xref: /petsc/src/ts/interface/ts.c (revision a2ae3dd2069408419adb665d006b6f86e5c8b40b)
1 
2 #include <petsc-private/tsimpl.h>        /*I "petscts.h"  I*/
3 #include <petscdmshell.h>
4 #include <petscdmda.h>
5 #include <petscviewer.h>
6 #include <petscdraw.h>
7 
8 /* Logging support */
9 PetscClassId  TS_CLASSID, DMTS_CLASSID;
10 PetscLogEvent TS_Step, TS_PseudoComputeTimeStep, TS_FunctionEval, TS_JacobianEval;
11 
12 const char *const TSExactFinalTimeOptions[] = {"STEPOVER","INTERPOLATE","MATCHSTEP","TSExactFinalTimeOption","TS_EXACTFINALTIME_",0};
13 
14 #undef __FUNCT__
15 #define __FUNCT__ "TSSetTypeFromOptions_Private"
16 /*
17   TSSetTypeFromOptions - Sets the type of ts from user options.
18 
19   Collective on TS
20 
21   Input Parameter:
22 . ts - The ts
23 
24   Level: intermediate
25 
26 .keywords: TS, set, options, database, type
27 .seealso: TSSetFromOptions(), TSSetType()
28 */
29 static PetscErrorCode TSSetTypeFromOptions_Private(PetscOptions *PetscOptionsObject,TS ts)
30 {
31   PetscBool      opt;
32   const char     *defaultType;
33   char           typeName[256];
34   PetscErrorCode ierr;
35 
36   PetscFunctionBegin;
37   if (((PetscObject)ts)->type_name) defaultType = ((PetscObject)ts)->type_name;
38   else defaultType = TSEULER;
39 
40   if (!TSRegisterAllCalled) {ierr = TSRegisterAll();CHKERRQ(ierr);}
41   ierr = PetscOptionsFList("-ts_type", "TS method"," TSSetType", TSList, defaultType, typeName, 256, &opt);CHKERRQ(ierr);
42   if (opt) {
43     ierr = TSSetType(ts, typeName);CHKERRQ(ierr);
44   } else {
45     ierr = TSSetType(ts, defaultType);CHKERRQ(ierr);
46   }
47   PetscFunctionReturn(0);
48 }
49 
50 struct _n_TSMonitorDrawCtx {
51   PetscViewer   viewer;
52   PetscDrawAxis axis;
53   Vec           initialsolution;
54   PetscBool     showinitial;
55   PetscInt      howoften;  /* when > 0 uses step % howoften, when negative only final solution plotted */
56   PetscBool     showtimestepandtime;
57   int           color;
58 };
59 
60 #undef __FUNCT__
61 #define __FUNCT__ "TSSetFromOptions"
62 /*@
63    TSSetFromOptions - Sets various TS parameters from user options.
64 
65    Collective on TS
66 
67    Input Parameter:
68 .  ts - the TS context obtained from TSCreate()
69 
70    Options Database Keys:
71 +  -ts_type <type> - TSEULER, TSBEULER, TSSUNDIALS, TSPSEUDO, TSCN, TSRK, TSTHETA, TSGL, TSSSP
72 .  -ts_checkpoint - checkpoint for adjoint sensitivity analysis
73 .  -ts_max_steps maxsteps - maximum number of time-steps to take
74 .  -ts_final_time time - maximum time to compute to
75 .  -ts_dt dt - initial time step
76 .  -ts_exact_final_time <stepover,interpolate,matchstep> whether to stop at the exact given final time and how to compute the solution at that ti,e
77 .  -ts_max_snes_failures <maxfailures> - Maximum number of nonlinear solve failures allowed
78 .  -ts_max_reject <maxrejects> - Maximum number of step rejections before step fails
79 .  -ts_error_if_step_fails <true,false> - Error if no step succeeds
80 .  -ts_rtol <rtol> - relative tolerance for local truncation error
81 .  -ts_atol <atol> Absolute tolerance for local truncation error
82 .  -ts_monitor - print information at each timestep
83 .  -ts_monitor_lg_timestep - Monitor timestep size graphically
84 .  -ts_monitor_lg_solution - Monitor solution graphically
85 .  -ts_monitor_lg_error - Monitor error graphically
86 .  -ts_monitor_lg_snes_iterations - Monitor number nonlinear iterations for each timestep graphically
87 .  -ts_monitor_lg_ksp_iterations - Monitor number nonlinear iterations for each timestep graphically
88 .  -ts_monitor_sp_eig - Monitor eigenvalues of linearized operator graphically
89 .  -ts_monitor_draw_solution - Monitor solution graphically
90 .  -ts_monitor_draw_solution_phase - Monitor solution graphically with phase diagram
91 .  -ts_monitor_draw_error - Monitor error graphically
92 .  -ts_monitor_solution_binary <filename> - Save each solution to a binary file
93 -  -ts_monitor_solution_vtk <filename.vts> - Save each time step to a binary file, use filename-%%03D.vts
94 
95    Developer Note: We should unify all the -ts_monitor options in the way that -xxx_view has been unified
96 
97    Level: beginner
98 
99 .keywords: TS, timestep, set, options, database
100 
101 .seealso: TSGetType()
102 @*/
103 PetscErrorCode  TSSetFromOptions(TS ts)
104 {
105   PetscBool              opt,flg;
106   PetscErrorCode         ierr;
107   PetscViewer            monviewer;
108   char                   monfilename[PETSC_MAX_PATH_LEN];
109   SNES                   snes;
110   TSAdapt                adapt;
111   PetscReal              time_step;
112   TSExactFinalTimeOption eftopt;
113   char                   dir[16];
114 
115   PetscFunctionBegin;
116   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
117   ierr = PetscObjectOptionsBegin((PetscObject)ts);CHKERRQ(ierr);
118   /* Handle TS type options */
119   ierr = TSSetTypeFromOptions_Private(PetscOptionsObject,ts);CHKERRQ(ierr);
120 
121   /* Handle generic TS options */
122   ierr = PetscOptionsBool("-ts_checkpoint","Checkpoint for adjoint sensitivity analysis","TSSetCheckpoint",ts->checkpoint,&ts->checkpoint,NULL);CHKERRQ(ierr);
123   ierr = PetscOptionsInt("-ts_max_steps","Maximum number of time steps","TSSetDuration",ts->max_steps,&ts->max_steps,NULL);CHKERRQ(ierr);
124   ierr = PetscOptionsReal("-ts_final_time","Time to run to","TSSetDuration",ts->max_time,&ts->max_time,NULL);CHKERRQ(ierr);
125   ierr = PetscOptionsReal("-ts_init_time","Initial time","TSSetTime",ts->ptime,&ts->ptime,NULL);CHKERRQ(ierr);
126   ierr = PetscOptionsReal("-ts_dt","Initial time step","TSSetTimeStep",ts->time_step,&time_step,&flg);CHKERRQ(ierr);
127   if (flg) {
128     ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
129   }
130   ierr = PetscOptionsEnum("-ts_exact_final_time","Option for handling of final time step","TSSetExactFinalTime",TSExactFinalTimeOptions,(PetscEnum)ts->exact_final_time,(PetscEnum*)&eftopt,&flg);CHKERRQ(ierr);
131   if (flg) {ierr = TSSetExactFinalTime(ts,eftopt);CHKERRQ(ierr);}
132   ierr = PetscOptionsInt("-ts_max_snes_failures","Maximum number of nonlinear solve failures","TSSetMaxSNESFailures",ts->max_snes_failures,&ts->max_snes_failures,NULL);CHKERRQ(ierr);
133   ierr = PetscOptionsInt("-ts_max_reject","Maximum number of step rejections before step fails","TSSetMaxStepRejections",ts->max_reject,&ts->max_reject,NULL);CHKERRQ(ierr);
134   ierr = PetscOptionsBool("-ts_error_if_step_fails","Error if no step succeeds","TSSetErrorIfStepFails",ts->errorifstepfailed,&ts->errorifstepfailed,NULL);CHKERRQ(ierr);
135   ierr = PetscOptionsReal("-ts_rtol","Relative tolerance for local truncation error","TSSetTolerances",ts->rtol,&ts->rtol,NULL);CHKERRQ(ierr);
136   ierr = PetscOptionsReal("-ts_atol","Absolute tolerance for local truncation error","TSSetTolerances",ts->atol,&ts->atol,NULL);CHKERRQ(ierr);
137 
138 #if defined(PETSC_HAVE_SAWS)
139   {
140   PetscBool set;
141   flg  = PETSC_FALSE;
142   ierr = PetscOptionsBool("-ts_saws_block","Block for SAWs memory snooper at end of TSSolve","PetscObjectSAWsBlock",((PetscObject)ts)->amspublishblock,&flg,&set);CHKERRQ(ierr);
143   if (set) {
144     ierr = PetscObjectSAWsSetBlock((PetscObject)ts,flg);CHKERRQ(ierr);
145   }
146   }
147 #endif
148 
149   /* Monitor options */
150   ierr = PetscOptionsString("-ts_monitor","Monitor timestep size","TSMonitorDefault","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
151   if (flg) {
152     ierr = PetscViewerASCIIOpen(PetscObjectComm((PetscObject)ts),monfilename,&monviewer);CHKERRQ(ierr);
153     ierr = TSMonitorSet(ts,TSMonitorDefault,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
154   }
155   ierr = PetscOptionsString("-ts_monitor_python","Use Python function","TSMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
156   if (flg) {ierr = PetscPythonMonitorSet((PetscObject)ts,monfilename);CHKERRQ(ierr);}
157 
158   ierr = PetscOptionsName("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",&opt);CHKERRQ(ierr);
159   if (opt) {
160     TSMonitorLGCtx ctx;
161     PetscInt       howoften = 1;
162 
163     ierr = PetscOptionsInt("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",howoften,&howoften,NULL);CHKERRQ(ierr);
164     ierr = TSMonitorLGCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
165     ierr = TSMonitorSet(ts,TSMonitorLGTimeStep,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
166   }
167   ierr = PetscOptionsName("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",&opt);CHKERRQ(ierr);
168   if (opt) {
169     TSMonitorLGCtx ctx;
170     PetscInt       howoften = 1;
171 
172     ierr = PetscOptionsInt("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
173     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
174     ierr = TSMonitorSet(ts,TSMonitorLGSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
175   }
176   ierr = PetscOptionsName("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",&opt);CHKERRQ(ierr);
177   if (opt) {
178     TSMonitorLGCtx ctx;
179     PetscInt       howoften = 1;
180 
181     ierr = PetscOptionsInt("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",howoften,&howoften,NULL);CHKERRQ(ierr);
182     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
183     ierr = TSMonitorSet(ts,TSMonitorLGError,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
184   }
185   ierr = PetscOptionsName("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",&opt);CHKERRQ(ierr);
186   if (opt) {
187     TSMonitorLGCtx ctx;
188     PetscInt       howoften = 1;
189 
190     ierr = PetscOptionsInt("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
191     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
192     ierr = TSMonitorSet(ts,TSMonitorLGSNESIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
193   }
194   ierr = PetscOptionsName("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",&opt);CHKERRQ(ierr);
195   if (opt) {
196     TSMonitorLGCtx ctx;
197     PetscInt       howoften = 1;
198 
199     ierr = PetscOptionsInt("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
200     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
201     ierr = TSMonitorSet(ts,TSMonitorLGKSPIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
202   }
203   ierr = PetscOptionsName("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",&opt);CHKERRQ(ierr);
204   if (opt) {
205     TSMonitorSPEigCtx ctx;
206     PetscInt          howoften = 1;
207 
208     ierr = PetscOptionsInt("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",howoften,&howoften,NULL);CHKERRQ(ierr);
209     ierr = TSMonitorSPEigCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
210     ierr = TSMonitorSet(ts,TSMonitorSPEig,ctx,(PetscErrorCode (*)(void**))TSMonitorSPEigCtxDestroy);CHKERRQ(ierr);
211   }
212   opt  = PETSC_FALSE;
213   ierr = PetscOptionsName("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",&opt);CHKERRQ(ierr);
214   if (opt) {
215     TSMonitorDrawCtx ctx;
216     PetscInt         howoften = 1;
217 
218     ierr = PetscOptionsInt("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
219     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
220     ierr = TSMonitorSet(ts,TSMonitorDrawSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
221   }
222   opt  = PETSC_FALSE;
223   ierr = PetscOptionsName("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",&opt);CHKERRQ(ierr);
224   if (opt) {
225     TSMonitorDrawCtx ctx;
226     PetscReal        bounds[4];
227     PetscInt         n = 4;
228     PetscDraw        draw;
229 
230     ierr = PetscOptionsRealArray("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",bounds,&n,NULL);CHKERRQ(ierr);
231     if (n != 4) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Must provide bounding box of phase field");
232     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,1,&ctx);CHKERRQ(ierr);
233     ierr = PetscViewerDrawGetDraw(ctx->viewer,0,&draw);CHKERRQ(ierr);
234     ierr = PetscDrawClear(draw);CHKERRQ(ierr);
235     ierr = PetscDrawAxisCreate(draw,&ctx->axis);CHKERRQ(ierr);
236     ierr = PetscDrawAxisSetLimits(ctx->axis,bounds[0],bounds[2],bounds[1],bounds[3]);CHKERRQ(ierr);
237     ierr = PetscDrawAxisSetLabels(ctx->axis,"Phase Diagram","Variable 1","Variable 2");CHKERRQ(ierr);
238     ierr = PetscDrawAxisDraw(ctx->axis);CHKERRQ(ierr);
239     /* ierr = PetscDrawSetCoordinates(draw,bounds[0],bounds[1],bounds[2],bounds[3]);CHKERRQ(ierr); */
240     ierr = TSMonitorSet(ts,TSMonitorDrawSolutionPhase,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
241   }
242   opt  = PETSC_FALSE;
243   ierr = PetscOptionsName("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",&opt);CHKERRQ(ierr);
244   if (opt) {
245     TSMonitorDrawCtx ctx;
246     PetscInt         howoften = 1;
247 
248     ierr = PetscOptionsInt("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",howoften,&howoften,NULL);CHKERRQ(ierr);
249     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
250     ierr = TSMonitorSet(ts,TSMonitorDrawError,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
251   }
252   opt  = PETSC_FALSE;
253   ierr = PetscOptionsString("-ts_monitor_solution_binary","Save each solution to a binary file","TSMonitorSolutionBinary",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
254   if (flg) {
255     PetscViewer ctx;
256     if (monfilename[0]) {
257       ierr = PetscViewerBinaryOpen(PetscObjectComm((PetscObject)ts),monfilename,FILE_MODE_WRITE,&ctx);CHKERRQ(ierr);
258       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
259     } else {
260       ctx = PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)ts));
261       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))NULL);CHKERRQ(ierr);
262     }
263   }
264   opt  = PETSC_FALSE;
265   ierr = PetscOptionsString("-ts_monitor_solution_vtk","Save each time step to a binary file, use filename-%%03D.vts","TSMonitorSolutionVTK",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
266   if (flg) {
267     const char *ptr,*ptr2;
268     char       *filetemplate;
269     if (!monfilename[0]) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
270     /* Do some cursory validation of the input. */
271     ierr = PetscStrstr(monfilename,"%",(char**)&ptr);CHKERRQ(ierr);
272     if (!ptr) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
273     for (ptr++; ptr && *ptr; ptr++) {
274       ierr = PetscStrchr("DdiouxX",*ptr,(char**)&ptr2);CHKERRQ(ierr);
275       if (!ptr2 && (*ptr < '0' || '9' < *ptr)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Invalid file template argument to -ts_monitor_solution_vtk, should look like filename-%%03D.vts");
276       if (ptr2) break;
277     }
278     ierr = PetscStrallocpy(monfilename,&filetemplate);CHKERRQ(ierr);
279     ierr = TSMonitorSet(ts,TSMonitorSolutionVTK,filetemplate,(PetscErrorCode (*)(void**))TSMonitorSolutionVTKDestroy);CHKERRQ(ierr);
280   }
281 
282   ierr = PetscOptionsString("-ts_monitor_dmda_ray","Display a ray of the solution","None","y=0",dir,16,&flg);CHKERRQ(ierr);
283   if (flg) {
284     TSMonitorDMDARayCtx *rayctx;
285     int                  ray = 0;
286     DMDADirection        ddir;
287     DM                   da;
288     PetscMPIInt          rank;
289 
290     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
291     if (dir[0] == 'x') ddir = DMDA_X;
292     else if (dir[0] == 'y') ddir = DMDA_Y;
293     else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
294     sscanf(dir+2,"%d",&ray);
295 
296     ierr = PetscInfo2(((PetscObject)ts),"Displaying DMDA ray %c = %D\n",dir[0],ray);CHKERRQ(ierr);
297     ierr = PetscNew(&rayctx);CHKERRQ(ierr);
298     ierr = TSGetDM(ts,&da);CHKERRQ(ierr);
299     ierr = DMDAGetRay(da,ddir,ray,&rayctx->ray,&rayctx->scatter);CHKERRQ(ierr);
300     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)ts),&rank);CHKERRQ(ierr);
301     if (!rank) {
302       ierr = PetscViewerDrawOpen(PETSC_COMM_SELF,0,0,0,0,600,300,&rayctx->viewer);CHKERRQ(ierr);
303     }
304     rayctx->lgctx = NULL;
305     ierr = TSMonitorSet(ts,TSMonitorDMDARay,rayctx,TSMonitorDMDARayDestroy);CHKERRQ(ierr);
306   }
307   ierr = PetscOptionsString("-ts_monitor_lg_dmda_ray","Display a ray of the solution","None","x=0",dir,16,&flg);CHKERRQ(ierr);
308   if (flg) {
309     TSMonitorDMDARayCtx *rayctx;
310     int                 ray = 0;
311     DMDADirection       ddir;
312     DM                  da;
313     PetscInt            howoften = 1;
314 
315     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Malformed ray %s", dir);
316     if      (dir[0] == 'x') ddir = DMDA_X;
317     else if (dir[0] == 'y') ddir = DMDA_Y;
318     else SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Unknown ray direction %s", dir);
319     sscanf(dir+2, "%d", &ray);
320 
321     ierr = PetscInfo2(((PetscObject) ts),"Displaying LG DMDA ray %c = %D\n", dir[0], ray);CHKERRQ(ierr);
322     ierr = PetscNew(&rayctx);CHKERRQ(ierr);
323     ierr = TSGetDM(ts, &da);CHKERRQ(ierr);
324     ierr = DMDAGetRay(da, ddir, ray, &rayctx->ray, &rayctx->scatter);CHKERRQ(ierr);
325     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&rayctx->lgctx);CHKERRQ(ierr);
326     ierr = TSMonitorSet(ts, TSMonitorLGDMDARay, rayctx, TSMonitorDMDARayDestroy);CHKERRQ(ierr);
327   }
328 
329   /*
330      This code is all wrong. One is creating objects inside the TSSetFromOptions() so if run with the options gui
331      will bleed memory. Also one is using a PetscOptionsBegin() inside a PetscOptionsBegin()
332   */
333   ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
334   ierr = TSAdaptSetFromOptions(PetscOptionsObject,adapt);CHKERRQ(ierr);
335 
336   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
337   if (ts->problem_type == TS_LINEAR) {ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);}
338 
339   /* Handle specific TS options */
340   if (ts->ops->setfromoptions) {
341     ierr = (*ts->ops->setfromoptions)(PetscOptionsObject,ts);CHKERRQ(ierr);
342   }
343 
344   /* process any options handlers added with PetscObjectAddOptionsHandler() */
345   ierr = PetscObjectProcessOptionsHandlers((PetscObject)ts);CHKERRQ(ierr);
346   ierr = PetscOptionsEnd();CHKERRQ(ierr);
347   PetscFunctionReturn(0);
348 }
349 
350 #undef __FUNCT__
351 #define __FUNCT__ "TSSetCheckpoint"
352 /*@
353    TSSetCheckpoint - Allows one to checkpoint the forward run,
354    useful for adjoint sensitivity analysis.
355 
356    Collective on TS
357 
358    Input Parameters:
359 +  ts - the TS context obtained from TSCreate()
360 -  checkpoint - flag that indicates if the forward solution will be checkpointed
361 
362    Level: intermediate
363 
364 .seealso:
365 
366 .keywords: TS, set, checkpoint
367 @*/
368 PetscErrorCode  TSSetCheckpoint(TS ts,PetscBool checkpoint)
369 {
370   PetscFunctionBegin;
371   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
372   ts->checkpoint = checkpoint;
373   PetscFunctionReturn(0);
374 }
375 
376 #undef __FUNCT__
377 #define __FUNCT__ "TSSetReverseMode"
378 /*@
379    TSSetReverseMode - Allows one to reset the run mode,
380    useful for adjoint sensitivity analysis.
381 
382    Collective on TS
383 
384    Input Parameters:
385 +  ts - the TS context obtained from TSCreate()
386 -  reverse_mode - run in forward (default) or reverse mode
387 
388    Level: intermediate
389 
390 .seealso:
391 
392 .keywords: TS, set, reverse
393 @*/
394 PetscErrorCode  TSSetReverseMode(TS ts,PetscBool reverse_mode)
395 {
396   PetscErrorCode ierr;
397   PetscFunctionBegin;
398   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
399   ts->reverse_mode = reverse_mode;
400   ts->setupcalled  = PETSC_FALSE;
401   ierr = TSSetUp(ts);CHKERRQ(ierr);
402   PetscFunctionReturn(0);
403 }
404 
405 #undef __FUNCT__
406 #define __FUNCT__ "TSComputeRHSJacobian"
407 /*@
408    TSComputeRHSJacobian - Computes the Jacobian matrix that has been
409       set with TSSetRHSJacobian().
410 
411    Collective on TS and Vec
412 
413    Input Parameters:
414 +  ts - the TS context
415 .  t - current timestep
416 -  U - input vector
417 
418    Output Parameters:
419 +  A - Jacobian matrix
420 .  B - optional preconditioning matrix
421 -  flag - flag indicating matrix structure
422 
423    Notes:
424    Most users should not need to explicitly call this routine, as it
425    is used internally within the nonlinear solvers.
426 
427    See KSPSetOperators() for important information about setting the
428    flag parameter.
429 
430    Level: developer
431 
432 .keywords: SNES, compute, Jacobian, matrix
433 
434 .seealso:  TSSetRHSJacobian(), KSPSetOperators()
435 @*/
436 PetscErrorCode  TSComputeRHSJacobian(TS ts,PetscReal t,Vec U,Mat A,Mat B)
437 {
438   PetscErrorCode ierr;
439   PetscObjectState Ustate;
440   DM             dm;
441   DMTS           tsdm;
442   TSRHSJacobian  rhsjacobianfunc;
443   void           *ctx;
444   TSIJacobian    ijacobianfunc;
445 
446   PetscFunctionBegin;
447   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
448   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
449   PetscCheckSameComm(ts,1,U,3);
450   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
451   ierr = DMGetDMTS(dm,&tsdm);CHKERRQ(ierr);
452   ierr = DMTSGetRHSJacobian(dm,&rhsjacobianfunc,&ctx);CHKERRQ(ierr);
453   ierr = DMTSGetIJacobian(dm,&ijacobianfunc,NULL);CHKERRQ(ierr);
454   ierr = PetscObjectStateGet((PetscObject)U,&Ustate);CHKERRQ(ierr);
455   if (ts->rhsjacobian.time == t && (ts->problem_type == TS_LINEAR || (ts->rhsjacobian.X == U && ts->rhsjacobian.Xstate == Ustate))) {
456     PetscFunctionReturn(0);
457   }
458 
459   if (!rhsjacobianfunc && !ijacobianfunc) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
460 
461   if (ts->rhsjacobian.reuse) {
462     ierr = MatShift(A,-ts->rhsjacobian.shift);CHKERRQ(ierr);
463     ierr = MatScale(A,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
464     if (A != B) {
465       ierr = MatShift(B,-ts->rhsjacobian.shift);CHKERRQ(ierr);
466       ierr = MatScale(B,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
467     }
468     ts->rhsjacobian.shift = 0;
469     ts->rhsjacobian.scale = 1.;
470   }
471 
472   if (rhsjacobianfunc) {
473     ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
474     PetscStackPush("TS user Jacobian function");
475     ierr = (*rhsjacobianfunc)(ts,t,U,A,B,ctx);CHKERRQ(ierr);
476     PetscStackPop;
477     ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
478     /* make sure user returned a correct Jacobian and preconditioner */
479     PetscValidHeaderSpecific(A,MAT_CLASSID,4);
480     PetscValidHeaderSpecific(B,MAT_CLASSID,5);
481   } else {
482     ierr = MatZeroEntries(A);CHKERRQ(ierr);
483     if (A != B) {ierr = MatZeroEntries(B);CHKERRQ(ierr);}
484   }
485   ts->rhsjacobian.time       = t;
486   ts->rhsjacobian.X          = U;
487   ierr                       = PetscObjectStateGet((PetscObject)U,&ts->rhsjacobian.Xstate);CHKERRQ(ierr);
488   PetscFunctionReturn(0);
489 }
490 
491 #undef __FUNCT__
492 #define __FUNCT__ "TSComputeRHSFunction"
493 /*@
494    TSComputeRHSFunction - Evaluates the right-hand-side function.
495 
496    Collective on TS and Vec
497 
498    Input Parameters:
499 +  ts - the TS context
500 .  t - current time
501 -  U - state vector
502 
503    Output Parameter:
504 .  y - right hand side
505 
506    Note:
507    Most users should not need to explicitly call this routine, as it
508    is used internally within the nonlinear solvers.
509 
510    Level: developer
511 
512 .keywords: TS, compute
513 
514 .seealso: TSSetRHSFunction(), TSComputeIFunction()
515 @*/
516 PetscErrorCode TSComputeRHSFunction(TS ts,PetscReal t,Vec U,Vec y)
517 {
518   PetscErrorCode ierr;
519   TSRHSFunction  rhsfunction;
520   TSIFunction    ifunction;
521   void           *ctx;
522   DM             dm;
523 
524   PetscFunctionBegin;
525   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
526   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
527   PetscValidHeaderSpecific(y,VEC_CLASSID,4);
528   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
529   ierr = DMTSGetRHSFunction(dm,&rhsfunction,&ctx);CHKERRQ(ierr);
530   ierr = DMTSGetIFunction(dm,&ifunction,NULL);CHKERRQ(ierr);
531 
532   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
533 
534   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
535   if (rhsfunction) {
536     PetscStackPush("TS user right-hand-side function");
537     ierr = (*rhsfunction)(ts,t,U,y,ctx);CHKERRQ(ierr);
538     PetscStackPop;
539   } else {
540     ierr = VecZeroEntries(y);CHKERRQ(ierr);
541   }
542 
543   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
544   PetscFunctionReturn(0);
545 }
546 
547 #undef __FUNCT__
548 #define __FUNCT__ "TSComputeSolutionFunction"
549 /*@
550    TSComputeSolutionFunction - Evaluates the solution function.
551 
552    Collective on TS and Vec
553 
554    Input Parameters:
555 +  ts - the TS context
556 -  t - current time
557 
558    Output Parameter:
559 .  U - the solution
560 
561    Note:
562    Most users should not need to explicitly call this routine, as it
563    is used internally within the nonlinear solvers.
564 
565    Level: developer
566 
567 .keywords: TS, compute
568 
569 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
570 @*/
571 PetscErrorCode TSComputeSolutionFunction(TS ts,PetscReal t,Vec U)
572 {
573   PetscErrorCode     ierr;
574   TSSolutionFunction solutionfunction;
575   void               *ctx;
576   DM                 dm;
577 
578   PetscFunctionBegin;
579   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
580   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
581   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
582   ierr = DMTSGetSolutionFunction(dm,&solutionfunction,&ctx);CHKERRQ(ierr);
583 
584   if (solutionfunction) {
585     PetscStackPush("TS user solution function");
586     ierr = (*solutionfunction)(ts,t,U,ctx);CHKERRQ(ierr);
587     PetscStackPop;
588   }
589   PetscFunctionReturn(0);
590 }
591 #undef __FUNCT__
592 #define __FUNCT__ "TSComputeForcingFunction"
593 /*@
594    TSComputeForcingFunction - Evaluates the forcing function.
595 
596    Collective on TS and Vec
597 
598    Input Parameters:
599 +  ts - the TS context
600 -  t - current time
601 
602    Output Parameter:
603 .  U - the function value
604 
605    Note:
606    Most users should not need to explicitly call this routine, as it
607    is used internally within the nonlinear solvers.
608 
609    Level: developer
610 
611 .keywords: TS, compute
612 
613 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
614 @*/
615 PetscErrorCode TSComputeForcingFunction(TS ts,PetscReal t,Vec U)
616 {
617   PetscErrorCode     ierr, (*forcing)(TS,PetscReal,Vec,void*);
618   void               *ctx;
619   DM                 dm;
620 
621   PetscFunctionBegin;
622   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
623   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
624   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
625   ierr = DMTSGetForcingFunction(dm,&forcing,&ctx);CHKERRQ(ierr);
626 
627   if (forcing) {
628     PetscStackPush("TS user forcing function");
629     ierr = (*forcing)(ts,t,U,ctx);CHKERRQ(ierr);
630     PetscStackPop;
631   }
632   PetscFunctionReturn(0);
633 }
634 
635 #undef __FUNCT__
636 #define __FUNCT__ "TSGetRHSVec_Private"
637 static PetscErrorCode TSGetRHSVec_Private(TS ts,Vec *Frhs)
638 {
639   Vec            F;
640   PetscErrorCode ierr;
641 
642   PetscFunctionBegin;
643   *Frhs = NULL;
644   ierr  = TSGetIFunction(ts,&F,NULL,NULL);CHKERRQ(ierr);
645   if (!ts->Frhs) {
646     ierr = VecDuplicate(F,&ts->Frhs);CHKERRQ(ierr);
647   }
648   *Frhs = ts->Frhs;
649   PetscFunctionReturn(0);
650 }
651 
652 #undef __FUNCT__
653 #define __FUNCT__ "TSGetRHSMats_Private"
654 static PetscErrorCode TSGetRHSMats_Private(TS ts,Mat *Arhs,Mat *Brhs)
655 {
656   Mat            A,B;
657   PetscErrorCode ierr;
658 
659   PetscFunctionBegin;
660   if (Arhs) *Arhs = NULL;
661   if (Brhs) *Brhs = NULL;
662   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
663   if (Arhs) {
664     if (!ts->Arhs) {
665       ierr = MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&ts->Arhs);CHKERRQ(ierr);
666     }
667     *Arhs = ts->Arhs;
668   }
669   if (Brhs) {
670     if (!ts->Brhs) {
671       if (A != B) {
672         ierr = MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&ts->Brhs);CHKERRQ(ierr);
673       } else {
674         ts->Brhs = ts->Arhs;
675         ierr = PetscObjectReference((PetscObject)ts->Arhs);CHKERRQ(ierr);
676       }
677     }
678     *Brhs = ts->Brhs;
679   }
680   PetscFunctionReturn(0);
681 }
682 
683 #undef __FUNCT__
684 #define __FUNCT__ "TSComputeIFunction"
685 /*@
686    TSComputeIFunction - Evaluates the DAE residual written in implicit form F(t,U,Udot)=0
687 
688    Collective on TS and Vec
689 
690    Input Parameters:
691 +  ts - the TS context
692 .  t - current time
693 .  U - state vector
694 .  Udot - time derivative of state vector
695 -  imex - flag indicates if the method is IMEX so that the RHSFunction should be kept separate
696 
697    Output Parameter:
698 .  Y - right hand side
699 
700    Note:
701    Most users should not need to explicitly call this routine, as it
702    is used internally within the nonlinear solvers.
703 
704    If the user did did not write their equations in implicit form, this
705    function recasts them in implicit form.
706 
707    Level: developer
708 
709 .keywords: TS, compute
710 
711 .seealso: TSSetIFunction(), TSComputeRHSFunction()
712 @*/
713 PetscErrorCode TSComputeIFunction(TS ts,PetscReal t,Vec U,Vec Udot,Vec Y,PetscBool imex)
714 {
715   PetscErrorCode ierr;
716   TSIFunction    ifunction;
717   TSRHSFunction  rhsfunction;
718   void           *ctx;
719   DM             dm;
720 
721   PetscFunctionBegin;
722   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
723   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
724   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
725   PetscValidHeaderSpecific(Y,VEC_CLASSID,5);
726 
727   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
728   ierr = DMTSGetIFunction(dm,&ifunction,&ctx);CHKERRQ(ierr);
729   ierr = DMTSGetRHSFunction(dm,&rhsfunction,NULL);CHKERRQ(ierr);
730 
731   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
732 
733   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
734   if (ifunction) {
735     PetscStackPush("TS user implicit function");
736     ierr = (*ifunction)(ts,t,U,Udot,Y,ctx);CHKERRQ(ierr);
737     PetscStackPop;
738   }
739   if (imex) {
740     if (!ifunction) {
741       ierr = VecCopy(Udot,Y);CHKERRQ(ierr);
742     }
743   } else if (rhsfunction) {
744     if (ifunction) {
745       Vec Frhs;
746       ierr = TSGetRHSVec_Private(ts,&Frhs);CHKERRQ(ierr);
747       ierr = TSComputeRHSFunction(ts,t,U,Frhs);CHKERRQ(ierr);
748       ierr = VecAXPY(Y,-1,Frhs);CHKERRQ(ierr);
749     } else {
750       ierr = TSComputeRHSFunction(ts,t,U,Y);CHKERRQ(ierr);
751       ierr = VecAYPX(Y,-1,Udot);CHKERRQ(ierr);
752     }
753   }
754   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
755   PetscFunctionReturn(0);
756 }
757 
758 #undef __FUNCT__
759 #define __FUNCT__ "TSComputeIJacobian"
760 /*@
761    TSComputeIJacobian - Evaluates the Jacobian of the DAE
762 
763    Collective on TS and Vec
764 
765    Input
766       Input Parameters:
767 +  ts - the TS context
768 .  t - current timestep
769 .  U - state vector
770 .  Udot - time derivative of state vector
771 .  shift - shift to apply, see note below
772 -  imex - flag indicates if the method is IMEX so that the RHSJacobian should be kept separate
773 
774    Output Parameters:
775 +  A - Jacobian matrix
776 .  B - optional preconditioning matrix
777 -  flag - flag indicating matrix structure
778 
779    Notes:
780    If F(t,U,Udot)=0 is the DAE, the required Jacobian is
781 
782    dF/dU + shift*dF/dUdot
783 
784    Most users should not need to explicitly call this routine, as it
785    is used internally within the nonlinear solvers.
786 
787    Level: developer
788 
789 .keywords: TS, compute, Jacobian, matrix
790 
791 .seealso:  TSSetIJacobian()
792 @*/
793 PetscErrorCode TSComputeIJacobian(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,PetscBool imex)
794 {
795   PetscErrorCode ierr;
796   TSIJacobian    ijacobian;
797   TSRHSJacobian  rhsjacobian;
798   DM             dm;
799   void           *ctx;
800 
801   PetscFunctionBegin;
802   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
803   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
804   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
805   PetscValidPointer(A,6);
806   PetscValidHeaderSpecific(A,MAT_CLASSID,6);
807   PetscValidPointer(B,7);
808   PetscValidHeaderSpecific(B,MAT_CLASSID,7);
809 
810   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
811   ierr = DMTSGetIJacobian(dm,&ijacobian,&ctx);CHKERRQ(ierr);
812   ierr = DMTSGetRHSJacobian(dm,&rhsjacobian,NULL);CHKERRQ(ierr);
813 
814   if (!rhsjacobian && !ijacobian) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
815 
816   ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
817   if (ijacobian) {
818     PetscStackPush("TS user implicit Jacobian");
819     ierr = (*ijacobian)(ts,t,U,Udot,shift,A,B,ctx);CHKERRQ(ierr);
820     PetscStackPop;
821     /* make sure user returned a correct Jacobian and preconditioner */
822     PetscValidHeaderSpecific(A,MAT_CLASSID,4);
823     PetscValidHeaderSpecific(B,MAT_CLASSID,5);
824   }
825   if (imex) {
826     if (!ijacobian) {  /* system was written as Udot = G(t,U) */
827       ierr = MatZeroEntries(A);CHKERRQ(ierr);
828       ierr = MatShift(A,shift);CHKERRQ(ierr);
829       if (A != B) {
830         ierr = MatZeroEntries(B);CHKERRQ(ierr);
831         ierr = MatShift(B,shift);CHKERRQ(ierr);
832       }
833     }
834   } else {
835     Mat Arhs = NULL,Brhs = NULL;
836     if (rhsjacobian) {
837       if (ijacobian) {
838         ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
839       } else {
840         ierr = TSGetIJacobian(ts,&Arhs,&Brhs,NULL,NULL);CHKERRQ(ierr);
841       }
842       ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
843     }
844     if (Arhs == A) {           /* No IJacobian, so we only have the RHS matrix */
845       ts->rhsjacobian.scale = -1;
846       ts->rhsjacobian.shift = shift;
847       ierr = MatScale(A,-1);CHKERRQ(ierr);
848       ierr = MatShift(A,shift);CHKERRQ(ierr);
849       if (A != B) {
850         ierr = MatScale(B,-1);CHKERRQ(ierr);
851         ierr = MatShift(B,shift);CHKERRQ(ierr);
852       }
853     } else if (Arhs) {          /* Both IJacobian and RHSJacobian */
854       MatStructure axpy = DIFFERENT_NONZERO_PATTERN;
855       if (!ijacobian) {         /* No IJacobian provided, but we have a separate RHS matrix */
856         ierr = MatZeroEntries(A);CHKERRQ(ierr);
857         ierr = MatShift(A,shift);CHKERRQ(ierr);
858         if (A != B) {
859           ierr = MatZeroEntries(B);CHKERRQ(ierr);
860           ierr = MatShift(B,shift);CHKERRQ(ierr);
861         }
862       }
863       ierr = MatAXPY(A,-1,Arhs,axpy);CHKERRQ(ierr);
864       if (A != B) {
865         ierr = MatAXPY(B,-1,Brhs,axpy);CHKERRQ(ierr);
866       }
867     }
868   }
869   ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
870   PetscFunctionReturn(0);
871 }
872 
873 #undef __FUNCT__
874 #define __FUNCT__ "TSSetRHSFunction"
875 /*@C
876     TSSetRHSFunction - Sets the routine for evaluating the function,
877     where U_t = G(t,u).
878 
879     Logically Collective on TS
880 
881     Input Parameters:
882 +   ts - the TS context obtained from TSCreate()
883 .   r - vector to put the computed right hand side (or NULL to have it created)
884 .   f - routine for evaluating the right-hand-side function
885 -   ctx - [optional] user-defined context for private data for the
886           function evaluation routine (may be NULL)
887 
888     Calling sequence of func:
889 $     func (TS ts,PetscReal t,Vec u,Vec F,void *ctx);
890 
891 +   t - current timestep
892 .   u - input vector
893 .   F - function vector
894 -   ctx - [optional] user-defined function context
895 
896     Level: beginner
897 
898 .keywords: TS, timestep, set, right-hand-side, function
899 
900 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSSetIFunction()
901 @*/
902 PetscErrorCode  TSSetRHSFunction(TS ts,Vec r,PetscErrorCode (*f)(TS,PetscReal,Vec,Vec,void*),void *ctx)
903 {
904   PetscErrorCode ierr;
905   SNES           snes;
906   Vec            ralloc = NULL;
907   DM             dm;
908 
909   PetscFunctionBegin;
910   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
911   if (r) PetscValidHeaderSpecific(r,VEC_CLASSID,2);
912 
913   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
914   ierr = DMTSSetRHSFunction(dm,f,ctx);CHKERRQ(ierr);
915   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
916   if (!r && !ts->dm && ts->vec_sol) {
917     ierr = VecDuplicate(ts->vec_sol,&ralloc);CHKERRQ(ierr);
918     r    = ralloc;
919   }
920   ierr = SNESSetFunction(snes,r,SNESTSFormFunction,ts);CHKERRQ(ierr);
921   ierr = VecDestroy(&ralloc);CHKERRQ(ierr);
922   PetscFunctionReturn(0);
923 }
924 
925 #undef __FUNCT__
926 #define __FUNCT__ "TSSetSolutionFunction"
927 /*@C
928     TSSetSolutionFunction - Provide a function that computes the solution of the ODE or DAE
929 
930     Logically Collective on TS
931 
932     Input Parameters:
933 +   ts - the TS context obtained from TSCreate()
934 .   f - routine for evaluating the solution
935 -   ctx - [optional] user-defined context for private data for the
936           function evaluation routine (may be NULL)
937 
938     Calling sequence of func:
939 $     func (TS ts,PetscReal t,Vec u,void *ctx);
940 
941 +   t - current timestep
942 .   u - output vector
943 -   ctx - [optional] user-defined function context
944 
945     Notes:
946     This routine is used for testing accuracy of time integration schemes when you already know the solution.
947     If analytic solutions are not known for your system, consider using the Method of Manufactured Solutions to
948     create closed-form solutions with non-physical forcing terms.
949 
950     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
951 
952     Level: beginner
953 
954 .keywords: TS, timestep, set, right-hand-side, function
955 
956 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetForcingFunction()
957 @*/
958 PetscErrorCode  TSSetSolutionFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
959 {
960   PetscErrorCode ierr;
961   DM             dm;
962 
963   PetscFunctionBegin;
964   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
965   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
966   ierr = DMTSSetSolutionFunction(dm,f,ctx);CHKERRQ(ierr);
967   PetscFunctionReturn(0);
968 }
969 
970 #undef __FUNCT__
971 #define __FUNCT__ "TSSetForcingFunction"
972 /*@C
973     TSSetForcingFunction - Provide a function that computes a forcing term for a ODE or PDE
974 
975     Logically Collective on TS
976 
977     Input Parameters:
978 +   ts - the TS context obtained from TSCreate()
979 .   f - routine for evaluating the forcing function
980 -   ctx - [optional] user-defined context for private data for the
981           function evaluation routine (may be NULL)
982 
983     Calling sequence of func:
984 $     func (TS ts,PetscReal t,Vec u,void *ctx);
985 
986 +   t - current timestep
987 .   u - output vector
988 -   ctx - [optional] user-defined function context
989 
990     Notes:
991     This routine is useful for testing accuracy of time integration schemes when using the Method of Manufactured Solutions to
992     create closed-form solutions with a non-physical forcing term.
993 
994     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
995 
996     Level: beginner
997 
998 .keywords: TS, timestep, set, right-hand-side, function
999 
1000 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetSolutionFunction()
1001 @*/
1002 PetscErrorCode  TSSetForcingFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
1003 {
1004   PetscErrorCode ierr;
1005   DM             dm;
1006 
1007   PetscFunctionBegin;
1008   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1009   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1010   ierr = DMTSSetForcingFunction(dm,f,ctx);CHKERRQ(ierr);
1011   PetscFunctionReturn(0);
1012 }
1013 
1014 #undef __FUNCT__
1015 #define __FUNCT__ "TSSetRHSJacobian"
1016 /*@C
1017    TSSetRHSJacobian - Sets the function to compute the Jacobian of F,
1018    where U_t = G(U,t), as well as the location to store the matrix.
1019 
1020    Logically Collective on TS
1021 
1022    Input Parameters:
1023 +  ts  - the TS context obtained from TSCreate()
1024 .  Amat - (approximate) Jacobian matrix
1025 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
1026 .  f   - the Jacobian evaluation routine
1027 -  ctx - [optional] user-defined context for private data for the
1028          Jacobian evaluation routine (may be NULL)
1029 
1030    Calling sequence of func:
1031 $     func (TS ts,PetscReal t,Vec u,Mat A,Mat B,void *ctx);
1032 
1033 +  t - current timestep
1034 .  u - input vector
1035 .  Amat - (approximate) Jacobian matrix
1036 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
1037 -  ctx - [optional] user-defined context for matrix evaluation routine
1038 
1039 
1040    Level: beginner
1041 
1042 .keywords: TS, timestep, set, right-hand-side, Jacobian
1043 
1044 .seealso: SNESComputeJacobianDefaultColor(), TSSetRHSFunction(), TSRHSJacobianSetReuse(), TSSetIJacobian()
1045 
1046 @*/
1047 PetscErrorCode  TSSetRHSJacobian(TS ts,Mat Amat,Mat Pmat,TSRHSJacobian f,void *ctx)
1048 {
1049   PetscErrorCode ierr;
1050   SNES           snes;
1051   DM             dm;
1052   TSIJacobian    ijacobian;
1053 
1054   PetscFunctionBegin;
1055   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1056   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1057   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1058   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1059   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1060 
1061   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1062   ierr = DMTSSetRHSJacobian(dm,f,ctx);CHKERRQ(ierr);
1063   if (f == TSComputeRHSJacobianConstant) {
1064     /* Handle this case automatically for the user; otherwise user should call themselves. */
1065     ierr = TSRHSJacobianSetReuse(ts,PETSC_TRUE);CHKERRQ(ierr);
1066   }
1067   ierr = DMTSGetIJacobian(dm,&ijacobian,NULL);CHKERRQ(ierr);
1068   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1069   if (!ijacobian) {
1070     ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1071   }
1072   if (Amat) {
1073     ierr = PetscObjectReference((PetscObject)Amat);CHKERRQ(ierr);
1074     ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1075 
1076     ts->Arhs = Amat;
1077   }
1078   if (Pmat) {
1079     ierr = PetscObjectReference((PetscObject)Pmat);CHKERRQ(ierr);
1080     ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1081 
1082     ts->Brhs = Pmat;
1083   }
1084   PetscFunctionReturn(0);
1085 }
1086 
1087 
1088 #undef __FUNCT__
1089 #define __FUNCT__ "TSSetIFunction"
1090 /*@C
1091    TSSetIFunction - Set the function to compute F(t,U,U_t) where F() = 0 is the DAE to be solved.
1092 
1093    Logically Collective on TS
1094 
1095    Input Parameters:
1096 +  ts  - the TS context obtained from TSCreate()
1097 .  r   - vector to hold the residual (or NULL to have it created internally)
1098 .  f   - the function evaluation routine
1099 -  ctx - user-defined context for private data for the function evaluation routine (may be NULL)
1100 
1101    Calling sequence of f:
1102 $  f(TS ts,PetscReal t,Vec u,Vec u_t,Vec F,ctx);
1103 
1104 +  t   - time at step/stage being solved
1105 .  u   - state vector
1106 .  u_t - time derivative of state vector
1107 .  F   - function vector
1108 -  ctx - [optional] user-defined context for matrix evaluation routine
1109 
1110    Important:
1111    The user MUST call either this routine, TSSetRHSFunction().  This routine must be used when not solving an ODE, for example a DAE.
1112 
1113    Level: beginner
1114 
1115 .keywords: TS, timestep, set, DAE, Jacobian
1116 
1117 .seealso: TSSetRHSJacobian(), TSSetRHSFunction(), TSSetIJacobian()
1118 @*/
1119 PetscErrorCode  TSSetIFunction(TS ts,Vec res,TSIFunction f,void *ctx)
1120 {
1121   PetscErrorCode ierr;
1122   SNES           snes;
1123   Vec            resalloc = NULL;
1124   DM             dm;
1125 
1126   PetscFunctionBegin;
1127   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1128   if (res) PetscValidHeaderSpecific(res,VEC_CLASSID,2);
1129 
1130   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1131   ierr = DMTSSetIFunction(dm,f,ctx);CHKERRQ(ierr);
1132 
1133   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1134   if (!res && !ts->dm && ts->vec_sol) {
1135     ierr = VecDuplicate(ts->vec_sol,&resalloc);CHKERRQ(ierr);
1136     res  = resalloc;
1137   }
1138   ierr = SNESSetFunction(snes,res,SNESTSFormFunction,ts);CHKERRQ(ierr);
1139   ierr = VecDestroy(&resalloc);CHKERRQ(ierr);
1140   PetscFunctionReturn(0);
1141 }
1142 
1143 #undef __FUNCT__
1144 #define __FUNCT__ "TSGetIFunction"
1145 /*@C
1146    TSGetIFunction - Returns the vector where the implicit residual is stored and the function/contex to compute it.
1147 
1148    Not Collective
1149 
1150    Input Parameter:
1151 .  ts - the TS context
1152 
1153    Output Parameter:
1154 +  r - vector to hold residual (or NULL)
1155 .  func - the function to compute residual (or NULL)
1156 -  ctx - the function context (or NULL)
1157 
1158    Level: advanced
1159 
1160 .keywords: TS, nonlinear, get, function
1161 
1162 .seealso: TSSetIFunction(), SNESGetFunction()
1163 @*/
1164 PetscErrorCode TSGetIFunction(TS ts,Vec *r,TSIFunction *func,void **ctx)
1165 {
1166   PetscErrorCode ierr;
1167   SNES           snes;
1168   DM             dm;
1169 
1170   PetscFunctionBegin;
1171   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1172   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1173   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1174   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1175   ierr = DMTSGetIFunction(dm,func,ctx);CHKERRQ(ierr);
1176   PetscFunctionReturn(0);
1177 }
1178 
1179 #undef __FUNCT__
1180 #define __FUNCT__ "TSGetRHSFunction"
1181 /*@C
1182    TSGetRHSFunction - Returns the vector where the right hand side is stored and the function/context to compute it.
1183 
1184    Not Collective
1185 
1186    Input Parameter:
1187 .  ts - the TS context
1188 
1189    Output Parameter:
1190 +  r - vector to hold computed right hand side (or NULL)
1191 .  func - the function to compute right hand side (or NULL)
1192 -  ctx - the function context (or NULL)
1193 
1194    Level: advanced
1195 
1196 .keywords: TS, nonlinear, get, function
1197 
1198 .seealso: TSSetRhsfunction(), SNESGetFunction()
1199 @*/
1200 PetscErrorCode TSGetRHSFunction(TS ts,Vec *r,TSRHSFunction *func,void **ctx)
1201 {
1202   PetscErrorCode ierr;
1203   SNES           snes;
1204   DM             dm;
1205 
1206   PetscFunctionBegin;
1207   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1208   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1209   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1210   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1211   ierr = DMTSGetRHSFunction(dm,func,ctx);CHKERRQ(ierr);
1212   PetscFunctionReturn(0);
1213 }
1214 
1215 #undef __FUNCT__
1216 #define __FUNCT__ "TSSetIJacobian"
1217 /*@C
1218    TSSetIJacobian - Set the function to compute the matrix dF/dU + a*dF/dU_t where F(t,U,U_t) is the function
1219         provided with TSSetIFunction().
1220 
1221    Logically Collective on TS
1222 
1223    Input Parameters:
1224 +  ts  - the TS context obtained from TSCreate()
1225 .  Amat - (approximate) Jacobian matrix
1226 .  Pmat - matrix used to compute preconditioner (usually the same as Amat)
1227 .  f   - the Jacobian evaluation routine
1228 -  ctx - user-defined context for private data for the Jacobian evaluation routine (may be NULL)
1229 
1230    Calling sequence of f:
1231 $  f(TS ts,PetscReal t,Vec U,Vec U_t,PetscReal a,Mat Amat,Mat Pmat,void *ctx);
1232 
1233 +  t    - time at step/stage being solved
1234 .  U    - state vector
1235 .  U_t  - time derivative of state vector
1236 .  a    - shift
1237 .  Amat - (approximate) Jacobian of F(t,U,W+a*U), equivalent to dF/dU + a*dF/dU_t
1238 .  Pmat - matrix used for constructing preconditioner, usually the same as Amat
1239 -  ctx  - [optional] user-defined context for matrix evaluation routine
1240 
1241    Notes:
1242    The matrices Amat and Pmat are exactly the matrices that are used by SNES for the nonlinear solve.
1243 
1244    The matrix dF/dU + a*dF/dU_t you provide turns out to be
1245    the Jacobian of F(t,U,W+a*U) where F(t,U,U_t) = 0 is the DAE to be solved.
1246    The time integrator internally approximates U_t by W+a*U where the positive "shift"
1247    a and vector W depend on the integration method, step size, and past states. For example with
1248    the backward Euler method a = 1/dt and W = -a*U(previous timestep) so
1249    W + a*U = a*(U - U(previous timestep)) = (U - U(previous timestep))/dt
1250 
1251    Level: beginner
1252 
1253 .keywords: TS, timestep, DAE, Jacobian
1254 
1255 .seealso: TSSetIFunction(), TSSetRHSJacobian(), SNESComputeJacobianDefaultColor(), SNESComputeJacobianDefault(), TSSetRHSFunction()
1256 
1257 @*/
1258 PetscErrorCode  TSSetIJacobian(TS ts,Mat Amat,Mat Pmat,TSIJacobian f,void *ctx)
1259 {
1260   PetscErrorCode ierr;
1261   SNES           snes;
1262   DM             dm;
1263 
1264   PetscFunctionBegin;
1265   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1266   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1267   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1268   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1269   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1270 
1271   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1272   ierr = DMTSSetIJacobian(dm,f,ctx);CHKERRQ(ierr);
1273 
1274   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1275   ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1276   PetscFunctionReturn(0);
1277 }
1278 
1279 #undef __FUNCT__
1280 #define __FUNCT__ "TSRHSJacobianSetReuse"
1281 /*@
1282    TSRHSJacobianSetReuse - restore RHS Jacobian before re-evaluating.  Without this flag, TS will change the sign and
1283    shift the RHS Jacobian for a finite-time-step implicit solve, in which case the user function will need to recompute
1284    the entire Jacobian.  The reuse flag must be set if the evaluation function will assume that the matrix entries have
1285    not been changed by the TS.
1286 
1287    Logically Collective
1288 
1289    Input Arguments:
1290 +  ts - TS context obtained from TSCreate()
1291 -  reuse - PETSC_TRUE if the RHS Jacobian
1292 
1293    Level: intermediate
1294 
1295 .seealso: TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
1296 @*/
1297 PetscErrorCode TSRHSJacobianSetReuse(TS ts,PetscBool reuse)
1298 {
1299   PetscFunctionBegin;
1300   ts->rhsjacobian.reuse = reuse;
1301   PetscFunctionReturn(0);
1302 }
1303 
1304 #undef __FUNCT__
1305 #define __FUNCT__ "TSLoad"
1306 /*@C
1307   TSLoad - Loads a KSP that has been stored in binary  with KSPView().
1308 
1309   Collective on PetscViewer
1310 
1311   Input Parameters:
1312 + newdm - the newly loaded TS, this needs to have been created with TSCreate() or
1313            some related function before a call to TSLoad().
1314 - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
1315 
1316    Level: intermediate
1317 
1318   Notes:
1319    The type is determined by the data in the file, any type set into the TS before this call is ignored.
1320 
1321   Notes for advanced users:
1322   Most users should not need to know the details of the binary storage
1323   format, since TSLoad() and TSView() completely hide these details.
1324   But for anyone who's interested, the standard binary matrix storage
1325   format is
1326 .vb
1327      has not yet been determined
1328 .ve
1329 
1330 .seealso: PetscViewerBinaryOpen(), TSView(), MatLoad(), VecLoad()
1331 @*/
1332 PetscErrorCode  TSLoad(TS ts, PetscViewer viewer)
1333 {
1334   PetscErrorCode ierr;
1335   PetscBool      isbinary;
1336   PetscInt       classid;
1337   char           type[256];
1338   DMTS           sdm;
1339   DM             dm;
1340 
1341   PetscFunctionBegin;
1342   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1343   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1344   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1345   if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
1346 
1347   ierr = PetscViewerBinaryRead(viewer,&classid,1,PETSC_INT);CHKERRQ(ierr);
1348   if (classid != TS_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Not TS next in file");
1349   ierr = PetscViewerBinaryRead(viewer,type,256,PETSC_CHAR);CHKERRQ(ierr);
1350   ierr = TSSetType(ts, type);CHKERRQ(ierr);
1351   if (ts->ops->load) {
1352     ierr = (*ts->ops->load)(ts,viewer);CHKERRQ(ierr);
1353   }
1354   ierr = DMCreate(PetscObjectComm((PetscObject)ts),&dm);CHKERRQ(ierr);
1355   ierr = DMLoad(dm,viewer);CHKERRQ(ierr);
1356   ierr = TSSetDM(ts,dm);CHKERRQ(ierr);
1357   ierr = DMCreateGlobalVector(ts->dm,&ts->vec_sol);CHKERRQ(ierr);
1358   ierr = VecLoad(ts->vec_sol,viewer);CHKERRQ(ierr);
1359   ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1360   ierr = DMTSLoad(sdm,viewer);CHKERRQ(ierr);
1361   PetscFunctionReturn(0);
1362 }
1363 
1364 #include <petscdraw.h>
1365 #if defined(PETSC_HAVE_SAWS)
1366 #include <petscviewersaws.h>
1367 #endif
1368 #undef __FUNCT__
1369 #define __FUNCT__ "TSView"
1370 /*@C
1371     TSView - Prints the TS data structure.
1372 
1373     Collective on TS
1374 
1375     Input Parameters:
1376 +   ts - the TS context obtained from TSCreate()
1377 -   viewer - visualization context
1378 
1379     Options Database Key:
1380 .   -ts_view - calls TSView() at end of TSStep()
1381 
1382     Notes:
1383     The available visualization contexts include
1384 +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
1385 -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
1386          output where only the first processor opens
1387          the file.  All other processors send their
1388          data to the first processor to print.
1389 
1390     The user can open an alternative visualization context with
1391     PetscViewerASCIIOpen() - output to a specified file.
1392 
1393     Level: beginner
1394 
1395 .keywords: TS, timestep, view
1396 
1397 .seealso: PetscViewerASCIIOpen()
1398 @*/
1399 PetscErrorCode  TSView(TS ts,PetscViewer viewer)
1400 {
1401   PetscErrorCode ierr;
1402   TSType         type;
1403   PetscBool      iascii,isstring,isundials,isbinary,isdraw;
1404   DMTS           sdm;
1405 #if defined(PETSC_HAVE_SAWS)
1406   PetscBool      isams;
1407 #endif
1408 
1409   PetscFunctionBegin;
1410   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1411   if (!viewer) {
1412     ierr = PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ts),&viewer);CHKERRQ(ierr);
1413   }
1414   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1415   PetscCheckSameComm(ts,1,viewer,2);
1416 
1417   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1418   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
1419   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1420   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1421 #if defined(PETSC_HAVE_SAWS)
1422   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&isams);CHKERRQ(ierr);
1423 #endif
1424   if (iascii) {
1425     ierr = PetscObjectPrintClassNamePrefixType((PetscObject)ts,viewer);CHKERRQ(ierr);
1426     ierr = PetscViewerASCIIPrintf(viewer,"  maximum steps=%D\n",ts->max_steps);CHKERRQ(ierr);
1427     ierr = PetscViewerASCIIPrintf(viewer,"  maximum time=%g\n",(double)ts->max_time);CHKERRQ(ierr);
1428     if (ts->problem_type == TS_NONLINEAR) {
1429       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solver iterations=%D\n",ts->snes_its);CHKERRQ(ierr);
1430       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solve failures=%D\n",ts->num_snes_failures);CHKERRQ(ierr);
1431     }
1432     ierr = PetscViewerASCIIPrintf(viewer,"  total number of linear solver iterations=%D\n",ts->ksp_its);CHKERRQ(ierr);
1433     ierr = PetscViewerASCIIPrintf(viewer,"  total number of rejected steps=%D\n",ts->reject);CHKERRQ(ierr);
1434     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1435     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1436     if (ts->ops->view) {
1437       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1438       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1439       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1440     }
1441   } else if (isstring) {
1442     ierr = TSGetType(ts,&type);CHKERRQ(ierr);
1443     ierr = PetscViewerStringSPrintf(viewer," %-7.7s",type);CHKERRQ(ierr);
1444   } else if (isbinary) {
1445     PetscInt    classid = TS_FILE_CLASSID;
1446     MPI_Comm    comm;
1447     PetscMPIInt rank;
1448     char        type[256];
1449 
1450     ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
1451     ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
1452     if (!rank) {
1453       ierr = PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);CHKERRQ(ierr);
1454       ierr = PetscStrncpy(type,((PetscObject)ts)->type_name,256);CHKERRQ(ierr);
1455       ierr = PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);CHKERRQ(ierr);
1456     }
1457     if (ts->ops->view) {
1458       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1459     }
1460     ierr = DMView(ts->dm,viewer);CHKERRQ(ierr);
1461     ierr = VecView(ts->vec_sol,viewer);CHKERRQ(ierr);
1462     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1463     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1464   } else if (isdraw) {
1465     PetscDraw draw;
1466     char      str[36];
1467     PetscReal x,y,bottom,h;
1468 
1469     ierr   = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1470     ierr   = PetscDrawGetCurrentPoint(draw,&x,&y);CHKERRQ(ierr);
1471     ierr   = PetscStrcpy(str,"TS: ");CHKERRQ(ierr);
1472     ierr   = PetscStrcat(str,((PetscObject)ts)->type_name);CHKERRQ(ierr);
1473     ierr   = PetscDrawBoxedString(draw,x,y,PETSC_DRAW_BLACK,PETSC_DRAW_BLACK,str,NULL,&h);CHKERRQ(ierr);
1474     bottom = y - h;
1475     ierr   = PetscDrawPushCurrentPoint(draw,x,bottom);CHKERRQ(ierr);
1476     if (ts->ops->view) {
1477       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1478     }
1479     ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr);
1480 #if defined(PETSC_HAVE_SAWS)
1481   } else if (isams) {
1482     PetscMPIInt rank;
1483     const char  *name;
1484 
1485     ierr = PetscObjectGetName((PetscObject)ts,&name);CHKERRQ(ierr);
1486     ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
1487     if (!((PetscObject)ts)->amsmem && !rank) {
1488       char       dir[1024];
1489 
1490       ierr = PetscObjectViewSAWs((PetscObject)ts,viewer);CHKERRQ(ierr);
1491       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time_step",name);CHKERRQ(ierr);
1492       PetscStackCallSAWs(SAWs_Register,(dir,&ts->steps,1,SAWs_READ,SAWs_INT));
1493       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time",name);CHKERRQ(ierr);
1494       PetscStackCallSAWs(SAWs_Register,(dir,&ts->ptime,1,SAWs_READ,SAWs_DOUBLE));
1495     }
1496     if (ts->ops->view) {
1497       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1498     }
1499 #endif
1500   }
1501 
1502   ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1503   ierr = PetscObjectTypeCompare((PetscObject)ts,TSSUNDIALS,&isundials);CHKERRQ(ierr);
1504   ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1505   PetscFunctionReturn(0);
1506 }
1507 
1508 
1509 #undef __FUNCT__
1510 #define __FUNCT__ "TSSetApplicationContext"
1511 /*@
1512    TSSetApplicationContext - Sets an optional user-defined context for
1513    the timesteppers.
1514 
1515    Logically Collective on TS
1516 
1517    Input Parameters:
1518 +  ts - the TS context obtained from TSCreate()
1519 -  usrP - optional user context
1520 
1521    Level: intermediate
1522 
1523 .keywords: TS, timestep, set, application, context
1524 
1525 .seealso: TSGetApplicationContext()
1526 @*/
1527 PetscErrorCode  TSSetApplicationContext(TS ts,void *usrP)
1528 {
1529   PetscFunctionBegin;
1530   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1531   ts->user = usrP;
1532   PetscFunctionReturn(0);
1533 }
1534 
1535 #undef __FUNCT__
1536 #define __FUNCT__ "TSGetApplicationContext"
1537 /*@
1538     TSGetApplicationContext - Gets the user-defined context for the
1539     timestepper.
1540 
1541     Not Collective
1542 
1543     Input Parameter:
1544 .   ts - the TS context obtained from TSCreate()
1545 
1546     Output Parameter:
1547 .   usrP - user context
1548 
1549     Level: intermediate
1550 
1551 .keywords: TS, timestep, get, application, context
1552 
1553 .seealso: TSSetApplicationContext()
1554 @*/
1555 PetscErrorCode  TSGetApplicationContext(TS ts,void *usrP)
1556 {
1557   PetscFunctionBegin;
1558   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1559   *(void**)usrP = ts->user;
1560   PetscFunctionReturn(0);
1561 }
1562 
1563 #undef __FUNCT__
1564 #define __FUNCT__ "TSGetTimeStepNumber"
1565 /*@
1566    TSGetTimeStepNumber - Gets the number of time steps completed.
1567 
1568    Not Collective
1569 
1570    Input Parameter:
1571 .  ts - the TS context obtained from TSCreate()
1572 
1573    Output Parameter:
1574 .  iter - number of steps completed so far
1575 
1576    Level: intermediate
1577 
1578 .keywords: TS, timestep, get, iteration, number
1579 .seealso: TSGetTime(), TSGetTimeStep(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSSetPostStep()
1580 @*/
1581 PetscErrorCode  TSGetTimeStepNumber(TS ts,PetscInt *iter)
1582 {
1583   PetscFunctionBegin;
1584   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1585   PetscValidIntPointer(iter,2);
1586   *iter = ts->steps;
1587   PetscFunctionReturn(0);
1588 }
1589 
1590 #undef __FUNCT__
1591 #define __FUNCT__ "TSSetInitialTimeStep"
1592 /*@
1593    TSSetInitialTimeStep - Sets the initial timestep to be used,
1594    as well as the initial time.
1595 
1596    Logically Collective on TS
1597 
1598    Input Parameters:
1599 +  ts - the TS context obtained from TSCreate()
1600 .  initial_time - the initial time
1601 -  time_step - the size of the timestep
1602 
1603    Level: intermediate
1604 
1605 .seealso: TSSetTimeStep(), TSGetTimeStep()
1606 
1607 .keywords: TS, set, initial, timestep
1608 @*/
1609 PetscErrorCode  TSSetInitialTimeStep(TS ts,PetscReal initial_time,PetscReal time_step)
1610 {
1611   PetscErrorCode ierr;
1612 
1613   PetscFunctionBegin;
1614   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1615   ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
1616   ierr = TSSetTime(ts,initial_time);CHKERRQ(ierr);
1617   PetscFunctionReturn(0);
1618 }
1619 
1620 #undef __FUNCT__
1621 #define __FUNCT__ "TSSetTimeStep"
1622 /*@
1623    TSSetTimeStep - Allows one to reset the timestep at any time,
1624    useful for simple pseudo-timestepping codes.
1625 
1626    Logically Collective on TS
1627 
1628    Input Parameters:
1629 +  ts - the TS context obtained from TSCreate()
1630 -  time_step - the size of the timestep
1631 
1632    Level: intermediate
1633 
1634 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1635 
1636 .keywords: TS, set, timestep
1637 @*/
1638 PetscErrorCode  TSSetTimeStep(TS ts,PetscReal time_step)
1639 {
1640   PetscFunctionBegin;
1641   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1642   PetscValidLogicalCollectiveReal(ts,time_step,2);
1643   ts->time_step      = time_step;
1644   ts->time_step_orig = time_step;
1645   PetscFunctionReturn(0);
1646 }
1647 
1648 #undef __FUNCT__
1649 #define __FUNCT__ "TSSetExactFinalTime"
1650 /*@
1651    TSSetExactFinalTime - Determines whether to adapt the final time step to
1652      match the exact final time, interpolate solution to the exact final time,
1653      or just return at the final time TS computed.
1654 
1655   Logically Collective on TS
1656 
1657    Input Parameter:
1658 +   ts - the time-step context
1659 -   eftopt - exact final time option
1660 
1661    Level: beginner
1662 
1663 .seealso: TSExactFinalTimeOption
1664 @*/
1665 PetscErrorCode  TSSetExactFinalTime(TS ts,TSExactFinalTimeOption eftopt)
1666 {
1667   PetscFunctionBegin;
1668   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1669   PetscValidLogicalCollectiveEnum(ts,eftopt,2);
1670   ts->exact_final_time = eftopt;
1671   PetscFunctionReturn(0);
1672 }
1673 
1674 #undef __FUNCT__
1675 #define __FUNCT__ "TSGetTimeStep"
1676 /*@
1677    TSGetTimeStep - Gets the current timestep size.
1678 
1679    Not Collective
1680 
1681    Input Parameter:
1682 .  ts - the TS context obtained from TSCreate()
1683 
1684    Output Parameter:
1685 .  dt - the current timestep size
1686 
1687    Level: intermediate
1688 
1689 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1690 
1691 .keywords: TS, get, timestep
1692 @*/
1693 PetscErrorCode  TSGetTimeStep(TS ts,PetscReal *dt)
1694 {
1695   PetscFunctionBegin;
1696   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1697   PetscValidRealPointer(dt,2);
1698   *dt = ts->time_step;
1699   PetscFunctionReturn(0);
1700 }
1701 
1702 #undef __FUNCT__
1703 #define __FUNCT__ "TSGetSolution"
1704 /*@
1705    TSGetSolution - Returns the solution at the present timestep. It
1706    is valid to call this routine inside the function that you are evaluating
1707    in order to move to the new timestep. This vector not changed until
1708    the solution at the next timestep has been calculated.
1709 
1710    Not Collective, but Vec returned is parallel if TS is parallel
1711 
1712    Input Parameter:
1713 .  ts - the TS context obtained from TSCreate()
1714 
1715    Output Parameter:
1716 .  v - the vector containing the solution
1717 
1718    Level: intermediate
1719 
1720 .seealso: TSGetTimeStep()
1721 
1722 .keywords: TS, timestep, get, solution
1723 @*/
1724 PetscErrorCode  TSGetSolution(TS ts,Vec *v)
1725 {
1726   PetscFunctionBegin;
1727   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1728   PetscValidPointer(v,2);
1729   *v = ts->vec_sol;
1730   PetscFunctionReturn(0);
1731 }
1732 
1733 #undef __FUNCT__
1734 #define __FUNCT__ "TSGetSensitivity"
1735 /*@
1736    TSGetSensitivity - Returns the sensitivity in the reverse mode.
1737 
1738    Not Collective, but Vec returned is parallel if TS is parallel
1739 
1740    Input Parameter:
1741 .  ts - the TS context obtained from TSCreate()
1742 
1743    Output Parameter:
1744 .  v - the vector containing the solution
1745 
1746    Level: intermediate
1747 
1748 .seealso: TSGetTimeStep()
1749 
1750 .keywords: TS, timestep, get, sensitivity
1751 @*/
1752 PetscErrorCode  TSGetSensitivity(TS ts,Vec **v,PetscInt *numberadjs)
1753 {
1754   PetscFunctionBegin;
1755   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1756   PetscValidPointer(v,2);
1757   *v          = ts->vecs_sensi;
1758   if(numberadjs) *numberadjs = ts->numberadjs;
1759   PetscFunctionReturn(0);
1760 }
1761 
1762 /* ----- Routines to initialize and destroy a timestepper ---- */
1763 #undef __FUNCT__
1764 #define __FUNCT__ "TSSetProblemType"
1765 /*@
1766   TSSetProblemType - Sets the type of problem to be solved.
1767 
1768   Not collective
1769 
1770   Input Parameters:
1771 + ts   - The TS
1772 - type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1773 .vb
1774          U_t - A U = 0      (linear)
1775          U_t - A(t) U = 0   (linear)
1776          F(t,U,U_t) = 0     (nonlinear)
1777 .ve
1778 
1779    Level: beginner
1780 
1781 .keywords: TS, problem type
1782 .seealso: TSSetUp(), TSProblemType, TS
1783 @*/
1784 PetscErrorCode  TSSetProblemType(TS ts, TSProblemType type)
1785 {
1786   PetscErrorCode ierr;
1787 
1788   PetscFunctionBegin;
1789   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1790   ts->problem_type = type;
1791   if (type == TS_LINEAR) {
1792     SNES snes;
1793     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1794     ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);
1795   }
1796   PetscFunctionReturn(0);
1797 }
1798 
1799 #undef __FUNCT__
1800 #define __FUNCT__ "TSGetProblemType"
1801 /*@C
1802   TSGetProblemType - Gets the type of problem to be solved.
1803 
1804   Not collective
1805 
1806   Input Parameter:
1807 . ts   - The TS
1808 
1809   Output Parameter:
1810 . type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1811 .vb
1812          M U_t = A U
1813          M(t) U_t = A(t) U
1814          F(t,U,U_t)
1815 .ve
1816 
1817    Level: beginner
1818 
1819 .keywords: TS, problem type
1820 .seealso: TSSetUp(), TSProblemType, TS
1821 @*/
1822 PetscErrorCode  TSGetProblemType(TS ts, TSProblemType *type)
1823 {
1824   PetscFunctionBegin;
1825   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1826   PetscValidIntPointer(type,2);
1827   *type = ts->problem_type;
1828   PetscFunctionReturn(0);
1829 }
1830 
1831 #undef __FUNCT__
1832 #define __FUNCT__ "TSSetUp"
1833 /*@
1834    TSSetUp - Sets up the internal data structures for the later use
1835    of a timestepper.
1836 
1837    Collective on TS
1838 
1839    Input Parameter:
1840 .  ts - the TS context obtained from TSCreate()
1841 
1842    Notes:
1843    For basic use of the TS solvers the user need not explicitly call
1844    TSSetUp(), since these actions will automatically occur during
1845    the call to TSStep().  However, if one wishes to control this
1846    phase separately, TSSetUp() should be called after TSCreate()
1847    and optional routines of the form TSSetXXX(), but before TSStep().
1848 
1849    Level: advanced
1850 
1851 .keywords: TS, timestep, setup
1852 
1853 .seealso: TSCreate(), TSStep(), TSDestroy()
1854 @*/
1855 PetscErrorCode  TSSetUp(TS ts)
1856 {
1857   PetscErrorCode ierr;
1858   DM             dm;
1859   PetscErrorCode (*func)(SNES,Vec,Vec,void*);
1860   PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
1861   TSIJacobian    ijac;
1862   TSRHSJacobian  rhsjac;
1863 
1864   PetscFunctionBegin;
1865   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1866   if (ts->setupcalled) PetscFunctionReturn(0);
1867 
1868   if (!((PetscObject)ts)->type_name) {
1869     ierr = TSSetType(ts,TSEULER);CHKERRQ(ierr);
1870   }
1871 
1872   if (!ts->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call TSSetSolution() first");
1873 
1874   if (ts->reverse_mode && !ts->vecs_sensi) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call TSSetSensitivity() first");
1875 
1876   ierr = TSGetAdapt(ts,&ts->adapt);CHKERRQ(ierr);
1877 
1878   if (ts->rhsjacobian.reuse) {
1879     Mat Amat,Pmat;
1880     SNES snes;
1881     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1882     ierr = SNESGetJacobian(snes,&Amat,&Pmat,NULL,NULL);CHKERRQ(ierr);
1883     /* Matching matrices implies that an IJacobian is NOT set, because if it had been set, the IJacobian's matrix would
1884      * have displaced the RHS matrix */
1885     if (Amat == ts->Arhs) {
1886       ierr = MatDuplicate(ts->Arhs,MAT_DO_NOT_COPY_VALUES,&Amat);CHKERRQ(ierr);
1887       ierr = SNESSetJacobian(snes,Amat,NULL,NULL,NULL);CHKERRQ(ierr);
1888       ierr = MatDestroy(&Amat);CHKERRQ(ierr);
1889     }
1890     if (Pmat == ts->Brhs) {
1891       ierr = MatDuplicate(ts->Brhs,MAT_DO_NOT_COPY_VALUES,&Pmat);CHKERRQ(ierr);
1892       ierr = SNESSetJacobian(snes,NULL,Pmat,NULL,NULL);CHKERRQ(ierr);
1893       ierr = MatDestroy(&Pmat);CHKERRQ(ierr);
1894     }
1895   }
1896   if (ts->ops->setup) {
1897     ierr = (*ts->ops->setup)(ts);CHKERRQ(ierr);
1898   }
1899 
1900   /* in the case where we've set a DMTSFunction or what have you, we need the default SNESFunction
1901    to be set right but can't do it elsewhere due to the overreliance on ctx=ts.
1902    */
1903   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1904   ierr = DMSNESGetFunction(dm,&func,NULL);CHKERRQ(ierr);
1905   if (!func) {
1906     ierr =DMSNESSetFunction(dm,SNESTSFormFunction,ts);CHKERRQ(ierr);
1907   }
1908   /* if the SNES doesn't have a jacobian set and the TS has an ijacobian or rhsjacobian set, set the SNES to use it.
1909      Otherwise, the SNES will use coloring internally to form the Jacobian.
1910    */
1911   ierr = DMSNESGetJacobian(dm,&jac,NULL);CHKERRQ(ierr);
1912   ierr = DMTSGetIJacobian(dm,&ijac,NULL);CHKERRQ(ierr);
1913   ierr = DMTSGetRHSJacobian(dm,&rhsjac,NULL);CHKERRQ(ierr);
1914   if (!jac && (ijac || rhsjac)) {
1915     ierr = DMSNESSetJacobian(dm,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1916   }
1917   ts->setupcalled = PETSC_TRUE;
1918   PetscFunctionReturn(0);
1919 }
1920 
1921 #undef __FUNCT__
1922 #define __FUNCT__ "TSReset"
1923 /*@
1924    TSReset - Resets a TS context and removes any allocated Vecs and Mats.
1925 
1926    Collective on TS
1927 
1928    Input Parameter:
1929 .  ts - the TS context obtained from TSCreate()
1930 
1931    Level: beginner
1932 
1933 .keywords: TS, timestep, reset
1934 
1935 .seealso: TSCreate(), TSSetup(), TSDestroy()
1936 @*/
1937 PetscErrorCode  TSReset(TS ts)
1938 {
1939   PetscErrorCode ierr;
1940 
1941   PetscFunctionBegin;
1942   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1943 
1944   if (ts->ops->reset) {
1945     ierr = (*ts->ops->reset)(ts);CHKERRQ(ierr);
1946   }
1947   if (ts->snes) {ierr = SNESReset(ts->snes);CHKERRQ(ierr);}
1948 
1949   ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1950   ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1951   ierr = VecDestroy(&ts->Frhs);CHKERRQ(ierr);
1952   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
1953   ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
1954   ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
1955   ierr = VecDestroyVecs(ts->nwork,&ts->work);CHKERRQ(ierr);
1956   if (ts->reverse_mode) {
1957     ts->vecs_sensi = 0;
1958     if (ts->vecs_sensip) {
1959       ts->vecs_sensip = 0;
1960       ierr = MatDestroy(&ts->Jacp);CHKERRQ(ierr);
1961     }
1962     if (ts->vec_costquad) {
1963       ierr = VecDestroy(&ts->vec_costquad);CHKERRQ(ierr);
1964       ierr = VecDestroy(&ts->vec_costintegrand);CHKERRQ(ierr);
1965     }
1966   }
1967   ts->setupcalled = PETSC_FALSE;
1968   PetscFunctionReturn(0);
1969 }
1970 
1971 #undef __FUNCT__
1972 #define __FUNCT__ "TSDestroy"
1973 /*@
1974    TSDestroy - Destroys the timestepper context that was created
1975    with TSCreate().
1976 
1977    Collective on TS
1978 
1979    Input Parameter:
1980 .  ts - the TS context obtained from TSCreate()
1981 
1982    Level: beginner
1983 
1984 .keywords: TS, timestepper, destroy
1985 
1986 .seealso: TSCreate(), TSSetUp(), TSSolve()
1987 @*/
1988 PetscErrorCode  TSDestroy(TS *ts)
1989 {
1990   PetscErrorCode ierr;
1991 
1992   PetscFunctionBegin;
1993   if (!*ts) PetscFunctionReturn(0);
1994   PetscValidHeaderSpecific((*ts),TS_CLASSID,1);
1995   if (--((PetscObject)(*ts))->refct > 0) {*ts = 0; PetscFunctionReturn(0);}
1996 
1997   ierr = TSReset((*ts));CHKERRQ(ierr);
1998 
1999   /* if memory was published with SAWs then destroy it */
2000   ierr = PetscObjectSAWsViewOff((PetscObject)*ts);CHKERRQ(ierr);
2001   if ((*ts)->ops->destroy) {ierr = (*(*ts)->ops->destroy)((*ts));CHKERRQ(ierr);}
2002 
2003   ierr = TSAdaptDestroy(&(*ts)->adapt);CHKERRQ(ierr);
2004   if ((*ts)->event) {
2005     ierr = TSEventMonitorDestroy(&(*ts)->event);CHKERRQ(ierr);
2006   }
2007   ierr = SNESDestroy(&(*ts)->snes);CHKERRQ(ierr);
2008   ierr = DMDestroy(&(*ts)->dm);CHKERRQ(ierr);
2009   ierr = TSMonitorCancel((*ts));CHKERRQ(ierr);
2010 
2011   ierr = PetscHeaderDestroy(ts);CHKERRQ(ierr);
2012   PetscFunctionReturn(0);
2013 }
2014 
2015 #undef __FUNCT__
2016 #define __FUNCT__ "TSGetSNES"
2017 /*@
2018    TSGetSNES - Returns the SNES (nonlinear solver) associated with
2019    a TS (timestepper) context. Valid only for nonlinear problems.
2020 
2021    Not Collective, but SNES is parallel if TS is parallel
2022 
2023    Input Parameter:
2024 .  ts - the TS context obtained from TSCreate()
2025 
2026    Output Parameter:
2027 .  snes - the nonlinear solver context
2028 
2029    Notes:
2030    The user can then directly manipulate the SNES context to set various
2031    options, etc.  Likewise, the user can then extract and manipulate the
2032    KSP, KSP, and PC contexts as well.
2033 
2034    TSGetSNES() does not work for integrators that do not use SNES; in
2035    this case TSGetSNES() returns NULL in snes.
2036 
2037    Level: beginner
2038 
2039 .keywords: timestep, get, SNES
2040 @*/
2041 PetscErrorCode  TSGetSNES(TS ts,SNES *snes)
2042 {
2043   PetscErrorCode ierr;
2044 
2045   PetscFunctionBegin;
2046   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2047   PetscValidPointer(snes,2);
2048   if (!ts->snes) {
2049     ierr = SNESCreate(PetscObjectComm((PetscObject)ts),&ts->snes);CHKERRQ(ierr);
2050     ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
2051     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->snes);CHKERRQ(ierr);
2052     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->snes,(PetscObject)ts,1);CHKERRQ(ierr);
2053     if (ts->dm) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
2054     if (ts->problem_type == TS_LINEAR) {
2055       ierr = SNESSetType(ts->snes,SNESKSPONLY);CHKERRQ(ierr);
2056     }
2057   }
2058   *snes = ts->snes;
2059   PetscFunctionReturn(0);
2060 }
2061 
2062 #undef __FUNCT__
2063 #define __FUNCT__ "TSSetSNES"
2064 /*@
2065    TSSetSNES - Set the SNES (nonlinear solver) to be used by the timestepping context
2066 
2067    Collective
2068 
2069    Input Parameter:
2070 +  ts - the TS context obtained from TSCreate()
2071 -  snes - the nonlinear solver context
2072 
2073    Notes:
2074    Most users should have the TS created by calling TSGetSNES()
2075 
2076    Level: developer
2077 
2078 .keywords: timestep, set, SNES
2079 @*/
2080 PetscErrorCode TSSetSNES(TS ts,SNES snes)
2081 {
2082   PetscErrorCode ierr;
2083   PetscErrorCode (*func)(SNES,Vec,Mat,Mat,void*);
2084 
2085   PetscFunctionBegin;
2086   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2087   PetscValidHeaderSpecific(snes,SNES_CLASSID,2);
2088   ierr = PetscObjectReference((PetscObject)snes);CHKERRQ(ierr);
2089   ierr = SNESDestroy(&ts->snes);CHKERRQ(ierr);
2090 
2091   ts->snes = snes;
2092 
2093   ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
2094   ierr = SNESGetJacobian(ts->snes,NULL,NULL,&func,NULL);CHKERRQ(ierr);
2095   if (func == SNESTSFormJacobian) {
2096     ierr = SNESSetJacobian(ts->snes,NULL,NULL,SNESTSFormJacobian,ts);CHKERRQ(ierr);
2097   }
2098   PetscFunctionReturn(0);
2099 }
2100 
2101 #undef __FUNCT__
2102 #define __FUNCT__ "TSGetKSP"
2103 /*@
2104    TSGetKSP - Returns the KSP (linear solver) associated with
2105    a TS (timestepper) context.
2106 
2107    Not Collective, but KSP is parallel if TS is parallel
2108 
2109    Input Parameter:
2110 .  ts - the TS context obtained from TSCreate()
2111 
2112    Output Parameter:
2113 .  ksp - the nonlinear solver context
2114 
2115    Notes:
2116    The user can then directly manipulate the KSP context to set various
2117    options, etc.  Likewise, the user can then extract and manipulate the
2118    KSP and PC contexts as well.
2119 
2120    TSGetKSP() does not work for integrators that do not use KSP;
2121    in this case TSGetKSP() returns NULL in ksp.
2122 
2123    Level: beginner
2124 
2125 .keywords: timestep, get, KSP
2126 @*/
2127 PetscErrorCode  TSGetKSP(TS ts,KSP *ksp)
2128 {
2129   PetscErrorCode ierr;
2130   SNES           snes;
2131 
2132   PetscFunctionBegin;
2133   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2134   PetscValidPointer(ksp,2);
2135   if (!((PetscObject)ts)->type_name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"KSP is not created yet. Call TSSetType() first");
2136   if (ts->problem_type != TS_LINEAR) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Linear only; use TSGetSNES()");
2137   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2138   ierr = SNESGetKSP(snes,ksp);CHKERRQ(ierr);
2139   PetscFunctionReturn(0);
2140 }
2141 
2142 /* ----------- Routines to set solver parameters ---------- */
2143 
2144 #undef __FUNCT__
2145 #define __FUNCT__ "TSGetDuration"
2146 /*@
2147    TSGetDuration - Gets the maximum number of timesteps to use and
2148    maximum time for iteration.
2149 
2150    Not Collective
2151 
2152    Input Parameters:
2153 +  ts       - the TS context obtained from TSCreate()
2154 .  maxsteps - maximum number of iterations to use, or NULL
2155 -  maxtime  - final time to iterate to, or NULL
2156 
2157    Level: intermediate
2158 
2159 .keywords: TS, timestep, get, maximum, iterations, time
2160 @*/
2161 PetscErrorCode  TSGetDuration(TS ts, PetscInt *maxsteps, PetscReal *maxtime)
2162 {
2163   PetscFunctionBegin;
2164   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2165   if (maxsteps) {
2166     PetscValidIntPointer(maxsteps,2);
2167     *maxsteps = ts->max_steps;
2168   }
2169   if (maxtime) {
2170     PetscValidScalarPointer(maxtime,3);
2171     *maxtime = ts->max_time;
2172   }
2173   PetscFunctionReturn(0);
2174 }
2175 
2176 #undef __FUNCT__
2177 #define __FUNCT__ "TSSetDuration"
2178 /*@
2179    TSSetDuration - Sets the maximum number of timesteps to use and
2180    maximum time for iteration.
2181 
2182    Logically Collective on TS
2183 
2184    Input Parameters:
2185 +  ts - the TS context obtained from TSCreate()
2186 .  maxsteps - maximum number of iterations to use
2187 -  maxtime - final time to iterate to
2188 
2189    Options Database Keys:
2190 .  -ts_max_steps <maxsteps> - Sets maxsteps
2191 .  -ts_final_time <maxtime> - Sets maxtime
2192 
2193    Notes:
2194    The default maximum number of iterations is 5000. Default time is 5.0
2195 
2196    Level: intermediate
2197 
2198 .keywords: TS, timestep, set, maximum, iterations
2199 
2200 .seealso: TSSetExactFinalTime()
2201 @*/
2202 PetscErrorCode  TSSetDuration(TS ts,PetscInt maxsteps,PetscReal maxtime)
2203 {
2204   PetscFunctionBegin;
2205   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2206   PetscValidLogicalCollectiveInt(ts,maxsteps,2);
2207   PetscValidLogicalCollectiveReal(ts,maxtime,2);
2208   if (maxsteps >= 0) ts->max_steps = maxsteps;
2209   if (maxtime != PETSC_DEFAULT) ts->max_time = maxtime;
2210   PetscFunctionReturn(0);
2211 }
2212 
2213 #undef __FUNCT__
2214 #define __FUNCT__ "TSSetSolution"
2215 /*@
2216    TSSetSolution - Sets the initial solution vector
2217    for use by the TS routines.
2218 
2219    Logically Collective on TS and Vec
2220 
2221    Input Parameters:
2222 +  ts - the TS context obtained from TSCreate()
2223 -  u - the solution vector
2224 
2225    Level: beginner
2226 
2227 .keywords: TS, timestep, set, solution, initial conditions
2228 @*/
2229 PetscErrorCode  TSSetSolution(TS ts,Vec u)
2230 {
2231   PetscErrorCode ierr;
2232   DM             dm;
2233 
2234   PetscFunctionBegin;
2235   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2236   PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2237   ierr = PetscObjectReference((PetscObject)u);CHKERRQ(ierr);
2238   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
2239 
2240   ts->vec_sol = u;
2241 
2242   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
2243   ierr = DMShellSetGlobalVector(dm,u);CHKERRQ(ierr);
2244   PetscFunctionReturn(0);
2245 }
2246 
2247 #undef __FUNCT__
2248 #define __FUNCT__ "TSSetSensitivity"
2249 /*@
2250    TSSetSensitivity - Sets the initial value of sensitivity (w.r.t. initial conditions)
2251    for use by the TS routines.
2252 
2253    Logically Collective on TS and Vec
2254 
2255    Input Parameters:
2256 +  ts - the TS context obtained from TSCreate()
2257 -  u - the solution vector
2258 
2259    Level: beginner
2260 
2261 .keywords: TS, timestep, set, sensitivity, initial conditions
2262 @*/
2263 PetscErrorCode  TSSetSensitivity(TS ts,Vec *u,PetscInt numberadjs)
2264 {
2265   PetscFunctionBegin;
2266   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2267   PetscValidPointer(u,2);
2268   ts->vecs_sensi = u;
2269   if(ts->numberadjs && ts->numberadjs!=numberadjs) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"The number of adjoint variables (3rd parameter) is inconsistent with the one set by TSSetSensitivityP()");
2270   ts->numberadjs = numberadjs;
2271 
2272   PetscFunctionReturn(0);
2273 }
2274 
2275 #undef __FUNCT__
2276 #define __FUNCT__ "TSSetSensitivityP"
2277 /*@
2278    TSSetSensitivityP - Sets the initial value of sensitivity (w.r.t. parameters)
2279    for use by the TS routines.
2280 
2281    Logically Collective on TS and Vec
2282 
2283    Input Parameters:
2284 +  ts - the TS context obtained from TSCreate()
2285 -  u - the solution vector
2286 
2287    Level: beginner
2288 
2289 .keywords: TS, timestep, set, sensitivity, initial conditions
2290 @*/
2291 PetscErrorCode  TSSetSensitivityP(TS ts,Vec *u,PetscInt numberadjs)
2292 {
2293   PetscFunctionBegin;
2294   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2295   PetscValidPointer(u,2);
2296   ts->vecs_sensip = u;
2297   if(ts->numberadjs && ts->numberadjs!=numberadjs) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"The number of adjoint variables (3rd parameter) is inconsistent with the one set by TSSetSensitivity()");
2298   ts->numberadjs = numberadjs;
2299 
2300   PetscFunctionReturn(0);
2301 }
2302 
2303 #undef __FUNCT__
2304 #define __FUNCT__ "TSSetRHSJacobianP"
2305 /*@C
2306   TSSetRHSJacobianP - Sets the function that computes the Jacobian w.r.t. parameters.
2307 
2308   Logically Collective on TS
2309 
2310   Input Parameters:
2311 + ts   - The TS context obtained from TSCreate()
2312 - func - The function
2313 
2314   Calling sequence of func:
2315 $ func (TS ts,PetscReal t,Vec u,Mat A,void *ctx);
2316 +   t - current timestep
2317 .   u - input vector
2318 .   A - output matrix
2319 -   ctx - [optional] user-defined function context
2320 
2321   Level: intermediate
2322 
2323 .keywords: TS, sensitivity
2324 .seealso:
2325 @*/
2326 PetscErrorCode  TSSetRHSJacobianP(TS ts,Mat Amat,PetscErrorCode (*func)(TS,PetscReal,Vec,Mat,void*),void *ctx)
2327 {
2328   PetscErrorCode ierr;
2329 
2330   PetscFunctionBegin;
2331   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2332   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
2333 
2334   ts->rhsjacobianp    = func;
2335   ts->rhsjacobianpctx = ctx;
2336   if(Amat) {
2337     ierr = PetscObjectReference((PetscObject)Amat);CHKERRQ(ierr);
2338     ierr = MatDestroy(&ts->Jacp);CHKERRQ(ierr);
2339 
2340     ts->Jacp = Amat;
2341   }
2342   PetscFunctionReturn(0);
2343 }
2344 
2345 #undef __FUNCT__
2346 #define __FUNCT__ "TSRHSJacobianP"
2347 /*@
2348   TSRHSJacobianP - Runs the user-defined JacobianP function.
2349 
2350   Collective on TS
2351 
2352   Input Parameters:
2353 . ts   - The TS context obtained from TSCreate()
2354 
2355   Notes:
2356   TSJacobianP() is typically used for sensitivity implementation,
2357   so most users would not generally call this routine themselves.
2358 
2359   Level: developer
2360 
2361 .keywords: TS, sensitivity
2362 .seealso: TSSetRHSJacobianP()
2363 @*/
2364 PetscErrorCode  TSRHSJacobianP(TS ts,PetscReal t,Vec X,Mat Amat)
2365 {
2366   PetscErrorCode ierr;
2367 
2368   PetscFunctionBegin;
2369   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2370   PetscValidHeaderSpecific(X,VEC_CLASSID,3);
2371   PetscValidPointer(Amat,4);
2372 
2373   PetscStackPush("TS user JacobianP function for sensitivity analysis");
2374   ierr = (*ts->rhsjacobianp)(ts,t,X,Amat,ts->rhsjacobianpctx); CHKERRQ(ierr);
2375   PetscStackPop;
2376 
2377   PetscFunctionReturn(0);
2378 }
2379 
2380 #undef __FUNCT__
2381 #define __FUNCT__ "TSSetCostIntegrand"
2382 /*@C
2383     TSSetCostIntegrand - Sets the routine for evaluating the quadrature (or integral) term in a cost function,
2384     where Q_t = r(t,u).
2385 
2386     Logically Collective on TS
2387 
2388     Input Parameters:
2389 +   ts - the TS context obtained from TSCreate()
2390 .   q -  vector to put the computed quadrature term in the cost function (or NULL to have it created)
2391 .   fq - routine for evaluating the right-hand-side function
2392 -   ctx - [optional] user-defined context for private data for the
2393           function evaluation routine (may be NULL)
2394 
2395     Calling sequence of func:
2396 $     TSCostIntegrand(TS ts,PetscReal t,Vec u,PetscReal *f,void *ctx);
2397 
2398 +   t - current timestep
2399 .   u - input vector
2400 .   f - function vector
2401 -   ctx - [optional] user-defined function context
2402 
2403     Level: beginner
2404 
2405 .keywords: TS, sensitivity analysis, timestep, set, quadrature, function
2406 
2407 .seealso: TSSetRHSJacobianP(),TSSetSensitivity(),TSSetSensitivityP()
2408 @*/
2409 PetscErrorCode  TSSetCostIntegrand(TS ts,PetscInt numberadjs,Vec q,TSCostIntegrand fq,void *ctx)
2410 {
2411   PetscErrorCode ierr;
2412   PetscInt size;
2413 
2414   PetscFunctionBegin;
2415   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2416   if (q) {
2417     PetscValidHeaderSpecific(q,VEC_CLASSID,2);
2418   } else {
2419     SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"TSSetCostIntegrand() requires a vector of size numberajds to hold the value of integrals as 3rd input parameter");
2420   }
2421   if (!ts->numberadjs) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Call TSSetSensitivity() or TSSetSensitivityP() first so that the number of cost functions can be determined.");
2422   if (ts->numberadjs && ts->numberadjs!=numberadjs) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"The number of cost functions (2rd parameter of TSSetCostIntegrand()) is inconsistent with the one set by TSSetSensitivity() or TSSetSensitivityP()");
2423   ierr = VecGetSize(q,&size);CHKERRQ(ierr);
2424   ierr = VecZeroEntries(q);CHKERRQ(ierr);
2425   if (size!=numberadjs) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"The number of cost functions is inconsistent with the number of integrals (size of the 3rd input vector of TSSetCostIntegrand()).");
2426 
2427   ierr = PetscObjectReference((PetscObject)q);CHKERRQ(ierr);
2428   ierr = VecDestroy(&ts->vec_costquad);CHKERRQ(ierr);
2429   ts->vec_costquad = q;
2430 
2431   ierr                  = VecDuplicate(ts->vec_costquad,&ts->vec_costintegrand);CHKERRQ(ierr);
2432   ts->costintegrand     = fq;
2433   ts->costintegrandctx  = ctx;
2434 
2435   PetscFunctionReturn(0);
2436 }
2437 
2438 #undef __FUNCT__
2439 #define __FUNCT__ "TSGetCostQuad"
2440 /*@
2441    TSGetCostQuad - Returns the values of the quadrature (or integral) terms in a cost function.
2442    It is valid to call the routine after a backward run.
2443 
2444    Not Collective
2445 
2446    Input Parameter:
2447 .  ts - the TS context obtained from TSCreate()
2448 
2449    Output Parameter:
2450 .  v - the vector containing the solution
2451 
2452    Level: intermediate
2453 
2454 .seealso: TSSetCostIntegrand()
2455 
2456 .keywords: TS, sensitivity analysis
2457 @*/
2458 PetscErrorCode  TSGetCostQuad(TS ts,Vec *v)
2459 {
2460   PetscFunctionBegin;
2461   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2462   PetscValidPointer(v,2);
2463   *v = ts->vec_costquad;
2464   PetscFunctionReturn(0);
2465 }
2466 
2467 #undef __FUNCT__
2468 #define __FUNCT__ "TSComputeCostIntegrand"
2469 /*@
2470    TSComputeCostIntegrand - Evaluates the quadrature function in the cost functions.
2471 
2472    Input Parameters:
2473 +  ts - the TS context
2474 .  t - current time
2475 -  U - state vector
2476 
2477    Output Parameter:
2478 .  q - vector of size numberadjs to hold the outputs
2479 
2480    Note:
2481    Most users should not need to explicitly call this routine, as it
2482    is used internally within the sensitivity analysis context.
2483 
2484    Level: developer
2485 
2486 .keywords: TS, compute
2487 
2488 .seealso: TSSetCostIntegrand()
2489 @*/
2490 PetscErrorCode TSComputeCostIntegrand(TS ts,PetscReal t,Vec U,Vec q)
2491 {
2492   PetscErrorCode ierr;
2493 
2494   PetscFunctionBegin;
2495   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2496   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2497   PetscValidHeaderSpecific(q,VEC_CLASSID,4);
2498 
2499   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,q,0);CHKERRQ(ierr);
2500   if (ts->costintegrand) {
2501     PetscStackPush("TS user integrand in the cost function");
2502     ierr = (*ts->costintegrand)(ts,t,U,q,ts->costintegrandctx);CHKERRQ(ierr);
2503     PetscStackPop;
2504   } else {
2505     ierr = VecZeroEntries(q);CHKERRQ(ierr);
2506   }
2507 
2508   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,q,0);CHKERRQ(ierr);
2509   PetscFunctionReturn(0);
2510 }
2511 
2512 #undef __FUNCT__
2513 #define __FUNCT__ "TSSetDRDYFunction"
2514 /*@C
2515   TSSetDRDYFunction - Sets the function that computes the gradient of the CostIntegrand function r w.r.t. states y.
2516 
2517   Logically Collective on TS
2518 
2519   Input Parameters:
2520 + ts   - The TS context obtained from TSCreate()
2521 - func - The function
2522 
2523   Calling sequence of func:
2524 . TSDRDYFunction(TS ts,PetscReal t,Vec U,Vec *drdy,void *ctx);
2525 
2526   Level: intermediate
2527 
2528 .keywords: TS, sensitivity
2529 .seealso:
2530 @*/
2531 PetscErrorCode  TSSetDRDYFunction(TS ts,Vec *drdy,TSDRDYFunction func,void *ctx)
2532 {
2533   PetscFunctionBegin;
2534   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2535 
2536   ts->drdyfunction    = func;
2537   ts->drdyfunctionctx = ctx;
2538   ts->vecs_drdy       = drdy;
2539 
2540   PetscFunctionReturn(0);
2541 }
2542 
2543 #undef __FUNCT__
2544 #define __FUNCT__ "TSComputeDRDYFunction"
2545 /*@
2546   TSComputeDRDYFunction - Runs the user-defined DRDY function.
2547 
2548   Collective on TS
2549 
2550   Input Parameters:
2551 . ts   - The TS context obtained from TSCreate()
2552 
2553   Notes:
2554   TSComputeDRDYFunction() is typically used for sensitivity implementation,
2555   so most users would not generally call this routine themselves.
2556 
2557   Level: developer
2558 
2559 .keywords: TS, sensitivity
2560 .seealso: TSComputeDRDYFunction()
2561 @*/
2562 PetscErrorCode  TSComputeDRDYFunction(TS ts,PetscReal t,Vec X,Vec *drdy)
2563 {
2564   PetscErrorCode ierr;
2565 
2566   PetscFunctionBegin;
2567   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2568   PetscValidHeaderSpecific(X,VEC_CLASSID,3);
2569 
2570   PetscStackPush("TS user DRDY function for sensitivity analysis");
2571   ierr = (*ts->drdyfunction)(ts,t,X,drdy,ts->drdyfunctionctx); CHKERRQ(ierr);
2572   PetscStackPop;
2573 
2574   PetscFunctionReturn(0);
2575 }
2576 
2577 #undef __FUNCT__
2578 #define __FUNCT__ "TSSetDRDPFunction"
2579 /*@C
2580   TSSetDRDPFunction - Sets the function that computes the gradient of the CostIntegrand function w.r.t. parameters.
2581 
2582   Logically Collective on TS
2583 
2584   Input Parameters:
2585 + ts   - The TS context obtained from TSCreate()
2586 - func - The function
2587 
2588   Calling sequence of func:
2589 .
2590 
2591   Level: intermediate
2592 
2593 .keywords: TS, sensitivity
2594 .seealso:
2595 @*/
2596 PetscErrorCode  TSSetDRDPFunction(TS ts,Vec *drdp,TSDRDPFunction func,void *ctx)
2597 {
2598   PetscFunctionBegin;
2599   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2600 
2601   ts->drdpfunction    = func;
2602   ts->drdpfunctionctx = ctx;
2603   ts->vecs_drdp       = drdp;
2604 
2605   PetscFunctionReturn(0);
2606 }
2607 
2608 #undef __FUNCT__
2609 #define __FUNCT__ "TSComputeDRDPFunction"
2610 /*@
2611   TSComputeDRDPFunction - Runs the user-defined DRDP function.
2612 
2613   Collective on TS
2614 
2615   Input Parameters:
2616 . ts   - The TS context obtained from TSCreate()
2617 
2618   Notes:
2619   TSDRDPFunction() is typically used for sensitivity implementation,
2620   so most users would not generally call this routine themselves.
2621 
2622   Level: developer
2623 
2624 .keywords: TS, sensitivity
2625 .seealso: TSSetDRDPFunction()
2626 @*/
2627 PetscErrorCode  TSComputeDRDPFunction(TS ts,PetscReal t,Vec X,Vec *drdp)
2628 {
2629   PetscErrorCode ierr;
2630 
2631   PetscFunctionBegin;
2632   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2633   PetscValidHeaderSpecific(X,VEC_CLASSID,3);
2634 
2635   PetscStackPush("TS user DRDP function for sensitivity analysis");
2636   ierr = (*ts->drdpfunction)(ts,t,X,drdp,ts->drdpfunctionctx); CHKERRQ(ierr);
2637   PetscStackPop;
2638 
2639   PetscFunctionReturn(0);
2640 }
2641 
2642 #undef __FUNCT__
2643 #define __FUNCT__ "TSSetPreStep"
2644 /*@C
2645   TSSetPreStep - Sets the general-purpose function
2646   called once at the beginning of each time step.
2647 
2648   Logically Collective on TS
2649 
2650   Input Parameters:
2651 + ts   - The TS context obtained from TSCreate()
2652 - func - The function
2653 
2654   Calling sequence of func:
2655 . func (TS ts);
2656 
2657   Level: intermediate
2658 
2659   Note:
2660   If a step is rejected, TSStep() will call this routine again before each attempt.
2661   The last completed time step number can be queried using TSGetTimeStepNumber(), the
2662   size of the step being attempted can be obtained using TSGetTimeStep().
2663 
2664 .keywords: TS, timestep
2665 .seealso: TSSetPreStage(), TSSetPostStage(), TSSetPostStep(), TSStep()
2666 @*/
2667 PetscErrorCode  TSSetPreStep(TS ts, PetscErrorCode (*func)(TS))
2668 {
2669   PetscFunctionBegin;
2670   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2671   ts->prestep = func;
2672   PetscFunctionReturn(0);
2673 }
2674 
2675 #undef __FUNCT__
2676 #define __FUNCT__ "TSPreStep"
2677 /*@
2678   TSPreStep - Runs the user-defined pre-step function.
2679 
2680   Collective on TS
2681 
2682   Input Parameters:
2683 . ts   - The TS context obtained from TSCreate()
2684 
2685   Notes:
2686   TSPreStep() is typically used within time stepping implementations,
2687   so most users would not generally call this routine themselves.
2688 
2689   Level: developer
2690 
2691 .keywords: TS, timestep
2692 .seealso: TSSetPreStep(), TSPreStage(), TSPostStage(), TSPostStep()
2693 @*/
2694 PetscErrorCode  TSPreStep(TS ts)
2695 {
2696   PetscErrorCode ierr;
2697 
2698   PetscFunctionBegin;
2699   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2700   if (ts->prestep) {
2701     PetscStackCallStandard((*ts->prestep),(ts));
2702   }
2703   PetscFunctionReturn(0);
2704 }
2705 
2706 #undef __FUNCT__
2707 #define __FUNCT__ "TSSetPreStage"
2708 /*@C
2709   TSSetPreStage - Sets the general-purpose function
2710   called once at the beginning of each stage.
2711 
2712   Logically Collective on TS
2713 
2714   Input Parameters:
2715 + ts   - The TS context obtained from TSCreate()
2716 - func - The function
2717 
2718   Calling sequence of func:
2719 . PetscErrorCode func(TS ts, PetscReal stagetime);
2720 
2721   Level: intermediate
2722 
2723   Note:
2724   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2725   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2726   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2727 
2728 .keywords: TS, timestep
2729 .seealso: TSSetPostStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2730 @*/
2731 PetscErrorCode  TSSetPreStage(TS ts, PetscErrorCode (*func)(TS,PetscReal))
2732 {
2733   PetscFunctionBegin;
2734   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2735   ts->prestage = func;
2736   PetscFunctionReturn(0);
2737 }
2738 
2739 #undef __FUNCT__
2740 #define __FUNCT__ "TSSetPostStage"
2741 /*@C
2742   TSSetPostStage - Sets the general-purpose function
2743   called once at the end of each stage.
2744 
2745   Logically Collective on TS
2746 
2747   Input Parameters:
2748 + ts   - The TS context obtained from TSCreate()
2749 - func - The function
2750 
2751   Calling sequence of func:
2752 . PetscErrorCode func(TS ts, PetscReal stagetime, PetscInt stageindex, Vec* Y);
2753 
2754   Level: intermediate
2755 
2756   Note:
2757   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2758   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2759   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2760 
2761 .keywords: TS, timestep
2762 .seealso: TSSetPreStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2763 @*/
2764 PetscErrorCode  TSSetPostStage(TS ts, PetscErrorCode (*func)(TS,PetscReal,PetscInt,Vec*))
2765 {
2766   PetscFunctionBegin;
2767   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2768   ts->poststage = func;
2769   PetscFunctionReturn(0);
2770 }
2771 
2772 #undef __FUNCT__
2773 #define __FUNCT__ "TSPreStage"
2774 /*@
2775   TSPreStage - Runs the user-defined pre-stage function set using TSSetPreStage()
2776 
2777   Collective on TS
2778 
2779   Input Parameters:
2780 . ts          - The TS context obtained from TSCreate()
2781   stagetime   - The absolute time of the current stage
2782 
2783   Notes:
2784   TSPreStage() is typically used within time stepping implementations,
2785   most users would not generally call this routine themselves.
2786 
2787   Level: developer
2788 
2789 .keywords: TS, timestep
2790 .seealso: TSPostStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2791 @*/
2792 PetscErrorCode  TSPreStage(TS ts, PetscReal stagetime)
2793 {
2794   PetscErrorCode ierr;
2795 
2796   PetscFunctionBegin;
2797   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2798   if (ts->prestage) {
2799     PetscStackCallStandard((*ts->prestage),(ts,stagetime));
2800   }
2801   PetscFunctionReturn(0);
2802 }
2803 
2804 #undef __FUNCT__
2805 #define __FUNCT__ "TSPostStage"
2806 /*@
2807   TSPostStage - Runs the user-defined post-stage function set using TSSetPostStage()
2808 
2809   Collective on TS
2810 
2811   Input Parameters:
2812 . ts          - The TS context obtained from TSCreate()
2813   stagetime   - The absolute time of the current stage
2814   stageindex  - Stage number
2815   Y           - Array of vectors (of size = total number
2816                 of stages) with the stage solutions
2817 
2818   Notes:
2819   TSPostStage() is typically used within time stepping implementations,
2820   most users would not generally call this routine themselves.
2821 
2822   Level: developer
2823 
2824 .keywords: TS, timestep
2825 .seealso: TSPreStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2826 @*/
2827 PetscErrorCode  TSPostStage(TS ts, PetscReal stagetime, PetscInt stageindex, Vec *Y)
2828 {
2829   PetscErrorCode ierr;
2830 
2831   PetscFunctionBegin;
2832   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2833   if (ts->poststage) {
2834     PetscStackCallStandard((*ts->poststage),(ts,stagetime,stageindex,Y));
2835   }
2836   PetscFunctionReturn(0);
2837 }
2838 
2839 #undef __FUNCT__
2840 #define __FUNCT__ "TSSetPostStep"
2841 /*@C
2842   TSSetPostStep - Sets the general-purpose function
2843   called once at the end of each time step.
2844 
2845   Logically Collective on TS
2846 
2847   Input Parameters:
2848 + ts   - The TS context obtained from TSCreate()
2849 - func - The function
2850 
2851   Calling sequence of func:
2852 $ func (TS ts);
2853 
2854   Level: intermediate
2855 
2856 .keywords: TS, timestep
2857 .seealso: TSSetPreStep(), TSSetPreStage(), TSGetTimeStep(), TSGetTimeStepNumber(), TSGetTime()
2858 @*/
2859 PetscErrorCode  TSSetPostStep(TS ts, PetscErrorCode (*func)(TS))
2860 {
2861   PetscFunctionBegin;
2862   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2863   ts->poststep = func;
2864   PetscFunctionReturn(0);
2865 }
2866 
2867 #undef __FUNCT__
2868 #define __FUNCT__ "TSPostStep"
2869 /*@
2870   TSPostStep - Runs the user-defined post-step function.
2871 
2872   Collective on TS
2873 
2874   Input Parameters:
2875 . ts   - The TS context obtained from TSCreate()
2876 
2877   Notes:
2878   TSPostStep() is typically used within time stepping implementations,
2879   so most users would not generally call this routine themselves.
2880 
2881   Level: developer
2882 
2883 .keywords: TS, timestep
2884 @*/
2885 PetscErrorCode  TSPostStep(TS ts)
2886 {
2887   PetscErrorCode ierr;
2888 
2889   PetscFunctionBegin;
2890   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2891   if (ts->poststep) {
2892     PetscStackCallStandard((*ts->poststep),(ts));
2893   }
2894   PetscFunctionReturn(0);
2895 }
2896 
2897 /* ------------ Routines to set performance monitoring options ----------- */
2898 
2899 #undef __FUNCT__
2900 #define __FUNCT__ "TSMonitorSet"
2901 /*@C
2902    TSMonitorSet - Sets an ADDITIONAL function that is to be used at every
2903    timestep to display the iteration's  progress.
2904 
2905    Logically Collective on TS
2906 
2907    Input Parameters:
2908 +  ts - the TS context obtained from TSCreate()
2909 .  monitor - monitoring routine
2910 .  mctx - [optional] user-defined context for private data for the
2911              monitor routine (use NULL if no context is desired)
2912 -  monitordestroy - [optional] routine that frees monitor context
2913           (may be NULL)
2914 
2915    Calling sequence of monitor:
2916 $    int monitor(TS ts,PetscInt steps,PetscReal time,Vec u,void *mctx)
2917 
2918 +    ts - the TS context
2919 .    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
2920                                been interpolated to)
2921 .    time - current time
2922 .    u - current iterate
2923 -    mctx - [optional] monitoring context
2924 
2925    Notes:
2926    This routine adds an additional monitor to the list of monitors that
2927    already has been loaded.
2928 
2929    Fortran notes: Only a single monitor function can be set for each TS object
2930 
2931    Level: intermediate
2932 
2933 .keywords: TS, timestep, set, monitor
2934 
2935 .seealso: TSMonitorDefault(), TSMonitorCancel()
2936 @*/
2937 PetscErrorCode  TSMonitorSet(TS ts,PetscErrorCode (*monitor)(TS,PetscInt,PetscReal,Vec,void*),void *mctx,PetscErrorCode (*mdestroy)(void**))
2938 {
2939   PetscFunctionBegin;
2940   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2941   if (ts->numbermonitors >= MAXTSMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
2942   ts->monitor[ts->numbermonitors]          = monitor;
2943   ts->monitordestroy[ts->numbermonitors]   = mdestroy;
2944   ts->monitorcontext[ts->numbermonitors++] = (void*)mctx;
2945   PetscFunctionReturn(0);
2946 }
2947 
2948 #undef __FUNCT__
2949 #define __FUNCT__ "TSMonitorCancel"
2950 /*@C
2951    TSMonitorCancel - Clears all the monitors that have been set on a time-step object.
2952 
2953    Logically Collective on TS
2954 
2955    Input Parameters:
2956 .  ts - the TS context obtained from TSCreate()
2957 
2958    Notes:
2959    There is no way to remove a single, specific monitor.
2960 
2961    Level: intermediate
2962 
2963 .keywords: TS, timestep, set, monitor
2964 
2965 .seealso: TSMonitorDefault(), TSMonitorSet()
2966 @*/
2967 PetscErrorCode  TSMonitorCancel(TS ts)
2968 {
2969   PetscErrorCode ierr;
2970   PetscInt       i;
2971 
2972   PetscFunctionBegin;
2973   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2974   for (i=0; i<ts->numbermonitors; i++) {
2975     if (ts->monitordestroy[i]) {
2976       ierr = (*ts->monitordestroy[i])(&ts->monitorcontext[i]);CHKERRQ(ierr);
2977     }
2978   }
2979   ts->numbermonitors = 0;
2980   PetscFunctionReturn(0);
2981 }
2982 
2983 #undef __FUNCT__
2984 #define __FUNCT__ "TSMonitorDefault"
2985 /*@
2986    TSMonitorDefault - Sets the Default monitor
2987 
2988    Level: intermediate
2989 
2990 .keywords: TS, set, monitor
2991 
2992 .seealso: TSMonitorDefault(), TSMonitorSet()
2993 @*/
2994 PetscErrorCode TSMonitorDefault(TS ts,PetscInt step,PetscReal ptime,Vec v,void *dummy)
2995 {
2996   PetscErrorCode ierr;
2997   PetscViewer    viewer = dummy ? (PetscViewer) dummy : PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)ts));
2998 
2999   PetscFunctionBegin;
3000   ierr = PetscViewerASCIIAddTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
3001   ierr = PetscViewerASCIIPrintf(viewer,"%D TS dt %g time %g\n",step,(double)ts->time_step,(double)ptime);CHKERRQ(ierr);
3002   ierr = PetscViewerASCIISubtractTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
3003   PetscFunctionReturn(0);
3004 }
3005 
3006 #undef __FUNCT__
3007 #define __FUNCT__ "TSSetRetainStages"
3008 /*@
3009    TSSetRetainStages - Request that all stages in the upcoming step be stored so that interpolation will be available.
3010 
3011    Logically Collective on TS
3012 
3013    Input Argument:
3014 .  ts - time stepping context
3015 
3016    Output Argument:
3017 .  flg - PETSC_TRUE or PETSC_FALSE
3018 
3019    Level: intermediate
3020 
3021 .keywords: TS, set
3022 
3023 .seealso: TSInterpolate(), TSSetPostStep()
3024 @*/
3025 PetscErrorCode TSSetRetainStages(TS ts,PetscBool flg)
3026 {
3027   PetscFunctionBegin;
3028   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3029   ts->retain_stages = flg;
3030   PetscFunctionReturn(0);
3031 }
3032 
3033 #undef __FUNCT__
3034 #define __FUNCT__ "TSInterpolate"
3035 /*@
3036    TSInterpolate - Interpolate the solution computed during the previous step to an arbitrary location in the interval
3037 
3038    Collective on TS
3039 
3040    Input Argument:
3041 +  ts - time stepping context
3042 -  t - time to interpolate to
3043 
3044    Output Argument:
3045 .  U - state at given time
3046 
3047    Notes:
3048    The user should call TSSetRetainStages() before taking a step in which interpolation will be requested.
3049 
3050    Level: intermediate
3051 
3052    Developer Notes:
3053    TSInterpolate() and the storing of previous steps/stages should be generalized to support delay differential equations and continuous adjoints.
3054 
3055 .keywords: TS, set
3056 
3057 .seealso: TSSetRetainStages(), TSSetPostStep()
3058 @*/
3059 PetscErrorCode TSInterpolate(TS ts,PetscReal t,Vec U)
3060 {
3061   PetscErrorCode ierr;
3062 
3063   PetscFunctionBegin;
3064   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3065   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
3066   if (t < ts->ptime - ts->time_step_prev || t > ts->ptime) SETERRQ3(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_OUTOFRANGE,"Requested time %g not in last time steps [%g,%g]",t,(double)(ts->ptime-ts->time_step_prev),(double)ts->ptime);
3067   if (!ts->ops->interpolate) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"%s does not provide interpolation",((PetscObject)ts)->type_name);
3068   ierr = (*ts->ops->interpolate)(ts,t,U);CHKERRQ(ierr);
3069   PetscFunctionReturn(0);
3070 }
3071 
3072 #undef __FUNCT__
3073 #define __FUNCT__ "TSStep"
3074 /*@
3075    TSStep - Steps one time step
3076 
3077    Collective on TS
3078 
3079    Input Parameter:
3080 .  ts - the TS context obtained from TSCreate()
3081 
3082    Level: intermediate
3083 
3084    Notes:
3085    The hook set using TSSetPreStep() is called before each attempt to take the step. In general, the time step size may
3086    be changed due to adaptive error controller or solve failures. Note that steps may contain multiple stages.
3087 
3088    This may over-step the final time provided in TSSetDuration() depending on the time-step used. TSSolve() interpolates to exactly the
3089    time provided in TSSetDuration(). One can use TSInterpolate() to determine an interpolated solution within the final timestep.
3090 
3091 .keywords: TS, timestep, solve
3092 
3093 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSInterpolate()
3094 @*/
3095 PetscErrorCode  TSStep(TS ts)
3096 {
3097   DM               dm;
3098   PetscErrorCode   ierr;
3099   static PetscBool cite = PETSC_FALSE;
3100 
3101   PetscFunctionBegin;
3102   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
3103   ierr = PetscCitationsRegister("@techreport{tspaper,\n"
3104                                 "  title       = {{PETSc/TS}: A Modern Scalable {DAE/ODE} Solver Library},\n"
3105                                 "  author      = {Shrirang Abhyankar and Jed Brown and Emil Constantinescu and Debojyoti Ghosh and Barry F. Smith},\n"
3106                                 "  type        = {Preprint},\n"
3107                                 "  number      = {ANL/MCS-P5061-0114},\n"
3108                                 "  institution = {Argonne National Laboratory},\n"
3109                                 "  year        = {2014}\n}\n",&cite);
3110 
3111   ierr = TSGetDM(ts, &dm);CHKERRQ(ierr);
3112   ierr = TSSetUp(ts);CHKERRQ(ierr);
3113 
3114   ts->reason = TS_CONVERGED_ITERATING;
3115   ts->ptime_prev = ts->ptime;
3116   ierr = DMSetOutputSequenceNumber(dm, ts->steps, ts->ptime);CHKERRQ(ierr);
3117   ierr = VecViewFromOptions(ts->vec_sol, ((PetscObject) ts)->prefix, "-ts_view_solution");CHKERRQ(ierr);
3118 
3119   if (!ts->ops->step) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSStep not implemented for type '%s'",((PetscObject)ts)->type_name);
3120   ierr = PetscLogEventBegin(TS_Step,ts,0,0,0);CHKERRQ(ierr);
3121   if(ts->reverse_mode) {
3122     if(!ts->ops->stepadj) {
3123       SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed because the adjoint of  %s has not been implemented, try other time stepping methods for adjoint sensitivity analysis",((PetscObject)ts)->type_name);
3124     }else {
3125       ierr = (*ts->ops->stepadj)(ts);CHKERRQ(ierr);
3126     }
3127   }else {
3128     ierr = (*ts->ops->step)(ts);CHKERRQ(ierr);
3129   }
3130   ierr = PetscLogEventEnd(TS_Step,ts,0,0,0);CHKERRQ(ierr);
3131 
3132   ts->time_step_prev = ts->ptime - ts->ptime_prev;
3133   ierr = DMSetOutputSequenceNumber(dm, ts->steps, ts->ptime);CHKERRQ(ierr);
3134 
3135   if (ts->reason < 0) {
3136     if (ts->errorifstepfailed) {
3137       if (ts->reason == TS_DIVERGED_NONLINEAR_SOLVE) {
3138         SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s, increase -ts_max_snes_failures or make negative to attempt recovery",TSConvergedReasons[ts->reason]);
3139       } else if (ts->reason == TS_DIVERGED_STEP_REJECTED) {
3140         SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s, increase -ts_max_reject or make negative to attempt recovery",TSConvergedReasons[ts->reason]);
3141       } else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s",TSConvergedReasons[ts->reason]);
3142     }
3143   } else if (!ts->reason) {
3144     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
3145     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
3146   }
3147   PetscFunctionReturn(0);
3148 }
3149 
3150 #undef __FUNCT__
3151 #define __FUNCT__ "TSEvaluateStep"
3152 /*@
3153    TSEvaluateStep - Evaluate the solution at the end of a time step with a given order of accuracy.
3154 
3155    Collective on TS
3156 
3157    Input Arguments:
3158 +  ts - time stepping context
3159 .  order - desired order of accuracy
3160 -  done - whether the step was evaluated at this order (pass NULL to generate an error if not available)
3161 
3162    Output Arguments:
3163 .  U - state at the end of the current step
3164 
3165    Level: advanced
3166 
3167    Notes:
3168    This function cannot be called until all stages have been evaluated.
3169    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.
3170 
3171 .seealso: TSStep(), TSAdapt
3172 @*/
3173 PetscErrorCode TSEvaluateStep(TS ts,PetscInt order,Vec U,PetscBool *done)
3174 {
3175   PetscErrorCode ierr;
3176 
3177   PetscFunctionBegin;
3178   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3179   PetscValidType(ts,1);
3180   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
3181   if (!ts->ops->evaluatestep) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSEvaluateStep not implemented for type '%s'",((PetscObject)ts)->type_name);
3182   ierr = (*ts->ops->evaluatestep)(ts,order,U,done);CHKERRQ(ierr);
3183   PetscFunctionReturn(0);
3184 }
3185 
3186 #undef __FUNCT__
3187 #define __FUNCT__ "TSSolve"
3188 /*@
3189    TSSolve - Steps the requested number of timesteps.
3190 
3191    Collective on TS
3192 
3193    Input Parameter:
3194 +  ts - the TS context obtained from TSCreate()
3195 -  u - the solution vector  (can be null if TSSetSolution() was used, otherwise must contain the initial conditions)
3196 
3197    Level: beginner
3198 
3199    Notes:
3200    The final time returned by this function may be different from the time of the internally
3201    held state accessible by TSGetSolution() and TSGetTime() because the method may have
3202    stepped over the final time.
3203 
3204 .keywords: TS, timestep, solve
3205 
3206 .seealso: TSCreate(), TSSetSolution(), TSStep()
3207 @*/
3208 PetscErrorCode TSSolve(TS ts,Vec u)
3209 {
3210   Vec               solution;
3211   PetscErrorCode    ierr;
3212 
3213   PetscFunctionBegin;
3214   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3215   if (u) PetscValidHeaderSpecific(u,VEC_CLASSID,2);
3216   if (!ts->reverse_mode && ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE) {   /* Need ts->vec_sol to be distinct so it is not overwritten when we interpolate at the end */
3217     PetscValidHeaderSpecific(u,VEC_CLASSID,2);
3218     if (!ts->vec_sol || u == ts->vec_sol) {
3219       ierr = VecDuplicate(u,&solution);CHKERRQ(ierr);
3220       ierr = TSSetSolution(ts,solution);CHKERRQ(ierr);
3221       ierr = VecDestroy(&solution);CHKERRQ(ierr); /* grant ownership */
3222     }
3223     ierr = VecCopy(u,ts->vec_sol);CHKERRQ(ierr);
3224   } else if (u) {
3225     ierr = TSSetSolution(ts,u);CHKERRQ(ierr);
3226   }
3227   ierr = TSSetUp(ts);CHKERRQ(ierr); /*compute adj coefficients if the reverse mode is on*/
3228   /* reset time step and iteration counters */
3229   ts->steps             = 0;
3230   ts->ksp_its           = 0;
3231   ts->snes_its          = 0;
3232   ts->num_snes_failures = 0;
3233   ts->reject            = 0;
3234   ts->reason            = TS_CONVERGED_ITERATING;
3235 
3236   ierr = TSViewFromOptions(ts,NULL,"-ts_view_pre");CHKERRQ(ierr);
3237 
3238   if (ts->ops->solve) {         /* This private interface is transitional and should be removed when all implementations are updated. */
3239     ierr = (*ts->ops->solve)(ts);CHKERRQ(ierr);
3240     ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);
3241     ts->solvetime = ts->ptime;
3242   } else {
3243     /* steps the requested number of timesteps. */
3244     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
3245     else if (!ts->reverse_mode && ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
3246     while (!ts->reason) {
3247       if(!ts->reverse_mode) {
3248         ierr = TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
3249       }else {
3250         ierr = TSMonitor(ts,ts->max_steps-ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
3251       }
3252       ierr = TSStep(ts);CHKERRQ(ierr);
3253       if (ts->event) {
3254 	ierr = TSEventMonitor(ts);CHKERRQ(ierr);
3255 	if (ts->event->status != TSEVENT_PROCESSING) {
3256 	  ierr = TSPostStep(ts);CHKERRQ(ierr);
3257 	}
3258       } else {
3259 	ierr = TSPostStep(ts);CHKERRQ(ierr);
3260       }
3261     }
3262     if (!ts->reverse_mode && ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE && ts->ptime > ts->max_time) {
3263       ierr = TSInterpolate(ts,ts->max_time,u);CHKERRQ(ierr);
3264       ts->solvetime = ts->max_time;
3265       solution = u;
3266     } else {
3267       if (u) {ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);}
3268       ts->solvetime = ts->ptime;
3269       solution = ts->vec_sol;
3270     }
3271     if(!ts->reverse_mode) {
3272       ierr = TSMonitor(ts,ts->steps,ts->solvetime,solution);CHKERRQ(ierr);
3273     }
3274     ierr = VecViewFromOptions(u, ((PetscObject) ts)->prefix, "-ts_view_solution");CHKERRQ(ierr);
3275   }
3276 
3277   ierr = TSViewFromOptions(ts,NULL,"-ts_view");CHKERRQ(ierr);
3278   ierr = PetscObjectSAWsBlock((PetscObject)ts);CHKERRQ(ierr);
3279   PetscFunctionReturn(0);
3280 }
3281 
3282 #undef __FUNCT__
3283 #define __FUNCT__ "TSMonitor"
3284 /*@
3285    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()
3286 
3287    Collective on TS
3288 
3289    Input Parameters:
3290 +  ts - time stepping context obtained from TSCreate()
3291 .  step - step number that has just completed
3292 .  ptime - model time of the state
3293 -  u - state at the current model time
3294 
3295    Notes:
3296    TSMonitor() is typically used within the time stepping implementations.
3297    Users might call this function when using the TSStep() interface instead of TSSolve().
3298 
3299    Level: advanced
3300 
3301 .keywords: TS, timestep
3302 @*/
3303 PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
3304 {
3305   PetscErrorCode ierr;
3306   PetscInt       i,n = ts->numbermonitors;
3307 
3308   PetscFunctionBegin;
3309   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3310   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
3311   ierr = VecLockPush(u);CHKERRQ(ierr);
3312   for (i=0; i<n; i++) {
3313     ierr = (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);CHKERRQ(ierr);
3314   }
3315   ierr = VecLockPop(u);CHKERRQ(ierr);
3316   PetscFunctionReturn(0);
3317 }
3318 
3319 /* ------------------------------------------------------------------------*/
3320 #undef __FUNCT__
3321 #define __FUNCT__ "TSMonitorLGCtxCreate"
3322 /*@C
3323    TSMonitorLGCtxCreate - Creates a line graph context for use with
3324    TS to monitor the solution process graphically in various ways
3325 
3326    Collective on TS
3327 
3328    Input Parameters:
3329 +  host - the X display to open, or null for the local machine
3330 .  label - the title to put in the title bar
3331 .  x, y - the screen coordinates of the upper left coordinate of the window
3332 .  m, n - the screen width and height in pixels
3333 -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time
3334 
3335    Output Parameter:
3336 .  ctx - the context
3337 
3338    Options Database Key:
3339 +  -ts_monitor_lg_timestep - automatically sets line graph monitor
3340 .  -ts_monitor_lg_solution -
3341 .  -ts_monitor_lg_error -
3342 .  -ts_monitor_lg_ksp_iterations -
3343 .  -ts_monitor_lg_snes_iterations -
3344 -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true
3345 
3346    Notes:
3347    Use TSMonitorLGCtxDestroy() to destroy.
3348 
3349    Level: intermediate
3350 
3351 .keywords: TS, monitor, line graph, residual, seealso
3352 
3353 .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()
3354 
3355 @*/
3356 PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
3357 {
3358   PetscDraw      win;
3359   PetscErrorCode ierr;
3360 
3361   PetscFunctionBegin;
3362   ierr = PetscNew(ctx);CHKERRQ(ierr);
3363   ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr);
3364   ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr);
3365   ierr = PetscDrawLGCreate(win,1,&(*ctx)->lg);CHKERRQ(ierr);
3366   ierr = PetscLogObjectParent((PetscObject)(*ctx)->lg,(PetscObject)win);CHKERRQ(ierr);
3367   ierr = PetscDrawLGIndicateDataPoints((*ctx)->lg,PETSC_TRUE);CHKERRQ(ierr);
3368   ierr = PetscDrawLGSetFromOptions((*ctx)->lg);CHKERRQ(ierr);
3369   (*ctx)->howoften = howoften;
3370   PetscFunctionReturn(0);
3371 }
3372 
3373 #undef __FUNCT__
3374 #define __FUNCT__ "TSMonitorLGTimeStep"
3375 PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx)
3376 {
3377   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
3378   PetscReal      x   = ptime,y;
3379   PetscErrorCode ierr;
3380 
3381   PetscFunctionBegin;
3382   if (!step) {
3383     PetscDrawAxis axis;
3384     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
3385     ierr = PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");CHKERRQ(ierr);
3386     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
3387     ierr = PetscDrawLGIndicateDataPoints(ctx->lg,PETSC_TRUE);CHKERRQ(ierr);
3388   }
3389   ierr = TSGetTimeStep(ts,&y);CHKERRQ(ierr);
3390   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
3391   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
3392     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
3393   }
3394   PetscFunctionReturn(0);
3395 }
3396 
3397 #undef __FUNCT__
3398 #define __FUNCT__ "TSMonitorLGCtxDestroy"
3399 /*@C
3400    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
3401    with TSMonitorLGCtxCreate().
3402 
3403    Collective on TSMonitorLGCtx
3404 
3405    Input Parameter:
3406 .  ctx - the monitor context
3407 
3408    Level: intermediate
3409 
3410 .keywords: TS, monitor, line graph, destroy
3411 
3412 .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
3413 @*/
3414 PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
3415 {
3416   PetscDraw      draw;
3417   PetscErrorCode ierr;
3418 
3419   PetscFunctionBegin;
3420   ierr = PetscDrawLGGetDraw((*ctx)->lg,&draw);CHKERRQ(ierr);
3421   ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
3422   ierr = PetscDrawLGDestroy(&(*ctx)->lg);CHKERRQ(ierr);
3423   ierr = PetscFree(*ctx);CHKERRQ(ierr);
3424   PetscFunctionReturn(0);
3425 }
3426 
3427 #undef __FUNCT__
3428 #define __FUNCT__ "TSGetTime"
3429 /*@
3430    TSGetTime - Gets the time of the most recently completed step.
3431 
3432    Not Collective
3433 
3434    Input Parameter:
3435 .  ts - the TS context obtained from TSCreate()
3436 
3437    Output Parameter:
3438 .  t  - the current time
3439 
3440    Level: beginner
3441 
3442    Note:
3443    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
3444    TSSetPreStage(), TSSetPostStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.
3445 
3446 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
3447 
3448 .keywords: TS, get, time
3449 @*/
3450 PetscErrorCode  TSGetTime(TS ts,PetscReal *t)
3451 {
3452   PetscFunctionBegin;
3453   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3454   PetscValidRealPointer(t,2);
3455   *t = ts->ptime;
3456   PetscFunctionReturn(0);
3457 }
3458 
3459 #undef __FUNCT__
3460 #define __FUNCT__ "TSGetPrevTime"
3461 /*@
3462    TSGetPrevTime - Gets the starting time of the previously completed step.
3463 
3464    Not Collective
3465 
3466    Input Parameter:
3467 .  ts - the TS context obtained from TSCreate()
3468 
3469    Output Parameter:
3470 .  t  - the previous time
3471 
3472    Level: beginner
3473 
3474 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
3475 
3476 .keywords: TS, get, time
3477 @*/
3478 PetscErrorCode  TSGetPrevTime(TS ts,PetscReal *t)
3479 {
3480   PetscFunctionBegin;
3481   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3482   PetscValidRealPointer(t,2);
3483   *t = ts->ptime_prev;
3484   PetscFunctionReturn(0);
3485 }
3486 
3487 #undef __FUNCT__
3488 #define __FUNCT__ "TSSetTime"
3489 /*@
3490    TSSetTime - Allows one to reset the time.
3491 
3492    Logically Collective on TS
3493 
3494    Input Parameters:
3495 +  ts - the TS context obtained from TSCreate()
3496 -  time - the time
3497 
3498    Level: intermediate
3499 
3500 .seealso: TSGetTime(), TSSetDuration()
3501 
3502 .keywords: TS, set, time
3503 @*/
3504 PetscErrorCode  TSSetTime(TS ts, PetscReal t)
3505 {
3506   PetscFunctionBegin;
3507   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3508   PetscValidLogicalCollectiveReal(ts,t,2);
3509   ts->ptime = t;
3510   PetscFunctionReturn(0);
3511 }
3512 
3513 #undef __FUNCT__
3514 #define __FUNCT__ "TSSetOptionsPrefix"
3515 /*@C
3516    TSSetOptionsPrefix - Sets the prefix used for searching for all
3517    TS options in the database.
3518 
3519    Logically Collective on TS
3520 
3521    Input Parameter:
3522 +  ts     - The TS context
3523 -  prefix - The prefix to prepend to all option names
3524 
3525    Notes:
3526    A hyphen (-) must NOT be given at the beginning of the prefix name.
3527    The first character of all runtime options is AUTOMATICALLY the
3528    hyphen.
3529 
3530    Level: advanced
3531 
3532 .keywords: TS, set, options, prefix, database
3533 
3534 .seealso: TSSetFromOptions()
3535 
3536 @*/
3537 PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
3538 {
3539   PetscErrorCode ierr;
3540   SNES           snes;
3541 
3542   PetscFunctionBegin;
3543   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3544   ierr = PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3545   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3546   ierr = SNESSetOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3547   PetscFunctionReturn(0);
3548 }
3549 
3550 
3551 #undef __FUNCT__
3552 #define __FUNCT__ "TSAppendOptionsPrefix"
3553 /*@C
3554    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
3555    TS options in the database.
3556 
3557    Logically Collective on TS
3558 
3559    Input Parameter:
3560 +  ts     - The TS context
3561 -  prefix - The prefix to prepend to all option names
3562 
3563    Notes:
3564    A hyphen (-) must NOT be given at the beginning of the prefix name.
3565    The first character of all runtime options is AUTOMATICALLY the
3566    hyphen.
3567 
3568    Level: advanced
3569 
3570 .keywords: TS, append, options, prefix, database
3571 
3572 .seealso: TSGetOptionsPrefix()
3573 
3574 @*/
3575 PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
3576 {
3577   PetscErrorCode ierr;
3578   SNES           snes;
3579 
3580   PetscFunctionBegin;
3581   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3582   ierr = PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3583   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3584   ierr = SNESAppendOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3585   PetscFunctionReturn(0);
3586 }
3587 
3588 #undef __FUNCT__
3589 #define __FUNCT__ "TSGetOptionsPrefix"
3590 /*@C
3591    TSGetOptionsPrefix - Sets the prefix used for searching for all
3592    TS options in the database.
3593 
3594    Not Collective
3595 
3596    Input Parameter:
3597 .  ts - The TS context
3598 
3599    Output Parameter:
3600 .  prefix - A pointer to the prefix string used
3601 
3602    Notes: On the fortran side, the user should pass in a string 'prifix' of
3603    sufficient length to hold the prefix.
3604 
3605    Level: intermediate
3606 
3607 .keywords: TS, get, options, prefix, database
3608 
3609 .seealso: TSAppendOptionsPrefix()
3610 @*/
3611 PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
3612 {
3613   PetscErrorCode ierr;
3614 
3615   PetscFunctionBegin;
3616   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3617   PetscValidPointer(prefix,2);
3618   ierr = PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3619   PetscFunctionReturn(0);
3620 }
3621 
3622 #undef __FUNCT__
3623 #define __FUNCT__ "TSGetRHSJacobian"
3624 /*@C
3625    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.
3626 
3627    Not Collective, but parallel objects are returned if TS is parallel
3628 
3629    Input Parameter:
3630 .  ts  - The TS context obtained from TSCreate()
3631 
3632    Output Parameters:
3633 +  Amat - The (approximate) Jacobian J of G, where U_t = G(U,t)  (or NULL)
3634 .  Pmat - The matrix from which the preconditioner is constructed, usually the same as Amat  (or NULL)
3635 .  func - Function to compute the Jacobian of the RHS  (or NULL)
3636 -  ctx - User-defined context for Jacobian evaluation routine  (or NULL)
3637 
3638    Notes: You can pass in NULL for any return argument you do not need.
3639 
3640    Level: intermediate
3641 
3642 .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3643 
3644 .keywords: TS, timestep, get, matrix, Jacobian
3645 @*/
3646 PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *Amat,Mat *Pmat,TSRHSJacobian *func,void **ctx)
3647 {
3648   PetscErrorCode ierr;
3649   SNES           snes;
3650   DM             dm;
3651 
3652   PetscFunctionBegin;
3653   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3654   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3655   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3656   ierr = DMTSGetRHSJacobian(dm,func,ctx);CHKERRQ(ierr);
3657   PetscFunctionReturn(0);
3658 }
3659 
3660 #undef __FUNCT__
3661 #define __FUNCT__ "TSGetIJacobian"
3662 /*@C
3663    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.
3664 
3665    Not Collective, but parallel objects are returned if TS is parallel
3666 
3667    Input Parameter:
3668 .  ts  - The TS context obtained from TSCreate()
3669 
3670    Output Parameters:
3671 +  Amat  - The (approximate) Jacobian of F(t,U,U_t)
3672 .  Pmat - The matrix from which the preconditioner is constructed, often the same as Amat
3673 .  f   - The function to compute the matrices
3674 - ctx - User-defined context for Jacobian evaluation routine
3675 
3676    Notes: You can pass in NULL for any return argument you do not need.
3677 
3678    Level: advanced
3679 
3680 .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3681 
3682 .keywords: TS, timestep, get, matrix, Jacobian
3683 @*/
3684 PetscErrorCode  TSGetIJacobian(TS ts,Mat *Amat,Mat *Pmat,TSIJacobian *f,void **ctx)
3685 {
3686   PetscErrorCode ierr;
3687   SNES           snes;
3688   DM             dm;
3689 
3690   PetscFunctionBegin;
3691   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3692   ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
3693   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3694   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3695   ierr = DMTSGetIJacobian(dm,f,ctx);CHKERRQ(ierr);
3696   PetscFunctionReturn(0);
3697 }
3698 
3699 
3700 #undef __FUNCT__
3701 #define __FUNCT__ "TSMonitorDrawSolution"
3702 /*@C
3703    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
3704    VecView() for the solution at each timestep
3705 
3706    Collective on TS
3707 
3708    Input Parameters:
3709 +  ts - the TS context
3710 .  step - current time-step
3711 .  ptime - current time
3712 -  dummy - either a viewer or NULL
3713 
3714    Options Database:
3715 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3716 
3717    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
3718        will look bad
3719 
3720    Level: intermediate
3721 
3722 .keywords: TS,  vector, monitor, view
3723 
3724 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3725 @*/
3726 PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3727 {
3728   PetscErrorCode   ierr;
3729   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
3730   PetscDraw        draw;
3731 
3732   PetscFunctionBegin;
3733   if (!step && ictx->showinitial) {
3734     if (!ictx->initialsolution) {
3735       ierr = VecDuplicate(u,&ictx->initialsolution);CHKERRQ(ierr);
3736     }
3737     ierr = VecCopy(u,ictx->initialsolution);CHKERRQ(ierr);
3738   }
3739   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften))) || ((ictx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3740 
3741   if (ictx->showinitial) {
3742     PetscReal pause;
3743     ierr = PetscViewerDrawGetPause(ictx->viewer,&pause);CHKERRQ(ierr);
3744     ierr = PetscViewerDrawSetPause(ictx->viewer,0.0);CHKERRQ(ierr);
3745     ierr = VecView(ictx->initialsolution,ictx->viewer);CHKERRQ(ierr);
3746     ierr = PetscViewerDrawSetPause(ictx->viewer,pause);CHKERRQ(ierr);
3747     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);CHKERRQ(ierr);
3748   }
3749   ierr = VecView(u,ictx->viewer);CHKERRQ(ierr);
3750   if (ictx->showtimestepandtime) {
3751     PetscReal xl,yl,xr,yr,tw,w,h;
3752     char      time[32];
3753     size_t    len;
3754 
3755     ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3756     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3757     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3758     ierr =  PetscStrlen(time,&len);CHKERRQ(ierr);
3759     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3760     w    = xl + .5*(xr - xl) - .5*len*tw;
3761     h    = yl + .95*(yr - yl);
3762     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3763     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3764   }
3765 
3766   if (ictx->showinitial) {
3767     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);CHKERRQ(ierr);
3768   }
3769   PetscFunctionReturn(0);
3770 }
3771 
3772 #undef __FUNCT__
3773 #define __FUNCT__ "TSMonitorDrawSolutionPhase"
3774 /*@C
3775    TSMonitorDrawSolutionPhase - Monitors progress of the TS solvers by plotting the solution as a phase diagram
3776 
3777    Collective on TS
3778 
3779    Input Parameters:
3780 +  ts - the TS context
3781 .  step - current time-step
3782 .  ptime - current time
3783 -  dummy - either a viewer or NULL
3784 
3785    Level: intermediate
3786 
3787 .keywords: TS,  vector, monitor, view
3788 
3789 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3790 @*/
3791 PetscErrorCode  TSMonitorDrawSolutionPhase(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3792 {
3793   PetscErrorCode    ierr;
3794   TSMonitorDrawCtx  ictx = (TSMonitorDrawCtx)dummy;
3795   PetscDraw         draw;
3796   MPI_Comm          comm;
3797   PetscInt          n;
3798   PetscMPIInt       size;
3799   PetscReal         xl,yl,xr,yr,tw,w,h;
3800   char              time[32];
3801   size_t            len;
3802   const PetscScalar *U;
3803 
3804   PetscFunctionBegin;
3805   ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
3806   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3807   if (size != 1) SETERRQ(comm,PETSC_ERR_SUP,"Only allowed for sequential runs");
3808   ierr = VecGetSize(u,&n);CHKERRQ(ierr);
3809   if (n != 2) SETERRQ(comm,PETSC_ERR_SUP,"Only for ODEs with two unknowns");
3810 
3811   ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3812 
3813   ierr = VecGetArrayRead(u,&U);CHKERRQ(ierr);
3814   ierr = PetscDrawAxisGetLimits(ictx->axis,&xl,&xr,&yl,&yr);CHKERRQ(ierr);
3815   if ((PetscRealPart(U[0]) < xl) || (PetscRealPart(U[1]) < yl) || (PetscRealPart(U[0]) > xr) || (PetscRealPart(U[1]) > yr)) {
3816       ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3817       PetscFunctionReturn(0);
3818   }
3819   if (!step) ictx->color++;
3820   ierr = PetscDrawPoint(draw,PetscRealPart(U[0]),PetscRealPart(U[1]),ictx->color);CHKERRQ(ierr);
3821   ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3822 
3823   if (ictx->showtimestepandtime) {
3824     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3825     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3826     ierr = PetscStrlen(time,&len);CHKERRQ(ierr);
3827     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3828     w    = xl + .5*(xr - xl) - .5*len*tw;
3829     h    = yl + .95*(yr - yl);
3830     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3831   }
3832   ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3833   PetscFunctionReturn(0);
3834 }
3835 
3836 
3837 #undef __FUNCT__
3838 #define __FUNCT__ "TSMonitorDrawCtxDestroy"
3839 /*@C
3840    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()
3841 
3842    Collective on TS
3843 
3844    Input Parameters:
3845 .    ctx - the monitor context
3846 
3847    Level: intermediate
3848 
3849 .keywords: TS,  vector, monitor, view
3850 
3851 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
3852 @*/
3853 PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
3854 {
3855   PetscErrorCode ierr;
3856 
3857   PetscFunctionBegin;
3858   ierr = PetscDrawAxisDestroy(&(*ictx)->axis);CHKERRQ(ierr);
3859   ierr = PetscViewerDestroy(&(*ictx)->viewer);CHKERRQ(ierr);
3860   ierr = VecDestroy(&(*ictx)->initialsolution);CHKERRQ(ierr);
3861   ierr = PetscFree(*ictx);CHKERRQ(ierr);
3862   PetscFunctionReturn(0);
3863 }
3864 
3865 #undef __FUNCT__
3866 #define __FUNCT__ "TSMonitorDrawCtxCreate"
3867 /*@C
3868    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx
3869 
3870    Collective on TS
3871 
3872    Input Parameter:
3873 .    ts - time-step context
3874 
3875    Output Patameter:
3876 .    ctx - the monitor context
3877 
3878    Options Database:
3879 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3880 
3881    Level: intermediate
3882 
3883 .keywords: TS,  vector, monitor, view
3884 
3885 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
3886 @*/
3887 PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
3888 {
3889   PetscErrorCode   ierr;
3890 
3891   PetscFunctionBegin;
3892   ierr = PetscNew(ctx);CHKERRQ(ierr);
3893   ierr = PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);CHKERRQ(ierr);
3894   ierr = PetscViewerSetFromOptions((*ctx)->viewer);CHKERRQ(ierr);
3895 
3896   (*ctx)->howoften    = howoften;
3897   (*ctx)->showinitial = PETSC_FALSE;
3898   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,NULL);CHKERRQ(ierr);
3899 
3900   (*ctx)->showtimestepandtime = PETSC_FALSE;
3901   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_show_time",&(*ctx)->showtimestepandtime,NULL);CHKERRQ(ierr);
3902   (*ctx)->color = PETSC_DRAW_WHITE;
3903   PetscFunctionReturn(0);
3904 }
3905 
3906 #undef __FUNCT__
3907 #define __FUNCT__ "TSMonitorDrawError"
3908 /*@C
3909    TSMonitorDrawError - Monitors progress of the TS solvers by calling
3910    VecView() for the error at each timestep
3911 
3912    Collective on TS
3913 
3914    Input Parameters:
3915 +  ts - the TS context
3916 .  step - current time-step
3917 .  ptime - current time
3918 -  dummy - either a viewer or NULL
3919 
3920    Level: intermediate
3921 
3922 .keywords: TS,  vector, monitor, view
3923 
3924 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3925 @*/
3926 PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3927 {
3928   PetscErrorCode   ierr;
3929   TSMonitorDrawCtx ctx    = (TSMonitorDrawCtx)dummy;
3930   PetscViewer      viewer = ctx->viewer;
3931   Vec              work;
3932 
3933   PetscFunctionBegin;
3934   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3935   ierr = VecDuplicate(u,&work);CHKERRQ(ierr);
3936   ierr = TSComputeSolutionFunction(ts,ptime,work);CHKERRQ(ierr);
3937   ierr = VecAXPY(work,-1.0,u);CHKERRQ(ierr);
3938   ierr = VecView(work,viewer);CHKERRQ(ierr);
3939   ierr = VecDestroy(&work);CHKERRQ(ierr);
3940   PetscFunctionReturn(0);
3941 }
3942 
3943 #include <petsc-private/dmimpl.h>
3944 #undef __FUNCT__
3945 #define __FUNCT__ "TSSetDM"
3946 /*@
3947    TSSetDM - Sets the DM that may be used by some preconditioners
3948 
3949    Logically Collective on TS and DM
3950 
3951    Input Parameters:
3952 +  ts - the preconditioner context
3953 -  dm - the dm
3954 
3955    Level: intermediate
3956 
3957 
3958 .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
3959 @*/
3960 PetscErrorCode  TSSetDM(TS ts,DM dm)
3961 {
3962   PetscErrorCode ierr;
3963   SNES           snes;
3964   DMTS           tsdm;
3965 
3966   PetscFunctionBegin;
3967   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3968   ierr = PetscObjectReference((PetscObject)dm);CHKERRQ(ierr);
3969   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
3970     if (ts->dm->dmts && !dm->dmts) {
3971       ierr = DMCopyDMTS(ts->dm,dm);CHKERRQ(ierr);
3972       ierr = DMGetDMTS(ts->dm,&tsdm);CHKERRQ(ierr);
3973       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
3974         tsdm->originaldm = dm;
3975       }
3976     }
3977     ierr = DMDestroy(&ts->dm);CHKERRQ(ierr);
3978   }
3979   ts->dm = dm;
3980 
3981   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3982   ierr = SNESSetDM(snes,dm);CHKERRQ(ierr);
3983   PetscFunctionReturn(0);
3984 }
3985 
3986 #undef __FUNCT__
3987 #define __FUNCT__ "TSGetDM"
3988 /*@
3989    TSGetDM - Gets the DM that may be used by some preconditioners
3990 
3991    Not Collective
3992 
3993    Input Parameter:
3994 . ts - the preconditioner context
3995 
3996    Output Parameter:
3997 .  dm - the dm
3998 
3999    Level: intermediate
4000 
4001 
4002 .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
4003 @*/
4004 PetscErrorCode  TSGetDM(TS ts,DM *dm)
4005 {
4006   PetscErrorCode ierr;
4007 
4008   PetscFunctionBegin;
4009   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4010   if (!ts->dm) {
4011     ierr = DMShellCreate(PetscObjectComm((PetscObject)ts),&ts->dm);CHKERRQ(ierr);
4012     if (ts->snes) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
4013   }
4014   *dm = ts->dm;
4015   PetscFunctionReturn(0);
4016 }
4017 
4018 #undef __FUNCT__
4019 #define __FUNCT__ "SNESTSFormFunction"
4020 /*@
4021    SNESTSFormFunction - Function to evaluate nonlinear residual
4022 
4023    Logically Collective on SNES
4024 
4025    Input Parameter:
4026 + snes - nonlinear solver
4027 . U - the current state at which to evaluate the residual
4028 - ctx - user context, must be a TS
4029 
4030    Output Parameter:
4031 . F - the nonlinear residual
4032 
4033    Notes:
4034    This function is not normally called by users and is automatically registered with the SNES used by TS.
4035    It is most frequently passed to MatFDColoringSetFunction().
4036 
4037    Level: advanced
4038 
4039 .seealso: SNESSetFunction(), MatFDColoringSetFunction()
4040 @*/
4041 PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
4042 {
4043   TS             ts = (TS)ctx;
4044   PetscErrorCode ierr;
4045 
4046   PetscFunctionBegin;
4047   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
4048   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
4049   PetscValidHeaderSpecific(F,VEC_CLASSID,3);
4050   PetscValidHeaderSpecific(ts,TS_CLASSID,4);
4051   ierr = (ts->ops->snesfunction)(snes,U,F,ts);CHKERRQ(ierr);
4052   PetscFunctionReturn(0);
4053 }
4054 
4055 #undef __FUNCT__
4056 #define __FUNCT__ "SNESTSFormJacobian"
4057 /*@
4058    SNESTSFormJacobian - Function to evaluate the Jacobian
4059 
4060    Collective on SNES
4061 
4062    Input Parameter:
4063 + snes - nonlinear solver
4064 . U - the current state at which to evaluate the residual
4065 - ctx - user context, must be a TS
4066 
4067    Output Parameter:
4068 + A - the Jacobian
4069 . B - the preconditioning matrix (may be the same as A)
4070 - flag - indicates any structure change in the matrix
4071 
4072    Notes:
4073    This function is not normally called by users and is automatically registered with the SNES used by TS.
4074 
4075    Level: developer
4076 
4077 .seealso: SNESSetJacobian()
4078 @*/
4079 PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat A,Mat B,void *ctx)
4080 {
4081   TS             ts = (TS)ctx;
4082   PetscErrorCode ierr;
4083 
4084   PetscFunctionBegin;
4085   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
4086   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
4087   PetscValidPointer(A,3);
4088   PetscValidHeaderSpecific(A,MAT_CLASSID,3);
4089   PetscValidPointer(B,4);
4090   PetscValidHeaderSpecific(B,MAT_CLASSID,4);
4091   PetscValidHeaderSpecific(ts,TS_CLASSID,6);
4092   ierr = (ts->ops->snesjacobian)(snes,U,A,B,ts);CHKERRQ(ierr);
4093   PetscFunctionReturn(0);
4094 }
4095 
4096 #undef __FUNCT__
4097 #define __FUNCT__ "TSComputeRHSFunctionLinear"
4098 /*@C
4099    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only
4100 
4101    Collective on TS
4102 
4103    Input Arguments:
4104 +  ts - time stepping context
4105 .  t - time at which to evaluate
4106 .  U - state at which to evaluate
4107 -  ctx - context
4108 
4109    Output Arguments:
4110 .  F - right hand side
4111 
4112    Level: intermediate
4113 
4114    Notes:
4115    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
4116    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().
4117 
4118 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
4119 @*/
4120 PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
4121 {
4122   PetscErrorCode ierr;
4123   Mat            Arhs,Brhs;
4124 
4125   PetscFunctionBegin;
4126   ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
4127   ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
4128   ierr = MatMult(Arhs,U,F);CHKERRQ(ierr);
4129   PetscFunctionReturn(0);
4130 }
4131 
4132 #undef __FUNCT__
4133 #define __FUNCT__ "TSComputeRHSJacobianConstant"
4134 /*@C
4135    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.
4136 
4137    Collective on TS
4138 
4139    Input Arguments:
4140 +  ts - time stepping context
4141 .  t - time at which to evaluate
4142 .  U - state at which to evaluate
4143 -  ctx - context
4144 
4145    Output Arguments:
4146 +  A - pointer to operator
4147 .  B - pointer to preconditioning matrix
4148 -  flg - matrix structure flag
4149 
4150    Level: intermediate
4151 
4152    Notes:
4153    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.
4154 
4155 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
4156 @*/
4157 PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat A,Mat B,void *ctx)
4158 {
4159   PetscFunctionBegin;
4160   PetscFunctionReturn(0);
4161 }
4162 
4163 #undef __FUNCT__
4164 #define __FUNCT__ "TSComputeIFunctionLinear"
4165 /*@C
4166    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only
4167 
4168    Collective on TS
4169 
4170    Input Arguments:
4171 +  ts - time stepping context
4172 .  t - time at which to evaluate
4173 .  U - state at which to evaluate
4174 .  Udot - time derivative of state vector
4175 -  ctx - context
4176 
4177    Output Arguments:
4178 .  F - left hand side
4179 
4180    Level: intermediate
4181 
4182    Notes:
4183    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
4184    user is required to write their own TSComputeIFunction.
4185    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
4186    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().
4187 
4188 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
4189 @*/
4190 PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
4191 {
4192   PetscErrorCode ierr;
4193   Mat            A,B;
4194 
4195   PetscFunctionBegin;
4196   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
4197   ierr = TSComputeIJacobian(ts,t,U,Udot,1.0,A,B,PETSC_TRUE);CHKERRQ(ierr);
4198   ierr = MatMult(A,Udot,F);CHKERRQ(ierr);
4199   PetscFunctionReturn(0);
4200 }
4201 
4202 #undef __FUNCT__
4203 #define __FUNCT__ "TSComputeIJacobianConstant"
4204 /*@C
4205    TSComputeIJacobianConstant - Reuses a time-independent for a semi-implicit DAE or ODE
4206 
4207    Collective on TS
4208 
4209    Input Arguments:
4210 +  ts - time stepping context
4211 .  t - time at which to evaluate
4212 .  U - state at which to evaluate
4213 .  Udot - time derivative of state vector
4214 .  shift - shift to apply
4215 -  ctx - context
4216 
4217    Output Arguments:
4218 +  A - pointer to operator
4219 .  B - pointer to preconditioning matrix
4220 -  flg - matrix structure flag
4221 
4222    Level: advanced
4223 
4224    Notes:
4225    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.
4226 
4227    It is only appropriate for problems of the form
4228 
4229 $     M Udot = F(U,t)
4230 
4231   where M is constant and F is non-stiff.  The user must pass M to TSSetIJacobian().  The current implementation only
4232   works with IMEX time integration methods such as TSROSW and TSARKIMEX, since there is no support for de-constructing
4233   an implicit operator of the form
4234 
4235 $    shift*M + J
4236 
4237   where J is the Jacobian of -F(U).  Support may be added in a future version of PETSc, but for now, the user must store
4238   a copy of M or reassemble it when requested.
4239 
4240 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
4241 @*/
4242 PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,void *ctx)
4243 {
4244   PetscErrorCode ierr;
4245 
4246   PetscFunctionBegin;
4247   ierr = MatScale(A, shift / ts->ijacobian.shift);CHKERRQ(ierr);
4248   ts->ijacobian.shift = shift;
4249   PetscFunctionReturn(0);
4250 }
4251 
4252 #undef __FUNCT__
4253 #define __FUNCT__ "TSGetEquationType"
4254 /*@
4255    TSGetEquationType - Gets the type of the equation that TS is solving.
4256 
4257    Not Collective
4258 
4259    Input Parameter:
4260 .  ts - the TS context
4261 
4262    Output Parameter:
4263 .  equation_type - see TSEquationType
4264 
4265    Level: beginner
4266 
4267 .keywords: TS, equation type
4268 
4269 .seealso: TSSetEquationType(), TSEquationType
4270 @*/
4271 PetscErrorCode  TSGetEquationType(TS ts,TSEquationType *equation_type)
4272 {
4273   PetscFunctionBegin;
4274   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4275   PetscValidPointer(equation_type,2);
4276   *equation_type = ts->equation_type;
4277   PetscFunctionReturn(0);
4278 }
4279 
4280 #undef __FUNCT__
4281 #define __FUNCT__ "TSSetEquationType"
4282 /*@
4283    TSSetEquationType - Sets the type of the equation that TS is solving.
4284 
4285    Not Collective
4286 
4287    Input Parameter:
4288 +  ts - the TS context
4289 .  equation_type - see TSEquationType
4290 
4291    Level: advanced
4292 
4293 .keywords: TS, equation type
4294 
4295 .seealso: TSGetEquationType(), TSEquationType
4296 @*/
4297 PetscErrorCode  TSSetEquationType(TS ts,TSEquationType equation_type)
4298 {
4299   PetscFunctionBegin;
4300   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4301   ts->equation_type = equation_type;
4302   PetscFunctionReturn(0);
4303 }
4304 
4305 #undef __FUNCT__
4306 #define __FUNCT__ "TSGetConvergedReason"
4307 /*@
4308    TSGetConvergedReason - Gets the reason the TS iteration was stopped.
4309 
4310    Not Collective
4311 
4312    Input Parameter:
4313 .  ts - the TS context
4314 
4315    Output Parameter:
4316 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
4317             manual pages for the individual convergence tests for complete lists
4318 
4319    Level: beginner
4320 
4321    Notes:
4322    Can only be called after the call to TSSolve() is complete.
4323 
4324 .keywords: TS, nonlinear, set, convergence, test
4325 
4326 .seealso: TSSetConvergenceTest(), TSConvergedReason
4327 @*/
4328 PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
4329 {
4330   PetscFunctionBegin;
4331   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4332   PetscValidPointer(reason,2);
4333   *reason = ts->reason;
4334   PetscFunctionReturn(0);
4335 }
4336 
4337 #undef __FUNCT__
4338 #define __FUNCT__ "TSSetConvergedReason"
4339 /*@
4340    TSSetConvergedReason - Sets the reason for handling the convergence of TSSolve.
4341 
4342    Not Collective
4343 
4344    Input Parameter:
4345 +  ts - the TS context
4346 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
4347             manual pages for the individual convergence tests for complete lists
4348 
4349    Level: advanced
4350 
4351    Notes:
4352    Can only be called during TSSolve() is active.
4353 
4354 .keywords: TS, nonlinear, set, convergence, test
4355 
4356 .seealso: TSConvergedReason
4357 @*/
4358 PetscErrorCode  TSSetConvergedReason(TS ts,TSConvergedReason reason)
4359 {
4360   PetscFunctionBegin;
4361   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4362   ts->reason = reason;
4363   PetscFunctionReturn(0);
4364 }
4365 
4366 #undef __FUNCT__
4367 #define __FUNCT__ "TSGetSolveTime"
4368 /*@
4369    TSGetSolveTime - Gets the time after a call to TSSolve()
4370 
4371    Not Collective
4372 
4373    Input Parameter:
4374 .  ts - the TS context
4375 
4376    Output Parameter:
4377 .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()
4378 
4379    Level: beginner
4380 
4381    Notes:
4382    Can only be called after the call to TSSolve() is complete.
4383 
4384 .keywords: TS, nonlinear, set, convergence, test
4385 
4386 .seealso: TSSetConvergenceTest(), TSConvergedReason
4387 @*/
4388 PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
4389 {
4390   PetscFunctionBegin;
4391   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4392   PetscValidPointer(ftime,2);
4393   *ftime = ts->solvetime;
4394   PetscFunctionReturn(0);
4395 }
4396 
4397 #undef __FUNCT__
4398 #define __FUNCT__ "TSGetSNESIterations"
4399 /*@
4400    TSGetSNESIterations - Gets the total number of nonlinear iterations
4401    used by the time integrator.
4402 
4403    Not Collective
4404 
4405    Input Parameter:
4406 .  ts - TS context
4407 
4408    Output Parameter:
4409 .  nits - number of nonlinear iterations
4410 
4411    Notes:
4412    This counter is reset to zero for each successive call to TSSolve().
4413 
4414    Level: intermediate
4415 
4416 .keywords: TS, get, number, nonlinear, iterations
4417 
4418 .seealso:  TSGetKSPIterations()
4419 @*/
4420 PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
4421 {
4422   PetscFunctionBegin;
4423   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4424   PetscValidIntPointer(nits,2);
4425   *nits = ts->snes_its;
4426   PetscFunctionReturn(0);
4427 }
4428 
4429 #undef __FUNCT__
4430 #define __FUNCT__ "TSGetKSPIterations"
4431 /*@
4432    TSGetKSPIterations - Gets the total number of linear iterations
4433    used by the time integrator.
4434 
4435    Not Collective
4436 
4437    Input Parameter:
4438 .  ts - TS context
4439 
4440    Output Parameter:
4441 .  lits - number of linear iterations
4442 
4443    Notes:
4444    This counter is reset to zero for each successive call to TSSolve().
4445 
4446    Level: intermediate
4447 
4448 .keywords: TS, get, number, linear, iterations
4449 
4450 .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
4451 @*/
4452 PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
4453 {
4454   PetscFunctionBegin;
4455   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4456   PetscValidIntPointer(lits,2);
4457   *lits = ts->ksp_its;
4458   PetscFunctionReturn(0);
4459 }
4460 
4461 #undef __FUNCT__
4462 #define __FUNCT__ "TSGetStepRejections"
4463 /*@
4464    TSGetStepRejections - Gets the total number of rejected steps.
4465 
4466    Not Collective
4467 
4468    Input Parameter:
4469 .  ts - TS context
4470 
4471    Output Parameter:
4472 .  rejects - number of steps rejected
4473 
4474    Notes:
4475    This counter is reset to zero for each successive call to TSSolve().
4476 
4477    Level: intermediate
4478 
4479 .keywords: TS, get, number
4480 
4481 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
4482 @*/
4483 PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
4484 {
4485   PetscFunctionBegin;
4486   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4487   PetscValidIntPointer(rejects,2);
4488   *rejects = ts->reject;
4489   PetscFunctionReturn(0);
4490 }
4491 
4492 #undef __FUNCT__
4493 #define __FUNCT__ "TSGetSNESFailures"
4494 /*@
4495    TSGetSNESFailures - Gets the total number of failed SNES solves
4496 
4497    Not Collective
4498 
4499    Input Parameter:
4500 .  ts - TS context
4501 
4502    Output Parameter:
4503 .  fails - number of failed nonlinear solves
4504 
4505    Notes:
4506    This counter is reset to zero for each successive call to TSSolve().
4507 
4508    Level: intermediate
4509 
4510 .keywords: TS, get, number
4511 
4512 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
4513 @*/
4514 PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
4515 {
4516   PetscFunctionBegin;
4517   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4518   PetscValidIntPointer(fails,2);
4519   *fails = ts->num_snes_failures;
4520   PetscFunctionReturn(0);
4521 }
4522 
4523 #undef __FUNCT__
4524 #define __FUNCT__ "TSSetMaxStepRejections"
4525 /*@
4526    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails
4527 
4528    Not Collective
4529 
4530    Input Parameter:
4531 +  ts - TS context
4532 -  rejects - maximum number of rejected steps, pass -1 for unlimited
4533 
4534    Notes:
4535    The counter is reset to zero for each step
4536 
4537    Options Database Key:
4538  .  -ts_max_reject - Maximum number of step rejections before a step fails
4539 
4540    Level: intermediate
4541 
4542 .keywords: TS, set, maximum, number
4543 
4544 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4545 @*/
4546 PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
4547 {
4548   PetscFunctionBegin;
4549   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4550   ts->max_reject = rejects;
4551   PetscFunctionReturn(0);
4552 }
4553 
4554 #undef __FUNCT__
4555 #define __FUNCT__ "TSSetMaxSNESFailures"
4556 /*@
4557    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves
4558 
4559    Not Collective
4560 
4561    Input Parameter:
4562 +  ts - TS context
4563 -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited
4564 
4565    Notes:
4566    The counter is reset to zero for each successive call to TSSolve().
4567 
4568    Options Database Key:
4569  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures
4570 
4571    Level: intermediate
4572 
4573 .keywords: TS, set, maximum, number
4574 
4575 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
4576 @*/
4577 PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
4578 {
4579   PetscFunctionBegin;
4580   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4581   ts->max_snes_failures = fails;
4582   PetscFunctionReturn(0);
4583 }
4584 
4585 #undef __FUNCT__
4586 #define __FUNCT__ "TSSetErrorIfStepFails"
4587 /*@
4588    TSSetErrorIfStepFails - Error if no step succeeds
4589 
4590    Not Collective
4591 
4592    Input Parameter:
4593 +  ts - TS context
4594 -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure
4595 
4596    Options Database Key:
4597  .  -ts_error_if_step_fails - Error if no step succeeds
4598 
4599    Level: intermediate
4600 
4601 .keywords: TS, set, error
4602 
4603 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4604 @*/
4605 PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
4606 {
4607   PetscFunctionBegin;
4608   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4609   ts->errorifstepfailed = err;
4610   PetscFunctionReturn(0);
4611 }
4612 
4613 #undef __FUNCT__
4614 #define __FUNCT__ "TSMonitorSolutionBinary"
4615 /*@C
4616    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file
4617 
4618    Collective on TS
4619 
4620    Input Parameters:
4621 +  ts - the TS context
4622 .  step - current time-step
4623 .  ptime - current time
4624 .  u - current state
4625 -  viewer - binary viewer
4626 
4627    Level: intermediate
4628 
4629 .keywords: TS,  vector, monitor, view
4630 
4631 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4632 @*/
4633 PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
4634 {
4635   PetscErrorCode ierr;
4636   PetscViewer    v = (PetscViewer)viewer;
4637 
4638   PetscFunctionBegin;
4639   ierr = VecView(u,v);CHKERRQ(ierr);
4640   PetscFunctionReturn(0);
4641 }
4642 
4643 #undef __FUNCT__
4644 #define __FUNCT__ "TSMonitorSolutionVTK"
4645 /*@C
4646    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.
4647 
4648    Collective on TS
4649 
4650    Input Parameters:
4651 +  ts - the TS context
4652 .  step - current time-step
4653 .  ptime - current time
4654 .  u - current state
4655 -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4656 
4657    Level: intermediate
4658 
4659    Notes:
4660    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.
4661    These are named according to the file name template.
4662 
4663    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().
4664 
4665 .keywords: TS,  vector, monitor, view
4666 
4667 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4668 @*/
4669 PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
4670 {
4671   PetscErrorCode ierr;
4672   char           filename[PETSC_MAX_PATH_LEN];
4673   PetscViewer    viewer;
4674 
4675   PetscFunctionBegin;
4676   ierr = PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);CHKERRQ(ierr);
4677   ierr = PetscViewerVTKOpen(PetscObjectComm((PetscObject)ts),filename,FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
4678   ierr = VecView(u,viewer);CHKERRQ(ierr);
4679   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
4680   PetscFunctionReturn(0);
4681 }
4682 
4683 #undef __FUNCT__
4684 #define __FUNCT__ "TSMonitorSolutionVTKDestroy"
4685 /*@C
4686    TSMonitorSolutionVTKDestroy - Destroy context for monitoring
4687 
4688    Collective on TS
4689 
4690    Input Parameters:
4691 .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4692 
4693    Level: intermediate
4694 
4695    Note:
4696    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().
4697 
4698 .keywords: TS,  vector, monitor, view
4699 
4700 .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
4701 @*/
4702 PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
4703 {
4704   PetscErrorCode ierr;
4705 
4706   PetscFunctionBegin;
4707   ierr = PetscFree(*(char**)filenametemplate);CHKERRQ(ierr);
4708   PetscFunctionReturn(0);
4709 }
4710 
4711 #undef __FUNCT__
4712 #define __FUNCT__ "TSGetAdapt"
4713 /*@
4714    TSGetAdapt - Get the adaptive controller context for the current method
4715 
4716    Collective on TS if controller has not been created yet
4717 
4718    Input Arguments:
4719 .  ts - time stepping context
4720 
4721    Output Arguments:
4722 .  adapt - adaptive controller
4723 
4724    Level: intermediate
4725 
4726 .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
4727 @*/
4728 PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
4729 {
4730   PetscErrorCode ierr;
4731 
4732   PetscFunctionBegin;
4733   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4734   PetscValidPointer(adapt,2);
4735   if (!ts->adapt) {
4736     ierr = TSAdaptCreate(PetscObjectComm((PetscObject)ts),&ts->adapt);CHKERRQ(ierr);
4737     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->adapt);CHKERRQ(ierr);
4738     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);CHKERRQ(ierr);
4739   }
4740   *adapt = ts->adapt;
4741   PetscFunctionReturn(0);
4742 }
4743 
4744 #undef __FUNCT__
4745 #define __FUNCT__ "TSSetTolerances"
4746 /*@
4747    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller
4748 
4749    Logically Collective
4750 
4751    Input Arguments:
4752 +  ts - time integration context
4753 .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
4754 .  vatol - vector of absolute tolerances or NULL, used in preference to atol if present
4755 .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
4756 -  vrtol - vector of relative tolerances or NULL, used in preference to atol if present
4757 
4758    Options Database keys:
4759 +  -ts_rtol <rtol> - relative tolerance for local truncation error
4760 -  -ts_atol <atol> Absolute tolerance for local truncation error
4761 
4762    Level: beginner
4763 
4764 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
4765 @*/
4766 PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
4767 {
4768   PetscErrorCode ierr;
4769 
4770   PetscFunctionBegin;
4771   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
4772   if (vatol) {
4773     ierr = PetscObjectReference((PetscObject)vatol);CHKERRQ(ierr);
4774     ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
4775 
4776     ts->vatol = vatol;
4777   }
4778   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
4779   if (vrtol) {
4780     ierr = PetscObjectReference((PetscObject)vrtol);CHKERRQ(ierr);
4781     ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
4782 
4783     ts->vrtol = vrtol;
4784   }
4785   PetscFunctionReturn(0);
4786 }
4787 
4788 #undef __FUNCT__
4789 #define __FUNCT__ "TSGetTolerances"
4790 /*@
4791    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller
4792 
4793    Logically Collective
4794 
4795    Input Arguments:
4796 .  ts - time integration context
4797 
4798    Output Arguments:
4799 +  atol - scalar absolute tolerances, NULL to ignore
4800 .  vatol - vector of absolute tolerances, NULL to ignore
4801 .  rtol - scalar relative tolerances, NULL to ignore
4802 -  vrtol - vector of relative tolerances, NULL to ignore
4803 
4804    Level: beginner
4805 
4806 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
4807 @*/
4808 PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
4809 {
4810   PetscFunctionBegin;
4811   if (atol)  *atol  = ts->atol;
4812   if (vatol) *vatol = ts->vatol;
4813   if (rtol)  *rtol  = ts->rtol;
4814   if (vrtol) *vrtol = ts->vrtol;
4815   PetscFunctionReturn(0);
4816 }
4817 
4818 #undef __FUNCT__
4819 #define __FUNCT__ "TSErrorNormWRMS"
4820 /*@
4821    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state
4822 
4823    Collective on TS
4824 
4825    Input Arguments:
4826 +  ts - time stepping context
4827 -  Y - state vector to be compared to ts->vec_sol
4828 
4829    Output Arguments:
4830 .  norm - weighted norm, a value of 1.0 is considered small
4831 
4832    Level: developer
4833 
4834 .seealso: TSSetTolerances()
4835 @*/
4836 PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
4837 {
4838   PetscErrorCode    ierr;
4839   PetscInt          i,n,N;
4840   const PetscScalar *u,*y;
4841   Vec               U;
4842   PetscReal         sum,gsum;
4843 
4844   PetscFunctionBegin;
4845   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4846   PetscValidHeaderSpecific(Y,VEC_CLASSID,2);
4847   PetscValidPointer(norm,3);
4848   U = ts->vec_sol;
4849   PetscCheckSameTypeAndComm(U,1,Y,2);
4850   if (U == Y) SETERRQ(PetscObjectComm((PetscObject)U),PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");
4851 
4852   ierr = VecGetSize(U,&N);CHKERRQ(ierr);
4853   ierr = VecGetLocalSize(U,&n);CHKERRQ(ierr);
4854   ierr = VecGetArrayRead(U,&u);CHKERRQ(ierr);
4855   ierr = VecGetArrayRead(Y,&y);CHKERRQ(ierr);
4856   sum  = 0.;
4857   if (ts->vatol && ts->vrtol) {
4858     const PetscScalar *atol,*rtol;
4859     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4860     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4861     for (i=0; i<n; i++) {
4862       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4863       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4864     }
4865     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4866     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4867   } else if (ts->vatol) {       /* vector atol, scalar rtol */
4868     const PetscScalar *atol;
4869     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4870     for (i=0; i<n; i++) {
4871       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4872       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4873     }
4874     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4875   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
4876     const PetscScalar *rtol;
4877     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4878     for (i=0; i<n; i++) {
4879       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4880       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4881     }
4882     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4883   } else {                      /* scalar atol, scalar rtol */
4884     for (i=0; i<n; i++) {
4885       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4886       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4887     }
4888   }
4889   ierr = VecRestoreArrayRead(U,&u);CHKERRQ(ierr);
4890   ierr = VecRestoreArrayRead(Y,&y);CHKERRQ(ierr);
4891 
4892   ierr  = MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4893   *norm = PetscSqrtReal(gsum / N);
4894   if (PetscIsInfOrNanReal(*norm)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
4895   PetscFunctionReturn(0);
4896 }
4897 
4898 #undef __FUNCT__
4899 #define __FUNCT__ "TSSetCFLTimeLocal"
4900 /*@
4901    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler
4902 
4903    Logically Collective on TS
4904 
4905    Input Arguments:
4906 +  ts - time stepping context
4907 -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)
4908 
4909    Note:
4910    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()
4911 
4912    Level: intermediate
4913 
4914 .seealso: TSGetCFLTime(), TSADAPTCFL
4915 @*/
4916 PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
4917 {
4918   PetscFunctionBegin;
4919   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4920   ts->cfltime_local = cfltime;
4921   ts->cfltime       = -1.;
4922   PetscFunctionReturn(0);
4923 }
4924 
4925 #undef __FUNCT__
4926 #define __FUNCT__ "TSGetCFLTime"
4927 /*@
4928    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler
4929 
4930    Collective on TS
4931 
4932    Input Arguments:
4933 .  ts - time stepping context
4934 
4935    Output Arguments:
4936 .  cfltime - maximum stable time step for forward Euler
4937 
4938    Level: advanced
4939 
4940 .seealso: TSSetCFLTimeLocal()
4941 @*/
4942 PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
4943 {
4944   PetscErrorCode ierr;
4945 
4946   PetscFunctionBegin;
4947   if (ts->cfltime < 0) {
4948     ierr = MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4949   }
4950   *cfltime = ts->cfltime;
4951   PetscFunctionReturn(0);
4952 }
4953 
4954 #undef __FUNCT__
4955 #define __FUNCT__ "TSVISetVariableBounds"
4956 /*@
4957    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu
4958 
4959    Input Parameters:
4960 .  ts   - the TS context.
4961 .  xl   - lower bound.
4962 .  xu   - upper bound.
4963 
4964    Notes:
4965    If this routine is not called then the lower and upper bounds are set to
4966    PETSC_NINFINITY and PETSC_INFINITY respectively during SNESSetUp().
4967 
4968    Level: advanced
4969 
4970 @*/
4971 PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
4972 {
4973   PetscErrorCode ierr;
4974   SNES           snes;
4975 
4976   PetscFunctionBegin;
4977   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
4978   ierr = SNESVISetVariableBounds(snes,xl,xu);CHKERRQ(ierr);
4979   PetscFunctionReturn(0);
4980 }
4981 
4982 #if defined(PETSC_HAVE_MATLAB_ENGINE)
4983 #include <mex.h>
4984 
4985 typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;
4986 
4987 #undef __FUNCT__
4988 #define __FUNCT__ "TSComputeFunction_Matlab"
4989 /*
4990    TSComputeFunction_Matlab - Calls the function that has been set with
4991                          TSSetFunctionMatlab().
4992 
4993    Collective on TS
4994 
4995    Input Parameters:
4996 +  snes - the TS context
4997 -  u - input vector
4998 
4999    Output Parameter:
5000 .  y - function vector, as set by TSSetFunction()
5001 
5002    Notes:
5003    TSComputeFunction() is typically used within nonlinear solvers
5004    implementations, so most users would not generally call this routine
5005    themselves.
5006 
5007    Level: developer
5008 
5009 .keywords: TS, nonlinear, compute, function
5010 
5011 .seealso: TSSetFunction(), TSGetFunction()
5012 */
5013 PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
5014 {
5015   PetscErrorCode  ierr;
5016   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
5017   int             nlhs  = 1,nrhs = 7;
5018   mxArray         *plhs[1],*prhs[7];
5019   long long int   lx = 0,lxdot = 0,ly = 0,ls = 0;
5020 
5021   PetscFunctionBegin;
5022   PetscValidHeaderSpecific(snes,TS_CLASSID,1);
5023   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
5024   PetscValidHeaderSpecific(udot,VEC_CLASSID,4);
5025   PetscValidHeaderSpecific(y,VEC_CLASSID,5);
5026   PetscCheckSameComm(snes,1,u,3);
5027   PetscCheckSameComm(snes,1,y,5);
5028 
5029   ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr);
5030   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
5031   ierr = PetscMemcpy(&lxdot,&udot,sizeof(udot));CHKERRQ(ierr);
5032   ierr = PetscMemcpy(&ly,&y,sizeof(u));CHKERRQ(ierr);
5033 
5034   prhs[0] =  mxCreateDoubleScalar((double)ls);
5035   prhs[1] =  mxCreateDoubleScalar(time);
5036   prhs[2] =  mxCreateDoubleScalar((double)lx);
5037   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
5038   prhs[4] =  mxCreateDoubleScalar((double)ly);
5039   prhs[5] =  mxCreateString(sctx->funcname);
5040   prhs[6] =  sctx->ctx;
5041   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");CHKERRQ(ierr);
5042   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
5043   mxDestroyArray(prhs[0]);
5044   mxDestroyArray(prhs[1]);
5045   mxDestroyArray(prhs[2]);
5046   mxDestroyArray(prhs[3]);
5047   mxDestroyArray(prhs[4]);
5048   mxDestroyArray(prhs[5]);
5049   mxDestroyArray(plhs[0]);
5050   PetscFunctionReturn(0);
5051 }
5052 
5053 
5054 #undef __FUNCT__
5055 #define __FUNCT__ "TSSetFunctionMatlab"
5056 /*
5057    TSSetFunctionMatlab - Sets the function evaluation routine and function
5058    vector for use by the TS routines in solving ODEs
5059    equations from MATLAB. Here the function is a string containing the name of a MATLAB function
5060 
5061    Logically Collective on TS
5062 
5063    Input Parameters:
5064 +  ts - the TS context
5065 -  func - function evaluation routine
5066 
5067    Calling sequence of func:
5068 $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);
5069 
5070    Level: beginner
5071 
5072 .keywords: TS, nonlinear, set, function
5073 
5074 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
5075 */
5076 PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
5077 {
5078   PetscErrorCode  ierr;
5079   TSMatlabContext *sctx;
5080 
5081   PetscFunctionBegin;
5082   /* currently sctx is memory bleed */
5083   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
5084   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
5085   /*
5086      This should work, but it doesn't
5087   sctx->ctx = ctx;
5088   mexMakeArrayPersistent(sctx->ctx);
5089   */
5090   sctx->ctx = mxDuplicateArray(ctx);
5091 
5092   ierr = TSSetIFunction(ts,NULL,TSComputeFunction_Matlab,sctx);CHKERRQ(ierr);
5093   PetscFunctionReturn(0);
5094 }
5095 
5096 #undef __FUNCT__
5097 #define __FUNCT__ "TSComputeJacobian_Matlab"
5098 /*
5099    TSComputeJacobian_Matlab - Calls the function that has been set with
5100                          TSSetJacobianMatlab().
5101 
5102    Collective on TS
5103 
5104    Input Parameters:
5105 +  ts - the TS context
5106 .  u - input vector
5107 .  A, B - the matrices
5108 -  ctx - user context
5109 
5110    Level: developer
5111 
5112 .keywords: TS, nonlinear, compute, function
5113 
5114 .seealso: TSSetFunction(), TSGetFunction()
5115 @*/
5116 PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat A,Mat B,void *ctx)
5117 {
5118   PetscErrorCode  ierr;
5119   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
5120   int             nlhs  = 2,nrhs = 9;
5121   mxArray         *plhs[2],*prhs[9];
5122   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;
5123 
5124   PetscFunctionBegin;
5125   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
5126   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
5127 
5128   /* call Matlab function in ctx with arguments u and y */
5129 
5130   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
5131   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
5132   ierr = PetscMemcpy(&lxdot,&udot,sizeof(u));CHKERRQ(ierr);
5133   ierr = PetscMemcpy(&lA,A,sizeof(u));CHKERRQ(ierr);
5134   ierr = PetscMemcpy(&lB,B,sizeof(u));CHKERRQ(ierr);
5135 
5136   prhs[0] =  mxCreateDoubleScalar((double)ls);
5137   prhs[1] =  mxCreateDoubleScalar((double)time);
5138   prhs[2] =  mxCreateDoubleScalar((double)lx);
5139   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
5140   prhs[4] =  mxCreateDoubleScalar((double)shift);
5141   prhs[5] =  mxCreateDoubleScalar((double)lA);
5142   prhs[6] =  mxCreateDoubleScalar((double)lB);
5143   prhs[7] =  mxCreateString(sctx->funcname);
5144   prhs[8] =  sctx->ctx;
5145   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");CHKERRQ(ierr);
5146   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
5147   mxDestroyArray(prhs[0]);
5148   mxDestroyArray(prhs[1]);
5149   mxDestroyArray(prhs[2]);
5150   mxDestroyArray(prhs[3]);
5151   mxDestroyArray(prhs[4]);
5152   mxDestroyArray(prhs[5]);
5153   mxDestroyArray(prhs[6]);
5154   mxDestroyArray(prhs[7]);
5155   mxDestroyArray(plhs[0]);
5156   mxDestroyArray(plhs[1]);
5157   PetscFunctionReturn(0);
5158 }
5159 
5160 
5161 #undef __FUNCT__
5162 #define __FUNCT__ "TSSetJacobianMatlab"
5163 /*
5164    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
5165    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
5166 
5167    Logically Collective on TS
5168 
5169    Input Parameters:
5170 +  ts - the TS context
5171 .  A,B - Jacobian matrices
5172 .  func - function evaluation routine
5173 -  ctx - user context
5174 
5175    Calling sequence of func:
5176 $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);
5177 
5178 
5179    Level: developer
5180 
5181 .keywords: TS, nonlinear, set, function
5182 
5183 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
5184 */
5185 PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
5186 {
5187   PetscErrorCode  ierr;
5188   TSMatlabContext *sctx;
5189 
5190   PetscFunctionBegin;
5191   /* currently sctx is memory bleed */
5192   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
5193   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
5194   /*
5195      This should work, but it doesn't
5196   sctx->ctx = ctx;
5197   mexMakeArrayPersistent(sctx->ctx);
5198   */
5199   sctx->ctx = mxDuplicateArray(ctx);
5200 
5201   ierr = TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);CHKERRQ(ierr);
5202   PetscFunctionReturn(0);
5203 }
5204 
5205 #undef __FUNCT__
5206 #define __FUNCT__ "TSMonitor_Matlab"
5207 /*
5208    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().
5209 
5210    Collective on TS
5211 
5212 .seealso: TSSetFunction(), TSGetFunction()
5213 @*/
5214 PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
5215 {
5216   PetscErrorCode  ierr;
5217   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
5218   int             nlhs  = 1,nrhs = 6;
5219   mxArray         *plhs[1],*prhs[6];
5220   long long int   lx = 0,ls = 0;
5221 
5222   PetscFunctionBegin;
5223   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
5224   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
5225 
5226   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
5227   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
5228 
5229   prhs[0] =  mxCreateDoubleScalar((double)ls);
5230   prhs[1] =  mxCreateDoubleScalar((double)it);
5231   prhs[2] =  mxCreateDoubleScalar((double)time);
5232   prhs[3] =  mxCreateDoubleScalar((double)lx);
5233   prhs[4] =  mxCreateString(sctx->funcname);
5234   prhs[5] =  sctx->ctx;
5235   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");CHKERRQ(ierr);
5236   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
5237   mxDestroyArray(prhs[0]);
5238   mxDestroyArray(prhs[1]);
5239   mxDestroyArray(prhs[2]);
5240   mxDestroyArray(prhs[3]);
5241   mxDestroyArray(prhs[4]);
5242   mxDestroyArray(plhs[0]);
5243   PetscFunctionReturn(0);
5244 }
5245 
5246 
5247 #undef __FUNCT__
5248 #define __FUNCT__ "TSMonitorSetMatlab"
5249 /*
5250    TSMonitorSetMatlab - Sets the monitor function from Matlab
5251 
5252    Level: developer
5253 
5254 .keywords: TS, nonlinear, set, function
5255 
5256 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
5257 */
5258 PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
5259 {
5260   PetscErrorCode  ierr;
5261   TSMatlabContext *sctx;
5262 
5263   PetscFunctionBegin;
5264   /* currently sctx is memory bleed */
5265   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
5266   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
5267   /*
5268      This should work, but it doesn't
5269   sctx->ctx = ctx;
5270   mexMakeArrayPersistent(sctx->ctx);
5271   */
5272   sctx->ctx = mxDuplicateArray(ctx);
5273 
5274   ierr = TSMonitorSet(ts,TSMonitor_Matlab,sctx,NULL);CHKERRQ(ierr);
5275   PetscFunctionReturn(0);
5276 }
5277 #endif
5278 
5279 
5280 
5281 #undef __FUNCT__
5282 #define __FUNCT__ "TSMonitorLGSolution"
5283 /*@C
5284    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
5285        in a time based line graph
5286 
5287    Collective on TS
5288 
5289    Input Parameters:
5290 +  ts - the TS context
5291 .  step - current time-step
5292 .  ptime - current time
5293 -  lg - a line graph object
5294 
5295    Level: intermediate
5296 
5297     Notes: each process in a parallel run displays its component solutions in a separate window
5298 
5299 .keywords: TS,  vector, monitor, view
5300 
5301 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
5302 @*/
5303 PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
5304 {
5305   PetscErrorCode    ierr;
5306   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
5307   const PetscScalar *yy;
5308   PetscInt          dim;
5309 
5310   PetscFunctionBegin;
5311   if (!step) {
5312     PetscDrawAxis axis;
5313     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
5314     ierr = PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");CHKERRQ(ierr);
5315     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
5316     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
5317     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
5318   }
5319   ierr = VecGetArrayRead(u,&yy);CHKERRQ(ierr);
5320 #if defined(PETSC_USE_COMPLEX)
5321   {
5322     PetscReal *yreal;
5323     PetscInt  i,n;
5324     ierr = VecGetLocalSize(u,&n);CHKERRQ(ierr);
5325     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
5326     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
5327     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
5328     ierr = PetscFree(yreal);CHKERRQ(ierr);
5329   }
5330 #else
5331   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
5332 #endif
5333   ierr = VecRestoreArrayRead(u,&yy);CHKERRQ(ierr);
5334   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
5335     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
5336   }
5337   PetscFunctionReturn(0);
5338 }
5339 
5340 #undef __FUNCT__
5341 #define __FUNCT__ "TSMonitorLGError"
5342 /*@C
5343    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
5344        in a time based line graph
5345 
5346    Collective on TS
5347 
5348    Input Parameters:
5349 +  ts - the TS context
5350 .  step - current time-step
5351 .  ptime - current time
5352 -  lg - a line graph object
5353 
5354    Level: intermediate
5355 
5356    Notes:
5357    Only for sequential solves.
5358 
5359    The user must provide the solution using TSSetSolutionFunction() to use this monitor.
5360 
5361    Options Database Keys:
5362 .  -ts_monitor_lg_error - create a graphical monitor of error history
5363 
5364 .keywords: TS,  vector, monitor, view
5365 
5366 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
5367 @*/
5368 PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
5369 {
5370   PetscErrorCode    ierr;
5371   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
5372   const PetscScalar *yy;
5373   Vec               y;
5374   PetscInt          dim;
5375 
5376   PetscFunctionBegin;
5377   if (!step) {
5378     PetscDrawAxis axis;
5379     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
5380     ierr = PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");CHKERRQ(ierr);
5381     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
5382     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
5383     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
5384   }
5385   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
5386   ierr = TSComputeSolutionFunction(ts,ptime,y);CHKERRQ(ierr);
5387   ierr = VecAXPY(y,-1.0,u);CHKERRQ(ierr);
5388   ierr = VecGetArrayRead(y,&yy);CHKERRQ(ierr);
5389 #if defined(PETSC_USE_COMPLEX)
5390   {
5391     PetscReal *yreal;
5392     PetscInt  i,n;
5393     ierr = VecGetLocalSize(y,&n);CHKERRQ(ierr);
5394     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
5395     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
5396     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
5397     ierr = PetscFree(yreal);CHKERRQ(ierr);
5398   }
5399 #else
5400   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
5401 #endif
5402   ierr = VecRestoreArrayRead(y,&yy);CHKERRQ(ierr);
5403   ierr = VecDestroy(&y);CHKERRQ(ierr);
5404   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
5405     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
5406   }
5407   PetscFunctionReturn(0);
5408 }
5409 
5410 #undef __FUNCT__
5411 #define __FUNCT__ "TSMonitorLGSNESIterations"
5412 PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
5413 {
5414   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
5415   PetscReal      x   = ptime,y;
5416   PetscErrorCode ierr;
5417   PetscInt       its;
5418 
5419   PetscFunctionBegin;
5420   if (!n) {
5421     PetscDrawAxis axis;
5422 
5423     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
5424     ierr = PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");CHKERRQ(ierr);
5425     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
5426 
5427     ctx->snes_its = 0;
5428   }
5429   ierr = TSGetSNESIterations(ts,&its);CHKERRQ(ierr);
5430   y    = its - ctx->snes_its;
5431   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
5432   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
5433     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
5434   }
5435   ctx->snes_its = its;
5436   PetscFunctionReturn(0);
5437 }
5438 
5439 #undef __FUNCT__
5440 #define __FUNCT__ "TSMonitorLGKSPIterations"
5441 PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
5442 {
5443   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
5444   PetscReal      x   = ptime,y;
5445   PetscErrorCode ierr;
5446   PetscInt       its;
5447 
5448   PetscFunctionBegin;
5449   if (!n) {
5450     PetscDrawAxis axis;
5451 
5452     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
5453     ierr = PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");CHKERRQ(ierr);
5454     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
5455 
5456     ctx->ksp_its = 0;
5457   }
5458   ierr = TSGetKSPIterations(ts,&its);CHKERRQ(ierr);
5459   y    = its - ctx->ksp_its;
5460   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
5461   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
5462     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
5463   }
5464   ctx->ksp_its = its;
5465   PetscFunctionReturn(0);
5466 }
5467 
5468 #undef __FUNCT__
5469 #define __FUNCT__ "TSComputeLinearStability"
5470 /*@
5471    TSComputeLinearStability - computes the linear stability function at a point
5472 
5473    Collective on TS and Vec
5474 
5475    Input Parameters:
5476 +  ts - the TS context
5477 -  xr,xi - real and imaginary part of input arguments
5478 
5479    Output Parameters:
5480 .  yr,yi - real and imaginary part of function value
5481 
5482    Level: developer
5483 
5484 .keywords: TS, compute
5485 
5486 .seealso: TSSetRHSFunction(), TSComputeIFunction()
5487 @*/
5488 PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
5489 {
5490   PetscErrorCode ierr;
5491 
5492   PetscFunctionBegin;
5493   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
5494   if (!ts->ops->linearstability) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"Linearized stability function not provided for this method");
5495   ierr = (*ts->ops->linearstability)(ts,xr,xi,yr,yi);CHKERRQ(ierr);
5496   PetscFunctionReturn(0);
5497 }
5498 
5499 #undef __FUNCT__
5500 #define __FUNCT__ "TSRollBack"
5501 /*@
5502    TSRollBack - Rolls back one time step
5503 
5504    Collective on TS
5505 
5506    Input Parameter:
5507 .  ts - the TS context obtained from TSCreate()
5508 
5509    Level: advanced
5510 
5511 .keywords: TS, timestep, rollback
5512 
5513 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSInterpolate()
5514 @*/
5515 PetscErrorCode  TSRollBack(TS ts)
5516 {
5517   PetscErrorCode ierr;
5518 
5519   PetscFunctionBegin;
5520   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
5521 
5522   if (!ts->ops->rollback) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSRollBack not implemented for type '%s'",((PetscObject)ts)->type_name);
5523   ierr = (*ts->ops->rollback)(ts);CHKERRQ(ierr);
5524   ts->time_step = ts->ptime - ts->ptime_prev;
5525   ts->ptime = ts->ptime_prev;
5526   PetscFunctionReturn(0);
5527 }
5528 
5529 #undef __FUNCT__
5530 #define __FUNCT__ "TSGetStages"
5531 /*@
5532    TSGetStages - Get the number of stages and stage values
5533 
5534    Input Parameter:
5535 .  ts - the TS context obtained from TSCreate()
5536 
5537    Level: advanced
5538 
5539 .keywords: TS, getstages
5540 
5541 .seealso: TSCreate()
5542 @*/
5543 PetscErrorCode  TSGetStages(TS ts,PetscInt *ns, Vec **Y)
5544 {
5545   PetscErrorCode ierr;
5546 
5547   PetscFunctionBegin;
5548   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
5549   PetscValidPointer(ns,2);
5550 
5551   if (!ts->ops->getstages) *ns=0;
5552   else {
5553     ierr = (*ts->ops->getstages)(ts,ns,Y);CHKERRQ(ierr);
5554   }
5555   PetscFunctionReturn(0);
5556 }
5557 
5558 
5559 
5560