be solved.
847 
848    Logically Collective on TS
849 
850    Input Parameters:
851 +  ts  - the TS context obtained from TSCreate()
852 .  r   - vector to hold the residual (or PETSC_NULL to have it created internally)
853 .  f   - the function evaluation routine
854 -  ctx - user-defined context for private data for the function evaluation routine (may be PETSC_NULL)
855 
856    Calling sequence of f:
857 $  f(TS ts,PetscReal t,Vec u,Vec u_t,Vec F,ctx);
858 
859 +  t   - time at step/stage being solved
860 .  u   - state vector
861 .  u_t - time derivative of state vector
862 .  F   - function vector
863 -  ctx - [optional] user-defined context for matrix evaluation routine
864 
865    Important:
866    The user MUST call either this routine, TSSetRHSFunction().  This routine must be used when not solving an ODE, for example a DAE.
867 
868    Level: beginner
869 
870 .keywords: TS, timestep, set, DAE, Jacobian
871 
872 .seealso: TSSetRHSJacobian(), TSSetRHSFunction(), TSSetIJacobian()
873 @*/
874 PetscErrorCode  TSSetIFunction(TS ts,Vec res,TSIFunction f,void *ctx)
875 {
876   PetscErrorCode ierr;
877   SNES           snes;
878   Vec            resalloc = PETSC_NULL;
879   DM             dm;
880 
881   PetscFunctionBegin;
882   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
883   if (res) PetscValidHeaderSpecific(res,VEC_CLASSID,2);
884 
885   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
886   ierr = DMTSSetIFunction(dm,f,ctx);CHKERRQ(ierr);
887 
888   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
889   if (!res && !ts->dm && ts->vec_sol) {
890     ierr = VecDuplicate(ts->vec_sol,&resalloc);CHKERRQ(ierr);
891     res = resalloc;
892   }
893   ierr = SNESSetFunction(snes,res,SNESTSFormFunction,ts);CHKERRQ(ierr);
894   ierr = VecDestroy(&resalloc);CHKERRQ(ierr);
895 
896   PetscFunctionReturn(0);
897 }
898 
899 #undef __FUNCT__
900 #define __FUNCT__ "TSGetIFunction"
901 /*@C
902    TSGetIFunction - Returns the vector where the implicit residual is stored and the function/contex to compute it.
903 
904    Not Collective
905 
906    Input Parameter:
907 .  ts - the TS context
908 
909    Output Parameter:
910 +  r - vector to hold residual (or PETSC_NULL)
911 .  func - the function to compute residual (or PETSC_NULL)
912 -  ctx - the function context (or PETSC_NULL)
913 
914    Level: advanced
915 
916 .keywords: TS, nonlinear, get, function
917 
918 .seealso: TSSetIFunction(), SNESGetFunction()
919 @*/
920 PetscErrorCode TSGetIFunction(TS ts,Vec *r,TSIFunction *func,void **ctx)
921 {
922   PetscErrorCode ierr;
923   SNES           snes;
924   DM             dm;
925 
926   PetscFunctionBegin;
927   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
928   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
929   ierr = SNESGetFunction(snes,r,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
930   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
931   ierr = DMTSGetIFunction(dm,func,ctx);CHKERRQ(ierr);
932   PetscFunctionReturn(0);
933 }
934 
935 #undef __FUNCT__
936 #define __FUNCT__ "TSGetRHSFunction"
937 /*@C
938    TSGetRHSFunction - Returns the vector where the right hand side is stored and the function/context to compute it.
939 
940    Not Collective
941 
942    Input Parameter:
943 .  ts - the TS context
944 
945    Output Parameter:
946 +  r - vector to hold computed right hand side (or PETSC_NULL)
947 .  func - the function to compute right hand side (or PETSC_NULL)
948 -  ctx - the function context (or PETSC_NULL)
949 
950    Level: advanced
951 
952 .keywords: TS, nonlinear, get, function
953 
954 .seealso: TSSetRhsfunction(), SNESGetFunction()
955 @*/
956 PetscErrorCode TSGetRHSFunction(TS ts,Vec *r,TSRHSFunction *func,void **ctx)
957 {
958   PetscErrorCode ierr;
959   SNES           snes;
960   DM             dm;
961 
962   PetscFunctionBegin;
963   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
964   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
965   ierr = SNESGetFunction(snes,r,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
966   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
967   ierr = DMTSGetRHSFunction(dm,func,ctx);CHKERRQ(ierr);
968   PetscFunctionReturn(0);
969 }
970 
971 #undef __FUNCT__
972 #define __FUNCT__ "TSSetIJacobian"
973 /*@C
974    TSSetIJacobian - Set the function to compute the matrix dF/dU + a*dF/dU_t where F(t,U,U_t) is the function
975         you provided with TSSetIFunction().
976 
977    Logically Collective on TS
978 
979    Input Parameters:
980 +  ts  - the TS context obtained from TSCreate()
981 .  A   - Jacobian matrix
982 .  B   - preconditioning matrix for A (may be same as A)
983 .  f   - the Jacobian evaluation routine
984 -  ctx - user-defined context for private data for the Jacobian evaluation routine (may be PETSC_NULL)
985 
986    Calling sequence of f:
987 $  f(TS ts,PetscReal t,Vec U,Vec U_t,PetscReal a,Mat *A,Mat *B,MatStructure *flag,void *ctx);
988 
989 +  t    - time at step/stage being solved
990 .  U    - state vector
991 .  U_t  - time derivative of state vector
992 .  a    - shift
993 .  A    - Jacobian of F(t,U,W+a*U), equivalent to dF/dU + a*dF/dU_t
994 .  B    - preconditioning matrix for A, may be same as A
995 .  flag - flag indicating information about the preconditioner matrix
996           structure (same as flag in KSPSetOperators())
997 -  ctx  - [optional] user-defined context for matrix evaluation routine
998 
999    Notes:
1000    The matrices A and B are exactly the matrices that are used by SNES for the nonlinear solve.
1001 
1002    The matrix dF/dU + a*dF/dU_t you provide turns out to be
1003    the Jacobian of F(t,U,W+a*U) where F(t,U,U_t) = 0 is the DAE to be solved.
1004    The time integrator internally approximates U_t by W+a*U where the positive "shift"
1005    a and vector W depend on the integration method, step size, and past states. For example with
1006    the backward Euler method a = 1/dt and W = -a*U(previous timestep) so
1007    W + a*U = a*(U - U(previous timestep)) = (U - U(previous timestep))/dt
1008 
1009    Level: beginner
1010 
1011 .keywords: TS, timestep, DAE, Jacobian
1012 
1013 .seealso: TSSetIFunction(), TSSetRHSJacobian(), SNESDefaultComputeJacobianColor(), SNESDefaultComputeJacobian()
1014 
1015 @*/
1016 PetscErrorCode  TSSetIJacobian(TS ts,Mat A,Mat B,TSIJacobian f,void *ctx)
1017 {
1018   PetscErrorCode ierr;
1019   SNES           snes;
1020   DM             dm;
1021 
1022   PetscFunctionBegin;
1023   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1024   if (A) PetscValidHeaderSpecific(A,MAT_CLASSID,2);
1025   if (B) PetscValidHeaderSpecific(B,MAT_CLASSID,3);
1026   if (A) PetscCheckSameComm(ts,1,A,2);
1027   if (B) PetscCheckSameComm(ts,1,B,3);
1028 
1029   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1030   ierr = DMTSSetIJacobian(dm,f,ctx);CHKERRQ(ierr);
1031 
1032   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1033   ierr = SNESSetJacobian(snes,A,B,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1034   PetscFunctionReturn(0);
1035 }
1036 
1037 #undef __FUNCT__
1038 #define __FUNCT__ "TSLoad"
1039 /*@C
1040   TSLoad - Loads a KSP that has been stored in binary  with KSPView().
1041 
1042   Collective on PetscViewer
1043 
1044   Input Parameters:
1045 + newdm - the newly loaded TS, this needs to have been created with TSCreate() or
1046            some related function before a call to TSLoad().
1047 - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
1048 
1049    Level: intermediate
1050 
1051   Notes:
1052    The type is determined by the data in the file, any type set into the TS before this call is ignored.
1053 
1054   Notes for advanced users:
1055   Most users should not need to know the details of the binary storage
1056   format, since TSLoad() and TSView() completely hide these details.
1057   But for anyone who's interested, the standard binary matrix storage
1058   format is
1059 .vb
1060      has not yet been determined
1061 .ve
1062 
1063 .seealso: PetscViewerBinaryOpen(), TSView(), MatLoad(), VecLoad()
1064 @*/
1065 PetscErrorCode  TSLoad(TS ts, PetscViewer viewer)
1066 {
1067   PetscErrorCode ierr;
1068   PetscBool      isbinary;
1069   PetscInt       classid;
1070   char           type[256];
1071 
1072   PetscFunctionBegin;
1073   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1074   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1075   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1076   if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
1077 
1078   ierr = PetscViewerBinaryRead(viewer,&classid,1,PETSC_INT);CHKERRQ(ierr);
1079   if (classid != TS_FILE_CLASSID) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_ARG_WRONG,"Not TS next in file");
1080   ierr = PetscViewerBinaryRead(viewer,type,256,PETSC_CHAR);CHKERRQ(ierr);
1081   ierr = TSSetType(ts, type);CHKERRQ(ierr);
1082   if (ts->ops->load) {
1083     ierr = (*ts->ops->load)(ts,viewer);CHKERRQ(ierr);
1084   }
1085   ierr = DMCreate(((PetscObject)ts)->comm,&ts->dm);CHKERRQ(ierr);
1086   ierr = DMLoad(ts->dm,viewer);CHKERRQ(ierr);
1087   ierr = DMCreateGlobalVector(ts->dm,&ts->vec_sol);CHKERRQ(ierr);
1088   ierr = VecLoad(ts->vec_sol,viewer);CHKERRQ(ierr);
1089   PetscFunctionReturn(0);
1090 }
1091 
1092 #undef __FUNCT__
1093 #define __FUNCT__ "TSView"
1094 /*@C
1095     TSView - Prints the TS data structure.
1096 
1097     Collective on TS
1098 
1099     Input Parameters:
1100 +   ts - the TS context obtained from TSCreate()
1101 -   viewer - visualization context
1102 
1103     Options Database Key:
1104 .   -ts_view - calls TSView() at end of TSStep()
1105 
1106     Notes:
1107     The available visualization contexts include
1108 +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
1109 -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
1110          output where only the first processor opens
1111          the file.  All other processors send their
1112          data to the first processor to print.
1113 
1114     The user can open an alternative visualization context with
1115     PetscViewerASCIIOpen() - output to a specified file.
1116 
1117     Level: beginner
1118 
1119 .keywords: TS, timestep, view
1120 
1121 .seealso: PetscViewerASCIIOpen()
1122 @*/
1123 PetscErrorCode  TSView(TS ts,PetscViewer viewer)
1124 {
1125   PetscErrorCode ierr;
1126   TSType         type;
1127   PetscBool      iascii,isstring,isundials,isbinary,isdraw;
1128 
1129   PetscFunctionBegin;
1130   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1131   if (!viewer) {
1132     ierr = PetscViewerASCIIGetStdout(((PetscObject)ts)->comm,&viewer);CHKERRQ(ierr);
1133   }
1134   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1135   PetscCheckSameComm(ts,1,viewer,2);
1136 
1137   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1138   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
1139   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1140   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1141   if (iascii) {
1142     ierr = PetscObjectPrintClassNamePrefixType((PetscObject)ts,viewer,"TS Object");CHKERRQ(ierr);
1143     ierr = PetscViewerASCIIPrintf(viewer,"  maximum steps=%D\n",ts->max_steps);CHKERRQ(ierr);
1144     ierr = PetscViewerASCIIPrintf(viewer,"  maximum time=%G\n",ts->max_time);CHKERRQ(ierr);
1145     if (ts->problem_type == TS_NONLINEAR) {
1146       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solver iterations=%D\n",ts->snes_its);CHKERRQ(ierr);
1147       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solve failures=%D\n",ts->num_snes_failures);CHKERRQ(ierr);
1148     }
1149     ierr = PetscViewerASCIIPrintf(viewer,"  total number of linear solver iterations=%D\n",ts->ksp_its);CHKERRQ(ierr);
1150     ierr = PetscViewerASCIIPrintf(viewer,"  total number of rejected steps=%D\n",ts->reject);CHKERRQ(ierr);
1151     if (ts->ops->view) {
1152       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1153       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1154       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1155     }
1156   } else if (isstring) {
1157     ierr = TSGetType(ts,&type);CHKERRQ(ierr);
1158     ierr = PetscViewerStringSPrintf(viewer," %-7.7s",type);CHKERRQ(ierr);
1159   } else if (isbinary) {
1160     PetscInt         classid = TS_FILE_CLASSID;
1161     MPI_Comm         comm;
1162     PetscMPIInt      rank;
1163     char             type[256];
1164 
1165     ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
1166     ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
1167     if (!rank) {
1168       ierr = PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);CHKERRQ(ierr);
1169       ierr = PetscStrncpy(type,((PetscObject)ts)->type_name,256);CHKERRQ(ierr);
1170       ierr = PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);CHKERRQ(ierr);
1171     }
1172     if (ts->ops->view) {
1173       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1174     }
1175     ierr = DMView(ts->dm,viewer);CHKERRQ(ierr);
1176     ierr = VecView(ts->vec_sol,viewer);CHKERRQ(ierr);
1177   } else if (isdraw) {
1178     PetscDraw draw;
1179     char      str[36];
1180     PetscReal x,y,bottom;
1181 
1182     ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1183     ierr = PetscDrawGetCurrentPoint(draw,&x,&y);CHKERRQ(ierr);
1184     ierr = PetscStrcpy(str,"TS: ");CHKERRQ(ierr);
1185     ierr = PetscStrcat(str,((PetscObject)ts)->type_name);CHKERRQ(ierr);
1186     ierr = PetscDrawBoxedString(draw,x,y,PETSC_DRAW_BLACK,PETSC_DRAW_BLACK,str,&bottom);CHKERRQ(ierr);
1187     ierr = PetscDrawPushCurrentPoint(draw,x,bottom);CHKERRQ(ierr);
1188     if (ts->ops->view) {
1189       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1190     }
1191     ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr);
1192   }
1193   ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1194   ierr = PetscObjectTypeCompare((PetscObject)ts,TSSUNDIALS,&isundials);CHKERRQ(ierr);
1195   ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1196   PetscFunctionReturn(0);
1197 }
1198 
1199 
1200 #undef __FUNCT__
1201 #define __FUNCT__ "TSSetApplicationContext"
1202 /*@
1203    TSSetApplicationContext - Sets an optional user-defined context for
1204    the timesteppers.
1205 
1206    Logically Collective on TS
1207 
1208    Input Parameters:
1209 +  ts - the TS context obtained from TSCreate()
1210 -  usrP - optional user context
1211 
1212    Level: intermediate
1213 
1214 .keywords: TS, timestep, set, application, context
1215 
1216 .seealso: TSGetApplicationContext()
1217 @*/
1218 PetscErrorCode  TSSetApplicationContext(TS ts,void *usrP)
1219 {
1220   PetscFunctionBegin;
1221   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1222   ts->user = usrP;
1223   PetscFunctionReturn(0);
1224 }
1225 
1226 #undef __FUNCT__
1227 #define __FUNCT__ "TSGetApplicationContext"
1228 /*@
1229     TSGetApplicationContext - Gets the user-defined context for the
1230     timestepper.
1231 
1232     Not Collective
1233 
1234     Input Parameter:
1235 .   ts - the TS context obtained from TSCreate()
1236 
1237     Output Parameter:
1238 .   usrP - user context
1239 
1240     Level: intermediate
1241 
1242 .keywords: TS, timestep, get, application, context
1243 
1244 .seealso: TSSetApplicationContext()
1245 @*/
1246 PetscErrorCode  TSGetApplicationContext(TS ts,void *usrP)
1247 {
1248   PetscFunctionBegin;
1249   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1250   *(void**)usrP = ts->user;
1251   PetscFunctionReturn(0);
1252 }
1253 
1254 #undef __FUNCT__
1255 #define __FUNCT__ "TSGetTimeStepNumber"
1256 /*@
1257    TSGetTimeStepNumber - Gets the number of time steps completed.
1258 
1259    Not Collective
1260 
1261    Input Parameter:
1262 .  ts - the TS context obtained from TSCreate()
1263 
1264    Output Parameter:
1265 .  iter - number of steps completed so far
1266 
1267    Level: intermediate
1268 
1269 .keywords: TS, timestep, get, iteration, number
1270 .seealso: TSGetTime(), TSGetTimeStep(), TSSetPreStep(), TSSetPreStage(), TSSetPostStep()
1271 @*/
1272 PetscErrorCode  TSGetTimeStepNumber(TS ts,PetscInt* iter)
1273 {
1274   PetscFunctionBegin;
1275   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1276   PetscValidIntPointer(iter,2);
1277   *iter = ts->steps;
1278   PetscFunctionReturn(0);
1279 }
1280 
1281 #undef __FUNCT__
1282 #define __FUNCT__ "TSSetInitialTimeStep"
1283 /*@
1284    TSSetInitialTimeStep - Sets the initial timestep to be used,
1285    as well as the initial time.
1286 
1287    Logically Collective on TS
1288 
1289    Input Parameters:
1290 +  ts - the TS context obtained from TSCreate()
1291 .  initial_time - the initial time
1292 -  time_step - the size of the timestep
1293 
1294    Level: intermediate
1295 
1296 .seealso: TSSetTimeStep(), TSGetTimeStep()
1297 
1298 .keywords: TS, set, initial, timestep
1299 @*/
1300 PetscErrorCode  TSSetInitialTimeStep(TS ts,PetscReal initial_time,PetscReal time_step)
1301 {
1302   PetscErrorCode ierr;
1303 
1304   PetscFunctionBegin;
1305   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1306   ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
1307   ierr = TSSetTime(ts,initial_time);CHKERRQ(ierr);
1308   PetscFunctionReturn(0);
1309 }
1310 
1311 #undef __FUNCT__
1312 #define __FUNCT__ "TSSetTimeStep"
1313 /*@
1314    TSSetTimeStep - Allows one to reset the timestep at any time,
1315    useful for simple pseudo-timestepping codes.
1316 
1317    Logically Collective on TS
1318 
1319    Input Parameters:
1320 +  ts - the TS context obtained from TSCreate()
1321 -  time_step - the size of the timestep
1322 
1323    Level: intermediate
1324 
1325 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1326 
1327 .keywords: TS, set, timestep
1328 @*/
1329 PetscErrorCode  TSSetTimeStep(TS ts,PetscReal time_step)
1330 {
1331   PetscFunctionBegin;
1332   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1333   PetscValidLogicalCollectiveReal(ts,time_step,2);
1334   ts->time_step = time_step;
1335   ts->time_step_orig = time_step;
1336   PetscFunctionReturn(0);
1337 }
1338 
1339 #undef __FUNCT__
1340 #define __FUNCT__ "TSSetExactFinalTime"
1341 /*@
1342    TSSetExactFinalTime - Determines whether to interpolate solution to the
1343       exact final time requested by the user or just returns it at the final time
1344       it computed.
1345 
1346   Logically Collective on TS
1347 
1348    Input Parameter:
1349 +   ts - the time-step context
1350 -   ft - PETSC_TRUE if interpolates, else PETSC_FALSE
1351 
1352    Level: beginner
1353 
1354 .seealso: TSSetDuration()
1355 @*/
1356 PetscErrorCode  TSSetExactFinalTime(TS ts,PetscBool flg)
1357 {
1358   PetscFunctionBegin;
1359   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1360   PetscValidLogicalCollectiveBool(ts,flg,2);
1361   ts->exact_final_time = flg;
1362   PetscFunctionReturn(0);
1363 }
1364 
1365 #undef __FUNCT__
1366 #define __FUNCT__ "TSGetTimeStep"
1367 /*@
1368    TSGetTimeStep - Gets the current timestep size.
1369 
1370    Not Collective
1371 
1372    Input Parameter:
1373 .  ts - the TS context obtained from TSCreate()
1374 
1375    Output Parameter:
1376 .  dt - the current timestep size
1377 
1378    Level: intermediate
1379 
1380 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1381 
1382 .keywords: TS, get, timestep
1383 @*/
1384 PetscErrorCode  TSGetTimeStep(TS ts,PetscReal* dt)
1385 {
1386   PetscFunctionBegin;
1387   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1388   PetscValidRealPointer(dt,2);
1389   *dt = ts->time_step;
1390   PetscFunctionReturn(0);
1391 }
1392 
1393 #undef __FUNCT__
1394 #define __FUNCT__ "TSGetSolution"
1395 /*@
1396    TSGetSolution - Returns the solution at the present timestep. It
1397    is valid to call this routine inside the function that you are evaluating
1398    in order to move to the new timestep. This vector not changed until
1399    the solution at the next timestep has been calculated.
1400 
1401    Not Collective, but Vec returned is parallel if TS is parallel
1402 
1403    Input Parameter:
1404 .  ts - the TS context obtained from TSCreate()
1405 
1406    Output Parameter:
1407 .  v - the vector containing the solution
1408 
1409    Level: intermediate
1410 
1411 .seealso: TSGetTimeStep()
1412 
1413 .keywords: TS, timestep, get, solution
1414 @*/
1415 PetscErrorCode  TSGetSolution(TS ts,Vec *v)
1416 {
1417   PetscFunctionBegin;
1418   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1419   PetscValidPointer(v,2);
1420   *v = ts->vec_sol;
1421   PetscFunctionReturn(0);
1422 }
1423 
1424 /* ----- Routines to initialize and destroy a timestepper ---- */
1425 #undef __FUNCT__
1426 #define __FUNCT__ "TSSetProblemType"
1427 /*@
1428   TSSetProblemType - Sets the type of problem to be solved.
1429 
1430   Not collective
1431 
1432   Input Parameters:
1433 + ts   - The TS
1434 - type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1435 .vb
1436          U_t - A U = 0      (linear)
1437          U_t - A(t) U = 0   (linear)
1438          F(t,U,U_t) = 0     (nonlinear)
1439 .ve
1440 
1441    Level: beginner
1442 
1443 .keywords: TS, problem type
1444 .seealso: TSSetUp(), TSProblemType, TS
1445 @*/
1446 PetscErrorCode  TSSetProblemType(TS ts, TSProblemType type)
1447 {
1448   PetscErrorCode ierr;
1449 
1450   PetscFunctionBegin;
1451   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1452   ts->problem_type = type;
1453   if (type == TS_LINEAR) {
1454     SNES snes;
1455     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1456     ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);
1457   }
1458   PetscFunctionReturn(0);
1459 }
1460 
1461 #undef __FUNCT__
1462 #define __FUNCT__ "TSGetProblemType"
1463 /*@C
1464   TSGetProblemType - Gets the type of problem to be solved.
1465 
1466   Not collective
1467 
1468   Input Parameter:
1469 . ts   - The TS
1470 
1471   Output Parameter:
1472 . type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1473 .vb
1474          M U_t = A U
1475          M(t) U_t = A(t) U
1476          F(t,U,U_t)
1477 .ve
1478 
1479    Level: beginner
1480 
1481 .keywords: TS, problem type
1482 .seealso: TSSetUp(), TSProblemType, TS
1483 @*/
1484 PetscErrorCode  TSGetProblemType(TS ts, TSProblemType *type)
1485 {
1486   PetscFunctionBegin;
1487   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1488   PetscValidIntPointer(type,2);
1489   *type = ts->problem_type;
1490   PetscFunctionReturn(0);
1491 }
1492 
1493 #undef __FUNCT__
1494 #define __FUNCT__ "TSSetUp"
1495 /*@
1496    TSSetUp - Sets up the internal data structures for the later use
1497    of a timestepper.
1498 
1499    Collective on TS
1500 
1501    Input Parameter:
1502 .  ts - the TS context obtained from TSCreate()
1503 
1504    Notes:
1505    For basic use of the TS solvers the user need not explicitly call
1506    TSSetUp(), since these actions will automatically occur during
1507    the call to TSStep().  However, if one wishes to control this
1508    phase separately, TSSetUp() should be called after TSCreate()
1509    and optional routines of the form TSSetXXX(), but before TSStep().
1510 
1511    Level: advanced
1512 
1513 .keywords: TS, timestep, setup
1514 
1515 .seealso: TSCreate(), TSStep(), TSDestroy()
1516 @*/
1517 PetscErrorCode  TSSetUp(TS ts)
1518 {
1519   PetscErrorCode ierr;
1520   DM             dm;
1521   PetscErrorCode (*func)(SNES,Vec,Vec,void*);
1522   PetscErrorCode (*jac)(SNES,Vec,Mat*,Mat*,MatStructure*,void*);
1523   TSIJacobian    ijac;
1524   TSRHSJacobian  rhsjac;
1525 
1526   PetscFunctionBegin;
1527   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1528   if (ts->setupcalled) PetscFunctionReturn(0);
1529 
1530   if (!((PetscObject)ts)->type_name) {
1531     ierr = TSSetType(ts,TSEULER);CHKERRQ(ierr);
1532   }
1533   if (ts->exact_final_time == PETSC_DECIDE) ts->exact_final_time = PETSC_FALSE;
1534 
1535   if (!ts->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call TSSetSolution() first");
1536 
1537   ierr = TSGetAdapt(ts,&ts->adapt);CHKERRQ(ierr);
1538 
1539   if (ts->ops->setup) {
1540     ierr = (*ts->ops->setup)(ts);CHKERRQ(ierr);
1541   }
1542 
1543   /* in the case where we've set a DMTSFunction or what have you, we need the default SNESFunction
1544    to be set right but can't do it elsewhere due to the overreliance on ctx=ts.
1545    */
1546   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1547   ierr = DMSNESGetFunction(dm,&func,PETSC_NULL);CHKERRQ(ierr);
1548   if (!func) {
1549     ierr =DMSNESSetFunction(dm,SNESTSFormFunction,ts);CHKERRQ(ierr);
1550   }
1551   /* if the SNES doesn't have a jacobian set and the TS has an ijacobian or rhsjacobian set, set the SNES to use it.
1552      Otherwise, the SNES will use coloring internally to form the Jacobian.
1553    */
1554   ierr = DMSNESGetJacobian(dm,&jac,PETSC_NULL);CHKERRQ(ierr);
1555   ierr = DMTSGetIJacobian(dm,&ijac,PETSC_NULL);CHKERRQ(ierr);
1556   ierr = DMTSGetRHSJacobian(dm,&rhsjac,PETSC_NULL);CHKERRQ(ierr);
1557   if (!jac && (ijac || rhsjac)) {
1558     ierr = DMSNESSetJacobian(dm,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1559   }
1560   ts->setupcalled = PETSC_TRUE;
1561   PetscFunctionReturn(0);
1562 }
1563 
1564 #undef __FUNCT__
1565 #define __FUNCT__ "TSReset"
1566 /*@
1567    TSReset - Resets a TS context and removes any allocated Vecs and Mats.
1568 
1569    Collective on TS
1570 
1571    Input Parameter:
1572 .  ts - the TS context obtained from TSCreate()
1573 
1574    Level: beginner
1575 
1576 .keywords: TS, timestep, reset
1577 
1578 .seealso: TSCreate(), TSSetup(), TSDestroy()
1579 @*/
1580 PetscErrorCode  TSReset(TS ts)
1581 {
1582   PetscErrorCode ierr;
1583 
1584   PetscFunctionBegin;
1585   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1586   if (ts->ops->reset) {
1587     ierr = (*ts->ops->reset)(ts);CHKERRQ(ierr);
1588   }
1589   if (ts->snes) {ierr = SNESReset(ts->snes);CHKERRQ(ierr);}
1590   ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1591   ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1592   ierr = VecDestroy(&ts->Frhs);CHKERRQ(ierr);
1593   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
1594   ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
1595   ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
1596   ierr = VecDestroyVecs(ts->nwork,&ts->work);CHKERRQ(ierr);
1597   ts->setupcalled = PETSC_FALSE;
1598   PetscFunctionReturn(0);
1599 }
1600 
1601 #undef __FUNCT__
1602 #define __FUNCT__ "TSDestroy"
1603 /*@
1604    TSDestroy - Destroys the timestepper context that was created
1605    with TSCreate().
1606 
1607    Collective on TS
1608 
1609    Input Parameter:
1610 .  ts - the TS context obtained from TSCreate()
1611 
1612    Level: beginner
1613 
1614 .keywords: TS, timestepper, destroy
1615 
1616 .seealso: TSCreate(), TSSetUp(), TSSolve()
1617 @*/
1618 PetscErrorCode  TSDestroy(TS *ts)
1619 {
1620   PetscErrorCode ierr;
1621 
1622   PetscFunctionBegin;
1623   if (!*ts) PetscFunctionReturn(0);
1624   PetscValidHeaderSpecific((*ts),TS_CLASSID,1);
1625   if (--((PetscObject)(*ts))->refct > 0) {*ts = 0; PetscFunctionReturn(0);}
1626 
1627   ierr = TSReset((*ts));CHKERRQ(ierr);
1628 
1629   /* if memory was published with AMS then destroy it */
1630   ierr = PetscObjectDepublish((*ts));CHKERRQ(ierr);
1631   if ((*ts)->ops->destroy) {ierr = (*(*ts)->ops->destroy)((*ts));CHKERRQ(ierr);}
1632 
1633   ierr = TSAdaptDestroy(&(*ts)->adapt);CHKERRQ(ierr);
1634   ierr = SNESDestroy(&(*ts)->snes);CHKERRQ(ierr);
1635   ierr = DMDestroy(&(*ts)->dm);CHKERRQ(ierr);
1636   ierr = TSMonitorCancel((*ts));CHKERRQ(ierr);
1637 
1638   ierr = PetscHeaderDestroy(ts);CHKERRQ(ierr);
1639   PetscFunctionReturn(0);
1640 }
1641 
1642 #undef __FUNCT__
1643 #define __FUNCT__ "TSGetSNES"
1644 /*@
1645    TSGetSNES - Returns the SNES (nonlinear solver) associated with
1646    a TS (timestepper) context. Valid only for nonlinear problems.
1647 
1648    Not Collective, but SNES is parallel if TS is parallel
1649 
1650    Input Parameter:
1651 .  ts - the TS context obtained from TSCreate()
1652 
1653    Output Parameter:
1654 .  snes - the nonlinear solver context
1655 
1656    Notes:
1657    The user can then directly manipulate the SNES context to set various
1658    options, etc.  Likewise, the user can then extract and manipulate the
1659    KSP, KSP, and PC contexts as well.
1660 
1661    TSGetSNES() does not work for integrators that do not use SNES; in
1662    this case TSGetSNES() returns PETSC_NULL in snes.
1663 
1664    Level: beginner
1665 
1666 .keywords: timestep, get, SNES
1667 @*/
1668 PetscErrorCode  TSGetSNES(TS ts,SNES *snes)
1669 {
1670   PetscErrorCode ierr;
1671 
1672   PetscFunctionBegin;
1673   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1674   PetscValidPointer(snes,2);
1675   if (!ts->snes) {
1676     ierr = SNESCreate(((PetscObject)ts)->comm,&ts->snes);CHKERRQ(ierr);
1677     ierr = SNESSetFunction(ts->snes,PETSC_NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
1678     ierr = PetscLogObjectParent(ts,ts->snes);CHKERRQ(ierr);
1679     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->snes,(PetscObject)ts,1);CHKERRQ(ierr);
1680     if (ts->dm) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
1681     if (ts->problem_type == TS_LINEAR) {
1682       ierr = SNESSetType(ts->snes,SNESKSPONLY);CHKERRQ(ierr);
1683     }
1684   }
1685   *snes = ts->snes;
1686   PetscFunctionReturn(0);
1687 }
1688 
1689 #undef __FUNCT__
1690 #define __FUNCT__ "TSGetKSP"
1691 /*@
1692    TSGetKSP - Returns the KSP (linear solver) associated with
1693    a TS (timestepper) context.
1694 
1695    Not Collective, but KSP is parallel if TS is parallel
1696 
1697    Input Parameter:
1698 .  ts - the TS context obtained from TSCreate()
1699 
1700    Output Parameter:
1701 .  ksp - the nonlinear solver context
1702 
1703    Notes:
1704    The user can then directly manipulate the KSP context to set various
1705    options, etc.  Likewise, the user can then extract and manipulate the
1706    KSP and PC contexts as well.
1707 
1708    TSGetKSP() does not work for integrators that do not use KSP;
1709    in this case TSGetKSP() returns PETSC_NULL in ksp.
1710 
1711    Level: beginner
1712 
1713 .keywords: timestep, get, KSP
1714 @*/
1715 PetscErrorCode  TSGetKSP(TS ts,KSP *ksp)
1716 {
1717   PetscErrorCode ierr;
1718   SNES           snes;
1719 
1720   PetscFunctionBegin;
1721   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1722   PetscValidPointer(ksp,2);
1723   if (!((PetscObject)ts)->type_name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"KSP is not created yet. Call TSSetType() first");
1724   if (ts->problem_type != TS_LINEAR) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Linear only; use TSGetSNES()");
1725   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1726   ierr = SNESGetKSP(snes,ksp);CHKERRQ(ierr);
1727   PetscFunctionReturn(0);
1728 }
1729 
1730 /* ----------- Routines to set solver parameters ---------- */
1731 
1732 #undef __FUNCT__
1733 #define __FUNCT__ "TSGetDuration"
1734 /*@
1735    TSGetDuration - Gets the maximum number of timesteps to use and
1736    maximum time for iteration.
1737 
1738    Not Collective
1739 
1740    Input Parameters:
1741 +  ts       - the TS context obtained from TSCreate()
1742 .  maxsteps - maximum number of iterations to use, or PETSC_NULL
1743 -  maxtime  - final time to iterate to, or PETSC_NULL
1744 
1745    Level: intermediate
1746 
1747 .keywords: TS, timestep, get, maximum, iterations, time
1748 @*/
1749 PetscErrorCode  TSGetDuration(TS ts, PetscInt *maxsteps, PetscReal *maxtime)
1750 {
1751   PetscFunctionBegin;
1752   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1753   if (maxsteps) {
1754     PetscValidIntPointer(maxsteps,2);
1755     *maxsteps = ts->max_steps;
1756   }
1757   if (maxtime) {
1758     PetscValidScalarPointer(maxtime,3);
1759     *maxtime  = ts->max_time;
1760   }
1761   PetscFunctionReturn(0);
1762 }
1763 
1764 #undef __FUNCT__
1765 #define __FUNCT__ "TSSetDuration"
1766 /*@
1767    TSSetDuration - Sets the maximum number of timesteps to use and
1768    maximum time for iteration.
1769 
1770    Logically Collective on TS
1771 
1772    Input Parameters:
1773 +  ts - the TS context obtained from TSCreate()
1774 .  maxsteps - maximum number of iterations to use
1775 -  maxtime - final time to iterate to
1776 
1777    Options Database Keys:
1778 .  -ts_max_steps <maxsteps> - Sets maxsteps
1779 .  -ts_final_time <maxtime> - Sets maxtime
1780 
1781    Notes:
1782    The default maximum number of iterations is 5000. Default time is 5.0
1783 
1784    Level: intermediate
1785 
1786 .keywords: TS, timestep, set, maximum, iterations
1787 
1788 .seealso: TSSetExactFinalTime()
1789 @*/
1790 PetscErrorCode  TSSetDuration(TS ts,PetscInt maxsteps,PetscReal maxtime)
1791 {
1792   PetscFunctionBegin;
1793   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1794   PetscValidLogicalCollectiveInt(ts,maxsteps,2);
1795   PetscValidLogicalCollectiveReal(ts,maxtime,2);
1796   if (maxsteps >= 0) ts->max_steps = maxsteps;
1797   if (maxtime != PETSC_DEFAULT) ts->max_time  = maxtime;
1798   PetscFunctionReturn(0);
1799 }
1800 
1801 #undef __FUNCT__
1802 #define __FUNCT__ "TSSetSolution"
1803 /*@
1804    TSSetSolution - Sets the initial solution vector
1805    for use by the TS routines.
1806 
1807    Logically Collective on TS and Vec
1808 
1809    Input Parameters:
1810 +  ts - the TS context obtained from TSCreate()
1811 -  u - the solution vector
1812 
1813    Level: beginner
1814 
1815 .keywords: TS, timestep, set, solution, initial conditions
1816 @*/
1817 PetscErrorCode  TSSetSolution(TS ts,Vec u)
1818 {
1819   PetscErrorCode ierr;
1820   DM             dm;
1821 
1822   PetscFunctionBegin;
1823   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1824   PetscValidHeaderSpecific(u,VEC_CLASSID,2);
1825   ierr = PetscObjectReference((PetscObject)u);CHKERRQ(ierr);
1826   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
1827   ts->vec_sol = u;
1828   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1829   ierr = DMShellSetGlobalVector(dm,u);CHKERRQ(ierr);
1830   PetscFunctionReturn(0);
1831 }
1832 
1833 #undef __FUNCT__
1834 #define __FUNCT__ "TSSetPreStep"
1835 /*@C
1836   TSSetPreStep - Sets the general-purpose function
1837   called once at the beginning of each time step.
1838 
1839   Logically Collective on TS
1840 
1841   Input Parameters:
1842 + ts   - The TS context obtained from TSCreate()
1843 - func - The function
1844 
1845   Calling sequence of func:
1846 . func (TS ts);
1847 
1848   Level: intermediate
1849 
1850   Note:
1851   If a step is rejected, TSStep() will call this routine again before each attempt.
1852   The last completed time step number can be queried using TSGetTimeStepNumber(), the
1853   size of the step being attempted can be obtained using TSGetTimeStep().
1854 
1855 .keywords: TS, timestep
1856 .seealso: TSSetPreStage(), TSSetPostStep(), TSStep()
1857 @*/
1858 PetscErrorCode  TSSetPreStep(TS ts, PetscErrorCode (*func)(TS))
1859 {
1860   PetscFunctionBegin;
1861   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1862   ts->ops->prestep = func;
1863   PetscFunctionReturn(0);
1864 }
1865 
1866 #undef __FUNCT__
1867 #define __FUNCT__ "TSPreStep"
1868 /*@
1869   TSPreStep - Runs the user-defined pre-step function.
1870 
1871   Collective on TS
1872 
1873   Input Parameters:
1874 . ts   - The TS context obtained from TSCreate()
1875 
1876   Notes:
1877   TSPreStep() is typically used within time stepping implementations,
1878   so most users would not generally call this routine themselves.
1879 
1880   Level: developer
1881 
1882 .keywords: TS, timestep
1883 .seealso: TSSetPreStep(), TSPreStage(), TSPostStep()
1884 @*/
1885 PetscErrorCode  TSPreStep(TS ts)
1886 {
1887   PetscErrorCode ierr;
1888 
1889   PetscFunctionBegin;
1890   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1891   if (ts->ops->prestep) {
1892     PetscStackPush("TS PreStep function");
1893     ierr = (*ts->ops->prestep)(ts);CHKERRQ(ierr);
1894     PetscStackPop;
1895   }
1896   PetscFunctionReturn(0);
1897 }
1898 
1899 #undef __FUNCT__
1900 #define __FUNCT__ "TSSetPreStage"
1901 /*@C
1902   TSSetPreStage - Sets the general-purpose function
1903   called once at the beginning of each stage.
1904 
1905   Logically Collective on TS
1906 
1907   Input Parameters:
1908 + ts   - The TS context obtained from TSCreate()
1909 - func - The function
1910 
1911   Calling sequence of func:
1912 . PetscErrorCode func(TS ts, PetscReal stagetime);
1913 
1914   Level: intermediate
1915 
1916   Note:
1917   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
1918   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
1919   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
1920 
1921 .keywords: TS, timestep
1922 .seealso: TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
1923 @*/
1924 PetscErrorCode  TSSetPreStage(TS ts, PetscErrorCode (*func)(TS,PetscReal))
1925 {
1926   PetscFunctionBegin;
1927   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1928   ts->ops->prestage = func;
1929   PetscFunctionReturn(0);
1930 }
1931 
1932 #undef __FUNCT__
1933 #define __FUNCT__ "TSPreStage"
1934 /*@
1935   TSPreStage - Runs the user-defined pre-stage function set using TSSetPreStage()
1936 
1937   Collective on TS
1938 
1939   Input Parameters:
1940 . ts   - The TS context obtained from TSCreate()
1941 
1942   Notes:
1943   TSPreStage() is typically used within time stepping implementations,
1944   most users would not generally call this routine themselves.
1945 
1946   Level: developer
1947 
1948 .keywords: TS, timestep
1949 .seealso: TSSetPreStep(), TSPreStep(), TSPostStep()
1950 @*/
1951 PetscErrorCode  TSPreStage(TS ts, PetscReal stagetime)
1952 {
1953   PetscErrorCode ierr;
1954 
1955   PetscFunctionBegin;
1956   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1957   if (ts->ops->prestage) {
1958     PetscStackPush("TS PreStage function");
1959     ierr = (*ts->ops->prestage)(ts,stagetime);CHKERRQ(ierr);
1960     PetscStackPop;
1961   }
1962   PetscFunctionReturn(0);
1963 }
1964 
1965 #undef __FUNCT__
1966 #define __FUNCT__ "TSSetPostStep"
1967 /*@C
1968   TSSetPostStep - Sets the general-purpose function
1969   called once at the end of each time step.
1970 
1971   Logically Collective on TS
1972 
1973   Input Parameters:
1974 + ts   - The TS context obtained from TSCreate()
1975 - func - The function
1976 
1977   Calling sequence of func:
1978 $ func (TS ts);
1979 
1980   Level: intermediate
1981 
1982 .keywords: TS, timestep
1983 .seealso: TSSetPreStep(), TSSetPreStage(), TSGetTimeStep(), TSGetTimeStepNumber(), TSGetTime()
1984 @*/
1985 PetscErrorCode  TSSetPostStep(TS ts, PetscErrorCode (*func)(TS))
1986 {
1987   PetscFunctionBegin;
1988   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1989   ts->ops->poststep = func;
1990   PetscFunctionReturn(0);
1991 }
1992 
1993 #undef __FUNCT__
1994 #define __FUNCT__ "TSPostStep"
1995 /*@
1996   TSPostStep - Runs the user-defined post-step function.
1997 
1998   Collective on TS
1999 
2000   Input Parameters:
2001 . ts   - The TS context obtained from TSCreate()
2002 
2003   Notes:
2004   TSPostStep() is typically used within time stepping implementations,
2005   so most users would not generally call this routine themselves.
2006 
2007   Level: developer
2008 
2009 .keywords: TS, timestep
2010 @*/
2011 PetscErrorCode  TSPostStep(TS ts)
2012 {
2013   PetscErrorCode ierr;
2014 
2015   PetscFunctionBegin;
2016   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2017   if (ts->ops->poststep) {
2018     PetscStackPush("TS PostStep function");
2019     ierr = (*ts->ops->poststep)(ts);CHKERRQ(ierr);
2020     PetscStackPop;
2021   }
2022   PetscFunctionReturn(0);
2023 }
2024 
2025 /* ------------ Routines to set performance monitoring options ----------- */
2026 
2027 #undef __FUNCT__
2028 #define __FUNCT__ "TSMonitorSet"
2029 /*@C
2030    TSMonitorSet - Sets an ADDITIONAL function that is to be used at every
2031    timestep to display the iteration's  progress.
2032 
2033    Logically Collective on TS
2034 
2035    Input Parameters:
2036 +  ts - the TS context obtained from TSCreate()
2037 .  monitor - monitoring routine
2038 .  mctx - [optional] user-defined context for private data for the
2039              monitor routine (use PETSC_NULL if no context is desired)
2040 -  monitordestroy - [optional] routine that frees monitor context
2041           (may be PETSC_NULL)
2042 
2043    Calling sequence of monitor:
2044 $    int monitor(TS ts,PetscInt steps,PetscReal time,Vec u,void *mctx)
2045 
2046 +    ts - the TS context
2047 .    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
2048                                been interpolated to)
2049 .    time - current time
2050 .    u - current iterate
2051 -    mctx - [optional] monitoring context
2052 
2053    Notes:
2054    This routine adds an additional monitor to the list of monitors that
2055    already has been loaded.
2056 
2057    Fortran notes: Only a single monitor function can be set for each TS object
2058 
2059    Level: intermediate
2060 
2061 .keywords: TS, timestep, set, monitor
2062 
2063 .seealso: TSMonitorDefault(), TSMonitorCancel()
2064 @*/
2065 PetscErrorCode  TSMonitorSet(TS ts,PetscErrorCode (*monitor)(TS,PetscInt,PetscReal,Vec,void*),void *mctx,PetscErrorCode (*mdestroy)(void**))
2066 {
2067   PetscFunctionBegin;
2068   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2069   if (ts->numbermonitors >= MAXTSMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
2070   ts->monitor[ts->numbermonitors]           = monitor;
2071   ts->monitordestroy[ts->numbermonitors]    = mdestroy;
2072   ts->monitorcontext[ts->numbermonitors++]  = (void*)mctx;
2073   PetscFunctionReturn(0);
2074 }
2075 
2076 #undef __FUNCT__
2077 #define __FUNCT__ "TSMonitorCancel"
2078 /*@C
2079    TSMonitorCancel - Clears all the monitors that have been set on a time-step object.
2080 
2081    Logically Collective on TS
2082 
2083    Input Parameters:
2084 .  ts - the TS context obtained from TSCreate()
2085 
2086    Notes:
2087    There is no way to remove a single, specific monitor.
2088 
2089    Level: intermediate
2090 
2091 .keywords: TS, timestep, set, monitor
2092 
2093 .seealso: TSMonitorDefault(), TSMonitorSet()
2094 @*/
2095 PetscErrorCode  TSMonitorCancel(TS ts)
2096 {
2097   PetscErrorCode ierr;
2098   PetscInt       i;
2099 
2100   PetscFunctionBegin;
2101   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2102   for (i=0; i<ts->numbermonitors; i++) {
2103     if (ts->monitordestroy[i]) {
2104       ierr = (*ts->monitordestroy[i])(&ts->monitorcontext[i]);CHKERRQ(ierr);
2105     }
2106   }
2107   ts->numbermonitors = 0;
2108   PetscFunctionReturn(0);
2109 }
2110 
2111 #undef __FUNCT__
2112 #define __FUNCT__ "TSMonitorDefault"
2113 /*@
2114    TSMonitorDefault - Sets the Default monitor
2115 
2116    Level: intermediate
2117 
2118 .keywords: TS, set, monitor
2119 
2120 .seealso: TSMonitorDefault(), TSMonitorSet()
2121 @*/
2122 PetscErrorCode TSMonitorDefault(TS ts,PetscInt step,PetscReal ptime,Vec v,void *dummy)
2123 {
2124   PetscErrorCode ierr;
2125   PetscViewer    viewer = dummy ? (PetscViewer) dummy : PETSC_VIEWER_STDOUT_(((PetscObject)ts)->comm);
2126 
2127   PetscFunctionBegin;
2128   ierr = PetscViewerASCIIAddTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2129   ierr = PetscViewerASCIIPrintf(viewer,"%D TS dt %g time %g\n",step,(double)ts->time_step,(double)ptime);CHKERRQ(ierr);
2130   ierr = PetscViewerASCIISubtractTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2131   PetscFunctionReturn(0);
2132 }
2133 
2134 #undef __FUNCT__
2135 #define __FUNCT__ "TSSetRetainStages"
2136 /*@
2137    TSSetRetainStages - Request that all stages in the upcoming step be stored so that interpolation will be available.
2138 
2139    Logically Collective on TS
2140 
2141    Input Argument:
2142 .  ts - time stepping context
2143 
2144    Output Argument:
2145 .  flg - PETSC_TRUE or PETSC_FALSE
2146 
2147    Level: intermediate
2148 
2149 .keywords: TS, set
2150 
2151 .seealso: TSInterpolate(), TSSetPostStep()
2152 @*/
2153 PetscErrorCode TSSetRetainStages(TS ts,PetscBool flg)
2154 {
2155   PetscFunctionBegin;
2156   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2157   ts->retain_stages = flg;
2158   PetscFunctionReturn(0);
2159 }
2160 
2161 #undef __FUNCT__
2162 #define __FUNCT__ "TSInterpolate"
2163 /*@
2164    TSInterpolate - Interpolate the solution computed during the previous step to an arbitrary location in the interval
2165 
2166    Collective on TS
2167 
2168    Input Argument:
2169 +  ts - time stepping context
2170 -  t - time to interpolate to
2171 
2172    Output Argument:
2173 .  U - state at given time
2174 
2175    Notes:
2176    The user should call TSSetRetainStages() before taking a step in which interpolation will be requested.
2177 
2178    Level: intermediate
2179 
2180    Developer Notes:
2181    TSInterpolate() and the storing of previous steps/stages should be generalized to support delay differential equations and continuous adjoints.
2182 
2183 .keywords: TS, set
2184 
2185 .seealso: TSSetRetainStages(), TSSetPostStep()
2186 @*/
2187 PetscErrorCode TSInterpolate(TS ts,PetscReal t,Vec U)
2188 {
2189   PetscErrorCode ierr;
2190 
2191   PetscFunctionBegin;
2192   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2193   if (t < ts->ptime - ts->time_step_prev || t > ts->ptime) SETERRQ3(((PetscObject)ts)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Requested time %G not in last time steps [%G,%G]",t,ts->ptime-ts->time_step_prev,ts->ptime);
2194   if (!ts->ops->interpolate) SETERRQ1(((PetscObject)ts)->comm,PETSC_ERR_SUP,"%s does not provide interpolation",((PetscObject)ts)->type_name);
2195   ierr = (*ts->ops->interpolate)(ts,t,U);CHKERRQ(ierr);
2196   PetscFunctionReturn(0);
2197 }
2198 
2199 #undef __FUNCT__
2200 #define __FUNCT__ "TSStep"
2201 /*@
2202    TSStep - Steps one time step
2203 
2204    Collective on TS
2205 
2206    Input Parameter:
2207 .  ts - the TS context obtained from TSCreate()
2208 
2209    Level: intermediate
2210 
2211    Notes:
2212    The hook set using TSSetPreStep() is called before each attempt to take the step. In general, the time step size may
2213    be changed due to adaptive error controller or solve failures. Note that steps may contain multiple stages.
2214 
2215    This may over-step the final time provided in TSSetDuration() depending on the time-step used. TSSolve() interpolates to exactly the
2216    time provided in TSSetDuration(). One can use TSInterpolate() to determine an interpolated solution within the final timestep.
2217 
2218 .keywords: TS, timestep, solve
2219 
2220 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSInterpolate()
2221 @*/
2222 PetscErrorCode  TSStep(TS ts)
2223 {
2224   PetscReal      ptime_prev;
2225   PetscErrorCode ierr;
2226 
2227   PetscFunctionBegin;
2228   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2229   ierr = TSSetUp(ts);CHKERRQ(ierr);
2230 
2231   ts->reason = TS_CONVERGED_ITERATING;
2232 
2233   ptime_prev = ts->ptime;
2234   ierr = PetscLogEventBegin(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2235   ierr = (*ts->ops->step)(ts);CHKERRQ(ierr);
2236   ierr = PetscLogEventEnd(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2237   ts->time_step_prev = ts->ptime - ptime_prev;
2238 
2239   if (ts->reason < 0) {
2240     if (ts->errorifstepfailed) {
2241       if (ts->reason == TS_DIVERGED_NONLINEAR_SOLVE) {
2242         SETERRQ1(((PetscObject)ts)->comm,PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s, increase -ts_max_snes_failures or make negative to attempt recovery",TSConvergedReasons[ts->reason]);
2243       } else SETERRQ1(((PetscObject)ts)->comm,PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s",TSConvergedReasons[ts->reason]);
2244     }
2245   } else if (!ts->reason) {
2246     if (ts->steps >= ts->max_steps)
2247       ts->reason = TS_CONVERGED_ITS;
2248     else if (ts->ptime >= ts->max_time)
2249       ts->reason = TS_CONVERGED_TIME;
2250   }
2251 
2252   PetscFunctionReturn(0);
2253 }
2254 
2255 #undef __FUNCT__
2256 #define __FUNCT__ "TSEvaluateStep"
2257 /*@
2258    TSEvaluateStep - Evaluate the solution at the end of a time step with a given order of accuracy.
2259 
2260    Collective on TS
2261 
2262    Input Arguments:
2263 +  ts - time stepping context
2264 .  order - desired order of accuracy
2265 -  done - whether the step was evaluated at this order (pass PETSC_NULL to generate an error if not available)
2266 
2267    Output Arguments:
2268 .  U - state at the end of the current step
2269 
2270    Level: advanced
2271 
2272    Notes:
2273    This function cannot be called until all stages have been evaluated.
2274    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.
2275 
2276 .seealso: TSStep(), TSAdapt
2277 @*/
2278 PetscErrorCode TSEvaluateStep(TS ts,PetscInt order,Vec U,PetscBool *done)
2279 {
2280   PetscErrorCode ierr;
2281 
2282   PetscFunctionBegin;
2283   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2284   PetscValidType(ts,1);
2285   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2286   if (!ts->ops->evaluatestep) SETERRQ1(((PetscObject)ts)->comm,PETSC_ERR_SUP,"TSEvaluateStep not implemented for type '%s'",((PetscObject)ts)->type_name);
2287   ierr = (*ts->ops->evaluatestep)(ts,order,U,done);CHKERRQ(ierr);
2288   PetscFunctionReturn(0);
2289 }
2290 
2291 #undef __FUNCT__
2292 #define __FUNCT__ "TSSolve"
2293 /*@
2294    TSSolve - Steps the requested number of timesteps.
2295 
2296    Collective on TS
2297 
2298    Input Parameter:
2299 +  ts - the TS context obtained from TSCreate()
2300 -  u - the solution vector  (can be null if TSSetSolution() was used, otherwise must contain the initial conditions)
2301 
2302    Level: beginner
2303 
2304    Notes:
2305    The final time returned by this function may be different from the time of the internally
2306    held state accessible by TSGetSolution() and TSGetTime() because the method may have
2307    stepped over the final time.
2308 
2309 .keywords: TS, timestep, solve
2310 
2311 .seealso: TSCreate(), TSSetSolution(), TSStep()
2312 @*/
2313 PetscErrorCode TSSolve(TS ts,Vec u)
2314 {
2315   PetscBool      flg;
2316   char           filename[PETSC_MAX_PATH_LEN];
2317   PetscViewer    viewer;
2318   PetscErrorCode ierr;
2319 
2320   PetscFunctionBegin;
2321   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2322   if (u) PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2323   if (ts->exact_final_time) {   /* Need ts->vec_sol to be distinct so it is not overwritten when we interpolate at the end */
2324     if (!ts->vec_sol || u == ts->vec_sol) {
2325       Vec y;
2326       ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
2327       ierr = TSSetSolution(ts,y);CHKERRQ(ierr);
2328       ierr = VecDestroy(&y);CHKERRQ(ierr); /* grant ownership */
2329     }
2330     if (u) {
2331       ierr = VecCopy(u,ts->vec_sol);CHKERRQ(ierr);
2332     }
2333   } else {
2334     if (u) {
2335       ierr = TSSetSolution(ts,u);CHKERRQ(ierr);
2336     }
2337   }
2338   ierr = TSSetUp(ts);CHKERRQ(ierr);
2339   /* reset time step and iteration counters */
2340   ts->steps = 0;
2341   ts->ksp_its = 0;
2342   ts->snes_its = 0;
2343   ts->num_snes_failures = 0;
2344   ts->reject = 0;
2345   ts->reason = TS_CONVERGED_ITERATING;
2346 
2347   if (ts->ops->solve) {         /* This private interface is transitional and should be removed when all implementations are updated. */
2348     ierr = (*ts->ops->solve)(ts);CHKERRQ(ierr);
2349     ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);
2350     ts->solvetime = ts->ptime;
2351   } else {
2352     /* steps the requested number of timesteps. */
2353     ierr = TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
2354     if (ts->steps >= ts->max_steps)
2355       ts->reason = TS_CONVERGED_ITS;
2356     else if (ts->ptime >= ts->max_time)
2357       ts->reason = TS_CONVERGED_TIME;
2358     while (!ts->reason) {
2359       ierr = TSStep(ts);CHKERRQ(ierr);
2360       ierr = TSPostStep(ts);CHKERRQ(ierr);
2361       ierr = TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
2362     }
2363     if (ts->exact_final_time && ts->ptime > ts->max_time) {
2364       ierr = TSInterpolate(ts,ts->max_time,u);CHKERRQ(ierr);
2365       ts->solvetime = ts->max_time;
2366     } else {
2367       ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);
2368       ts->solvetime = ts->ptime;
2369     }
2370   }
2371   ierr = TSMonitor(ts,-1,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
2372   ierr = PetscOptionsGetString(((PetscObject)ts)->prefix,"-ts_view",filename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
2373   if (flg && !PetscPreLoadingOn) {
2374     ierr = PetscViewerASCIIOpen(((PetscObject)ts)->comm,filename,&viewer);CHKERRQ(ierr);
2375     ierr = TSView(ts,viewer);CHKERRQ(ierr);
2376     ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
2377   }
2378   flg = PETSC_FALSE;
2379   ierr = PetscOptionsGetBool(((PetscObject)ts)->prefix,"-ts_view_draw",&flg,PETSC_NULL);CHKERRQ(ierr);
2380   if (flg) {
2381     ierr = PetscViewerDrawOpen(((PetscObject)ts)->comm,PETSC_NULL,"TS Solver",0,0,600,600,&viewer);CHKERRQ(ierr);
2382     ierr = TSView(ts,viewer);CHKERRQ(ierr);
2383     ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
2384   }
2385   PetscFunctionReturn(0);
2386 }
2387 
2388 #undef __FUNCT__
2389 #define __FUNCT__ "TSMonitor"
2390 /*@
2391    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()
2392 
2393    Collective on TS
2394 
2395    Input Parameters:
2396 +  ts - time stepping context obtained from TSCreate()
2397 .  step - step number that has just completed
2398 .  ptime - model time of the state
2399 -  u - state at the current model time
2400 
2401    Notes:
2402    TSMonitor() is typically used within the time stepping implementations.
2403    Users might call this function when using the TSStep() interface instead of TSSolve().
2404 
2405    Level: advanced
2406 
2407 .keywords: TS, timestep
2408 @*/
2409 PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
2410 {
2411   PetscErrorCode ierr;
2412   PetscInt       i,n = ts->numbermonitors;
2413 
2414   PetscFunctionBegin;
2415   for (i=0; i<n; i++) {
2416     ierr = (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);CHKERRQ(ierr);
2417   }
2418   PetscFunctionReturn(0);
2419 }
2420 
2421 /* ------------------------------------------------------------------------*/
2422 struct _n_TSMonitorLGCtx {
2423   PetscDrawLG lg;
2424   PetscInt    howoften;  /* when > 0 uses step % howoften, when negative only final solution plotted */
2425   PetscInt    ksp_its,snes_its;
2426 };
2427 
2428 
2429 #undef __FUNCT__
2430 #define __FUNCT__ "TSMonitorLGCtxCreate"
2431 /*@C
2432    TSMonitorLGCtxCreate - Creates a line graph context for use with
2433    TS to monitor the solution process graphically in various ways
2434 
2435    Collective on TS
2436 
2437    Input Parameters:
2438 +  host - the X display to open, or null for the local machine
2439 .  label - the title to put in the title bar
2440 .  x, y - the screen coordinates of the upper left coordinate of the window
2441 .  m, n - the screen width and height in pixels
2442 -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time
2443 
2444    Output Parameter:
2445 .  ctx - the context
2446 
2447    Options Database Key:
2448 +  -ts_monitor_lg_timestep - automatically sets line graph monitor
2449 .  -ts_monitor_lg_solution -
2450 .  -ts_monitor_lg_error -
2451 .  -ts_monitor_lg_ksp_iterations -
2452 .  -ts_monitor_lg_snes_iterations -
2453 -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true
2454 
2455    Notes:
2456    Use TSMonitorLGCtxDestroy() to destroy.
2457 
2458    Level: intermediate
2459 
2460 .keywords: TS, monitor, line graph, residual, seealso
2461 
2462 .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()
2463 
2464 @*/
2465 PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
2466 {
2467   PetscDraw      win;
2468   PetscErrorCode ierr;
2469   PetscBool      flg = PETSC_TRUE;
2470 
2471   PetscFunctionBegin;
2472   ierr = PetscNew(struct _n_TSMonitorLGCtx,ctx);CHKERRQ(ierr);
2473   ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr);
2474   ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr);
2475   ierr = PetscDrawLGCreate(win,1,&(*ctx)->lg);CHKERRQ(ierr);
2476   ierr = PetscOptionsGetBool(PETSC_NULL,"-lg_indicate_data_points",&flg,PETSC_NULL);CHKERRQ(ierr);
2477   if (flg) {
2478     ierr = PetscDrawLGIndicateDataPoints((*ctx)->lg);CHKERRQ(ierr);
2479   }
2480   ierr = PetscLogObjectParent((*ctx)->lg,win);CHKERRQ(ierr);
2481   (*ctx)->howoften = howoften;
2482   PetscFunctionReturn(0);
2483 }
2484 
2485 #undef __FUNCT__
2486 #define __FUNCT__ "TSMonitorLGTimeStep"
2487 PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
2488 {
2489   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
2490   PetscReal      x = ptime,y;
2491   PetscErrorCode ierr;
2492 
2493   PetscFunctionBegin;
2494   if (!n) {
2495     PetscDrawAxis  axis;
2496     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
2497     ierr = PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");CHKERRQ(ierr);
2498     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
2499   }
2500   ierr = TSGetTimeStep(ts,&y);CHKERRQ(ierr);
2501   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
2502   if (((ctx->howoften > 0) && (!(n % ctx->howoften))) || ((ctx->howoften == -1) && (n == -1))){
2503     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
2504   }
2505   PetscFunctionReturn(0);
2506 }
2507 
2508 #undef __FUNCT__
2509 #define __FUNCT__ "TSMonitorLGCtxDestroy"
2510 /*@C
2511    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
2512    with TSMonitorLGCtxCreate().
2513 
2514    Collective on TSMonitorLGCtx
2515 
2516    Input Parameter:
2517 .  ctx - the monitor context
2518 
2519    Level: intermediate
2520 
2521 .keywords: TS, monitor, line graph, destroy
2522 
2523 .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
2524 @*/
2525 PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
2526 {
2527   PetscDraw      draw;
2528   PetscErrorCode ierr;
2529 
2530   PetscFunctionBegin;
2531   ierr = PetscDrawLGGetDraw((*ctx)->lg,&draw);CHKERRQ(ierr);
2532   ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
2533   ierr = PetscDrawLGDestroy(&(*ctx)->lg);CHKERRQ(ierr);
2534   ierr = PetscFree(*ctx);CHKERRQ(ierr);
2535   PetscFunctionReturn(0);
2536 }
2537 
2538 #undef __FUNCT__
2539 #define __FUNCT__ "TSGetTime"
2540 /*@
2541    TSGetTime - Gets the time of the most recently completed step.
2542 
2543    Not Collective
2544 
2545    Input Parameter:
2546 .  ts - the TS context obtained from TSCreate()
2547 
2548    Output Parameter:
2549 .  t  - the current time
2550 
2551    Level: beginner
2552 
2553    Note:
2554    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
2555    TSSetPreStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.
2556 
2557 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
2558 
2559 .keywords: TS, get, time
2560 @*/
2561 PetscErrorCode  TSGetTime(TS ts,PetscReal* t)
2562 {
2563   PetscFunctionBegin;
2564   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2565   PetscValidRealPointer(t,2);
2566   *t = ts->ptime;
2567   PetscFunctionReturn(0);
2568 }
2569 
2570 #undef __FUNCT__
2571 #define __FUNCT__ "TSSetTime"
2572 /*@
2573    TSSetTime - Allows one to reset the time.
2574 
2575    Logically Collective on TS
2576 
2577    Input Parameters:
2578 +  ts - the TS context obtained from TSCreate()
2579 -  time - the time
2580 
2581    Level: intermediate
2582 
2583 .seealso: TSGetTime(), TSSetDuration()
2584 
2585 .keywords: TS, set, time
2586 @*/
2587 PetscErrorCode  TSSetTime(TS ts, PetscReal t)
2588 {
2589   PetscFunctionBegin;
2590   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2591   PetscValidLogicalCollectiveReal(ts,t,2);
2592   ts->ptime = t;
2593   PetscFunctionReturn(0);
2594 }
2595 
2596 #undef __FUNCT__
2597 #define __FUNCT__ "TSSetOptionsPrefix"
2598 /*@C
2599    TSSetOptionsPrefix - Sets the prefix used for searching for all
2600    TS options in the database.
2601 
2602    Logically Collective on TS
2603 
2604    Input Parameter:
2605 +  ts     - The TS context
2606 -  prefix - The prefix to prepend to all option names
2607 
2608    Notes:
2609    A hyphen (-) must NOT be given at the beginning of the prefix name.
2610    The first character of all runtime options is AUTOMATICALLY the
2611    hyphen.
2612 
2613    Level: advanced
2614 
2615 .keywords: TS, set, options, prefix, database
2616 
2617 .seealso: TSSetFromOptions()
2618 
2619 @*/
2620 PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
2621 {
2622   PetscErrorCode ierr;
2623   SNES           snes;
2624 
2625   PetscFunctionBegin;
2626   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2627   ierr = PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
2628   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2629   ierr = SNESSetOptionsPrefix(snes,prefix);CHKERRQ(ierr);
2630   PetscFunctionReturn(0);
2631 }
2632 
2633 
2634 #undef __FUNCT__
2635 #define __FUNCT__ "TSAppendOptionsPrefix"
2636 /*@C
2637    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
2638    TS options in the database.
2639 
2640    Logically Collective on TS
2641 
2642    Input Parameter:
2643 +  ts     - The TS context
2644 -  prefix - The prefix to prepend to all option names
2645 
2646    Notes:
2647    A hyphen (-) must NOT be given at the beginning of the prefix name.
2648    The first character of all runtime options is AUTOMATICALLY the
2649    hyphen.
2650 
2651    Level: advanced
2652 
2653 .keywords: TS, append, options, prefix, database
2654 
2655 .seealso: TSGetOptionsPrefix()
2656 
2657 @*/
2658 PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
2659 {
2660   PetscErrorCode ierr;
2661   SNES           snes;
2662 
2663   PetscFunctionBegin;
2664   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2665   ierr = PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
2666   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2667   ierr = SNESAppendOptionsPrefix(snes,prefix);CHKERRQ(ierr);
2668   PetscFunctionReturn(0);
2669 }
2670 
2671 #undef __FUNCT__
2672 #define __FUNCT__ "TSGetOptionsPrefix"
2673 /*@C
2674    TSGetOptionsPrefix - Sets the prefix used for searching for all
2675    TS options in the database.
2676 
2677    Not Collective
2678 
2679    Input Parameter:
2680 .  ts - The TS context
2681 
2682    Output Parameter:
2683 .  prefix - A pointer to the prefix string used
2684 
2685    Notes: On the fortran side, the user should pass in a string 'prifix' of
2686    sufficient length to hold the prefix.
2687 
2688    Level: intermediate
2689 
2690 .keywords: TS, get, options, prefix, database
2691 
2692 .seealso: TSAppendOptionsPrefix()
2693 @*/
2694 PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
2695 {
2696   PetscErrorCode ierr;
2697 
2698   PetscFunctionBegin;
2699   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2700   PetscValidPointer(prefix,2);
2701   ierr = PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
2702   PetscFunctionReturn(0);
2703 }
2704 
2705 #undef __FUNCT__
2706 #define __FUNCT__ "TSGetRHSJacobian"
2707 /*@C
2708    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.
2709 
2710    Not Collective, but parallel objects are returned if TS is parallel
2711 
2712    Input Parameter:
2713 .  ts  - The TS context obtained from TSCreate()
2714 
2715    Output Parameters:
2716 +  J   - The Jacobian J of F, where U_t = G(U,t)
2717 .  M   - The preconditioner matrix, usually the same as J
2718 .  func - Function to compute the Jacobian of the RHS
2719 -  ctx - User-defined context for Jacobian evaluation routine
2720 
2721    Notes: You can pass in PETSC_NULL for any return argument you do not need.
2722 
2723    Level: intermediate
2724 
2725 .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
2726 
2727 .keywords: TS, timestep, get, matrix, Jacobian
2728 @*/
2729 PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *J,Mat *M,TSRHSJacobian *func,void **ctx)
2730 {
2731   PetscErrorCode ierr;
2732   SNES           snes;
2733   DM             dm;
2734 
2735   PetscFunctionBegin;
2736   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2737   ierr = SNESGetJacobian(snes,J,M,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
2738   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
2739   ierr = DMTSGetRHSJacobian(dm,func,ctx);CHKERRQ(ierr);
2740   PetscFunctionReturn(0);
2741 }
2742 
2743 #undef __FUNCT__
2744 #define __FUNCT__ "TSGetIJacobian"
2745 /*@C
2746    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.
2747 
2748    Not Collective, but parallel objects are returned if TS is parallel
2749 
2750    Input Parameter:
2751 .  ts  - The TS context obtained from TSCreate()
2752 
2753    Output Parameters:
2754 +  A   - The Jacobian of F(t,U,U_t)
2755 .  B   - The preconditioner matrix, often the same as A
2756 .  f   - The function to compute the matrices
2757 - ctx - User-defined context for Jacobian evaluation routine
2758 
2759    Notes: You can pass in PETSC_NULL for any return argument you do not need.
2760 
2761    Level: advanced
2762 
2763 .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
2764 
2765 .keywords: TS, timestep, get, matrix, Jacobian
2766 @*/
2767 PetscErrorCode  TSGetIJacobian(TS ts,Mat *A,Mat *B,TSIJacobian *f,void **ctx)
2768 {
2769   PetscErrorCode ierr;
2770   SNES           snes;
2771   DM             dm;
2772 
2773   PetscFunctionBegin;
2774   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2775   ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
2776   ierr = SNESGetJacobian(snes,A,B,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
2777   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
2778   ierr = DMTSGetIJacobian(dm,f,ctx);CHKERRQ(ierr);
2779   PetscFunctionReturn(0);
2780 }
2781 
2782 struct _n_TSMonitorDrawCtx {
2783   PetscViewer viewer;
2784   Vec         initialsolution;
2785   PetscBool   showinitial;
2786   PetscInt    howoften;  /* when > 0 uses step % howoften, when negative only final solution plotted */
2787 };
2788 
2789 #undef __FUNCT__
2790 #define __FUNCT__ "TSMonitorDrawSolution"
2791 /*@C
2792    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
2793    VecView() for the solution at each timestep
2794 
2795    Collective on TS
2796 
2797    Input Parameters:
2798 +  ts - the TS context
2799 .  step - current time-step
2800 .  ptime - current time
2801 -  dummy - either a viewer or PETSC_NULL
2802 
2803    Options Database:
2804 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
2805 
2806    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
2807        will look bad
2808 
2809    Level: intermediate
2810 
2811 .keywords: TS,  vector, monitor, view
2812 
2813 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
2814 @*/
2815 PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
2816 {
2817   PetscErrorCode   ierr;
2818   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
2819 
2820   PetscFunctionBegin;
2821   if (!step && ictx->showinitial) {
2822     if (!ictx->initialsolution) {
2823       ierr = VecDuplicate(u,&ictx->initialsolution);CHKERRQ(ierr);
2824     }
2825     ierr = VecCopy(u,ictx->initialsolution);CHKERRQ(ierr);
2826   }
2827   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften)) && (step > -1)) || ((ictx->howoften == -1) && (step == -1)))) PetscFunctionReturn(0);
2828 
2829   if (ictx->showinitial) {
2830     PetscReal pause;
2831     ierr = PetscViewerDrawGetPause(ictx->viewer,&pause);CHKERRQ(ierr);
2832     ierr = PetscViewerDrawSetPause(ictx->viewer,0.0);CHKERRQ(ierr);
2833     ierr = VecView(ictx->initialsolution,ictx->viewer);CHKERRQ(ierr);
2834     ierr = PetscViewerDrawSetPause(ictx->viewer,pause);CHKERRQ(ierr);
2835     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);CHKERRQ(ierr);
2836   }
2837   ierr = VecView(u,ictx->viewer);CHKERRQ(ierr);
2838   if (ictx->showinitial) {
2839     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);CHKERRQ(ierr);
2840   }
2841   PetscFunctionReturn(0);
2842 }
2843 
2844 
2845 #undef __FUNCT__
2846 #define __FUNCT__ "TSMonitorDrawCtxDestroy"
2847 /*@C
2848    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()
2849 
2850    Collective on TS
2851 
2852    Input Parameters:
2853 .    ctx - the monitor context
2854 
2855    Level: intermediate
2856 
2857 .keywords: TS,  vector, monitor, view
2858 
2859 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
2860 @*/
2861 PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
2862 {
2863   PetscErrorCode       ierr;
2864 
2865   PetscFunctionBegin;
2866   ierr = PetscViewerDestroy(&(*ictx)->viewer);CHKERRQ(ierr);
2867   ierr = VecDestroy(&(*ictx)->initialsolution);CHKERRQ(ierr);
2868   ierr = PetscFree(*ictx);CHKERRQ(ierr);
2869   PetscFunctionReturn(0);
2870 }
2871 
2872 #undef __FUNCT__
2873 #define __FUNCT__ "TSMonitorDrawCtxCreate"
2874 /*@C
2875    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx
2876 
2877    Collective on TS
2878 
2879    Input Parameter:
2880 .    ts - time-step context
2881 
2882    Output Patameter:
2883 .    ctx - the monitor context
2884 
2885    Options Database:
2886 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
2887 
2888    Level: intermediate
2889 
2890 .keywords: TS,  vector, monitor, view
2891 
2892 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
2893 @*/
2894 PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
2895 {
2896   PetscErrorCode   ierr;
2897 
2898   PetscFunctionBegin;
2899   ierr = PetscNew(struct _n_TSMonitorDrawCtx,ctx);CHKERRQ(ierr);
2900   ierr = PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);CHKERRQ(ierr);
2901   (*ctx)->showinitial = PETSC_FALSE;
2902   (*ctx)->howoften    = howoften;
2903   ierr = PetscOptionsGetBool(PETSC_NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,PETSC_NULL);CHKERRQ(ierr);
2904   PetscFunctionReturn(0);
2905 }
2906 
2907 #undef __FUNCT__
2908 #define __FUNCT__ "TSMonitorDrawError"
2909 /*@C
2910    TSMonitorDrawError - Monitors progress of the TS solvers by calling
2911    VecView() for the error at each timestep
2912 
2913    Collective on TS
2914 
2915    Input Parameters:
2916 +  ts - the TS context
2917 .  step - current time-step
2918 .  ptime - current time
2919 -  dummy - either a viewer or PETSC_NULL
2920 
2921    Level: intermediate
2922 
2923 .keywords: TS,  vector, monitor, view
2924 
2925 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
2926 @*/
2927 PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
2928 {
2929   PetscErrorCode   ierr;
2930   TSMonitorDrawCtx ctx = (TSMonitorDrawCtx)dummy;
2931   PetscViewer      viewer = ctx->viewer;
2932   Vec              work;
2933 
2934   PetscFunctionBegin;
2935   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften)) && (step > -1)) || ((ctx->howoften == -1) && (step == -1)))) PetscFunctionReturn(0);
2936   ierr = VecDuplicate(u,&work);CHKERRQ(ierr);
2937   ierr = TSComputeSolutionFunction(ts,ptime,work);CHKERRQ(ierr);
2938   ierr = VecAXPY(work,-1.0,u);CHKERRQ(ierr);
2939   ierr = VecView(work,viewer);CHKERRQ(ierr);
2940   ierr = VecDestroy(&work);CHKERRQ(ierr);
2941   PetscFunctionReturn(0);
2942 }
2943 
2944 #include <petsc-private/dmimpl.h>
2945 #undef __FUNCT__
2946 #define __FUNCT__ "TSSetDM"
2947 /*@
2948    TSSetDM - Sets the DM that may be used by some preconditioners
2949 
2950    Logically Collective on TS and DM
2951 
2952    Input Parameters:
2953 +  ts - the preconditioner context
2954 -  dm - the dm
2955 
2956    Level: intermediate
2957 
2958 
2959 .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
2960 @*/
2961 PetscErrorCode  TSSetDM(TS ts,DM dm)
2962 {
2963   PetscErrorCode ierr;
2964   SNES           snes;
2965   DMTS           tsdm;
2966 
2967   PetscFunctionBegin;
2968   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2969   ierr = PetscObjectReference((PetscObject)dm);CHKERRQ(ierr);
2970   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
2971     if (ts->dm->dmts && !dm->dmts) {
2972       ierr = DMCopyDMTS(ts->dm,dm);CHKERRQ(ierr);
2973       ierr = DMGetDMTS(ts->dm,&tsdm);CHKERRQ(ierr);
2974       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
2975         tsdm->originaldm = dm;
2976       }
2977     }
2978     ierr = DMDestroy(&ts->dm);CHKERRQ(ierr);
2979   }
2980   ts->dm = dm;
2981   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2982   ierr = SNESSetDM(snes,dm);CHKERRQ(ierr);
2983   PetscFunctionReturn(0);
2984 }
2985 
2986 #undef __FUNCT__
2987 #define __FUNCT__ "TSGetDM"
2988 /*@
2989    TSGetDM - Gets the DM that may be used by some preconditioners
2990 
2991    Not Collective
2992 
2993    Input Parameter:
2994 . ts - the preconditioner context
2995 
2996    Output Parameter:
2997 .  dm - the dm
2998 
2999    Level: intermediate
3000 
3001 
3002 .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
3003 @*/
3004 PetscErrorCode  TSGetDM(TS ts,DM *dm)
3005 {
3006   PetscErrorCode ierr;
3007 
3008   PetscFunctionBegin;
3009   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3010   if (!ts->dm) {
3011     ierr = DMShellCreate(((PetscObject)ts)->comm,&ts->dm);CHKERRQ(ierr);
3012     if (ts->snes) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
3013   }
3014   *dm = ts->dm;
3015   PetscFunctionReturn(0);
3016 }
3017 
3018 #undef __FUNCT__
3019 #define __FUNCT__ "SNESTSFormFunction"
3020 /*@
3021    SNESTSFormFunction - Function to evaluate nonlinear residual
3022 
3023    Logically Collective on SNES
3024 
3025    Input Parameter:
3026 + snes - nonlinear solver
3027 . U - the current state at which to evaluate the residual
3028 - ctx - user context, must be a TS
3029 
3030    Output Parameter:
3031 . F - the nonlinear residual
3032 
3033    Notes:
3034    This function is not normally called by users and is automatically registered with the SNES used by TS.
3035    It is most frequently passed to MatFDColoringSetFunction().
3036 
3037    Level: advanced
3038 
3039 .seealso: SNESSetFunction(), MatFDColoringSetFunction()
3040 @*/
3041 PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
3042 {
3043   TS             ts = (TS)ctx;
3044   PetscErrorCode ierr;
3045 
3046   PetscFunctionBegin;
3047   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3048   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3049   PetscValidHeaderSpecific(F,VEC_CLASSID,3);
3050   PetscValidHeaderSpecific(ts,TS_CLASSID,4);
3051   ierr = (ts->ops->snesfunction)(snes,U,F,ts);CHKERRQ(ierr);
3052   PetscFunctionReturn(0);
3053 }
3054 
3055 #undef __FUNCT__
3056 #define __FUNCT__ "SNESTSFormJacobian"
3057 /*@
3058    SNESTSFormJacobian - Function to evaluate the Jacobian
3059 
3060    Collective on SNES
3061 
3062    Input Parameter:
3063 + snes - nonlinear solver
3064 . U - the current state at which to evaluate the residual
3065 - ctx - user context, must be a TS
3066 
3067    Output Parameter:
3068 + A - the Jacobian
3069 . B - the preconditioning matrix (may be the same as A)
3070 - flag - indicates any structure change in the matrix
3071 
3072    Notes:
3073    This function is not normally called by users and is automatically registered with the SNES used by TS.
3074 
3075    Level: developer
3076 
3077 .seealso: SNESSetJacobian()
3078 @*/
3079 PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat *A,Mat *B,MatStructure *flag,void *ctx)
3080 {
3081   TS             ts = (TS)ctx;
3082   PetscErrorCode ierr;
3083 
3084   PetscFunctionBegin;
3085   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3086   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3087   PetscValidPointer(A,3);
3088   PetscValidHeaderSpecific(*A,MAT_CLASSID,3);
3089   PetscValidPointer(B,4);
3090   PetscValidHeaderSpecific(*B,MAT_CLASSID,4);
3091   PetscValidPointer(flag,5);
3092   PetscValidHeaderSpecific(ts,TS_CLASSID,6);
3093   ierr = (ts->ops->snesjacobian)(snes,U,A,B,flag,ts);CHKERRQ(ierr);
3094   PetscFunctionReturn(0);
3095 }
3096 
3097 #undef __FUNCT__
3098 #define __FUNCT__ "TSComputeRHSFunctionLinear"
3099 /*@C
3100    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only
3101 
3102    Collective on TS
3103 
3104    Input Arguments:
3105 +  ts - time stepping context
3106 .  t - time at which to evaluate
3107 .  U - state at which to evaluate
3108 -  ctx - context
3109 
3110    Output Arguments:
3111 .  F - right hand side
3112 
3113    Level: intermediate
3114 
3115    Notes:
3116    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
3117    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().
3118 
3119 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
3120 @*/
3121 PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
3122 {
3123   PetscErrorCode ierr;
3124   Mat            Arhs,Brhs;
3125   MatStructure   flg2;
3126 
3127   PetscFunctionBegin;
3128   ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
3129   ierr = TSComputeRHSJacobian(ts,t,U,&Arhs,&Brhs,&flg2);CHKERRQ(ierr);
3130   ierr = MatMult(Arhs,U,F);CHKERRQ(ierr);
3131   PetscFunctionReturn(0);
3132 }
3133 
3134 #undef __FUNCT__
3135 #define __FUNCT__ "TSComputeRHSJacobianConstant"
3136 /*@C
3137    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.
3138 
3139    Collective on TS
3140 
3141    Input Arguments:
3142 +  ts - time stepping context
3143 .  t - time at which to evaluate
3144 .  U - state at which to evaluate
3145 -  ctx - context
3146 
3147    Output Arguments:
3148 +  A - pointer to operator
3149 .  B - pointer to preconditioning matrix
3150 -  flg - matrix structure flag
3151 
3152    Level: intermediate
3153 
3154    Notes:
3155    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.
3156 
3157 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
3158 @*/
3159 PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat *A,Mat *B,MatStructure *flg,void *ctx)
3160 {
3161   PetscFunctionBegin;
3162   *flg = SAME_PRECONDITIONER;
3163   PetscFunctionReturn(0);
3164 }
3165 
3166 #undef __FUNCT__
3167 #define __FUNCT__ "TSComputeIFunctionLinear"
3168 /*@C
3169    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only
3170 
3171    Collective on TS
3172 
3173    Input Arguments:
3174 +  ts - time stepping context
3175 .  t - time at which to evaluate
3176 .  U - state at which to evaluate
3177 .  Udot - time derivative of state vector
3178 -  ctx - context
3179 
3180    Output Arguments:
3181 .  F - left hand side
3182 
3183    Level: intermediate
3184 
3185    Notes:
3186    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
3187    user is required to write their own TSComputeIFunction.
3188    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
3189    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().
3190 
3191 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
3192 @*/
3193 PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
3194 {
3195   PetscErrorCode ierr;
3196   Mat            A,B;
3197   MatStructure   flg2;
3198 
3199   PetscFunctionBegin;
3200   ierr = TSGetIJacobian(ts,&A,&B,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
3201   ierr = TSComputeIJacobian(ts,t,U,Udot,1.0,&A,&B,&flg2,PETSC_TRUE);CHKERRQ(ierr);
3202   ierr = MatMult(A,Udot,F);CHKERRQ(ierr);
3203   PetscFunctionReturn(0);
3204 }
3205 
3206 #undef __FUNCT__
3207 #define __FUNCT__ "TSComputeIJacobianConstant"
3208 /*@C
3209    TSComputeIJacobianConstant - Reuses a Jacobian that is time-independent.
3210 
3211    Collective on TS
3212 
3213    Input Arguments:
3214 +  ts - time stepping context
3215 .  t - time at which to evaluate
3216 .  U - state at which to evaluate
3217 .  Udot - time derivative of state vector
3218 .  shift - shift to apply
3219 -  ctx - context
3220 
3221    Output Arguments:
3222 +  A - pointer to operator
3223 .  B - pointer to preconditioning matrix
3224 -  flg - matrix structure flag
3225 
3226    Level: intermediate
3227 
3228    Notes:
3229    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.
3230 
3231 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
3232 @*/
3233 PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flg,void *ctx)
3234 {
3235   PetscFunctionBegin;
3236   *flg = SAME_PRECONDITIONER;
3237   PetscFunctionReturn(0);
3238 }
3239 
3240 #undef __FUNCT__
3241 #define __FUNCT__ "TSGetConvergedReason"
3242 /*@
3243    TSGetConvergedReason - Gets the reason the TS iteration was stopped.
3244 
3245    Not Collective
3246 
3247    Input Parameter:
3248 .  ts - the TS context
3249 
3250    Output Parameter:
3251 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3252             manual pages for the individual convergence tests for complete lists
3253 
3254    Level: beginner
3255 
3256    Notes:
3257    Can only be called after the call to TSSolve() is complete.
3258 
3259 .keywords: TS, nonlinear, set, convergence, test
3260 
3261 .seealso: TSSetConvergenceTest(), TSConvergedReason
3262 @*/
3263 PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
3264 {
3265   PetscFunctionBegin;
3266   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3267   PetscValidPointer(reason,2);
3268   *reason = ts->reason;
3269   PetscFunctionReturn(0);
3270 }
3271 
3272 #undef __FUNCT__
3273 #define __FUNCT__ "TSGetSolveTime"
3274 /*@
3275    TSGetSolveTime - Gets the time after a call to TSSolve()
3276 
3277    Not Collective
3278 
3279    Input Parameter:
3280 .  ts - the TS context
3281 
3282    Output Parameter:
3283 .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()
3284 
3285    Level: beginner
3286 
3287    Notes:
3288    Can only be called after the call to TSSolve() is complete.
3289 
3290 .keywords: TS, nonlinear, set, convergence, test
3291 
3292 .seealso: TSSetConvergenceTest(), TSConvergedReason
3293 @*/
3294 PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
3295 {
3296   PetscFunctionBegin;
3297   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3298   PetscValidPointer(ftime,2);
3299   *ftime = ts->solvetime;
3300   PetscFunctionReturn(0);
3301 }
3302 
3303 #undef __FUNCT__
3304 #define __FUNCT__ "TSGetSNESIterations"
3305 /*@
3306    TSGetSNESIterations - Gets the total number of nonlinear iterations
3307    used by the time integrator.
3308 
3309    Not Collective
3310 
3311    Input Parameter:
3312 .  ts - TS context
3313 
3314    Output Parameter:
3315 .  nits - number of nonlinear iterations
3316 
3317    Notes:
3318    This counter is reset to zero for each successive call to TSSolve().
3319 
3320    Level: intermediate
3321 
3322 .keywords: TS, get, number, nonlinear, iterations
3323 
3324 .seealso:  TSGetKSPIterations()
3325 @*/
3326 PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
3327 {
3328   PetscFunctionBegin;
3329   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3330   PetscValidIntPointer(nits,2);
3331   *nits = ts->snes_its;
3332   PetscFunctionReturn(0);
3333 }
3334 
3335 #undef __FUNCT__
3336 #define __FUNCT__ "TSGetKSPIterations"
3337 /*@
3338    TSGetKSPIterations - Gets the total number of linear iterations
3339    used by the time integrator.
3340 
3341    Not Collective
3342 
3343    Input Parameter:
3344 .  ts - TS context
3345 
3346    Output Parameter:
3347 .  lits - number of linear iterations
3348 
3349    Notes:
3350    This counter is reset to zero for each successive call to TSSolve().
3351 
3352    Level: intermediate
3353 
3354 .keywords: TS, get, number, linear, iterations
3355 
3356 .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
3357 @*/
3358 PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
3359 {
3360   PetscFunctionBegin;
3361   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3362   PetscValidIntPointer(lits,2);
3363   *lits = ts->ksp_its;
3364   PetscFunctionReturn(0);
3365 }
3366 
3367 #undef __FUNCT__
3368 #define __FUNCT__ "TSGetStepRejections"
3369 /*@
3370    TSGetStepRejections - Gets the total number of rejected steps.
3371 
3372    Not Collective
3373 
3374    Input Parameter:
3375 .  ts - TS context
3376 
3377    Output Parameter:
3378 .  rejects - number of steps rejected
3379 
3380    Notes:
3381    This counter is reset to zero for each successive call to TSSolve().
3382 
3383    Level: intermediate
3384 
3385 .keywords: TS, get, number
3386 
3387 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
3388 @*/
3389 PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
3390 {
3391   PetscFunctionBegin;
3392   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3393   PetscValidIntPointer(rejects,2);
3394   *rejects = ts->reject;
3395   PetscFunctionReturn(0);
3396 }
3397 
3398 #undef __FUNCT__
3399 #define __FUNCT__ "TSGetSNESFailures"
3400 /*@
3401    TSGetSNESFailures - Gets the total number of failed SNES solves
3402 
3403    Not Collective
3404 
3405    Input Parameter:
3406 .  ts - TS context
3407 
3408    Output Parameter:
3409 .  fails - number of failed nonlinear solves
3410 
3411    Notes:
3412    This counter is reset to zero for each successive call to TSSolve().
3413 
3414    Level: intermediate
3415 
3416 .keywords: TS, get, number
3417 
3418 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
3419 @*/
3420 PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
3421 {
3422   PetscFunctionBegin;
3423   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3424   PetscValidIntPointer(fails,2);
3425   *fails = ts->num_snes_failures;
3426   PetscFunctionReturn(0);
3427 }
3428 
3429 #undef __FUNCT__
3430 #define __FUNCT__ "TSSetMaxStepRejections"
3431 /*@
3432    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails
3433 
3434    Not Collective
3435 
3436    Input Parameter:
3437 +  ts - TS context
3438 -  rejects - maximum number of rejected steps, pass -1 for unlimited
3439 
3440    Notes:
3441    The counter is reset to zero for each step
3442 
3443    Options Database Key:
3444  .  -ts_max_reject - Maximum number of step rejections before a step fails
3445 
3446    Level: intermediate
3447 
3448 .keywords: TS, set, maximum, number
3449 
3450 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
3451 @*/
3452 PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
3453 {
3454   PetscFunctionBegin;
3455   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3456   ts->max_reject = rejects;
3457   PetscFunctionReturn(0);
3458 }
3459 
3460 #undef __FUNCT__
3461 #define __FUNCT__ "TSSetMaxSNESFailures"
3462 /*@
3463    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves
3464 
3465    Not Collective
3466 
3467    Input Parameter:
3468 +  ts - TS context
3469 -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited
3470 
3471    Notes:
3472    The counter is reset to zero for each successive call to TSSolve().
3473 
3474    Options Database Key:
3475  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures
3476 
3477    Level: intermediate
3478 
3479 .keywords: TS, set, maximum, number
3480 
3481 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
3482 @*/
3483 PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
3484 {
3485   PetscFunctionBegin;
3486   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3487   ts->max_snes_failures = fails;
3488   PetscFunctionReturn(0);
3489 }
3490 
3491 #undef __FUNCT__
3492 #define __FUNCT__ "TSSetErrorIfStepFails()"
3493 /*@
3494    TSSetErrorIfStepFails - Error if no step succeeds
3495 
3496    Not Collective
3497 
3498    Input Parameter:
3499 +  ts - TS context
3500 -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure
3501 
3502    Options Database Key:
3503  .  -ts_error_if_step_fails - Error if no step succeeds
3504 
3505    Level: intermediate
3506 
3507 .keywords: TS, set, error
3508 
3509 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
3510 @*/
3511 PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
3512 {
3513   PetscFunctionBegin;
3514   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3515   ts->errorifstepfailed = err;
3516   PetscFunctionReturn(0);
3517 }
3518 
3519 #undef __FUNCT__
3520 #define __FUNCT__ "TSMonitorSolutionBinary"
3521 /*@C
3522    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file
3523 
3524    Collective on TS
3525 
3526    Input Parameters:
3527 +  ts - the TS context
3528 .  step - current time-step
3529 .  ptime - current time
3530 .  u - current state
3531 -  viewer - binary viewer
3532 
3533    Level: intermediate
3534 
3535 .keywords: TS,  vector, monitor, view
3536 
3537 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3538 @*/
3539 PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
3540 {
3541   PetscErrorCode ierr;
3542   PetscViewer    v = (PetscViewer)viewer;
3543 
3544   PetscFunctionBegin;
3545   ierr = VecView(u,v);CHKERRQ(ierr);
3546   PetscFunctionReturn(0);
3547 }
3548 
3549 #undef __FUNCT__
3550 #define __FUNCT__ "TSMonitorSolutionVTK"
3551 /*@C
3552    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.
3553 
3554    Collective on TS
3555 
3556    Input Parameters:
3557 +  ts - the TS context
3558 .  step - current time-step
3559 .  ptime - current time
3560 .  u - current state
3561 -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
3562 
3563    Level: intermediate
3564 
3565    Notes:
3566    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.
3567    These are named according to the file name template.
3568 
3569    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().
3570 
3571 .keywords: TS,  vector, monitor, view
3572 
3573 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3574 @*/
3575 PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
3576 {
3577   PetscErrorCode ierr;
3578   char           filename[PETSC_MAX_PATH_LEN];
3579   PetscViewer    viewer;
3580 
3581   PetscFunctionBegin;
3582   ierr = PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);CHKERRQ(ierr);
3583   ierr = PetscViewerVTKOpen(((PetscObject)ts)->comm,filename,FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
3584   ierr = VecView(u,viewer);CHKERRQ(ierr);
3585   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
3586   PetscFunctionReturn(0);
3587 }
3588 
3589 #undef __FUNCT__
3590 #define __FUNCT__ "TSMonitorSolutionVTKDestroy"
3591 /*@C
3592    TSMonitorSolutionVTKDestroy - Destroy context for monitoring
3593 
3594    Collective on TS
3595 
3596    Input Parameters:
3597 .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
3598 
3599    Level: intermediate
3600 
3601    Note:
3602    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().
3603 
3604 .keywords: TS,  vector, monitor, view
3605 
3606 .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
3607 @*/
3608 PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
3609 {
3610   PetscErrorCode ierr;
3611 
3612   PetscFunctionBegin;
3613   ierr = PetscFree(*(char**)filenametemplate);CHKERRQ(ierr);
3614   PetscFunctionReturn(0);
3615 }
3616 
3617 #undef __FUNCT__
3618 #define __FUNCT__ "TSGetAdapt"
3619 /*@
3620    TSGetAdapt - Get the adaptive controller context for the current method
3621 
3622    Collective on TS if controller has not been created yet
3623 
3624    Input Arguments:
3625 .  ts - time stepping context
3626 
3627    Output Arguments:
3628 .  adapt - adaptive controller
3629 
3630    Level: intermediate
3631 
3632 .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
3633 @*/
3634 PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
3635 {
3636   PetscErrorCode ierr;
3637 
3638   PetscFunctionBegin;
3639   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3640   PetscValidPointer(adapt,2);
3641   if (!ts->adapt) {
3642     ierr = TSAdaptCreate(((PetscObject)ts)->comm,&ts->adapt);CHKERRQ(ierr);
3643     ierr = PetscLogObjectParent(ts,ts->adapt);CHKERRQ(ierr);
3644     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);CHKERRQ(ierr);
3645   }
3646   *adapt = ts->adapt;
3647   PetscFunctionReturn(0);
3648 }
3649 
3650 #undef __FUNCT__
3651 #define __FUNCT__ "TSSetTolerances"
3652 /*@
3653    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller
3654 
3655    Logically Collective
3656 
3657    Input Arguments:
3658 +  ts - time integration context
3659 .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
3660 .  vatol - vector of absolute tolerances or PETSC_NULL, used in preference to atol if present
3661 .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
3662 -  vrtol - vector of relative tolerances or PETSC_NULL, used in preference to atol if present
3663 
3664    Level: beginner
3665 
3666 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
3667 @*/
3668 PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
3669 {
3670   PetscErrorCode ierr;
3671 
3672   PetscFunctionBegin;
3673   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
3674   if (vatol) {
3675     ierr = PetscObjectReference((PetscObject)vatol);CHKERRQ(ierr);
3676     ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
3677     ts->vatol = vatol;
3678   }
3679   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
3680   if (vrtol) {
3681     ierr = PetscObjectReference((PetscObject)vrtol);CHKERRQ(ierr);
3682     ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
3683     ts->vrtol = vrtol;
3684   }
3685   PetscFunctionReturn(0);
3686 }
3687 
3688 #undef __FUNCT__
3689 #define __FUNCT__ "TSGetTolerances"
3690 /*@
3691    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller
3692 
3693    Logically Collective
3694 
3695    Input Arguments:
3696 .  ts - time integration context
3697 
3698    Output Arguments:
3699 +  atol - scalar absolute tolerances, PETSC_NULL to ignore
3700 .  vatol - vector of absolute tolerances, PETSC_NULL to ignore
3701 .  rtol - scalar relative tolerances, PETSC_NULL to ignore
3702 -  vrtol - vector of relative tolerances, PETSC_NULL to ignore
3703 
3704    Level: beginner
3705 
3706 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
3707 @*/
3708 PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
3709 {
3710   PetscFunctionBegin;
3711   if (atol)  *atol  = ts->atol;
3712   if (vatol) *vatol = ts->vatol;
3713   if (rtol)  *rtol  = ts->rtol;
3714   if (vrtol) *vrtol = ts->vrtol;
3715   PetscFunctionReturn(0);
3716 }
3717 
3718 #undef __FUNCT__
3719 #define __FUNCT__ "TSErrorNormWRMS"
3720 /*@
3721    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state
3722 
3723    Collective on TS
3724 
3725    Input Arguments:
3726 +  ts - time stepping context
3727 -  Y - state vector to be compared to ts->vec_sol
3728 
3729    Output Arguments:
3730 .  norm - weighted norm, a value of 1.0 is considered small
3731 
3732    Level: developer
3733 
3734 .seealso: TSSetTolerances()
3735 @*/
3736 PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
3737 {
3738   PetscErrorCode    ierr;
3739   PetscInt          i,n,N;
3740   const PetscScalar *u,*y;
3741   Vec               U;
3742   PetscReal         sum,gsum;
3743 
3744   PetscFunctionBegin;
3745   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3746   PetscValidHeaderSpecific(Y,VEC_CLASSID,2);
3747   PetscValidPointer(norm,3);
3748   U = ts->vec_sol;
3749   PetscCheckSameTypeAndComm(U,1,Y,2);
3750   if (U == Y) SETERRQ(((PetscObject)U)->comm,PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");
3751 
3752   ierr = VecGetSize(U,&N);CHKERRQ(ierr);
3753   ierr = VecGetLocalSize(U,&n);CHKERRQ(ierr);
3754   ierr = VecGetArrayRead(U,&u);CHKERRQ(ierr);
3755   ierr = VecGetArrayRead(Y,&y);CHKERRQ(ierr);
3756   sum = 0.;
3757   if (ts->vatol && ts->vrtol) {
3758     const PetscScalar *atol,*rtol;
3759     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
3760     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
3761     for (i=0; i<n; i++) {
3762       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
3763       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
3764     }
3765     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
3766     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
3767   } else if (ts->vatol) {       /* vector atol, scalar rtol */
3768     const PetscScalar *atol;
3769     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
3770     for (i=0; i<n; i++) {
3771       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
3772       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
3773     }
3774     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
3775   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
3776     const PetscScalar *rtol;
3777     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
3778     for (i=0; i<n; i++) {
3779       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
3780       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
3781     }
3782     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
3783   } else {                      /* scalar atol, scalar rtol */
3784     for (i=0; i<n; i++) {
3785       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
3786       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
3787     }
3788   }
3789   ierr = VecRestoreArrayRead(U,&u);CHKERRQ(ierr);
3790   ierr = VecRestoreArrayRead(Y,&y);CHKERRQ(ierr);
3791 
3792   ierr = MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,((PetscObject)ts)->comm);CHKERRQ(ierr);
3793   *norm = PetscSqrtReal(gsum / N);
3794   if (PetscIsInfOrNanScalar(*norm)) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
3795   PetscFunctionReturn(0);
3796 }
3797 
3798 #undef __FUNCT__
3799 #define __FUNCT__ "TSSetCFLTimeLocal"
3800 /*@
3801    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler
3802 
3803    Logically Collective on TS
3804 
3805    Input Arguments:
3806 +  ts - time stepping context
3807 -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)
3808 
3809    Note:
3810    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()
3811 
3812    Level: intermediate
3813 
3814 .seealso: TSGetCFLTime(), TSADAPTCFL
3815 @*/
3816 PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
3817 {
3818   PetscFunctionBegin;
3819   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3820   ts->cfltime_local = cfltime;
3821   ts->cfltime = -1.;
3822   PetscFunctionReturn(0);
3823 }
3824 
3825 #undef __FUNCT__
3826 #define __FUNCT__ "TSGetCFLTime"
3827 /*@
3828    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler
3829 
3830    Collective on TS
3831 
3832    Input Arguments:
3833 .  ts - time stepping context
3834 
3835    Output Arguments:
3836 .  cfltime - maximum stable time step for forward Euler
3837 
3838    Level: advanced
3839 
3840 .seealso: TSSetCFLTimeLocal()
3841 @*/
3842 PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
3843 {
3844   PetscErrorCode ierr;
3845 
3846   PetscFunctionBegin;
3847   if (ts->cfltime < 0) {
3848     ierr = MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,((PetscObject)ts)->comm);CHKERRQ(ierr);
3849   }
3850   *cfltime = ts->cfltime;
3851   PetscFunctionReturn(0);
3852 }
3853 
3854 #undef __FUNCT__
3855 #define __FUNCT__ "TSVISetVariableBounds"
3856 /*@
3857    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu
3858 
3859    Input Parameters:
3860 .  ts   - the TS context.
3861 .  xl   - lower bound.
3862 .  xu   - upper bound.
3863 
3864    Notes:
3865    If this routine is not called then the lower and upper bounds are set to
3866    SNES_VI_NINF and SNES_VI_INF respectively during SNESSetUp().
3867 
3868    Level: advanced
3869 
3870 @*/
3871 PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
3872 {
3873   PetscErrorCode ierr;
3874   SNES           snes;
3875 
3876   PetscFunctionBegin;
3877   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3878   ierr = SNESVISetVariableBounds(snes,xl,xu);CHKERRQ(ierr);
3879   PetscFunctionReturn(0);
3880 }
3881 
3882 #if defined(PETSC_HAVE_MATLAB_ENGINE)
3883 #include <mex.h>
3884 
3885 typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;
3886 
3887 #undef __FUNCT__
3888 #define __FUNCT__ "TSComputeFunction_Matlab"
3889 /*
3890    TSComputeFunction_Matlab - Calls the function that has been set with
3891                          TSSetFunctionMatlab().
3892 
3893    Collective on TS
3894 
3895    Input Parameters:
3896 +  snes - the TS context
3897 -  u - input vector
3898 
3899    Output Parameter:
3900 .  y - function vector, as set by TSSetFunction()
3901 
3902    Notes:
3903    TSComputeFunction() is typically used within nonlinear solvers
3904    implementations, so most users would not generally call this routine
3905    themselves.
3906 
3907    Level: developer
3908 
3909 .keywords: TS, nonlinear, compute, function
3910 
3911 .seealso: TSSetFunction(), TSGetFunction()
3912 */
3913 PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
3914 {
3915   PetscErrorCode   ierr;
3916   TSMatlabContext *sctx = (TSMatlabContext *)ctx;
3917   int              nlhs = 1,nrhs = 7;
3918   mxArray          *plhs[1],*prhs[7];
3919   long long int    lx = 0,lxdot = 0,ly = 0,ls = 0;
3920 
3921   PetscFunctionBegin;
3922   PetscValidHeaderSpecific(snes,TS_CLASSID,1);
3923   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
3924   PetscValidHeaderSpecific(udot,VEC_CLASSID,4);
3925   PetscValidHeaderSpecific(y,VEC_CLASSID,5);
3926   PetscCheckSameComm(snes,1,u,3);
3927   PetscCheckSameComm(snes,1,y,5);
3928 
3929   ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr);
3930   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
3931   ierr = PetscMemcpy(&lxdot,&udot,sizeof(udot));CHKERRQ(ierr);
3932   ierr = PetscMemcpy(&ly,&y,sizeof(u));CHKERRQ(ierr);
3933   prhs[0] =  mxCreateDoubleScalar((double)ls);
3934   prhs[1] =  mxCreateDoubleScalar(time);
3935   prhs[2] =  mxCreateDoubleScalar((double)lx);
3936   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
3937   prhs[4] =  mxCreateDoubleScalar((double)ly);
3938   prhs[5] =  mxCreateString(sctx->funcname);
3939   prhs[6] =  sctx->ctx;
3940   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");CHKERRQ(ierr);
3941   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
3942   mxDestroyArray(prhs[0]);
3943   mxDestroyArray(prhs[1]);
3944   mxDestroyArray(prhs[2]);
3945   mxDestroyArray(prhs[3]);
3946   mxDestroyArray(prhs[4]);
3947   mxDestroyArray(prhs[5]);
3948   mxDestroyArray(plhs[0]);
3949   PetscFunctionReturn(0);
3950 }
3951 
3952 
3953 #undef __FUNCT__
3954 #define __FUNCT__ "TSSetFunctionMatlab"
3955 /*
3956    TSSetFunctionMatlab - Sets the function evaluation routine and function
3957    vector for use by the TS routines in solving ODEs
3958    equations from MATLAB. Here the function is a string containing the name of a MATLAB function
3959 
3960    Logically Collective on TS
3961 
3962    Input Parameters:
3963 +  ts - the TS context
3964 -  func - function evaluation routine
3965 
3966    Calling sequence of func:
3967 $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);
3968 
3969    Level: beginner
3970 
3971 .keywords: TS, nonlinear, set, function
3972 
3973 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
3974 */
3975 PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
3976 {
3977   PetscErrorCode  ierr;
3978   TSMatlabContext *sctx;
3979 
3980   PetscFunctionBegin;
3981   /* currently sctx is memory bleed */
3982   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
3983   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
3984   /*
3985      This should work, but it doesn't
3986   sctx->ctx = ctx;
3987   mexMakeArrayPersistent(sctx->ctx);
3988   */
3989   sctx->ctx = mxDuplicateArray(ctx);
3990   ierr = TSSetIFunction(ts,PETSC_NULL,TSComputeFunction_Matlab,sctx);CHKERRQ(ierr);
3991   PetscFunctionReturn(0);
3992 }
3993 
3994 #undef __FUNCT__
3995 #define __FUNCT__ "TSComputeJacobian_Matlab"
3996 /*
3997    TSComputeJacobian_Matlab - Calls the function that has been set with
3998                          TSSetJacobianMatlab().
3999 
4000    Collective on TS
4001 
4002    Input Parameters:
4003 +  ts - the TS context
4004 .  u - input vector
4005 .  A, B - the matrices
4006 -  ctx - user context
4007 
4008    Output Parameter:
4009 .  flag - structure of the matrix
4010 
4011    Level: developer
4012 
4013 .keywords: TS, nonlinear, compute, function
4014 
4015 .seealso: TSSetFunction(), TSGetFunction()
4016 @*/
4017 PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flag, void *ctx)
4018 {
4019   PetscErrorCode  ierr;
4020   TSMatlabContext *sctx = (TSMatlabContext *)ctx;
4021   int             nlhs = 2,nrhs = 9;
4022   mxArray         *plhs[2],*prhs[9];
4023   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;
4024 
4025   PetscFunctionBegin;
4026   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4027   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4028 
4029   /* call Matlab function in ctx with arguments u and y */
4030 
4031   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4032   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4033   ierr = PetscMemcpy(&lxdot,&udot,sizeof(u));CHKERRQ(ierr);
4034   ierr = PetscMemcpy(&lA,A,sizeof(u));CHKERRQ(ierr);
4035   ierr = PetscMemcpy(&lB,B,sizeof(u));CHKERRQ(ierr);
4036   prhs[0] =  mxCreateDoubleScalar((double)ls);
4037   prhs[1] =  mxCreateDoubleScalar((double)time);
4038   prhs[2] =  mxCreateDoubleScalar((double)lx);
4039   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4040   prhs[4] =  mxCreateDoubleScalar((double)shift);
4041   prhs[5] =  mxCreateDoubleScalar((double)lA);
4042   prhs[6] =  mxCreateDoubleScalar((double)lB);
4043   prhs[7] =  mxCreateString(sctx->funcname);
4044   prhs[8] =  sctx->ctx;
4045   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");CHKERRQ(ierr);
4046   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4047   *flag   =  (MatStructure) mxGetScalar(plhs[1]);CHKERRQ(ierr);
4048   mxDestroyArray(prhs[0]);
4049   mxDestroyArray(prhs[1]);
4050   mxDestroyArray(prhs[2]);
4051   mxDestroyArray(prhs[3]);
4052   mxDestroyArray(prhs[4]);
4053   mxDestroyArray(prhs[5]);
4054   mxDestroyArray(prhs[6]);
4055   mxDestroyArray(prhs[7]);
4056   mxDestroyArray(plhs[0]);
4057   mxDestroyArray(plhs[1]);
4058   PetscFunctionReturn(0);
4059 }
4060 
4061 
4062 #undef __FUNCT__
4063 #define __FUNCT__ "TSSetJacobianMatlab"
4064 /*
4065    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
4066    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
4067 
4068    Logically Collective on TS
4069 
4070    Input Parameters:
4071 +  ts - the TS context
4072 .  A,B - Jacobian matrices
4073 .  func - function evaluation routine
4074 -  ctx - user context
4075 
4076    Calling sequence of func:
4077 $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);
4078 
4079 
4080    Level: developer
4081 
4082 .keywords: TS, nonlinear, set, function
4083 
4084 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4085 */
4086 PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
4087 {
4088   PetscErrorCode    ierr;
4089   TSMatlabContext *sctx;
4090 
4091   PetscFunctionBegin;
4092   /* currently sctx is memory bleed */
4093   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4094   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4095   /*
4096      This should work, but it doesn't
4097   sctx->ctx = ctx;
4098   mexMakeArrayPersistent(sctx->ctx);
4099   */
4100   sctx->ctx = mxDuplicateArray(ctx);
4101   ierr = TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);CHKERRQ(ierr);
4102   PetscFunctionReturn(0);
4103 }
4104 
4105 #undef __FUNCT__
4106 #define __FUNCT__ "TSMonitor_Matlab"
4107 /*
4108    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().
4109 
4110    Collective on TS
4111 
4112 .seealso: TSSetFunction(), TSGetFunction()
4113 @*/
4114 PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
4115 {
4116   PetscErrorCode  ierr;
4117   TSMatlabContext *sctx = (TSMatlabContext *)ctx;
4118   int             nlhs = 1,nrhs = 6;
4119   mxArray         *plhs[1],*prhs[6];
4120   long long int   lx = 0,ls = 0;
4121 
4122   PetscFunctionBegin;
4123   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4124   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
4125 
4126   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4127   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4128   prhs[0] =  mxCreateDoubleScalar((double)ls);
4129   prhs[1] =  mxCreateDoubleScalar((double)it);
4130   prhs[2] =  mxCreateDoubleScalar((double)time);
4131   prhs[3] =  mxCreateDoubleScalar((double)lx);
4132   prhs[4] =  mxCreateString(sctx->funcname);
4133   prhs[5] =  sctx->ctx;
4134   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");CHKERRQ(ierr);
4135   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4136   mxDestroyArray(prhs[0]);
4137   mxDestroyArray(prhs[1]);
4138   mxDestroyArray(prhs[2]);
4139   mxDestroyArray(prhs[3]);
4140   mxDestroyArray(prhs[4]);
4141   mxDestroyArray(plhs[0]);
4142   PetscFunctionReturn(0);
4143 }
4144 
4145 
4146 #undef __FUNCT__
4147 #define __FUNCT__ "TSMonitorSetMatlab"
4148 /*
4149    TSMonitorSetMatlab - Sets the monitor function from Matlab
4150 
4151    Level: developer
4152 
4153 .keywords: TS, nonlinear, set, function
4154 
4155 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4156 */
4157 PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
4158 {
4159   PetscErrorCode    ierr;
4160   TSMatlabContext *sctx;
4161 
4162   PetscFunctionBegin;
4163   /* currently sctx is memory bleed */
4164   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4165   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4166   /*
4167      This should work, but it doesn't
4168   sctx->ctx = ctx;
4169   mexMakeArrayPersistent(sctx->ctx);
4170   */
4171   sctx->ctx = mxDuplicateArray(ctx);
4172   ierr = TSMonitorSet(ts,TSMonitor_Matlab,sctx,PETSC_NULL);CHKERRQ(ierr);
4173   PetscFunctionReturn(0);
4174 }
4175 #endif
4176 
4177 
4178 
4179 #undef __FUNCT__
4180 #define __FUNCT__ "TSMonitorLGSolution"
4181 /*@C
4182    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
4183        in a time based line graph
4184 
4185    Collective on TS
4186 
4187    Input Parameters:
4188 +  ts - the TS context
4189 .  step - current time-step
4190 .  ptime - current time
4191 -  lg - a line graph object
4192 
4193    Level: intermediate
4194 
4195     Notes: each process in a parallel run displays its component solutions in a separate window
4196 
4197 .keywords: TS,  vector, monitor, view
4198 
4199 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4200 @*/
4201 PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4202 {
4203   PetscErrorCode    ierr;
4204   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4205   const PetscScalar *yy;
4206   PetscInt          dim;
4207 
4208   PetscFunctionBegin;
4209   if (!step) {
4210     PetscDrawAxis  axis;
4211     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4212     ierr = PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");CHKERRQ(ierr);
4213     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4214     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4215     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4216   }
4217   ierr = VecGetArrayRead(u,&yy);CHKERRQ(ierr);
4218 #if defined(PETSC_USE_COMPLEX)
4219   {
4220     PetscReal *yreal;
4221     PetscInt i,n;
4222     ierr = VecGetLocalSize(u,&n);CHKERRQ(ierr);
4223     ierr = PetscMalloc(n*sizeof(PetscReal),&yreal);CHKERRQ(ierr);
4224     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4225     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4226     ierr = PetscFree(yreal);CHKERRQ(ierr);
4227   }
4228 #else
4229   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4230 #endif
4231   ierr = VecRestoreArrayRead(u,&yy);CHKERRQ(ierr);
4232   if (((ctx->howoften > 0) && (!(step % ctx->howoften)) && (step > -1)) || ((ctx->howoften == -1) && (step == -1))){
4233     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4234   }
4235   PetscFunctionReturn(0);
4236 }
4237 
4238 #undef __FUNCT__
4239 #define __FUNCT__ "TSMonitorLGError"
4240 /*@C
4241    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
4242        in a time based line graph
4243 
4244    Collective on TS
4245 
4246    Input Parameters:
4247 +  ts - the TS context
4248 .  step - current time-step
4249 .  ptime - current time
4250 -  lg - a line graph object
4251 
4252    Level: intermediate
4253 
4254    Notes:
4255    Only for sequential solves.
4256 
4257    The user must provide the solution using TSSetSolutionFunction() to use this monitor.
4258 
4259    Options Database Keys:
4260 .  -ts_monitor_lg_error - create a graphical monitor of error history
4261 
4262 .keywords: TS,  vector, monitor, view
4263 
4264 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
4265 @*/
4266 PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4267 {
4268   PetscErrorCode    ierr;
4269   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4270   const PetscScalar *yy;
4271   Vec               y;
4272   PetscInt          dim;
4273 
4274   PetscFunctionBegin;
4275   if (!step) {
4276     PetscDrawAxis  axis;
4277     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4278     ierr = PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");CHKERRQ(ierr);
4279     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4280     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4281     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4282   }
4283   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
4284   ierr = TSComputeSolutionFunction(ts,ptime,y);CHKERRQ(ierr);
4285   ierr = VecAXPY(y,-1.0,u);CHKERRQ(ierr);
4286   ierr = VecGetArrayRead(y,&yy);CHKERRQ(ierr);
4287 #if defined(PETSC_USE_COMPLEX)
4288   {
4289     PetscReal *yreal;
4290     PetscInt  i,n;
4291     ierr = VecGetLocalSize(y,&n);CHKERRQ(ierr);
4292     ierr = PetscMalloc(n*sizeof(PetscReal),&yreal);CHKERRQ(ierr);
4293     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4294     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4295     ierr = PetscFree(yreal);CHKERRQ(ierr);
4296   }
4297 #else
4298   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4299 #endif
4300   ierr = VecRestoreArrayRead(y,&yy);CHKERRQ(ierr);
4301   ierr = VecDestroy(&y);CHKERRQ(ierr);
4302   if (((ctx->howoften > 0) && (!(step % ctx->howoften)) && (step > -1)) || ((ctx->howoften == -1) && (step == -1))){
4303     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4304   }
4305   PetscFunctionReturn(0);
4306 }
4307 
4308 #undef __FUNCT__
4309 #define __FUNCT__ "TSMonitorLGSNESIterations"
4310 PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4311 {
4312   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4313   PetscReal      x = ptime,y;
4314   PetscErrorCode ierr;
4315   PetscInt       its;
4316 
4317   PetscFunctionBegin;
4318   if (!n) {
4319     PetscDrawAxis  axis;
4320     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4321     ierr = PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");CHKERRQ(ierr);
4322     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4323     ctx->snes_its  = 0;
4324   }
4325   ierr = TSGetSNESIterations(ts,&its);CHKERRQ(ierr);
4326   y    = its - ctx->snes_its;
4327   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4328   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))){
4329     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4330   }
4331   ctx->snes_its = its;
4332   PetscFunctionReturn(0);
4333 }
4334 
4335 #undef __FUNCT__
4336 #define __FUNCT__ "TSMonitorLGKSPIterations"
4337 PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4338 {
4339   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4340   PetscReal      x = ptime,y;
4341   PetscErrorCode ierr;
4342   PetscInt       its;
4343 
4344   PetscFunctionBegin;
4345   if (!n) {
4346     PetscDrawAxis  axis;
4347     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4348     ierr = PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");CHKERRQ(ierr);
4349     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4350     ctx->ksp_its = 0;
4351   }
4352   ierr = TSGetKSPIterations(ts,&its);CHKERRQ(ierr);
4353   y    = its - ctx->ksp_its;
4354   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4355   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))){
4356     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4357   }
4358   ctx->ksp_its = its;
4359   PetscFunctionReturn(0);
4360 }
4361 
4362 #undef __FUNCT__
4363 #define __FUNCT__ "TSComputeLinearStability"
4364 /*@
4365    TSComputeLinearStability - computes the linear stability function at a point
4366 
4367    Collective on TS and Vec
4368 
4369    Input Parameters:
4370 +  ts - the TS context
4371 -  xr,xi - real and imaginary part of input arguments
4372 
4373    Output Parameters:
4374 .  yr,yi - real and imaginary part of function value
4375 
4376    Level: developer
4377 
4378 .keywords: TS, compute
4379 
4380 .seealso: TSSetRHSFunction(), TSComputeIFunction()
4381 @*/
4382 PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
4383 {
4384   PetscErrorCode ierr;
4385 
4386   PetscFunctionBegin;
4387   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4388   if (!ts->ops->linearstability) SETERRQ(((PetscObject)ts)->comm,PETSC_ERR_SUP,"Linearized stability function not provided for this method");
4389   ierr = (*ts->ops->linearstability)(ts,xr,xi,yr,yi);CHKERRQ(ierr);
4390   PetscFunctionReturn(0);
4391 }
4392