xref: /petsc/src/ts/interface/ts.c (revision 2e826d6f168293946e7dc17f87075462a7cd4791)
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"
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(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_max_steps maxsteps - maximum number of time-steps to take
73 .  -ts_final_time time - maximum time to compute to
74 .  -ts_dt dt - initial time step
75 .  -ts_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
76 .  -ts_max_snes_failures <maxfailures> - Maximum number of nonlinear solve failures allowed
77 .  -ts_max_reject <maxrejects> - Maximum number of step rejections before step fails
78 .  -ts_error_if_step_fails <true,false> - Error if no step succeeds
79 .  -ts_rtol <rtol> - relative tolerance for local truncation error
80 .  -ts_atol <atol> Absolute tolerance for local truncation error
81 .  -ts_monitor - print information at each timestep
82 .  -ts_monitor_lg_timestep - Monitor timestep size graphically
83 .  -ts_monitor_lg_solution - Monitor solution graphically
84 .  -ts_monitor_lg_error - Monitor error graphically
85 .  -ts_monitor_lg_snes_iterations - Monitor number nonlinear iterations for each timestep graphically
86 .  -ts_monitor_lg_ksp_iterations - Monitor number nonlinear iterations for each timestep graphically
87 .  -ts_monitor_sp_eig - Monitor eigenvalues of linearized operator graphically
88 .  -ts_monitor_draw_solution - Monitor solution graphically
89 .  -ts_monitor_draw_solution_phase - Monitor solution graphically with phase diagram
90 .  -ts_monitor_draw_error - Monitor error graphically
91 .  -ts_monitor_solution_binary <filename> - Save each solution to a binary file
92 -  -ts_monitor_solution_vtk <filename.vts> - Save each time step to a binary file, use filename-%%03D.vts
93 
94    Developer Note: We should unify all the -ts_monitor options in the way that -xxx_view has been unified
95 
96    Level: beginner
97 
98 .keywords: TS, timestep, set, options, database
99 
100 .seealso: TSGetType()
101 @*/
102 PetscErrorCode  TSSetFromOptions(TS ts)
103 {
104   PetscBool              opt,flg;
105   PetscErrorCode         ierr;
106   PetscViewer            monviewer;
107   char                   monfilename[PETSC_MAX_PATH_LEN];
108   SNES                   snes;
109   TSAdapt                adapt;
110   PetscReal              time_step;
111   TSExactFinalTimeOption eftopt;
112   char                   dir[16];
113 
114   PetscFunctionBegin;
115   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
116   ierr = PetscObjectOptionsBegin((PetscObject)ts);CHKERRQ(ierr);
117   /* Handle TS type options */
118   ierr = TSSetTypeFromOptions(ts);CHKERRQ(ierr);
119 
120   /* Handle generic TS options */
121   ierr = PetscOptionsInt("-ts_max_steps","Maximum number of time steps","TSSetDuration",ts->max_steps,&ts->max_steps,NULL);CHKERRQ(ierr);
122   ierr = PetscOptionsReal("-ts_final_time","Time to run to","TSSetDuration",ts->max_time,&ts->max_time,NULL);CHKERRQ(ierr);
123   ierr = PetscOptionsReal("-ts_init_time","Initial time","TSSetTime",ts->ptime,&ts->ptime,NULL);CHKERRQ(ierr);
124   ierr = PetscOptionsReal("-ts_dt","Initial time step","TSSetTimeStep",ts->time_step,&time_step,&flg);CHKERRQ(ierr);
125   if (flg) {
126     ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
127   }
128   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);
129   if (flg) {ierr = TSSetExactFinalTime(ts,eftopt);CHKERRQ(ierr);}
130   ierr = PetscOptionsInt("-ts_max_snes_failures","Maximum number of nonlinear solve failures","TSSetMaxSNESFailures",ts->max_snes_failures,&ts->max_snes_failures,NULL);CHKERRQ(ierr);
131   ierr = PetscOptionsInt("-ts_max_reject","Maximum number of step rejections before step fails","TSSetMaxStepRejections",ts->max_reject,&ts->max_reject,NULL);CHKERRQ(ierr);
132   ierr = PetscOptionsBool("-ts_error_if_step_fails","Error if no step succeeds","TSSetErrorIfStepFails",ts->errorifstepfailed,&ts->errorifstepfailed,NULL);CHKERRQ(ierr);
133   ierr = PetscOptionsReal("-ts_rtol","Relative tolerance for local truncation error","TSSetTolerances",ts->rtol,&ts->rtol,NULL);CHKERRQ(ierr);
134   ierr = PetscOptionsReal("-ts_atol","Absolute tolerance for local truncation error","TSSetTolerances",ts->atol,&ts->atol,NULL);CHKERRQ(ierr);
135 
136 #if defined(PETSC_HAVE_SAWS)
137   {
138   PetscBool set;
139   flg  = PETSC_FALSE;
140   ierr = PetscOptionsBool("-ts_saws_block","Block for SAWs memory snooper at end of TSSolve","PetscObjectSAWsBlock",((PetscObject)ts)->amspublishblock,&flg,&set);CHKERRQ(ierr);
141   if (set) {
142     ierr = PetscObjectSAWsSetBlock((PetscObject)ts,flg);CHKERRQ(ierr);
143   }
144   }
145 #endif
146 
147   /* Monitor options */
148   ierr = PetscOptionsString("-ts_monitor","Monitor timestep size","TSMonitorDefault","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
149   if (flg) {
150     ierr = PetscViewerASCIIOpen(PetscObjectComm((PetscObject)ts),monfilename,&monviewer);CHKERRQ(ierr);
151     ierr = TSMonitorSet(ts,TSMonitorDefault,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
152   }
153   ierr = PetscOptionsString("-ts_monitor_python","Use Python function","TSMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
154   if (flg) {ierr = PetscPythonMonitorSet((PetscObject)ts,monfilename);CHKERRQ(ierr);}
155 
156   ierr = PetscOptionsName("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",&opt);CHKERRQ(ierr);
157   if (opt) {
158     TSMonitorLGCtx ctx;
159     PetscInt       howoften = 1;
160 
161     ierr = PetscOptionsInt("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",howoften,&howoften,NULL);CHKERRQ(ierr);
162     ierr = TSMonitorLGCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
163     ierr = TSMonitorSet(ts,TSMonitorLGTimeStep,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
164   }
165   ierr = PetscOptionsName("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",&opt);CHKERRQ(ierr);
166   if (opt) {
167     TSMonitorLGCtx ctx;
168     PetscInt       howoften = 1;
169 
170     ierr = PetscOptionsInt("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
171     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
172     ierr = TSMonitorSet(ts,TSMonitorLGSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
173   }
174   ierr = PetscOptionsName("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",&opt);CHKERRQ(ierr);
175   if (opt) {
176     TSMonitorLGCtx ctx;
177     PetscInt       howoften = 1;
178 
179     ierr = PetscOptionsInt("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",howoften,&howoften,NULL);CHKERRQ(ierr);
180     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
181     ierr = TSMonitorSet(ts,TSMonitorLGError,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
182   }
183   ierr = PetscOptionsName("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",&opt);CHKERRQ(ierr);
184   if (opt) {
185     TSMonitorLGCtx ctx;
186     PetscInt       howoften = 1;
187 
188     ierr = PetscOptionsInt("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
189     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
190     ierr = TSMonitorSet(ts,TSMonitorLGSNESIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
191   }
192   ierr = PetscOptionsName("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",&opt);CHKERRQ(ierr);
193   if (opt) {
194     TSMonitorLGCtx ctx;
195     PetscInt       howoften = 1;
196 
197     ierr = PetscOptionsInt("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
198     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
199     ierr = TSMonitorSet(ts,TSMonitorLGKSPIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
200   }
201   ierr = PetscOptionsName("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",&opt);CHKERRQ(ierr);
202   if (opt) {
203     TSMonitorSPEigCtx ctx;
204     PetscInt          howoften = 1;
205 
206     ierr = PetscOptionsInt("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",howoften,&howoften,NULL);CHKERRQ(ierr);
207     ierr = TSMonitorSPEigCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
208     ierr = TSMonitorSet(ts,TSMonitorSPEig,ctx,(PetscErrorCode (*)(void**))TSMonitorSPEigCtxDestroy);CHKERRQ(ierr);
209   }
210   opt  = PETSC_FALSE;
211   ierr = PetscOptionsName("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",&opt);CHKERRQ(ierr);
212   if (opt) {
213     TSMonitorDrawCtx ctx;
214     PetscInt         howoften = 1;
215 
216     ierr = PetscOptionsInt("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
217     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
218     ierr = TSMonitorSet(ts,TSMonitorDrawSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
219   }
220   opt  = PETSC_FALSE;
221   ierr = PetscOptionsName("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",&opt);CHKERRQ(ierr);
222   if (opt) {
223     TSMonitorDrawCtx ctx;
224     PetscReal        bounds[4];
225     PetscInt         n = 4;
226     PetscDraw        draw;
227 
228     ierr = PetscOptionsRealArray("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",bounds,&n,NULL);CHKERRQ(ierr);
229     if (n != 4) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Must provide bounding box of phase field");
230     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,1,&ctx);CHKERRQ(ierr);
231     ierr = PetscViewerDrawGetDraw(ctx->viewer,0,&draw);CHKERRQ(ierr);
232     ierr = PetscDrawClear(draw);CHKERRQ(ierr);
233     ierr = PetscDrawAxisCreate(draw,&ctx->axis);CHKERRQ(ierr);
234     ierr = PetscDrawAxisSetLimits(ctx->axis,bounds[0],bounds[2],bounds[1],bounds[3]);CHKERRQ(ierr);
235     ierr = PetscDrawAxisSetLabels(ctx->axis,"Phase Diagram","Variable 1","Variable 2");CHKERRQ(ierr);
236     ierr = PetscDrawAxisDraw(ctx->axis);CHKERRQ(ierr);
237     /* ierr = PetscDrawSetCoordinates(draw,bounds[0],bounds[1],bounds[2],bounds[3]);CHKERRQ(ierr); */
238     ierr = TSMonitorSet(ts,TSMonitorDrawSolutionPhase,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
239   }
240   opt  = PETSC_FALSE;
241   ierr = PetscOptionsName("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",&opt);CHKERRQ(ierr);
242   if (opt) {
243     TSMonitorDrawCtx ctx;
244     PetscInt         howoften = 1;
245 
246     ierr = PetscOptionsInt("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",howoften,&howoften,NULL);CHKERRQ(ierr);
247     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
248     ierr = TSMonitorSet(ts,TSMonitorDrawError,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
249   }
250   opt  = PETSC_FALSE;
251   ierr = PetscOptionsString("-ts_monitor_solution_binary","Save each solution to a binary file","TSMonitorSolutionBinary",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
252   if (flg) {
253     PetscViewer ctx;
254     if (monfilename[0]) {
255       ierr = PetscViewerBinaryOpen(PetscObjectComm((PetscObject)ts),monfilename,FILE_MODE_WRITE,&ctx);CHKERRQ(ierr);
256       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
257     } else {
258       ctx = PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)ts));
259       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))NULL);CHKERRQ(ierr);
260     }
261   }
262   opt  = PETSC_FALSE;
263   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);
264   if (flg) {
265     const char *ptr,*ptr2;
266     char       *filetemplate;
267     if (!monfilename[0]) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
268     /* Do some cursory validation of the input. */
269     ierr = PetscStrstr(monfilename,"%",(char**)&ptr);CHKERRQ(ierr);
270     if (!ptr) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
271     for (ptr++; ptr && *ptr; ptr++) {
272       ierr = PetscStrchr("DdiouxX",*ptr,(char**)&ptr2);CHKERRQ(ierr);
273       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");
274       if (ptr2) break;
275     }
276     ierr = PetscStrallocpy(monfilename,&filetemplate);CHKERRQ(ierr);
277     ierr = TSMonitorSet(ts,TSMonitorSolutionVTK,filetemplate,(PetscErrorCode (*)(void**))TSMonitorSolutionVTKDestroy);CHKERRQ(ierr);
278   }
279 
280   ierr = PetscOptionsString("-ts_monitor_dmda_ray","Display a ray of the solution","None","y=0",dir,16,&flg);CHKERRQ(ierr);
281   if (flg) {
282     TSMonitorDMDARayCtx *rayctx;
283     int                  ray = 0;
284     DMDADirection        ddir;
285     DM                   da;
286     PetscMPIInt          rank;
287 
288     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
289     if (dir[0] == 'x') ddir = DMDA_X;
290     else if (dir[0] == 'y') ddir = DMDA_Y;
291     else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
292     sscanf(dir+2,"%d",&ray);
293 
294     ierr = PetscInfo2(((PetscObject)ts),"Displaying DMDA ray %c = %D\n",dir[0],ray);CHKERRQ(ierr);
295     ierr = PetscNew(&rayctx);CHKERRQ(ierr);
296     ierr = TSGetDM(ts,&da);CHKERRQ(ierr);
297     ierr = DMDAGetRay(da,ddir,ray,&rayctx->ray,&rayctx->scatter);CHKERRQ(ierr);
298     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)ts),&rank);CHKERRQ(ierr);
299     if (!rank) {
300       ierr = PetscViewerDrawOpen(PETSC_COMM_SELF,0,0,0,0,600,300,&rayctx->viewer);CHKERRQ(ierr);
301     }
302     rayctx->lgctx = NULL;
303     ierr = TSMonitorSet(ts,TSMonitorDMDARay,rayctx,TSMonitorDMDARayDestroy);CHKERRQ(ierr);
304   }
305   ierr = PetscOptionsString("-ts_monitor_lg_dmda_ray","Display a ray of the solution","None","x=0",dir,16,&flg);CHKERRQ(ierr);
306   if (flg) {
307     TSMonitorDMDARayCtx *rayctx;
308     int                 ray = 0;
309     DMDADirection       ddir;
310     DM                  da;
311     PetscInt            howoften = 1;
312 
313     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Malformed ray %s", dir);
314     if      (dir[0] == 'x') ddir = DMDA_X;
315     else if (dir[0] == 'y') ddir = DMDA_Y;
316     else SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Unknown ray direction %s", dir);
317     sscanf(dir+2, "%d", &ray);
318 
319     ierr = PetscInfo2(((PetscObject) ts),"Displaying LG DMDA ray %c = %D\n", dir[0], ray);CHKERRQ(ierr);
320     ierr = PetscNew(&rayctx);CHKERRQ(ierr);
321     ierr = TSGetDM(ts, &da);CHKERRQ(ierr);
322     ierr = DMDAGetRay(da, ddir, ray, &rayctx->ray, &rayctx->scatter);CHKERRQ(ierr);
323     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&rayctx->lgctx);CHKERRQ(ierr);
324     ierr = TSMonitorSet(ts, TSMonitorLGDMDARay, rayctx, TSMonitorDMDARayDestroy);CHKERRQ(ierr);
325   }
326 
327   /*
328      This code is all wrong. One is creating objects inside the TSSetFromOptions() so if run with the options gui
329      will bleed memory. Also one is using a PetscOptionsBegin() inside a PetscOptionsBegin()
330   */
331   ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
332   ierr = TSAdaptSetFromOptions(adapt);CHKERRQ(ierr);
333 
334   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
335   if (ts->problem_type == TS_LINEAR) {ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);}
336 
337   /* Handle specific TS options */
338   if (ts->ops->setfromoptions) {
339     ierr = (*ts->ops->setfromoptions)(ts);CHKERRQ(ierr);
340   }
341 
342   /* process any options handlers added with PetscObjectAddOptionsHandler() */
343   ierr = PetscObjectProcessOptionsHandlers((PetscObject)ts);CHKERRQ(ierr);
344   ierr = PetscOptionsEnd();CHKERRQ(ierr);
345   PetscFunctionReturn(0);
346 }
347 
348 #undef __FUNCT__
349 #undef __FUNCT__
350 #define __FUNCT__ "TSComputeRHSJacobian"
351 /*@
352    TSComputeRHSJacobian - Computes the Jacobian matrix that has been
353       set with TSSetRHSJacobian().
354 
355    Collective on TS and Vec
356 
357    Input Parameters:
358 +  ts - the TS context
359 .  t - current timestep
360 -  U - input vector
361 
362    Output Parameters:
363 +  A - Jacobian matrix
364 .  B - optional preconditioning matrix
365 -  flag - flag indicating matrix structure
366 
367    Notes:
368    Most users should not need to explicitly call this routine, as it
369    is used internally within the nonlinear solvers.
370 
371    See KSPSetOperators() for important information about setting the
372    flag parameter.
373 
374    Level: developer
375 
376 .keywords: SNES, compute, Jacobian, matrix
377 
378 .seealso:  TSSetRHSJacobian(), KSPSetOperators()
379 @*/
380 PetscErrorCode  TSComputeRHSJacobian(TS ts,PetscReal t,Vec U,Mat A,Mat B)
381 {
382   PetscErrorCode ierr;
383   PetscObjectState Ustate;
384   DM             dm;
385   DMTS           tsdm;
386   TSRHSJacobian  rhsjacobianfunc;
387   void           *ctx;
388   TSIJacobian    ijacobianfunc;
389 
390   PetscFunctionBegin;
391   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
392   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
393   PetscCheckSameComm(ts,1,U,3);
394   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
395   ierr = DMGetDMTS(dm,&tsdm);CHKERRQ(ierr);
396   ierr = DMTSGetRHSJacobian(dm,&rhsjacobianfunc,&ctx);CHKERRQ(ierr);
397   ierr = DMTSGetIJacobian(dm,&ijacobianfunc,NULL);CHKERRQ(ierr);
398   ierr = PetscObjectStateGet((PetscObject)U,&Ustate);CHKERRQ(ierr);
399   if (ts->rhsjacobian.time == t && (ts->problem_type == TS_LINEAR || (ts->rhsjacobian.X == U && ts->rhsjacobian.Xstate == Ustate))) {
400     PetscFunctionReturn(0);
401   }
402 
403   if (!rhsjacobianfunc && !ijacobianfunc) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
404 
405   if (ts->rhsjacobian.reuse) {
406     ierr = MatShift(A,-ts->rhsjacobian.shift);CHKERRQ(ierr);
407     ierr = MatScale(A,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
408     if (A != B) {
409       ierr = MatShift(B,-ts->rhsjacobian.shift);CHKERRQ(ierr);
410       ierr = MatScale(B,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
411     }
412     ts->rhsjacobian.shift = 0;
413     ts->rhsjacobian.scale = 1.;
414   }
415 
416   if (rhsjacobianfunc) {
417     ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
418     PetscStackPush("TS user Jacobian function");
419     ierr = (*rhsjacobianfunc)(ts,t,U,A,B,ctx);CHKERRQ(ierr);
420     PetscStackPop;
421     ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
422     /* make sure user returned a correct Jacobian and preconditioner */
423     PetscValidHeaderSpecific(A,MAT_CLASSID,4);
424     PetscValidHeaderSpecific(B,MAT_CLASSID,5);
425   } else {
426     ierr = MatZeroEntries(A);CHKERRQ(ierr);
427     if (A != B) {ierr = MatZeroEntries(B);CHKERRQ(ierr);}
428   }
429   ts->rhsjacobian.time       = t;
430   ts->rhsjacobian.X          = U;
431   ierr                       = PetscObjectStateGet((PetscObject)U,&ts->rhsjacobian.Xstate);CHKERRQ(ierr);
432   PetscFunctionReturn(0);
433 }
434 
435 #undef __FUNCT__
436 #define __FUNCT__ "TSComputeRHSFunction"
437 /*@
438    TSComputeRHSFunction - Evaluates the right-hand-side function.
439 
440    Collective on TS and Vec
441 
442    Input Parameters:
443 +  ts - the TS context
444 .  t - current time
445 -  U - state vector
446 
447    Output Parameter:
448 .  y - right hand side
449 
450    Note:
451    Most users should not need to explicitly call this routine, as it
452    is used internally within the nonlinear solvers.
453 
454    Level: developer
455 
456 .keywords: TS, compute
457 
458 .seealso: TSSetRHSFunction(), TSComputeIFunction()
459 @*/
460 PetscErrorCode TSComputeRHSFunction(TS ts,PetscReal t,Vec U,Vec y)
461 {
462   PetscErrorCode ierr;
463   TSRHSFunction  rhsfunction;
464   TSIFunction    ifunction;
465   void           *ctx;
466   DM             dm;
467 
468   PetscFunctionBegin;
469   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
470   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
471   PetscValidHeaderSpecific(y,VEC_CLASSID,4);
472   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
473   ierr = DMTSGetRHSFunction(dm,&rhsfunction,&ctx);CHKERRQ(ierr);
474   ierr = DMTSGetIFunction(dm,&ifunction,NULL);CHKERRQ(ierr);
475 
476   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
477 
478   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
479   if (rhsfunction) {
480     PetscStackPush("TS user right-hand-side function");
481     ierr = (*rhsfunction)(ts,t,U,y,ctx);CHKERRQ(ierr);
482     PetscStackPop;
483   } else {
484     ierr = VecZeroEntries(y);CHKERRQ(ierr);
485   }
486 
487   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
488   PetscFunctionReturn(0);
489 }
490 
491 #undef __FUNCT__
492 #define __FUNCT__ "TSComputeSolutionFunction"
493 /*@
494    TSComputeSolutionFunction - Evaluates the solution function.
495 
496    Collective on TS and Vec
497 
498    Input Parameters:
499 +  ts - the TS context
500 -  t - current time
501 
502    Output Parameter:
503 .  U - the solution
504 
505    Note:
506    Most users should not need to explicitly call this routine, as it
507    is used internally within the nonlinear solvers.
508 
509    Level: developer
510 
511 .keywords: TS, compute
512 
513 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
514 @*/
515 PetscErrorCode TSComputeSolutionFunction(TS ts,PetscReal t,Vec U)
516 {
517   PetscErrorCode     ierr;
518   TSSolutionFunction solutionfunction;
519   void               *ctx;
520   DM                 dm;
521 
522   PetscFunctionBegin;
523   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
524   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
525   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
526   ierr = DMTSGetSolutionFunction(dm,&solutionfunction,&ctx);CHKERRQ(ierr);
527 
528   if (solutionfunction) {
529     PetscStackPush("TS user solution function");
530     ierr = (*solutionfunction)(ts,t,U,ctx);CHKERRQ(ierr);
531     PetscStackPop;
532   }
533   PetscFunctionReturn(0);
534 }
535 #undef __FUNCT__
536 #define __FUNCT__ "TSComputeForcingFunction"
537 /*@
538    TSComputeForcingFunction - Evaluates the forcing function.
539 
540    Collective on TS and Vec
541 
542    Input Parameters:
543 +  ts - the TS context
544 -  t - current time
545 
546    Output Parameter:
547 .  U - the function value
548 
549    Note:
550    Most users should not need to explicitly call this routine, as it
551    is used internally within the nonlinear solvers.
552 
553    Level: developer
554 
555 .keywords: TS, compute
556 
557 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
558 @*/
559 PetscErrorCode TSComputeForcingFunction(TS ts,PetscReal t,Vec U)
560 {
561   PetscErrorCode     ierr, (*forcing)(TS,PetscReal,Vec,void*);
562   void               *ctx;
563   DM                 dm;
564 
565   PetscFunctionBegin;
566   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
567   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
568   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
569   ierr = DMTSGetForcingFunction(dm,&forcing,&ctx);CHKERRQ(ierr);
570 
571   if (forcing) {
572     PetscStackPush("TS user forcing function");
573     ierr = (*forcing)(ts,t,U,ctx);CHKERRQ(ierr);
574     PetscStackPop;
575   }
576   PetscFunctionReturn(0);
577 }
578 
579 #undef __FUNCT__
580 #define __FUNCT__ "TSGetRHSVec_Private"
581 static PetscErrorCode TSGetRHSVec_Private(TS ts,Vec *Frhs)
582 {
583   Vec            F;
584   PetscErrorCode ierr;
585 
586   PetscFunctionBegin;
587   *Frhs = NULL;
588   ierr  = TSGetIFunction(ts,&F,NULL,NULL);CHKERRQ(ierr);
589   if (!ts->Frhs) {
590     ierr = VecDuplicate(F,&ts->Frhs);CHKERRQ(ierr);
591   }
592   *Frhs = ts->Frhs;
593   PetscFunctionReturn(0);
594 }
595 
596 #undef __FUNCT__
597 #define __FUNCT__ "TSGetRHSMats_Private"
598 static PetscErrorCode TSGetRHSMats_Private(TS ts,Mat *Arhs,Mat *Brhs)
599 {
600   Mat            A,B;
601   PetscErrorCode ierr;
602 
603   PetscFunctionBegin;
604   if (Arhs) *Arhs = NULL;
605   if (Brhs) *Brhs = NULL;
606   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
607   if (Arhs) {
608     if (!ts->Arhs) {
609       ierr = MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&ts->Arhs);CHKERRQ(ierr);
610     }
611     *Arhs = ts->Arhs;
612   }
613   if (Brhs) {
614     if (!ts->Brhs) {
615       if (A != B) {
616         ierr = MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&ts->Brhs);CHKERRQ(ierr);
617       } else {
618         ts->Brhs = ts->Arhs;
619         ierr = PetscObjectReference((PetscObject)ts->Arhs);CHKERRQ(ierr);
620       }
621     }
622     *Brhs = ts->Brhs;
623   }
624   PetscFunctionReturn(0);
625 }
626 
627 #undef __FUNCT__
628 #define __FUNCT__ "TSComputeIFunction"
629 /*@
630    TSComputeIFunction - Evaluates the DAE residual written in implicit form F(t,U,Udot)=0
631 
632    Collective on TS and Vec
633 
634    Input Parameters:
635 +  ts - the TS context
636 .  t - current time
637 .  U - state vector
638 .  Udot - time derivative of state vector
639 -  imex - flag indicates if the method is IMEX so that the RHSFunction should be kept separate
640 
641    Output Parameter:
642 .  Y - right hand side
643 
644    Note:
645    Most users should not need to explicitly call this routine, as it
646    is used internally within the nonlinear solvers.
647 
648    If the user did did not write their equations in implicit form, this
649    function recasts them in implicit form.
650 
651    Level: developer
652 
653 .keywords: TS, compute
654 
655 .seealso: TSSetIFunction(), TSComputeRHSFunction()
656 @*/
657 PetscErrorCode TSComputeIFunction(TS ts,PetscReal t,Vec U,Vec Udot,Vec Y,PetscBool imex)
658 {
659   PetscErrorCode ierr;
660   TSIFunction    ifunction;
661   TSRHSFunction  rhsfunction;
662   void           *ctx;
663   DM             dm;
664 
665   PetscFunctionBegin;
666   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
667   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
668   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
669   PetscValidHeaderSpecific(Y,VEC_CLASSID,5);
670 
671   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
672   ierr = DMTSGetIFunction(dm,&ifunction,&ctx);CHKERRQ(ierr);
673   ierr = DMTSGetRHSFunction(dm,&rhsfunction,NULL);CHKERRQ(ierr);
674 
675   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
676 
677   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
678   if (ifunction) {
679     PetscStackPush("TS user implicit function");
680     ierr = (*ifunction)(ts,t,U,Udot,Y,ctx);CHKERRQ(ierr);
681     PetscStackPop;
682   }
683   if (imex) {
684     if (!ifunction) {
685       ierr = VecCopy(Udot,Y);CHKERRQ(ierr);
686     }
687   } else if (rhsfunction) {
688     if (ifunction) {
689       Vec Frhs;
690       ierr = TSGetRHSVec_Private(ts,&Frhs);CHKERRQ(ierr);
691       ierr = TSComputeRHSFunction(ts,t,U,Frhs);CHKERRQ(ierr);
692       ierr = VecAXPY(Y,-1,Frhs);CHKERRQ(ierr);
693     } else {
694       ierr = TSComputeRHSFunction(ts,t,U,Y);CHKERRQ(ierr);
695       ierr = VecAYPX(Y,-1,Udot);CHKERRQ(ierr);
696     }
697   }
698   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
699   PetscFunctionReturn(0);
700 }
701 
702 #undef __FUNCT__
703 #define __FUNCT__ "TSComputeIJacobian"
704 /*@
705    TSComputeIJacobian - Evaluates the Jacobian of the DAE
706 
707    Collective on TS and Vec
708 
709    Input
710       Input Parameters:
711 +  ts - the TS context
712 .  t - current timestep
713 .  U - state vector
714 .  Udot - time derivative of state vector
715 .  shift - shift to apply, see note below
716 -  imex - flag indicates if the method is IMEX so that the RHSJacobian should be kept separate
717 
718    Output Parameters:
719 +  A - Jacobian matrix
720 .  B - optional preconditioning matrix
721 -  flag - flag indicating matrix structure
722 
723    Notes:
724    If F(t,U,Udot)=0 is the DAE, the required Jacobian is
725 
726    dF/dU + shift*dF/dUdot
727 
728    Most users should not need to explicitly call this routine, as it
729    is used internally within the nonlinear solvers.
730 
731    Level: developer
732 
733 .keywords: TS, compute, Jacobian, matrix
734 
735 .seealso:  TSSetIJacobian()
736 @*/
737 PetscErrorCode TSComputeIJacobian(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,PetscBool imex)
738 {
739   PetscErrorCode ierr;
740   TSIJacobian    ijacobian;
741   TSRHSJacobian  rhsjacobian;
742   DM             dm;
743   void           *ctx;
744 
745   PetscFunctionBegin;
746   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
747   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
748   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
749   PetscValidPointer(A,6);
750   PetscValidHeaderSpecific(A,MAT_CLASSID,6);
751   PetscValidPointer(B,7);
752   PetscValidHeaderSpecific(B,MAT_CLASSID,7);
753 
754   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
755   ierr = DMTSGetIJacobian(dm,&ijacobian,&ctx);CHKERRQ(ierr);
756   ierr = DMTSGetRHSJacobian(dm,&rhsjacobian,NULL);CHKERRQ(ierr);
757 
758   if (!rhsjacobian && !ijacobian) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
759 
760   ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
761   if (ijacobian) {
762     PetscStackPush("TS user implicit Jacobian");
763     ierr = (*ijacobian)(ts,t,U,Udot,shift,A,B,ctx);CHKERRQ(ierr);
764     PetscStackPop;
765     /* make sure user returned a correct Jacobian and preconditioner */
766     PetscValidHeaderSpecific(A,MAT_CLASSID,4);
767     PetscValidHeaderSpecific(B,MAT_CLASSID,5);
768   }
769   if (imex) {
770     if (!ijacobian) {  /* system was written as Udot = G(t,U) */
771       ierr = MatZeroEntries(A);CHKERRQ(ierr);
772       ierr = MatShift(A,shift);CHKERRQ(ierr);
773       if (A != B) {
774         ierr = MatZeroEntries(B);CHKERRQ(ierr);
775         ierr = MatShift(B,shift);CHKERRQ(ierr);
776       }
777     }
778   } else {
779     Mat Arhs = NULL,Brhs = NULL;
780     if (rhsjacobian) {
781       if (ijacobian) {
782         ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
783       } else {
784         ierr = TSGetIJacobian(ts,&Arhs,&Brhs,NULL,NULL);CHKERRQ(ierr);
785       }
786       ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
787     }
788     if (Arhs == A) {           /* No IJacobian, so we only have the RHS matrix */
789       ts->rhsjacobian.scale = -1;
790       ts->rhsjacobian.shift = shift;
791       ierr = MatScale(A,-1);CHKERRQ(ierr);
792       ierr = MatShift(A,shift);CHKERRQ(ierr);
793       if (A != B) {
794         ierr = MatScale(B,-1);CHKERRQ(ierr);
795         ierr = MatShift(B,shift);CHKERRQ(ierr);
796       }
797     } else if (Arhs) {          /* Both IJacobian and RHSJacobian */
798       MatStructure axpy = DIFFERENT_NONZERO_PATTERN;
799       if (!ijacobian) {         /* No IJacobian provided, but we have a separate RHS matrix */
800         ierr = MatZeroEntries(A);CHKERRQ(ierr);
801         ierr = MatShift(A,shift);CHKERRQ(ierr);
802         if (A != B) {
803           ierr = MatZeroEntries(B);CHKERRQ(ierr);
804           ierr = MatShift(B,shift);CHKERRQ(ierr);
805         }
806       }
807       ierr = MatAXPY(A,-1,Arhs,axpy);CHKERRQ(ierr);
808       if (A != B) {
809         ierr = MatAXPY(B,-1,Brhs,axpy);CHKERRQ(ierr);
810       }
811     }
812   }
813   ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
814   PetscFunctionReturn(0);
815 }
816 
817 #undef __FUNCT__
818 #define __FUNCT__ "TSSetRHSFunction"
819 /*@C
820     TSSetRHSFunction - Sets the routine for evaluating the function,
821     where U_t = G(t,u).
822 
823     Logically Collective on TS
824 
825     Input Parameters:
826 +   ts - the TS context obtained from TSCreate()
827 .   r - vector to put the computed right hand side (or NULL to have it created)
828 .   f - routine for evaluating the right-hand-side function
829 -   ctx - [optional] user-defined context for private data for the
830           function evaluation routine (may be NULL)
831 
832     Calling sequence of func:
833 $     func (TS ts,PetscReal t,Vec u,Vec F,void *ctx);
834 
835 +   t - current timestep
836 .   u - input vector
837 .   F - function vector
838 -   ctx - [optional] user-defined function context
839 
840     Level: beginner
841 
842 .keywords: TS, timestep, set, right-hand-side, function
843 
844 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSSetIFunction()
845 @*/
846 PetscErrorCode  TSSetRHSFunction(TS ts,Vec r,PetscErrorCode (*f)(TS,PetscReal,Vec,Vec,void*),void *ctx)
847 {
848   PetscErrorCode ierr;
849   SNES           snes;
850   Vec            ralloc = NULL;
851   DM             dm;
852 
853   PetscFunctionBegin;
854   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
855   if (r) PetscValidHeaderSpecific(r,VEC_CLASSID,2);
856 
857   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
858   ierr = DMTSSetRHSFunction(dm,f,ctx);CHKERRQ(ierr);
859   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
860   if (!r && !ts->dm && ts->vec_sol) {
861     ierr = VecDuplicate(ts->vec_sol,&ralloc);CHKERRQ(ierr);
862     r    = ralloc;
863   }
864   ierr = SNESSetFunction(snes,r,SNESTSFormFunction,ts);CHKERRQ(ierr);
865   ierr = VecDestroy(&ralloc);CHKERRQ(ierr);
866   PetscFunctionReturn(0);
867 }
868 
869 #undef __FUNCT__
870 #define __FUNCT__ "TSSetSolutionFunction"
871 /*@C
872     TSSetSolutionFunction - Provide a function that computes the solution of the ODE or DAE
873 
874     Logically Collective on TS
875 
876     Input Parameters:
877 +   ts - the TS context obtained from TSCreate()
878 .   f - routine for evaluating the solution
879 -   ctx - [optional] user-defined context for private data for the
880           function evaluation routine (may be NULL)
881 
882     Calling sequence of func:
883 $     func (TS ts,PetscReal t,Vec u,void *ctx);
884 
885 +   t - current timestep
886 .   u - output vector
887 -   ctx - [optional] user-defined function context
888 
889     Notes:
890     This routine is used for testing accuracy of time integration schemes when you already know the solution.
891     If analytic solutions are not known for your system, consider using the Method of Manufactured Solutions to
892     create closed-form solutions with non-physical forcing terms.
893 
894     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
895 
896     Level: beginner
897 
898 .keywords: TS, timestep, set, right-hand-side, function
899 
900 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetForcingFunction()
901 @*/
902 PetscErrorCode  TSSetSolutionFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
903 {
904   PetscErrorCode ierr;
905   DM             dm;
906 
907   PetscFunctionBegin;
908   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
909   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
910   ierr = DMTSSetSolutionFunction(dm,f,ctx);CHKERRQ(ierr);
911   PetscFunctionReturn(0);
912 }
913 
914 #undef __FUNCT__
915 #define __FUNCT__ "TSSetForcingFunction"
916 /*@C
917     TSSetForcingFunction - Provide a function that computes a forcing term for a ODE or PDE
918 
919     Logically Collective on TS
920 
921     Input Parameters:
922 +   ts - the TS context obtained from TSCreate()
923 .   f - routine for evaluating the forcing function
924 -   ctx - [optional] user-defined context for private data for the
925           function evaluation routine (may be NULL)
926 
927     Calling sequence of func:
928 $     func (TS ts,PetscReal t,Vec u,void *ctx);
929 
930 +   t - current timestep
931 .   u - output vector
932 -   ctx - [optional] user-defined function context
933 
934     Notes:
935     This routine is useful for testing accuracy of time integration schemes when using the Method of Manufactured Solutions to
936     create closed-form solutions with a non-physical forcing term.
937 
938     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
939 
940     Level: beginner
941 
942 .keywords: TS, timestep, set, right-hand-side, function
943 
944 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetSolutionFunction()
945 @*/
946 PetscErrorCode  TSSetForcingFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
947 {
948   PetscErrorCode ierr;
949   DM             dm;
950 
951   PetscFunctionBegin;
952   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
953   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
954   ierr = DMTSSetForcingFunction(dm,f,ctx);CHKERRQ(ierr);
955   PetscFunctionReturn(0);
956 }
957 
958 #undef __FUNCT__
959 #define __FUNCT__ "TSSetRHSJacobian"
960 /*@C
961    TSSetRHSJacobian - Sets the function to compute the Jacobian of F,
962    where U_t = G(U,t), as well as the location to store the matrix.
963 
964    Logically Collective on TS
965 
966    Input Parameters:
967 +  ts  - the TS context obtained from TSCreate()
968 .  Amat - (approximate) Jacobian matrix
969 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
970 .  f   - the Jacobian evaluation routine
971 -  ctx - [optional] user-defined context for private data for the
972          Jacobian evaluation routine (may be NULL)
973 
974    Calling sequence of func:
975 $     func (TS ts,PetscReal t,Vec u,Mat A,Mat B,void *ctx);
976 
977 +  t - current timestep
978 .  u - input vector
979 .  Amat - (approximate) Jacobian matrix
980 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
981 -  ctx - [optional] user-defined context for matrix evaluation routine
982 
983 
984    Level: beginner
985 
986 .keywords: TS, timestep, set, right-hand-side, Jacobian
987 
988 .seealso: SNESComputeJacobianDefaultColor(), TSSetRHSFunction(), TSRHSJacobianSetReuse(), TSSetIJacobian()
989 
990 @*/
991 PetscErrorCode  TSSetRHSJacobian(TS ts,Mat Amat,Mat Pmat,TSRHSJacobian f,void *ctx)
992 {
993   PetscErrorCode ierr;
994   SNES           snes;
995   DM             dm;
996   TSIJacobian    ijacobian;
997 
998   PetscFunctionBegin;
999   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1000   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1001   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1002   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1003   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1004 
1005   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1006   ierr = DMTSSetRHSJacobian(dm,f,ctx);CHKERRQ(ierr);
1007   if (f == TSComputeRHSJacobianConstant) {
1008     /* Handle this case automatically for the user; otherwise user should call themselves. */
1009     ierr = TSRHSJacobianSetReuse(ts,PETSC_TRUE);CHKERRQ(ierr);
1010   }
1011   ierr = DMTSGetIJacobian(dm,&ijacobian,NULL);CHKERRQ(ierr);
1012   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1013   if (!ijacobian) {
1014     ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1015   }
1016   if (Amat) {
1017     ierr = PetscObjectReference((PetscObject)Amat);CHKERRQ(ierr);
1018     ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1019 
1020     ts->Arhs = Amat;
1021   }
1022   if (Pmat) {
1023     ierr = PetscObjectReference((PetscObject)Pmat);CHKERRQ(ierr);
1024     ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1025 
1026     ts->Brhs = Pmat;
1027   }
1028   PetscFunctionReturn(0);
1029 }
1030 
1031 
1032 #undef __FUNCT__
1033 #define __FUNCT__ "TSSetIFunction"
1034 /*@C
1035    TSSetIFunction - Set the function to compute F(t,U,U_t) where F() = 0 is the DAE to be solved.
1036 
1037    Logically Collective on TS
1038 
1039    Input Parameters:
1040 +  ts  - the TS context obtained from TSCreate()
1041 .  r   - vector to hold the residual (or NULL to have it created internally)
1042 .  f   - the function evaluation routine
1043 -  ctx - user-defined context for private data for the function evaluation routine (may be NULL)
1044 
1045    Calling sequence of f:
1046 $  f(TS ts,PetscReal t,Vec u,Vec u_t,Vec F,ctx);
1047 
1048 +  t   - time at step/stage being solved
1049 .  u   - state vector
1050 .  u_t - time derivative of state vector
1051 .  F   - function vector
1052 -  ctx - [optional] user-defined context for matrix evaluation routine
1053 
1054    Important:
1055    The user MUST call either this routine, TSSetRHSFunction().  This routine must be used when not solving an ODE, for example a DAE.
1056 
1057    Level: beginner
1058 
1059 .keywords: TS, timestep, set, DAE, Jacobian
1060 
1061 .seealso: TSSetRHSJacobian(), TSSetRHSFunction(), TSSetIJacobian()
1062 @*/
1063 PetscErrorCode  TSSetIFunction(TS ts,Vec res,TSIFunction f,void *ctx)
1064 {
1065   PetscErrorCode ierr;
1066   SNES           snes;
1067   Vec            resalloc = NULL;
1068   DM             dm;
1069 
1070   PetscFunctionBegin;
1071   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1072   if (res) PetscValidHeaderSpecific(res,VEC_CLASSID,2);
1073 
1074   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1075   ierr = DMTSSetIFunction(dm,f,ctx);CHKERRQ(ierr);
1076 
1077   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1078   if (!res && !ts->dm && ts->vec_sol) {
1079     ierr = VecDuplicate(ts->vec_sol,&resalloc);CHKERRQ(ierr);
1080     res  = resalloc;
1081   }
1082   ierr = SNESSetFunction(snes,res,SNESTSFormFunction,ts);CHKERRQ(ierr);
1083   ierr = VecDestroy(&resalloc);CHKERRQ(ierr);
1084   PetscFunctionReturn(0);
1085 }
1086 
1087 #undef __FUNCT__
1088 #define __FUNCT__ "TSGetIFunction"
1089 /*@C
1090    TSGetIFunction - Returns the vector where the implicit residual is stored and the function/contex to compute it.
1091 
1092    Not Collective
1093 
1094    Input Parameter:
1095 .  ts - the TS context
1096 
1097    Output Parameter:
1098 +  r - vector to hold residual (or NULL)
1099 .  func - the function to compute residual (or NULL)
1100 -  ctx - the function context (or NULL)
1101 
1102    Level: advanced
1103 
1104 .keywords: TS, nonlinear, get, function
1105 
1106 .seealso: TSSetIFunction(), SNESGetFunction()
1107 @*/
1108 PetscErrorCode TSGetIFunction(TS ts,Vec *r,TSIFunction *func,void **ctx)
1109 {
1110   PetscErrorCode ierr;
1111   SNES           snes;
1112   DM             dm;
1113 
1114   PetscFunctionBegin;
1115   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1116   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1117   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1118   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1119   ierr = DMTSGetIFunction(dm,func,ctx);CHKERRQ(ierr);
1120   PetscFunctionReturn(0);
1121 }
1122 
1123 #undef __FUNCT__
1124 #define __FUNCT__ "TSGetRHSFunction"
1125 /*@C
1126    TSGetRHSFunction - Returns the vector where the right hand side is stored and the function/context to compute it.
1127 
1128    Not Collective
1129 
1130    Input Parameter:
1131 .  ts - the TS context
1132 
1133    Output Parameter:
1134 +  r - vector to hold computed right hand side (or NULL)
1135 .  func - the function to compute right hand side (or NULL)
1136 -  ctx - the function context (or NULL)
1137 
1138    Level: advanced
1139 
1140 .keywords: TS, nonlinear, get, function
1141 
1142 .seealso: TSSetRhsfunction(), SNESGetFunction()
1143 @*/
1144 PetscErrorCode TSGetRHSFunction(TS ts,Vec *r,TSRHSFunction *func,void **ctx)
1145 {
1146   PetscErrorCode ierr;
1147   SNES           snes;
1148   DM             dm;
1149 
1150   PetscFunctionBegin;
1151   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1152   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1153   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1154   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1155   ierr = DMTSGetRHSFunction(dm,func,ctx);CHKERRQ(ierr);
1156   PetscFunctionReturn(0);
1157 }
1158 
1159 #undef __FUNCT__
1160 #define __FUNCT__ "TSSetIJacobian"
1161 /*@C
1162    TSSetIJacobian - Set the function to compute the matrix dF/dU + a*dF/dU_t where F(t,U,U_t) is the function
1163         provided with TSSetIFunction().
1164 
1165    Logically Collective on TS
1166 
1167    Input Parameters:
1168 +  ts  - the TS context obtained from TSCreate()
1169 .  Amat - (approximate) Jacobian matrix
1170 .  Pmat - matrix used to compute preconditioner (usually the same as Amat)
1171 .  f   - the Jacobian evaluation routine
1172 -  ctx - user-defined context for private data for the Jacobian evaluation routine (may be NULL)
1173 
1174    Calling sequence of f:
1175 $  f(TS ts,PetscReal t,Vec U,Vec U_t,PetscReal a,Mat Amat,Mat Pmat,void *ctx);
1176 
1177 +  t    - time at step/stage being solved
1178 .  U    - state vector
1179 .  U_t  - time derivative of state vector
1180 .  a    - shift
1181 .  Amat - (approximate) Jacobian of F(t,U,W+a*U), equivalent to dF/dU + a*dF/dU_t
1182 .  Pmat - matrix used for constructing preconditioner, usually the same as Amat
1183 -  ctx  - [optional] user-defined context for matrix evaluation routine
1184 
1185    Notes:
1186    The matrices Amat and Pmat are exactly the matrices that are used by SNES for the nonlinear solve.
1187 
1188    The matrix dF/dU + a*dF/dU_t you provide turns out to be
1189    the Jacobian of F(t,U,W+a*U) where F(t,U,U_t) = 0 is the DAE to be solved.
1190    The time integrator internally approximates U_t by W+a*U where the positive "shift"
1191    a and vector W depend on the integration method, step size, and past states. For example with
1192    the backward Euler method a = 1/dt and W = -a*U(previous timestep) so
1193    W + a*U = a*(U - U(previous timestep)) = (U - U(previous timestep))/dt
1194 
1195    Level: beginner
1196 
1197 .keywords: TS, timestep, DAE, Jacobian
1198 
1199 .seealso: TSSetIFunction(), TSSetRHSJacobian(), SNESComputeJacobianDefaultColor(), SNESComputeJacobianDefault(), TSSetRHSFunction()
1200 
1201 @*/
1202 PetscErrorCode  TSSetIJacobian(TS ts,Mat Amat,Mat Pmat,TSIJacobian f,void *ctx)
1203 {
1204   PetscErrorCode ierr;
1205   SNES           snes;
1206   DM             dm;
1207 
1208   PetscFunctionBegin;
1209   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1210   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1211   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1212   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1213   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1214 
1215   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1216   ierr = DMTSSetIJacobian(dm,f,ctx);CHKERRQ(ierr);
1217 
1218   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1219   ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1220   PetscFunctionReturn(0);
1221 }
1222 
1223 #undef __FUNCT__
1224 #define __FUNCT__ "TSRHSJacobianSetReuse"
1225 /*@
1226    TSRHSJacobianSetReuse - restore RHS Jacobian before re-evaluating.  Without this flag, TS will change the sign and
1227    shift the RHS Jacobian for a finite-time-step implicit solve, in which case the user function will need to recompute
1228    the entire Jacobian.  The reuse flag must be set if the evaluation function will assume that the matrix entries have
1229    not been changed by the TS.
1230 
1231    Logically Collective
1232 
1233    Input Arguments:
1234 +  ts - TS context obtained from TSCreate()
1235 -  reuse - PETSC_TRUE if the RHS Jacobian
1236 
1237    Level: intermediate
1238 
1239 .seealso: TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
1240 @*/
1241 PetscErrorCode TSRHSJacobianSetReuse(TS ts,PetscBool reuse)
1242 {
1243   PetscFunctionBegin;
1244   ts->rhsjacobian.reuse = reuse;
1245   PetscFunctionReturn(0);
1246 }
1247 
1248 #undef __FUNCT__
1249 #define __FUNCT__ "TSLoad"
1250 /*@C
1251   TSLoad - Loads a KSP that has been stored in binary  with KSPView().
1252 
1253   Collective on PetscViewer
1254 
1255   Input Parameters:
1256 + newdm - the newly loaded TS, this needs to have been created with TSCreate() or
1257            some related function before a call to TSLoad().
1258 - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
1259 
1260    Level: intermediate
1261 
1262   Notes:
1263    The type is determined by the data in the file, any type set into the TS before this call is ignored.
1264 
1265   Notes for advanced users:
1266   Most users should not need to know the details of the binary storage
1267   format, since TSLoad() and TSView() completely hide these details.
1268   But for anyone who's interested, the standard binary matrix storage
1269   format is
1270 .vb
1271      has not yet been determined
1272 .ve
1273 
1274 .seealso: PetscViewerBinaryOpen(), TSView(), MatLoad(), VecLoad()
1275 @*/
1276 PetscErrorCode  TSLoad(TS ts, PetscViewer viewer)
1277 {
1278   PetscErrorCode ierr;
1279   PetscBool      isbinary;
1280   PetscInt       classid;
1281   char           type[256];
1282   DMTS           sdm;
1283   DM             dm;
1284 
1285   PetscFunctionBegin;
1286   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1287   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1288   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1289   if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
1290 
1291   ierr = PetscViewerBinaryRead(viewer,&classid,1,PETSC_INT);CHKERRQ(ierr);
1292   if (classid != TS_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Not TS next in file");
1293   ierr = PetscViewerBinaryRead(viewer,type,256,PETSC_CHAR);CHKERRQ(ierr);
1294   ierr = TSSetType(ts, type);CHKERRQ(ierr);
1295   if (ts->ops->load) {
1296     ierr = (*ts->ops->load)(ts,viewer);CHKERRQ(ierr);
1297   }
1298   ierr = DMCreate(PetscObjectComm((PetscObject)ts),&dm);CHKERRQ(ierr);
1299   ierr = DMLoad(dm,viewer);CHKERRQ(ierr);
1300   ierr = TSSetDM(ts,dm);CHKERRQ(ierr);
1301   ierr = DMCreateGlobalVector(ts->dm,&ts->vec_sol);CHKERRQ(ierr);
1302   ierr = VecLoad(ts->vec_sol,viewer);CHKERRQ(ierr);
1303   ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1304   ierr = DMTSLoad(sdm,viewer);CHKERRQ(ierr);
1305   PetscFunctionReturn(0);
1306 }
1307 
1308 #include <petscdraw.h>
1309 #if defined(PETSC_HAVE_SAWS)
1310 #include <petscviewersaws.h>
1311 #endif
1312 #undef __FUNCT__
1313 #define __FUNCT__ "TSView"
1314 /*@C
1315     TSView - Prints the TS data structure.
1316 
1317     Collective on TS
1318 
1319     Input Parameters:
1320 +   ts - the TS context obtained from TSCreate()
1321 -   viewer - visualization context
1322 
1323     Options Database Key:
1324 .   -ts_view - calls TSView() at end of TSStep()
1325 
1326     Notes:
1327     The available visualization contexts include
1328 +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
1329 -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
1330          output where only the first processor opens
1331          the file.  All other processors send their
1332          data to the first processor to print.
1333 
1334     The user can open an alternative visualization context with
1335     PetscViewerASCIIOpen() - output to a specified file.
1336 
1337     Level: beginner
1338 
1339 .keywords: TS, timestep, view
1340 
1341 .seealso: PetscViewerASCIIOpen()
1342 @*/
1343 PetscErrorCode  TSView(TS ts,PetscViewer viewer)
1344 {
1345   PetscErrorCode ierr;
1346   TSType         type;
1347   PetscBool      iascii,isstring,isundials,isbinary,isdraw;
1348   DMTS           sdm;
1349 #if defined(PETSC_HAVE_SAWS)
1350   PetscBool      isams;
1351 #endif
1352 
1353   PetscFunctionBegin;
1354   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1355   if (!viewer) {
1356     ierr = PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ts),&viewer);CHKERRQ(ierr);
1357   }
1358   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1359   PetscCheckSameComm(ts,1,viewer,2);
1360 
1361   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1362   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
1363   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1364   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1365 #if defined(PETSC_HAVE_SAWS)
1366   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&isams);CHKERRQ(ierr);
1367 #endif
1368   if (iascii) {
1369     ierr = PetscObjectPrintClassNamePrefixType((PetscObject)ts,viewer);CHKERRQ(ierr);
1370     ierr = PetscViewerASCIIPrintf(viewer,"  maximum steps=%D\n",ts->max_steps);CHKERRQ(ierr);
1371     ierr = PetscViewerASCIIPrintf(viewer,"  maximum time=%g\n",(double)ts->max_time);CHKERRQ(ierr);
1372     if (ts->problem_type == TS_NONLINEAR) {
1373       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solver iterations=%D\n",ts->snes_its);CHKERRQ(ierr);
1374       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solve failures=%D\n",ts->num_snes_failures);CHKERRQ(ierr);
1375     }
1376     ierr = PetscViewerASCIIPrintf(viewer,"  total number of linear solver iterations=%D\n",ts->ksp_its);CHKERRQ(ierr);
1377     ierr = PetscViewerASCIIPrintf(viewer,"  total number of rejected steps=%D\n",ts->reject);CHKERRQ(ierr);
1378     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1379     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1380     if (ts->ops->view) {
1381       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1382       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1383       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1384     }
1385   } else if (isstring) {
1386     ierr = TSGetType(ts,&type);CHKERRQ(ierr);
1387     ierr = PetscViewerStringSPrintf(viewer," %-7.7s",type);CHKERRQ(ierr);
1388   } else if (isbinary) {
1389     PetscInt    classid = TS_FILE_CLASSID;
1390     MPI_Comm    comm;
1391     PetscMPIInt rank;
1392     char        type[256];
1393 
1394     ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
1395     ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
1396     if (!rank) {
1397       ierr = PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);CHKERRQ(ierr);
1398       ierr = PetscStrncpy(type,((PetscObject)ts)->type_name,256);CHKERRQ(ierr);
1399       ierr = PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);CHKERRQ(ierr);
1400     }
1401     if (ts->ops->view) {
1402       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1403     }
1404     ierr = DMView(ts->dm,viewer);CHKERRQ(ierr);
1405     ierr = VecView(ts->vec_sol,viewer);CHKERRQ(ierr);
1406     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1407     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1408   } else if (isdraw) {
1409     PetscDraw draw;
1410     char      str[36];
1411     PetscReal x,y,bottom,h;
1412 
1413     ierr   = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1414     ierr   = PetscDrawGetCurrentPoint(draw,&x,&y);CHKERRQ(ierr);
1415     ierr   = PetscStrcpy(str,"TS: ");CHKERRQ(ierr);
1416     ierr   = PetscStrcat(str,((PetscObject)ts)->type_name);CHKERRQ(ierr);
1417     ierr   = PetscDrawBoxedString(draw,x,y,PETSC_DRAW_BLACK,PETSC_DRAW_BLACK,str,NULL,&h);CHKERRQ(ierr);
1418     bottom = y - h;
1419     ierr   = PetscDrawPushCurrentPoint(draw,x,bottom);CHKERRQ(ierr);
1420     if (ts->ops->view) {
1421       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1422     }
1423     ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr);
1424 #if defined(PETSC_HAVE_SAWS)
1425   } else if (isams) {
1426     PetscMPIInt rank;
1427     const char  *name;
1428 
1429     ierr = PetscObjectGetName((PetscObject)ts,&name);CHKERRQ(ierr);
1430     ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
1431     if (!((PetscObject)ts)->amsmem && !rank) {
1432       char       dir[1024];
1433 
1434       ierr = PetscObjectViewSAWs((PetscObject)ts,viewer);CHKERRQ(ierr);
1435       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time_step",name);CHKERRQ(ierr);
1436       PetscStackCallSAWs(SAWs_Register,(dir,&ts->steps,1,SAWs_READ,SAWs_INT));
1437       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time",name);CHKERRQ(ierr);
1438       PetscStackCallSAWs(SAWs_Register,(dir,&ts->ptime,1,SAWs_READ,SAWs_DOUBLE));
1439     }
1440     if (ts->ops->view) {
1441       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1442     }
1443 #endif
1444   }
1445 
1446   ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1447   ierr = PetscObjectTypeCompare((PetscObject)ts,TSSUNDIALS,&isundials);CHKERRQ(ierr);
1448   ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1449   PetscFunctionReturn(0);
1450 }
1451 
1452 
1453 #undef __FUNCT__
1454 #define __FUNCT__ "TSSetApplicationContext"
1455 /*@
1456    TSSetApplicationContext - Sets an optional user-defined context for
1457    the timesteppers.
1458 
1459    Logically Collective on TS
1460 
1461    Input Parameters:
1462 +  ts - the TS context obtained from TSCreate()
1463 -  usrP - optional user context
1464 
1465    Level: intermediate
1466 
1467 .keywords: TS, timestep, set, application, context
1468 
1469 .seealso: TSGetApplicationContext()
1470 @*/
1471 PetscErrorCode  TSSetApplicationContext(TS ts,void *usrP)
1472 {
1473   PetscFunctionBegin;
1474   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1475   ts->user = usrP;
1476   PetscFunctionReturn(0);
1477 }
1478 
1479 #undef __FUNCT__
1480 #define __FUNCT__ "TSGetApplicationContext"
1481 /*@
1482     TSGetApplicationContext - Gets the user-defined context for the
1483     timestepper.
1484 
1485     Not Collective
1486 
1487     Input Parameter:
1488 .   ts - the TS context obtained from TSCreate()
1489 
1490     Output Parameter:
1491 .   usrP - user context
1492 
1493     Level: intermediate
1494 
1495 .keywords: TS, timestep, get, application, context
1496 
1497 .seealso: TSSetApplicationContext()
1498 @*/
1499 PetscErrorCode  TSGetApplicationContext(TS ts,void *usrP)
1500 {
1501   PetscFunctionBegin;
1502   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1503   *(void**)usrP = ts->user;
1504   PetscFunctionReturn(0);
1505 }
1506 
1507 #undef __FUNCT__
1508 #define __FUNCT__ "TSGetTimeStepNumber"
1509 /*@
1510    TSGetTimeStepNumber - Gets the number of time steps completed.
1511 
1512    Not Collective
1513 
1514    Input Parameter:
1515 .  ts - the TS context obtained from TSCreate()
1516 
1517    Output Parameter:
1518 .  iter - number of steps completed so far
1519 
1520    Level: intermediate
1521 
1522 .keywords: TS, timestep, get, iteration, number
1523 .seealso: TSGetTime(), TSGetTimeStep(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSSetPostStep()
1524 @*/
1525 PetscErrorCode  TSGetTimeStepNumber(TS ts,PetscInt *iter)
1526 {
1527   PetscFunctionBegin;
1528   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1529   PetscValidIntPointer(iter,2);
1530   *iter = ts->steps;
1531   PetscFunctionReturn(0);
1532 }
1533 
1534 #undef __FUNCT__
1535 #define __FUNCT__ "TSSetInitialTimeStep"
1536 /*@
1537    TSSetInitialTimeStep - Sets the initial timestep to be used,
1538    as well as the initial time.
1539 
1540    Logically Collective on TS
1541 
1542    Input Parameters:
1543 +  ts - the TS context obtained from TSCreate()
1544 .  initial_time - the initial time
1545 -  time_step - the size of the timestep
1546 
1547    Level: intermediate
1548 
1549 .seealso: TSSetTimeStep(), TSGetTimeStep()
1550 
1551 .keywords: TS, set, initial, timestep
1552 @*/
1553 PetscErrorCode  TSSetInitialTimeStep(TS ts,PetscReal initial_time,PetscReal time_step)
1554 {
1555   PetscErrorCode ierr;
1556 
1557   PetscFunctionBegin;
1558   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1559   ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
1560   ierr = TSSetTime(ts,initial_time);CHKERRQ(ierr);
1561   PetscFunctionReturn(0);
1562 }
1563 
1564 #undef __FUNCT__
1565 #define __FUNCT__ "TSSetTimeStep"
1566 /*@
1567    TSSetTimeStep - Allows one to reset the timestep at any time,
1568    useful for simple pseudo-timestepping codes.
1569 
1570    Logically Collective on TS
1571 
1572    Input Parameters:
1573 +  ts - the TS context obtained from TSCreate()
1574 -  time_step - the size of the timestep
1575 
1576    Level: intermediate
1577 
1578 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1579 
1580 .keywords: TS, set, timestep
1581 @*/
1582 PetscErrorCode  TSSetTimeStep(TS ts,PetscReal time_step)
1583 {
1584   PetscFunctionBegin;
1585   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1586   PetscValidLogicalCollectiveReal(ts,time_step,2);
1587   ts->time_step      = time_step;
1588   ts->time_step_orig = time_step;
1589   PetscFunctionReturn(0);
1590 }
1591 
1592 #undef __FUNCT__
1593 #define __FUNCT__ "TSSetExactFinalTime"
1594 /*@
1595    TSSetExactFinalTime - Determines whether to adapt the final time step to
1596      match the exact final time, interpolate solution to the exact final time,
1597      or just return at the final time TS computed.
1598 
1599   Logically Collective on TS
1600 
1601    Input Parameter:
1602 +   ts - the time-step context
1603 -   eftopt - exact final time option
1604 
1605    Level: beginner
1606 
1607 .seealso: TSExactFinalTimeOption
1608 @*/
1609 PetscErrorCode  TSSetExactFinalTime(TS ts,TSExactFinalTimeOption eftopt)
1610 {
1611   PetscFunctionBegin;
1612   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1613   PetscValidLogicalCollectiveEnum(ts,eftopt,2);
1614   ts->exact_final_time = eftopt;
1615   PetscFunctionReturn(0);
1616 }
1617 
1618 #undef __FUNCT__
1619 #define __FUNCT__ "TSGetTimeStep"
1620 /*@
1621    TSGetTimeStep - Gets the current timestep size.
1622 
1623    Not Collective
1624 
1625    Input Parameter:
1626 .  ts - the TS context obtained from TSCreate()
1627 
1628    Output Parameter:
1629 .  dt - the current timestep size
1630 
1631    Level: intermediate
1632 
1633 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1634 
1635 .keywords: TS, get, timestep
1636 @*/
1637 PetscErrorCode  TSGetTimeStep(TS ts,PetscReal *dt)
1638 {
1639   PetscFunctionBegin;
1640   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1641   PetscValidRealPointer(dt,2);
1642   *dt = ts->time_step;
1643   PetscFunctionReturn(0);
1644 }
1645 
1646 #undef __FUNCT__
1647 #define __FUNCT__ "TSGetSolution"
1648 /*@
1649    TSGetSolution - Returns the solution at the present timestep. It
1650    is valid to call this routine inside the function that you are evaluating
1651    in order to move to the new timestep. This vector not changed until
1652    the solution at the next timestep has been calculated.
1653 
1654    Not Collective, but Vec returned is parallel if TS is parallel
1655 
1656    Input Parameter:
1657 .  ts - the TS context obtained from TSCreate()
1658 
1659    Output Parameter:
1660 .  v - the vector containing the solution
1661 
1662    Level: intermediate
1663 
1664 .seealso: TSGetTimeStep()
1665 
1666 .keywords: TS, timestep, get, solution
1667 @*/
1668 PetscErrorCode  TSGetSolution(TS ts,Vec *v)
1669 {
1670   PetscFunctionBegin;
1671   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1672   PetscValidPointer(v,2);
1673   *v = ts->vec_sol;
1674   PetscFunctionReturn(0);
1675 }
1676 
1677 /* ----- Routines to initialize and destroy a timestepper ---- */
1678 #undef __FUNCT__
1679 #define __FUNCT__ "TSSetProblemType"
1680 /*@
1681   TSSetProblemType - Sets the type of problem to be solved.
1682 
1683   Not collective
1684 
1685   Input Parameters:
1686 + ts   - The TS
1687 - type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1688 .vb
1689          U_t - A U = 0      (linear)
1690          U_t - A(t) U = 0   (linear)
1691          F(t,U,U_t) = 0     (nonlinear)
1692 .ve
1693 
1694    Level: beginner
1695 
1696 .keywords: TS, problem type
1697 .seealso: TSSetUp(), TSProblemType, TS
1698 @*/
1699 PetscErrorCode  TSSetProblemType(TS ts, TSProblemType type)
1700 {
1701   PetscErrorCode ierr;
1702 
1703   PetscFunctionBegin;
1704   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1705   ts->problem_type = type;
1706   if (type == TS_LINEAR) {
1707     SNES snes;
1708     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1709     ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);
1710   }
1711   PetscFunctionReturn(0);
1712 }
1713 
1714 #undef __FUNCT__
1715 #define __FUNCT__ "TSGetProblemType"
1716 /*@C
1717   TSGetProblemType - Gets the type of problem to be solved.
1718 
1719   Not collective
1720 
1721   Input Parameter:
1722 . ts   - The TS
1723 
1724   Output Parameter:
1725 . type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1726 .vb
1727          M U_t = A U
1728          M(t) U_t = A(t) U
1729          F(t,U,U_t)
1730 .ve
1731 
1732    Level: beginner
1733 
1734 .keywords: TS, problem type
1735 .seealso: TSSetUp(), TSProblemType, TS
1736 @*/
1737 PetscErrorCode  TSGetProblemType(TS ts, TSProblemType *type)
1738 {
1739   PetscFunctionBegin;
1740   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1741   PetscValidIntPointer(type,2);
1742   *type = ts->problem_type;
1743   PetscFunctionReturn(0);
1744 }
1745 
1746 #undef __FUNCT__
1747 #define __FUNCT__ "TSSetUp"
1748 /*@
1749    TSSetUp - Sets up the internal data structures for the later use
1750    of a timestepper.
1751 
1752    Collective on TS
1753 
1754    Input Parameter:
1755 .  ts - the TS context obtained from TSCreate()
1756 
1757    Notes:
1758    For basic use of the TS solvers the user need not explicitly call
1759    TSSetUp(), since these actions will automatically occur during
1760    the call to TSStep().  However, if one wishes to control this
1761    phase separately, TSSetUp() should be called after TSCreate()
1762    and optional routines of the form TSSetXXX(), but before TSStep().
1763 
1764    Level: advanced
1765 
1766 .keywords: TS, timestep, setup
1767 
1768 .seealso: TSCreate(), TSStep(), TSDestroy()
1769 @*/
1770 PetscErrorCode  TSSetUp(TS ts)
1771 {
1772   PetscErrorCode ierr;
1773   DM             dm;
1774   PetscErrorCode (*func)(SNES,Vec,Vec,void*);
1775   PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
1776   TSIJacobian    ijac;
1777   TSRHSJacobian  rhsjac;
1778 
1779   PetscFunctionBegin;
1780   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1781   if (ts->setupcalled) PetscFunctionReturn(0);
1782 
1783   if (!((PetscObject)ts)->type_name) {
1784     ierr = TSSetType(ts,TSEULER);CHKERRQ(ierr);
1785   }
1786 
1787   if (!ts->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call TSSetSolution() first");
1788 
1789   ierr = TSGetAdapt(ts,&ts->adapt);CHKERRQ(ierr);
1790 
1791   if (ts->rhsjacobian.reuse) {
1792     Mat Amat,Pmat;
1793     SNES snes;
1794     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1795     ierr = SNESGetJacobian(snes,&Amat,&Pmat,NULL,NULL);CHKERRQ(ierr);
1796     /* Matching matrices implies that an IJacobian is NOT set, because if it had been set, the IJacobian's matrix would
1797      * have displaced the RHS matrix */
1798     if (Amat == ts->Arhs) {
1799       ierr = MatDuplicate(ts->Arhs,MAT_DO_NOT_COPY_VALUES,&Amat);CHKERRQ(ierr);
1800       ierr = SNESSetJacobian(snes,Amat,NULL,NULL,NULL);CHKERRQ(ierr);
1801       ierr = MatDestroy(&Amat);CHKERRQ(ierr);
1802     }
1803     if (Pmat == ts->Brhs) {
1804       ierr = MatDuplicate(ts->Brhs,MAT_DO_NOT_COPY_VALUES,&Pmat);CHKERRQ(ierr);
1805       ierr = SNESSetJacobian(snes,NULL,Pmat,NULL,NULL);CHKERRQ(ierr);
1806       ierr = MatDestroy(&Pmat);CHKERRQ(ierr);
1807     }
1808   }
1809 
1810   if (ts->ops->setup) {
1811     ierr = (*ts->ops->setup)(ts);CHKERRQ(ierr);
1812   }
1813 
1814   /* in the case where we've set a DMTSFunction or what have you, we need the default SNESFunction
1815    to be set right but can't do it elsewhere due to the overreliance on ctx=ts.
1816    */
1817   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1818   ierr = DMSNESGetFunction(dm,&func,NULL);CHKERRQ(ierr);
1819   if (!func) {
1820     ierr =DMSNESSetFunction(dm,SNESTSFormFunction,ts);CHKERRQ(ierr);
1821   }
1822   /* if the SNES doesn't have a jacobian set and the TS has an ijacobian or rhsjacobian set, set the SNES to use it.
1823      Otherwise, the SNES will use coloring internally to form the Jacobian.
1824    */
1825   ierr = DMSNESGetJacobian(dm,&jac,NULL);CHKERRQ(ierr);
1826   ierr = DMTSGetIJacobian(dm,&ijac,NULL);CHKERRQ(ierr);
1827   ierr = DMTSGetRHSJacobian(dm,&rhsjac,NULL);CHKERRQ(ierr);
1828   if (!jac && (ijac || rhsjac)) {
1829     ierr = DMSNESSetJacobian(dm,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1830   }
1831   ts->setupcalled = PETSC_TRUE;
1832   PetscFunctionReturn(0);
1833 }
1834 
1835 #undef __FUNCT__
1836 #define __FUNCT__ "TSReset"
1837 /*@
1838    TSReset - Resets a TS context and removes any allocated Vecs and Mats.
1839 
1840    Collective on TS
1841 
1842    Input Parameter:
1843 .  ts - the TS context obtained from TSCreate()
1844 
1845    Level: beginner
1846 
1847 .keywords: TS, timestep, reset
1848 
1849 .seealso: TSCreate(), TSSetup(), TSDestroy()
1850 @*/
1851 PetscErrorCode  TSReset(TS ts)
1852 {
1853   PetscErrorCode ierr;
1854 
1855   PetscFunctionBegin;
1856   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1857   if (ts->ops->reset) {
1858     ierr = (*ts->ops->reset)(ts);CHKERRQ(ierr);
1859   }
1860   if (ts->snes) {ierr = SNESReset(ts->snes);CHKERRQ(ierr);}
1861 
1862   ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1863   ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1864   ierr = VecDestroy(&ts->Frhs);CHKERRQ(ierr);
1865   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
1866   ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
1867   ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
1868   ierr = VecDestroyVecs(ts->nwork,&ts->work);CHKERRQ(ierr);
1869 
1870   ts->setupcalled = PETSC_FALSE;
1871   PetscFunctionReturn(0);
1872 }
1873 
1874 #undef __FUNCT__
1875 #define __FUNCT__ "TSDestroy"
1876 /*@
1877    TSDestroy - Destroys the timestepper context that was created
1878    with TSCreate().
1879 
1880    Collective on TS
1881 
1882    Input Parameter:
1883 .  ts - the TS context obtained from TSCreate()
1884 
1885    Level: beginner
1886 
1887 .keywords: TS, timestepper, destroy
1888 
1889 .seealso: TSCreate(), TSSetUp(), TSSolve()
1890 @*/
1891 PetscErrorCode  TSDestroy(TS *ts)
1892 {
1893   PetscErrorCode ierr;
1894 
1895   PetscFunctionBegin;
1896   if (!*ts) PetscFunctionReturn(0);
1897   PetscValidHeaderSpecific((*ts),TS_CLASSID,1);
1898   if (--((PetscObject)(*ts))->refct > 0) {*ts = 0; PetscFunctionReturn(0);}
1899 
1900   ierr = TSReset((*ts));CHKERRQ(ierr);
1901 
1902   /* if memory was published with SAWs then destroy it */
1903   ierr = PetscObjectSAWsViewOff((PetscObject)*ts);CHKERRQ(ierr);
1904   if ((*ts)->ops->destroy) {ierr = (*(*ts)->ops->destroy)((*ts));CHKERRQ(ierr);}
1905 
1906   ierr = TSAdaptDestroy(&(*ts)->adapt);CHKERRQ(ierr);
1907   if ((*ts)->event) {
1908     ierr = TSEventMonitorDestroy(&(*ts)->event);CHKERRQ(ierr);
1909   }
1910   ierr = SNESDestroy(&(*ts)->snes);CHKERRQ(ierr);
1911   ierr = DMDestroy(&(*ts)->dm);CHKERRQ(ierr);
1912   ierr = TSMonitorCancel((*ts));CHKERRQ(ierr);
1913 
1914   ierr = PetscHeaderDestroy(ts);CHKERRQ(ierr);
1915   PetscFunctionReturn(0);
1916 }
1917 
1918 #undef __FUNCT__
1919 #define __FUNCT__ "TSGetSNES"
1920 /*@
1921    TSGetSNES - Returns the SNES (nonlinear solver) associated with
1922    a TS (timestepper) context. Valid only for nonlinear problems.
1923 
1924    Not Collective, but SNES is parallel if TS is parallel
1925 
1926    Input Parameter:
1927 .  ts - the TS context obtained from TSCreate()
1928 
1929    Output Parameter:
1930 .  snes - the nonlinear solver context
1931 
1932    Notes:
1933    The user can then directly manipulate the SNES context to set various
1934    options, etc.  Likewise, the user can then extract and manipulate the
1935    KSP, KSP, and PC contexts as well.
1936 
1937    TSGetSNES() does not work for integrators that do not use SNES; in
1938    this case TSGetSNES() returns NULL in snes.
1939 
1940    Level: beginner
1941 
1942 .keywords: timestep, get, SNES
1943 @*/
1944 PetscErrorCode  TSGetSNES(TS ts,SNES *snes)
1945 {
1946   PetscErrorCode ierr;
1947 
1948   PetscFunctionBegin;
1949   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1950   PetscValidPointer(snes,2);
1951   if (!ts->snes) {
1952     ierr = SNESCreate(PetscObjectComm((PetscObject)ts),&ts->snes);CHKERRQ(ierr);
1953     ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
1954     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->snes);CHKERRQ(ierr);
1955     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->snes,(PetscObject)ts,1);CHKERRQ(ierr);
1956     if (ts->dm) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
1957     if (ts->problem_type == TS_LINEAR) {
1958       ierr = SNESSetType(ts->snes,SNESKSPONLY);CHKERRQ(ierr);
1959     }
1960   }
1961   *snes = ts->snes;
1962   PetscFunctionReturn(0);
1963 }
1964 
1965 #undef __FUNCT__
1966 #define __FUNCT__ "TSSetSNES"
1967 /*@
1968    TSSetSNES - Set the SNES (nonlinear solver) to be used by the timestepping context
1969 
1970    Collective
1971 
1972    Input Parameter:
1973 +  ts - the TS context obtained from TSCreate()
1974 -  snes - the nonlinear solver context
1975 
1976    Notes:
1977    Most users should have the TS created by calling TSGetSNES()
1978 
1979    Level: developer
1980 
1981 .keywords: timestep, set, SNES
1982 @*/
1983 PetscErrorCode TSSetSNES(TS ts,SNES snes)
1984 {
1985   PetscErrorCode ierr;
1986   PetscErrorCode (*func)(SNES,Vec,Mat,Mat,void*);
1987 
1988   PetscFunctionBegin;
1989   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1990   PetscValidHeaderSpecific(snes,SNES_CLASSID,2);
1991   ierr = PetscObjectReference((PetscObject)snes);CHKERRQ(ierr);
1992   ierr = SNESDestroy(&ts->snes);CHKERRQ(ierr);
1993 
1994   ts->snes = snes;
1995 
1996   ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
1997   ierr = SNESGetJacobian(ts->snes,NULL,NULL,&func,NULL);CHKERRQ(ierr);
1998   if (func == SNESTSFormJacobian) {
1999     ierr = SNESSetJacobian(ts->snes,NULL,NULL,SNESTSFormJacobian,ts);CHKERRQ(ierr);
2000   }
2001   PetscFunctionReturn(0);
2002 }
2003 
2004 #undef __FUNCT__
2005 #define __FUNCT__ "TSGetKSP"
2006 /*@
2007    TSGetKSP - Returns the KSP (linear solver) associated with
2008    a TS (timestepper) context.
2009 
2010    Not Collective, but KSP is parallel if TS is parallel
2011 
2012    Input Parameter:
2013 .  ts - the TS context obtained from TSCreate()
2014 
2015    Output Parameter:
2016 .  ksp - the nonlinear solver context
2017 
2018    Notes:
2019    The user can then directly manipulate the KSP context to set various
2020    options, etc.  Likewise, the user can then extract and manipulate the
2021    KSP and PC contexts as well.
2022 
2023    TSGetKSP() does not work for integrators that do not use KSP;
2024    in this case TSGetKSP() returns NULL in ksp.
2025 
2026    Level: beginner
2027 
2028 .keywords: timestep, get, KSP
2029 @*/
2030 PetscErrorCode  TSGetKSP(TS ts,KSP *ksp)
2031 {
2032   PetscErrorCode ierr;
2033   SNES           snes;
2034 
2035   PetscFunctionBegin;
2036   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2037   PetscValidPointer(ksp,2);
2038   if (!((PetscObject)ts)->type_name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"KSP is not created yet. Call TSSetType() first");
2039   if (ts->problem_type != TS_LINEAR) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Linear only; use TSGetSNES()");
2040   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2041   ierr = SNESGetKSP(snes,ksp);CHKERRQ(ierr);
2042   PetscFunctionReturn(0);
2043 }
2044 
2045 /* ----------- Routines to set solver parameters ---------- */
2046 
2047 #undef __FUNCT__
2048 #define __FUNCT__ "TSGetDuration"
2049 /*@
2050    TSGetDuration - Gets the maximum number of timesteps to use and
2051    maximum time for iteration.
2052 
2053    Not Collective
2054 
2055    Input Parameters:
2056 +  ts       - the TS context obtained from TSCreate()
2057 .  maxsteps - maximum number of iterations to use, or NULL
2058 -  maxtime  - final time to iterate to, or NULL
2059 
2060    Level: intermediate
2061 
2062 .keywords: TS, timestep, get, maximum, iterations, time
2063 @*/
2064 PetscErrorCode  TSGetDuration(TS ts, PetscInt *maxsteps, PetscReal *maxtime)
2065 {
2066   PetscFunctionBegin;
2067   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2068   if (maxsteps) {
2069     PetscValidIntPointer(maxsteps,2);
2070     *maxsteps = ts->max_steps;
2071   }
2072   if (maxtime) {
2073     PetscValidScalarPointer(maxtime,3);
2074     *maxtime = ts->max_time;
2075   }
2076   PetscFunctionReturn(0);
2077 }
2078 
2079 #undef __FUNCT__
2080 #define __FUNCT__ "TSSetDuration"
2081 /*@
2082    TSSetDuration - Sets the maximum number of timesteps to use and
2083    maximum time for iteration.
2084 
2085    Logically Collective on TS
2086 
2087    Input Parameters:
2088 +  ts - the TS context obtained from TSCreate()
2089 .  maxsteps - maximum number of iterations to use
2090 -  maxtime - final time to iterate to
2091 
2092    Options Database Keys:
2093 .  -ts_max_steps <maxsteps> - Sets maxsteps
2094 .  -ts_final_time <maxtime> - Sets maxtime
2095 
2096    Notes:
2097    The default maximum number of iterations is 5000. Default time is 5.0
2098 
2099    Level: intermediate
2100 
2101 .keywords: TS, timestep, set, maximum, iterations
2102 
2103 .seealso: TSSetExactFinalTime()
2104 @*/
2105 PetscErrorCode  TSSetDuration(TS ts,PetscInt maxsteps,PetscReal maxtime)
2106 {
2107   PetscFunctionBegin;
2108   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2109   PetscValidLogicalCollectiveInt(ts,maxsteps,2);
2110   PetscValidLogicalCollectiveReal(ts,maxtime,2);
2111   if (maxsteps >= 0) ts->max_steps = maxsteps;
2112   if (maxtime != PETSC_DEFAULT) ts->max_time = maxtime;
2113   PetscFunctionReturn(0);
2114 }
2115 
2116 #undef __FUNCT__
2117 #define __FUNCT__ "TSSetSolution"
2118 /*@
2119    TSSetSolution - Sets the initial solution vector
2120    for use by the TS routines.
2121 
2122    Logically Collective on TS and Vec
2123 
2124    Input Parameters:
2125 +  ts - the TS context obtained from TSCreate()
2126 -  u - the solution vector
2127 
2128    Level: beginner
2129 
2130 .keywords: TS, timestep, set, solution, initial conditions
2131 @*/
2132 PetscErrorCode  TSSetSolution(TS ts,Vec u)
2133 {
2134   PetscErrorCode ierr;
2135   DM             dm;
2136 
2137   PetscFunctionBegin;
2138   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2139   PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2140   ierr = PetscObjectReference((PetscObject)u);CHKERRQ(ierr);
2141   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
2142 
2143   ts->vec_sol = u;
2144 
2145   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
2146   ierr = DMShellSetGlobalVector(dm,u);CHKERRQ(ierr);
2147   PetscFunctionReturn(0);
2148 }
2149 
2150 #undef __FUNCT__
2151 #define __FUNCT__ "TSSetPreStep"
2152 /*@C
2153   TSSetPreStep - Sets the general-purpose function
2154   called once at the beginning of each time step.
2155 
2156   Logically Collective on TS
2157 
2158   Input Parameters:
2159 + ts   - The TS context obtained from TSCreate()
2160 - func - The function
2161 
2162   Calling sequence of func:
2163 . func (TS ts);
2164 
2165   Level: intermediate
2166 
2167   Note:
2168   If a step is rejected, TSStep() will call this routine again before each attempt.
2169   The last completed time step number can be queried using TSGetTimeStepNumber(), the
2170   size of the step being attempted can be obtained using TSGetTimeStep().
2171 
2172 .keywords: TS, timestep
2173 .seealso: TSSetPreStage(), TSSetPostStage(), TSSetPostStep(), TSStep()
2174 @*/
2175 PetscErrorCode  TSSetPreStep(TS ts, PetscErrorCode (*func)(TS))
2176 {
2177   PetscFunctionBegin;
2178   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2179   ts->prestep = func;
2180   PetscFunctionReturn(0);
2181 }
2182 
2183 #undef __FUNCT__
2184 #define __FUNCT__ "TSPreStep"
2185 /*@
2186   TSPreStep - Runs the user-defined pre-step function.
2187 
2188   Collective on TS
2189 
2190   Input Parameters:
2191 . ts   - The TS context obtained from TSCreate()
2192 
2193   Notes:
2194   TSPreStep() is typically used within time stepping implementations,
2195   so most users would not generally call this routine themselves.
2196 
2197   Level: developer
2198 
2199 .keywords: TS, timestep
2200 .seealso: TSSetPreStep(), TSPreStage(), TSPostStage(), TSPostStep()
2201 @*/
2202 PetscErrorCode  TSPreStep(TS ts)
2203 {
2204   PetscErrorCode ierr;
2205 
2206   PetscFunctionBegin;
2207   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2208   if (ts->prestep) {
2209     PetscStackCallStandard((*ts->prestep),(ts));
2210   }
2211   PetscFunctionReturn(0);
2212 }
2213 
2214 #undef __FUNCT__
2215 #define __FUNCT__ "TSSetPreStage"
2216 /*@C
2217   TSSetPreStage - Sets the general-purpose function
2218   called once at the beginning of each stage.
2219 
2220   Logically Collective on TS
2221 
2222   Input Parameters:
2223 + ts   - The TS context obtained from TSCreate()
2224 - func - The function
2225 
2226   Calling sequence of func:
2227 . PetscErrorCode func(TS ts, PetscReal stagetime);
2228 
2229   Level: intermediate
2230 
2231   Note:
2232   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2233   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2234   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2235 
2236 .keywords: TS, timestep
2237 .seealso: TSSetPostStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2238 @*/
2239 PetscErrorCode  TSSetPreStage(TS ts, PetscErrorCode (*func)(TS,PetscReal))
2240 {
2241   PetscFunctionBegin;
2242   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2243   ts->prestage = func;
2244   PetscFunctionReturn(0);
2245 }
2246 
2247 #undef __FUNCT__
2248 #define __FUNCT__ "TSSetPostStage"
2249 /*@C
2250   TSSetPostStage - Sets the general-purpose function
2251   called once at the end of each stage.
2252 
2253   Logically Collective on TS
2254 
2255   Input Parameters:
2256 + ts   - The TS context obtained from TSCreate()
2257 - func - The function
2258 
2259   Calling sequence of func:
2260 . PetscErrorCode func(TS ts, PetscReal stagetime, PetscInt stageindex, Vec* Y);
2261 
2262   Level: intermediate
2263 
2264   Note:
2265   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2266   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2267   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2268 
2269 .keywords: TS, timestep
2270 .seealso: TSSetPreStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2271 @*/
2272 PetscErrorCode  TSSetPostStage(TS ts, PetscErrorCode (*func)(TS,PetscReal,PetscInt,Vec*))
2273 {
2274   PetscFunctionBegin;
2275   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2276   ts->poststage = func;
2277   PetscFunctionReturn(0);
2278 }
2279 
2280 #undef __FUNCT__
2281 #define __FUNCT__ "TSPreStage"
2282 /*@
2283   TSPreStage - Runs the user-defined pre-stage function set using TSSetPreStage()
2284 
2285   Collective on TS
2286 
2287   Input Parameters:
2288 . ts          - The TS context obtained from TSCreate()
2289   stagetime   - The absolute time of the current stage
2290 
2291   Notes:
2292   TSPreStage() is typically used within time stepping implementations,
2293   most users would not generally call this routine themselves.
2294 
2295   Level: developer
2296 
2297 .keywords: TS, timestep
2298 .seealso: TSPostStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2299 @*/
2300 PetscErrorCode  TSPreStage(TS ts, PetscReal stagetime)
2301 {
2302   PetscErrorCode ierr;
2303 
2304   PetscFunctionBegin;
2305   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2306   if (ts->prestage) {
2307     PetscStackCallStandard((*ts->prestage),(ts,stagetime));
2308   }
2309   PetscFunctionReturn(0);
2310 }
2311 
2312 #undef __FUNCT__
2313 #define __FUNCT__ "TSPostStage"
2314 /*@
2315   TSPostStage - Runs the user-defined post-stage function set using TSSetPostStage()
2316 
2317   Collective on TS
2318 
2319   Input Parameters:
2320 . ts          - The TS context obtained from TSCreate()
2321   stagetime   - The absolute time of the current stage
2322   stageindex  - Stage number
2323   Y           - Array of vectors (of size = total number
2324                 of stages) with the stage solutions
2325 
2326   Notes:
2327   TSPostStage() is typically used within time stepping implementations,
2328   most users would not generally call this routine themselves.
2329 
2330   Level: developer
2331 
2332 .keywords: TS, timestep
2333 .seealso: TSPreStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2334 @*/
2335 PetscErrorCode  TSPostStage(TS ts, PetscReal stagetime, PetscInt stageindex, Vec *Y)
2336 {
2337   PetscErrorCode ierr;
2338 
2339   PetscFunctionBegin;
2340   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2341   if (ts->prestage) {
2342     PetscStackCallStandard((*ts->poststage),(ts,stagetime,stageindex,Y));
2343   }
2344   PetscFunctionReturn(0);
2345 }
2346 
2347 #undef __FUNCT__
2348 #define __FUNCT__ "TSSetPostStep"
2349 /*@C
2350   TSSetPostStep - Sets the general-purpose function
2351   called once at the end of each time step.
2352 
2353   Logically Collective on TS
2354 
2355   Input Parameters:
2356 + ts   - The TS context obtained from TSCreate()
2357 - func - The function
2358 
2359   Calling sequence of func:
2360 $ func (TS ts);
2361 
2362   Level: intermediate
2363 
2364 .keywords: TS, timestep
2365 .seealso: TSSetPreStep(), TSSetPreStage(), TSGetTimeStep(), TSGetTimeStepNumber(), TSGetTime()
2366 @*/
2367 PetscErrorCode  TSSetPostStep(TS ts, PetscErrorCode (*func)(TS))
2368 {
2369   PetscFunctionBegin;
2370   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2371   ts->poststep = func;
2372   PetscFunctionReturn(0);
2373 }
2374 
2375 #undef __FUNCT__
2376 #define __FUNCT__ "TSPostStep"
2377 /*@
2378   TSPostStep - Runs the user-defined post-step function.
2379 
2380   Collective on TS
2381 
2382   Input Parameters:
2383 . ts   - The TS context obtained from TSCreate()
2384 
2385   Notes:
2386   TSPostStep() is typically used within time stepping implementations,
2387   so most users would not generally call this routine themselves.
2388 
2389   Level: developer
2390 
2391 .keywords: TS, timestep
2392 @*/
2393 PetscErrorCode  TSPostStep(TS ts)
2394 {
2395   PetscErrorCode ierr;
2396 
2397   PetscFunctionBegin;
2398   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2399   if (ts->poststep) {
2400     PetscStackCallStandard((*ts->poststep),(ts));
2401   }
2402   PetscFunctionReturn(0);
2403 }
2404 
2405 /* ------------ Routines to set performance monitoring options ----------- */
2406 
2407 #undef __FUNCT__
2408 #define __FUNCT__ "TSMonitorSet"
2409 /*@C
2410    TSMonitorSet - Sets an ADDITIONAL function that is to be used at every
2411    timestep to display the iteration's  progress.
2412 
2413    Logically Collective on TS
2414 
2415    Input Parameters:
2416 +  ts - the TS context obtained from TSCreate()
2417 .  monitor - monitoring routine
2418 .  mctx - [optional] user-defined context for private data for the
2419              monitor routine (use NULL if no context is desired)
2420 -  monitordestroy - [optional] routine that frees monitor context
2421           (may be NULL)
2422 
2423    Calling sequence of monitor:
2424 $    int monitor(TS ts,PetscInt steps,PetscReal time,Vec u,void *mctx)
2425 
2426 +    ts - the TS context
2427 .    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
2428                                been interpolated to)
2429 .    time - current time
2430 .    u - current iterate
2431 -    mctx - [optional] monitoring context
2432 
2433    Notes:
2434    This routine adds an additional monitor to the list of monitors that
2435    already has been loaded.
2436 
2437    Fortran notes: Only a single monitor function can be set for each TS object
2438 
2439    Level: intermediate
2440 
2441 .keywords: TS, timestep, set, monitor
2442 
2443 .seealso: TSMonitorDefault(), TSMonitorCancel()
2444 @*/
2445 PetscErrorCode  TSMonitorSet(TS ts,PetscErrorCode (*monitor)(TS,PetscInt,PetscReal,Vec,void*),void *mctx,PetscErrorCode (*mdestroy)(void**))
2446 {
2447   PetscFunctionBegin;
2448   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2449   if (ts->numbermonitors >= MAXTSMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
2450   ts->monitor[ts->numbermonitors]          = monitor;
2451   ts->monitordestroy[ts->numbermonitors]   = mdestroy;
2452   ts->monitorcontext[ts->numbermonitors++] = (void*)mctx;
2453   PetscFunctionReturn(0);
2454 }
2455 
2456 #undef __FUNCT__
2457 #define __FUNCT__ "TSMonitorCancel"
2458 /*@C
2459    TSMonitorCancel - Clears all the monitors that have been set on a time-step object.
2460 
2461    Logically Collective on TS
2462 
2463    Input Parameters:
2464 .  ts - the TS context obtained from TSCreate()
2465 
2466    Notes:
2467    There is no way to remove a single, specific monitor.
2468 
2469    Level: intermediate
2470 
2471 .keywords: TS, timestep, set, monitor
2472 
2473 .seealso: TSMonitorDefault(), TSMonitorSet()
2474 @*/
2475 PetscErrorCode  TSMonitorCancel(TS ts)
2476 {
2477   PetscErrorCode ierr;
2478   PetscInt       i;
2479 
2480   PetscFunctionBegin;
2481   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2482   for (i=0; i<ts->numbermonitors; i++) {
2483     if (ts->monitordestroy[i]) {
2484       ierr = (*ts->monitordestroy[i])(&ts->monitorcontext[i]);CHKERRQ(ierr);
2485     }
2486   }
2487   ts->numbermonitors = 0;
2488   PetscFunctionReturn(0);
2489 }
2490 
2491 #undef __FUNCT__
2492 #define __FUNCT__ "TSMonitorDefault"
2493 /*@
2494    TSMonitorDefault - Sets the Default monitor
2495 
2496    Level: intermediate
2497 
2498 .keywords: TS, set, monitor
2499 
2500 .seealso: TSMonitorDefault(), TSMonitorSet()
2501 @*/
2502 PetscErrorCode TSMonitorDefault(TS ts,PetscInt step,PetscReal ptime,Vec v,void *dummy)
2503 {
2504   PetscErrorCode ierr;
2505   PetscViewer    viewer = dummy ? (PetscViewer) dummy : PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)ts));
2506 
2507   PetscFunctionBegin;
2508   ierr = PetscViewerASCIIAddTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2509   ierr = PetscViewerASCIIPrintf(viewer,"%D TS dt %g time %g\n",step,(double)ts->time_step,(double)ptime);CHKERRQ(ierr);
2510   ierr = PetscViewerASCIISubtractTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2511   PetscFunctionReturn(0);
2512 }
2513 
2514 #undef __FUNCT__
2515 #define __FUNCT__ "TSSetRetainStages"
2516 /*@
2517    TSSetRetainStages - Request that all stages in the upcoming step be stored so that interpolation will be available.
2518 
2519    Logically Collective on TS
2520 
2521    Input Argument:
2522 .  ts - time stepping context
2523 
2524    Output Argument:
2525 .  flg - PETSC_TRUE or PETSC_FALSE
2526 
2527    Level: intermediate
2528 
2529 .keywords: TS, set
2530 
2531 .seealso: TSInterpolate(), TSSetPostStep()
2532 @*/
2533 PetscErrorCode TSSetRetainStages(TS ts,PetscBool flg)
2534 {
2535   PetscFunctionBegin;
2536   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2537   ts->retain_stages = flg;
2538   PetscFunctionReturn(0);
2539 }
2540 
2541 #undef __FUNCT__
2542 #define __FUNCT__ "TSInterpolate"
2543 /*@
2544    TSInterpolate - Interpolate the solution computed during the previous step to an arbitrary location in the interval
2545 
2546    Collective on TS
2547 
2548    Input Argument:
2549 +  ts - time stepping context
2550 -  t - time to interpolate to
2551 
2552    Output Argument:
2553 .  U - state at given time
2554 
2555    Notes:
2556    The user should call TSSetRetainStages() before taking a step in which interpolation will be requested.
2557 
2558    Level: intermediate
2559 
2560    Developer Notes:
2561    TSInterpolate() and the storing of previous steps/stages should be generalized to support delay differential equations and continuous adjoints.
2562 
2563 .keywords: TS, set
2564 
2565 .seealso: TSSetRetainStages(), TSSetPostStep()
2566 @*/
2567 PetscErrorCode TSInterpolate(TS ts,PetscReal t,Vec U)
2568 {
2569   PetscErrorCode ierr;
2570 
2571   PetscFunctionBegin;
2572   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2573   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2574   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);
2575   if (!ts->ops->interpolate) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"%s does not provide interpolation",((PetscObject)ts)->type_name);
2576   ierr = (*ts->ops->interpolate)(ts,t,U);CHKERRQ(ierr);
2577   PetscFunctionReturn(0);
2578 }
2579 
2580 #undef __FUNCT__
2581 #define __FUNCT__ "TSStep"
2582 /*@
2583    TSStep - Steps one time step
2584 
2585    Collective on TS
2586 
2587    Input Parameter:
2588 .  ts - the TS context obtained from TSCreate()
2589 
2590    Level: intermediate
2591 
2592    Notes:
2593    The hook set using TSSetPreStep() is called before each attempt to take the step. In general, the time step size may
2594    be changed due to adaptive error controller or solve failures. Note that steps may contain multiple stages.
2595 
2596    This may over-step the final time provided in TSSetDuration() depending on the time-step used. TSSolve() interpolates to exactly the
2597    time provided in TSSetDuration(). One can use TSInterpolate() to determine an interpolated solution within the final timestep.
2598 
2599 .keywords: TS, timestep, solve
2600 
2601 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSInterpolate()
2602 @*/
2603 PetscErrorCode  TSStep(TS ts)
2604 {
2605   DM               dm;
2606   PetscErrorCode   ierr;
2607   static PetscBool cite = PETSC_FALSE;
2608 
2609   PetscFunctionBegin;
2610   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2611   ierr = PetscCitationsRegister("@techreport{tspaper,\n"
2612                                 "  title       = {{PETSc/TS}: A Modern Scalable {DAE/ODE} Solver Library},\n"
2613                                 "  author      = {Shrirang Abhyankar and Jed Brown and Emil Constantinescu and Debojyoti Ghosh and Barry F. Smith},\n"
2614                                 "  type        = {Preprint},\n"
2615                                 "  number      = {ANL/MCS-P5061-0114},\n"
2616                                 "  institution = {Argonne National Laboratory},\n"
2617                                 "  year        = {2014}\n}\n",&cite);
2618 
2619   ierr = TSGetDM(ts, &dm);CHKERRQ(ierr);
2620   ierr = TSSetUp(ts);CHKERRQ(ierr);
2621 
2622   ts->reason = TS_CONVERGED_ITERATING;
2623   ts->ptime_prev = ts->ptime;
2624   ierr = DMSetOutputSequenceNumber(dm, ts->steps, ts->ptime);CHKERRQ(ierr);
2625   ierr = VecViewFromOptions(ts->vec_sol, ((PetscObject) ts)->prefix, "-ts_view_solution");CHKERRQ(ierr);
2626 
2627   ierr = PetscLogEventBegin(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2628   ierr = (*ts->ops->step)(ts);CHKERRQ(ierr);
2629   ierr = PetscLogEventEnd(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2630 
2631   ts->time_step_prev = ts->ptime - ts->ptime_prev;
2632   ierr = DMSetOutputSequenceNumber(dm, ts->steps, ts->ptime);CHKERRQ(ierr);
2633 
2634   if (ts->reason < 0) {
2635     if (ts->errorifstepfailed) {
2636       if (ts->reason == TS_DIVERGED_NONLINEAR_SOLVE) {
2637         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]);
2638       } else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s",TSConvergedReasons[ts->reason]);
2639     }
2640   } else if (!ts->reason) {
2641     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2642     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2643   }
2644   PetscFunctionReturn(0);
2645 }
2646 
2647 #undef __FUNCT__
2648 #define __FUNCT__ "TSEvaluateStep"
2649 /*@
2650    TSEvaluateStep - Evaluate the solution at the end of a time step with a given order of accuracy.
2651 
2652    Collective on TS
2653 
2654    Input Arguments:
2655 +  ts - time stepping context
2656 .  order - desired order of accuracy
2657 -  done - whether the step was evaluated at this order (pass NULL to generate an error if not available)
2658 
2659    Output Arguments:
2660 .  U - state at the end of the current step
2661 
2662    Level: advanced
2663 
2664    Notes:
2665    This function cannot be called until all stages have been evaluated.
2666    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.
2667 
2668 .seealso: TSStep(), TSAdapt
2669 @*/
2670 PetscErrorCode TSEvaluateStep(TS ts,PetscInt order,Vec U,PetscBool *done)
2671 {
2672   PetscErrorCode ierr;
2673 
2674   PetscFunctionBegin;
2675   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2676   PetscValidType(ts,1);
2677   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2678   if (!ts->ops->evaluatestep) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSEvaluateStep not implemented for type '%s'",((PetscObject)ts)->type_name);
2679   ierr = (*ts->ops->evaluatestep)(ts,order,U,done);CHKERRQ(ierr);
2680   PetscFunctionReturn(0);
2681 }
2682 
2683 #undef __FUNCT__
2684 #define __FUNCT__ "TSSolve"
2685 /*@
2686    TSSolve - Steps the requested number of timesteps.
2687 
2688    Collective on TS
2689 
2690    Input Parameter:
2691 +  ts - the TS context obtained from TSCreate()
2692 -  u - the solution vector  (can be null if TSSetSolution() was used, otherwise must contain the initial conditions)
2693 
2694    Level: beginner
2695 
2696    Notes:
2697    The final time returned by this function may be different from the time of the internally
2698    held state accessible by TSGetSolution() and TSGetTime() because the method may have
2699    stepped over the final time.
2700 
2701 .keywords: TS, timestep, solve
2702 
2703 .seealso: TSCreate(), TSSetSolution(), TSStep()
2704 @*/
2705 PetscErrorCode TSSolve(TS ts,Vec u)
2706 {
2707   Vec               solution;
2708   PetscErrorCode    ierr;
2709 
2710   PetscFunctionBegin;
2711   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2712   if (u) PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2713   if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE) {   /* Need ts->vec_sol to be distinct so it is not overwritten when we interpolate at the end */
2714     PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2715     if (!ts->vec_sol || u == ts->vec_sol) {
2716       ierr = VecDuplicate(u,&solution);CHKERRQ(ierr);
2717       ierr = TSSetSolution(ts,solution);CHKERRQ(ierr);
2718       ierr = VecDestroy(&solution);CHKERRQ(ierr); /* grant ownership */
2719     }
2720     ierr = VecCopy(u,ts->vec_sol);CHKERRQ(ierr);
2721   } else if (u) {
2722     ierr = TSSetSolution(ts,u);CHKERRQ(ierr);
2723   }
2724   ierr = TSSetUp(ts);CHKERRQ(ierr);
2725   /* reset time step and iteration counters */
2726   ts->steps             = 0;
2727   ts->ksp_its           = 0;
2728   ts->snes_its          = 0;
2729   ts->num_snes_failures = 0;
2730   ts->reject            = 0;
2731   ts->reason            = TS_CONVERGED_ITERATING;
2732 
2733   ierr = TSViewFromOptions(ts,NULL,"-ts_view_pre");CHKERRQ(ierr);
2734 
2735   if (ts->ops->solve) {         /* This private interface is transitional and should be removed when all implementations are updated. */
2736     ierr = (*ts->ops->solve)(ts);CHKERRQ(ierr);
2737     ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);
2738     ts->solvetime = ts->ptime;
2739   } else {
2740     /* steps the requested number of timesteps. */
2741     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2742     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2743     while (!ts->reason) {
2744       ierr = TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
2745       ierr = TSStep(ts);CHKERRQ(ierr);
2746       if (ts->event) {
2747 	ierr = TSEventMonitor(ts);CHKERRQ(ierr);
2748 	if (ts->event->status != TSEVENT_PROCESSING) {
2749 	  ierr = TSPostStep(ts);CHKERRQ(ierr);
2750 	}
2751       } else {
2752 	ierr = TSPostStep(ts);CHKERRQ(ierr);
2753       }
2754     }
2755     if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE && ts->ptime > ts->max_time) {
2756       ierr = TSInterpolate(ts,ts->max_time,u);CHKERRQ(ierr);
2757       ts->solvetime = ts->max_time;
2758       solution = u;
2759     } else {
2760       if (u) {ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);}
2761       ts->solvetime = ts->ptime;
2762       solution = ts->vec_sol;
2763     }
2764     ierr = TSMonitor(ts,ts->steps,ts->solvetime,solution);CHKERRQ(ierr);
2765     ierr = VecViewFromOptions(u, ((PetscObject) ts)->prefix, "-ts_view_solution");CHKERRQ(ierr);
2766   }
2767   ierr = TSViewFromOptions(ts,NULL,"-ts_view");CHKERRQ(ierr);
2768   ierr = PetscObjectSAWsBlock((PetscObject)ts);CHKERRQ(ierr);
2769   PetscFunctionReturn(0);
2770 }
2771 
2772 #undef __FUNCT__
2773 #define __FUNCT__ "TSMonitor"
2774 /*@
2775    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()
2776 
2777    Collective on TS
2778 
2779    Input Parameters:
2780 +  ts - time stepping context obtained from TSCreate()
2781 .  step - step number that has just completed
2782 .  ptime - model time of the state
2783 -  u - state at the current model time
2784 
2785    Notes:
2786    TSMonitor() is typically used within the time stepping implementations.
2787    Users might call this function when using the TSStep() interface instead of TSSolve().
2788 
2789    Level: advanced
2790 
2791 .keywords: TS, timestep
2792 @*/
2793 PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
2794 {
2795   PetscErrorCode ierr;
2796   PetscInt       i,n = ts->numbermonitors;
2797 
2798   PetscFunctionBegin;
2799   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2800   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
2801   for (i=0; i<n; i++) {
2802     ierr = (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);CHKERRQ(ierr);
2803   }
2804   PetscFunctionReturn(0);
2805 }
2806 
2807 /* ------------------------------------------------------------------------*/
2808 #undef __FUNCT__
2809 #define __FUNCT__ "TSMonitorLGCtxCreate"
2810 /*@C
2811    TSMonitorLGCtxCreate - Creates a line graph context for use with
2812    TS to monitor the solution process graphically in various ways
2813 
2814    Collective on TS
2815 
2816    Input Parameters:
2817 +  host - the X display to open, or null for the local machine
2818 .  label - the title to put in the title bar
2819 .  x, y - the screen coordinates of the upper left coordinate of the window
2820 .  m, n - the screen width and height in pixels
2821 -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time
2822 
2823    Output Parameter:
2824 .  ctx - the context
2825 
2826    Options Database Key:
2827 +  -ts_monitor_lg_timestep - automatically sets line graph monitor
2828 .  -ts_monitor_lg_solution -
2829 .  -ts_monitor_lg_error -
2830 .  -ts_monitor_lg_ksp_iterations -
2831 .  -ts_monitor_lg_snes_iterations -
2832 -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true
2833 
2834    Notes:
2835    Use TSMonitorLGCtxDestroy() to destroy.
2836 
2837    Level: intermediate
2838 
2839 .keywords: TS, monitor, line graph, residual, seealso
2840 
2841 .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()
2842 
2843 @*/
2844 PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
2845 {
2846   PetscDraw      win;
2847   PetscErrorCode ierr;
2848 
2849   PetscFunctionBegin;
2850   ierr = PetscNew(ctx);CHKERRQ(ierr);
2851   ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr);
2852   ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr);
2853   ierr = PetscDrawLGCreate(win,1,&(*ctx)->lg);CHKERRQ(ierr);
2854   ierr = PetscLogObjectParent((PetscObject)(*ctx)->lg,(PetscObject)win);CHKERRQ(ierr);
2855   ierr = PetscDrawLGIndicateDataPoints((*ctx)->lg,PETSC_TRUE);CHKERRQ(ierr);
2856   ierr = PetscDrawLGSetFromOptions((*ctx)->lg);CHKERRQ(ierr);
2857   (*ctx)->howoften = howoften;
2858   PetscFunctionReturn(0);
2859 }
2860 
2861 #undef __FUNCT__
2862 #define __FUNCT__ "TSMonitorLGTimeStep"
2863 PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx)
2864 {
2865   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
2866   PetscReal      x   = ptime,y;
2867   PetscErrorCode ierr;
2868 
2869   PetscFunctionBegin;
2870   if (!step) {
2871     PetscDrawAxis axis;
2872     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
2873     ierr = PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");CHKERRQ(ierr);
2874     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
2875     ierr = PetscDrawLGIndicateDataPoints(ctx->lg,PETSC_TRUE);CHKERRQ(ierr);
2876   }
2877   ierr = TSGetTimeStep(ts,&y);CHKERRQ(ierr);
2878   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
2879   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
2880     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
2881   }
2882   PetscFunctionReturn(0);
2883 }
2884 
2885 #undef __FUNCT__
2886 #define __FUNCT__ "TSMonitorLGCtxDestroy"
2887 /*@C
2888    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
2889    with TSMonitorLGCtxCreate().
2890 
2891    Collective on TSMonitorLGCtx
2892 
2893    Input Parameter:
2894 .  ctx - the monitor context
2895 
2896    Level: intermediate
2897 
2898 .keywords: TS, monitor, line graph, destroy
2899 
2900 .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
2901 @*/
2902 PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
2903 {
2904   PetscDraw      draw;
2905   PetscErrorCode ierr;
2906 
2907   PetscFunctionBegin;
2908   ierr = PetscDrawLGGetDraw((*ctx)->lg,&draw);CHKERRQ(ierr);
2909   ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
2910   ierr = PetscDrawLGDestroy(&(*ctx)->lg);CHKERRQ(ierr);
2911   ierr = PetscFree(*ctx);CHKERRQ(ierr);
2912   PetscFunctionReturn(0);
2913 }
2914 
2915 #undef __FUNCT__
2916 #define __FUNCT__ "TSGetTime"
2917 /*@
2918    TSGetTime - Gets the time of the most recently completed step.
2919 
2920    Not Collective
2921 
2922    Input Parameter:
2923 .  ts - the TS context obtained from TSCreate()
2924 
2925    Output Parameter:
2926 .  t  - the current time
2927 
2928    Level: beginner
2929 
2930    Note:
2931    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
2932    TSSetPreStage(), TSSetPostStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.
2933 
2934 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
2935 
2936 .keywords: TS, get, time
2937 @*/
2938 PetscErrorCode  TSGetTime(TS ts,PetscReal *t)
2939 {
2940   PetscFunctionBegin;
2941   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2942   PetscValidRealPointer(t,2);
2943   *t = ts->ptime;
2944   PetscFunctionReturn(0);
2945 }
2946 
2947 #undef __FUNCT__
2948 #define __FUNCT__ "TSSetTime"
2949 /*@
2950    TSSetTime - Allows one to reset the time.
2951 
2952    Logically Collective on TS
2953 
2954    Input Parameters:
2955 +  ts - the TS context obtained from TSCreate()
2956 -  time - the time
2957 
2958    Level: intermediate
2959 
2960 .seealso: TSGetTime(), TSSetDuration()
2961 
2962 .keywords: TS, set, time
2963 @*/
2964 PetscErrorCode  TSSetTime(TS ts, PetscReal t)
2965 {
2966   PetscFunctionBegin;
2967   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2968   PetscValidLogicalCollectiveReal(ts,t,2);
2969   ts->ptime = t;
2970   PetscFunctionReturn(0);
2971 }
2972 
2973 #undef __FUNCT__
2974 #define __FUNCT__ "TSSetOptionsPrefix"
2975 /*@C
2976    TSSetOptionsPrefix - Sets the prefix used for searching for all
2977    TS options in the database.
2978 
2979    Logically Collective on TS
2980 
2981    Input Parameter:
2982 +  ts     - The TS context
2983 -  prefix - The prefix to prepend to all option names
2984 
2985    Notes:
2986    A hyphen (-) must NOT be given at the beginning of the prefix name.
2987    The first character of all runtime options is AUTOMATICALLY the
2988    hyphen.
2989 
2990    Level: advanced
2991 
2992 .keywords: TS, set, options, prefix, database
2993 
2994 .seealso: TSSetFromOptions()
2995 
2996 @*/
2997 PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
2998 {
2999   PetscErrorCode ierr;
3000   SNES           snes;
3001 
3002   PetscFunctionBegin;
3003   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3004   ierr = PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3005   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3006   ierr = SNESSetOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3007   PetscFunctionReturn(0);
3008 }
3009 
3010 
3011 #undef __FUNCT__
3012 #define __FUNCT__ "TSAppendOptionsPrefix"
3013 /*@C
3014    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
3015    TS options in the database.
3016 
3017    Logically Collective on TS
3018 
3019    Input Parameter:
3020 +  ts     - The TS context
3021 -  prefix - The prefix to prepend to all option names
3022 
3023    Notes:
3024    A hyphen (-) must NOT be given at the beginning of the prefix name.
3025    The first character of all runtime options is AUTOMATICALLY the
3026    hyphen.
3027 
3028    Level: advanced
3029 
3030 .keywords: TS, append, options, prefix, database
3031 
3032 .seealso: TSGetOptionsPrefix()
3033 
3034 @*/
3035 PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
3036 {
3037   PetscErrorCode ierr;
3038   SNES           snes;
3039 
3040   PetscFunctionBegin;
3041   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3042   ierr = PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3043   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3044   ierr = SNESAppendOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3045   PetscFunctionReturn(0);
3046 }
3047 
3048 #undef __FUNCT__
3049 #define __FUNCT__ "TSGetOptionsPrefix"
3050 /*@C
3051    TSGetOptionsPrefix - Sets the prefix used for searching for all
3052    TS options in the database.
3053 
3054    Not Collective
3055 
3056    Input Parameter:
3057 .  ts - The TS context
3058 
3059    Output Parameter:
3060 .  prefix - A pointer to the prefix string used
3061 
3062    Notes: On the fortran side, the user should pass in a string 'prifix' of
3063    sufficient length to hold the prefix.
3064 
3065    Level: intermediate
3066 
3067 .keywords: TS, get, options, prefix, database
3068 
3069 .seealso: TSAppendOptionsPrefix()
3070 @*/
3071 PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
3072 {
3073   PetscErrorCode ierr;
3074 
3075   PetscFunctionBegin;
3076   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3077   PetscValidPointer(prefix,2);
3078   ierr = PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3079   PetscFunctionReturn(0);
3080 }
3081 
3082 #undef __FUNCT__
3083 #define __FUNCT__ "TSGetRHSJacobian"
3084 /*@C
3085    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.
3086 
3087    Not Collective, but parallel objects are returned if TS is parallel
3088 
3089    Input Parameter:
3090 .  ts  - The TS context obtained from TSCreate()
3091 
3092    Output Parameters:
3093 +  Amat - The (approximate) Jacobian J of G, where U_t = G(U,t)  (or NULL)
3094 .  Pmat - The matrix from which the preconditioner is constructed, usually the same as Amat  (or NULL)
3095 .  func - Function to compute the Jacobian of the RHS  (or NULL)
3096 -  ctx - User-defined context for Jacobian evaluation routine  (or NULL)
3097 
3098    Notes: You can pass in NULL for any return argument you do not need.
3099 
3100    Level: intermediate
3101 
3102 .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3103 
3104 .keywords: TS, timestep, get, matrix, Jacobian
3105 @*/
3106 PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *Amat,Mat *Pmat,TSRHSJacobian *func,void **ctx)
3107 {
3108   PetscErrorCode ierr;
3109   SNES           snes;
3110   DM             dm;
3111 
3112   PetscFunctionBegin;
3113   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3114   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3115   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3116   ierr = DMTSGetRHSJacobian(dm,func,ctx);CHKERRQ(ierr);
3117   PetscFunctionReturn(0);
3118 }
3119 
3120 #undef __FUNCT__
3121 #define __FUNCT__ "TSGetIJacobian"
3122 /*@C
3123    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.
3124 
3125    Not Collective, but parallel objects are returned if TS is parallel
3126 
3127    Input Parameter:
3128 .  ts  - The TS context obtained from TSCreate()
3129 
3130    Output Parameters:
3131 +  Amat  - The (approximate) Jacobian of F(t,U,U_t)
3132 .  Pmat - The matrix from which the preconditioner is constructed, often the same as Amat
3133 .  f   - The function to compute the matrices
3134 - ctx - User-defined context for Jacobian evaluation routine
3135 
3136    Notes: You can pass in NULL for any return argument you do not need.
3137 
3138    Level: advanced
3139 
3140 .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3141 
3142 .keywords: TS, timestep, get, matrix, Jacobian
3143 @*/
3144 PetscErrorCode  TSGetIJacobian(TS ts,Mat *Amat,Mat *Pmat,TSIJacobian *f,void **ctx)
3145 {
3146   PetscErrorCode ierr;
3147   SNES           snes;
3148   DM             dm;
3149 
3150   PetscFunctionBegin;
3151   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3152   ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
3153   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3154   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3155   ierr = DMTSGetIJacobian(dm,f,ctx);CHKERRQ(ierr);
3156   PetscFunctionReturn(0);
3157 }
3158 
3159 
3160 #undef __FUNCT__
3161 #define __FUNCT__ "TSMonitorDrawSolution"
3162 /*@C
3163    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
3164    VecView() for the solution at each timestep
3165 
3166    Collective on TS
3167 
3168    Input Parameters:
3169 +  ts - the TS context
3170 .  step - current time-step
3171 .  ptime - current time
3172 -  dummy - either a viewer or NULL
3173 
3174    Options Database:
3175 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3176 
3177    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
3178        will look bad
3179 
3180    Level: intermediate
3181 
3182 .keywords: TS,  vector, monitor, view
3183 
3184 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3185 @*/
3186 PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3187 {
3188   PetscErrorCode   ierr;
3189   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
3190   PetscDraw        draw;
3191 
3192   PetscFunctionBegin;
3193   if (!step && ictx->showinitial) {
3194     if (!ictx->initialsolution) {
3195       ierr = VecDuplicate(u,&ictx->initialsolution);CHKERRQ(ierr);
3196     }
3197     ierr = VecCopy(u,ictx->initialsolution);CHKERRQ(ierr);
3198   }
3199   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften))) || ((ictx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3200 
3201   if (ictx->showinitial) {
3202     PetscReal pause;
3203     ierr = PetscViewerDrawGetPause(ictx->viewer,&pause);CHKERRQ(ierr);
3204     ierr = PetscViewerDrawSetPause(ictx->viewer,0.0);CHKERRQ(ierr);
3205     ierr = VecView(ictx->initialsolution,ictx->viewer);CHKERRQ(ierr);
3206     ierr = PetscViewerDrawSetPause(ictx->viewer,pause);CHKERRQ(ierr);
3207     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);CHKERRQ(ierr);
3208   }
3209   ierr = VecView(u,ictx->viewer);CHKERRQ(ierr);
3210   if (ictx->showtimestepandtime) {
3211     PetscReal xl,yl,xr,yr,tw,w,h;
3212     char      time[32];
3213     size_t    len;
3214 
3215     ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3216     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3217     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3218     ierr =  PetscStrlen(time,&len);CHKERRQ(ierr);
3219     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3220     w    = xl + .5*(xr - xl) - .5*len*tw;
3221     h    = yl + .95*(yr - yl);
3222     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3223     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3224   }
3225 
3226   if (ictx->showinitial) {
3227     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);CHKERRQ(ierr);
3228   }
3229   PetscFunctionReturn(0);
3230 }
3231 
3232 #undef __FUNCT__
3233 #define __FUNCT__ "TSMonitorDrawSolutionPhase"
3234 /*@C
3235    TSMonitorDrawSolutionPhase - Monitors progress of the TS solvers by plotting the solution as a phase diagram
3236 
3237    Collective on TS
3238 
3239    Input Parameters:
3240 +  ts - the TS context
3241 .  step - current time-step
3242 .  ptime - current time
3243 -  dummy - either a viewer or NULL
3244 
3245    Level: intermediate
3246 
3247 .keywords: TS,  vector, monitor, view
3248 
3249 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3250 @*/
3251 PetscErrorCode  TSMonitorDrawSolutionPhase(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3252 {
3253   PetscErrorCode    ierr;
3254   TSMonitorDrawCtx  ictx = (TSMonitorDrawCtx)dummy;
3255   PetscDraw         draw;
3256   MPI_Comm          comm;
3257   PetscInt          n;
3258   PetscMPIInt       size;
3259   PetscReal         xl,yl,xr,yr,tw,w,h;
3260   char              time[32];
3261   size_t            len;
3262   const PetscScalar *U;
3263 
3264   PetscFunctionBegin;
3265   ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
3266   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3267   if (size != 1) SETERRQ(comm,PETSC_ERR_SUP,"Only allowed for sequential runs");
3268   ierr = VecGetSize(u,&n);CHKERRQ(ierr);
3269   if (n != 2) SETERRQ(comm,PETSC_ERR_SUP,"Only for ODEs with two unknowns");
3270 
3271   ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3272 
3273   ierr = VecGetArrayRead(u,&U);CHKERRQ(ierr);
3274   ierr = PetscDrawAxisGetLimits(ictx->axis,&xl,&xr,&yl,&yr);CHKERRQ(ierr);
3275   if ((PetscRealPart(U[0]) < xl) || (PetscRealPart(U[1]) < yl) || (PetscRealPart(U[0]) > xr) || (PetscRealPart(U[1]) > yr)) {
3276       ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3277       PetscFunctionReturn(0);
3278   }
3279   if (!step) ictx->color++;
3280   ierr = PetscDrawPoint(draw,PetscRealPart(U[0]),PetscRealPart(U[1]),ictx->color);CHKERRQ(ierr);
3281   ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3282 
3283   if (ictx->showtimestepandtime) {
3284     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3285     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3286     ierr = PetscStrlen(time,&len);CHKERRQ(ierr);
3287     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3288     w    = xl + .5*(xr - xl) - .5*len*tw;
3289     h    = yl + .95*(yr - yl);
3290     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3291   }
3292   ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3293   PetscFunctionReturn(0);
3294 }
3295 
3296 
3297 #undef __FUNCT__
3298 #define __FUNCT__ "TSMonitorDrawCtxDestroy"
3299 /*@C
3300    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()
3301 
3302    Collective on TS
3303 
3304    Input Parameters:
3305 .    ctx - the monitor context
3306 
3307    Level: intermediate
3308 
3309 .keywords: TS,  vector, monitor, view
3310 
3311 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
3312 @*/
3313 PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
3314 {
3315   PetscErrorCode ierr;
3316 
3317   PetscFunctionBegin;
3318   ierr = PetscDrawAxisDestroy(&(*ictx)->axis);CHKERRQ(ierr);
3319   ierr = PetscViewerDestroy(&(*ictx)->viewer);CHKERRQ(ierr);
3320   ierr = VecDestroy(&(*ictx)->initialsolution);CHKERRQ(ierr);
3321   ierr = PetscFree(*ictx);CHKERRQ(ierr);
3322   PetscFunctionReturn(0);
3323 }
3324 
3325 #undef __FUNCT__
3326 #define __FUNCT__ "TSMonitorDrawCtxCreate"
3327 /*@C
3328    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx
3329 
3330    Collective on TS
3331 
3332    Input Parameter:
3333 .    ts - time-step context
3334 
3335    Output Patameter:
3336 .    ctx - the monitor context
3337 
3338    Options Database:
3339 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3340 
3341    Level: intermediate
3342 
3343 .keywords: TS,  vector, monitor, view
3344 
3345 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
3346 @*/
3347 PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
3348 {
3349   PetscErrorCode   ierr;
3350 
3351   PetscFunctionBegin;
3352   ierr = PetscNew(ctx);CHKERRQ(ierr);
3353   ierr = PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);CHKERRQ(ierr);
3354   ierr = PetscViewerSetFromOptions((*ctx)->viewer);CHKERRQ(ierr);
3355 
3356   (*ctx)->howoften    = howoften;
3357   (*ctx)->showinitial = PETSC_FALSE;
3358   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,NULL);CHKERRQ(ierr);
3359 
3360   (*ctx)->showtimestepandtime = PETSC_FALSE;
3361   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_show_time",&(*ctx)->showtimestepandtime,NULL);CHKERRQ(ierr);
3362   (*ctx)->color = PETSC_DRAW_WHITE;
3363   PetscFunctionReturn(0);
3364 }
3365 
3366 #undef __FUNCT__
3367 #define __FUNCT__ "TSMonitorDrawError"
3368 /*@C
3369    TSMonitorDrawError - Monitors progress of the TS solvers by calling
3370    VecView() for the error at each timestep
3371 
3372    Collective on TS
3373 
3374    Input Parameters:
3375 +  ts - the TS context
3376 .  step - current time-step
3377 .  ptime - current time
3378 -  dummy - either a viewer or NULL
3379 
3380    Level: intermediate
3381 
3382 .keywords: TS,  vector, monitor, view
3383 
3384 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3385 @*/
3386 PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3387 {
3388   PetscErrorCode   ierr;
3389   TSMonitorDrawCtx ctx    = (TSMonitorDrawCtx)dummy;
3390   PetscViewer      viewer = ctx->viewer;
3391   Vec              work;
3392 
3393   PetscFunctionBegin;
3394   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3395   ierr = VecDuplicate(u,&work);CHKERRQ(ierr);
3396   ierr = TSComputeSolutionFunction(ts,ptime,work);CHKERRQ(ierr);
3397   ierr = VecAXPY(work,-1.0,u);CHKERRQ(ierr);
3398   ierr = VecView(work,viewer);CHKERRQ(ierr);
3399   ierr = VecDestroy(&work);CHKERRQ(ierr);
3400   PetscFunctionReturn(0);
3401 }
3402 
3403 #include <petsc-private/dmimpl.h>
3404 #undef __FUNCT__
3405 #define __FUNCT__ "TSSetDM"
3406 /*@
3407    TSSetDM - Sets the DM that may be used by some preconditioners
3408 
3409    Logically Collective on TS and DM
3410 
3411    Input Parameters:
3412 +  ts - the preconditioner context
3413 -  dm - the dm
3414 
3415    Level: intermediate
3416 
3417 
3418 .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
3419 @*/
3420 PetscErrorCode  TSSetDM(TS ts,DM dm)
3421 {
3422   PetscErrorCode ierr;
3423   SNES           snes;
3424   DMTS           tsdm;
3425 
3426   PetscFunctionBegin;
3427   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3428   ierr = PetscObjectReference((PetscObject)dm);CHKERRQ(ierr);
3429   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
3430     if (ts->dm->dmts && !dm->dmts) {
3431       ierr = DMCopyDMTS(ts->dm,dm);CHKERRQ(ierr);
3432       ierr = DMGetDMTS(ts->dm,&tsdm);CHKERRQ(ierr);
3433       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
3434         tsdm->originaldm = dm;
3435       }
3436     }
3437     ierr = DMDestroy(&ts->dm);CHKERRQ(ierr);
3438   }
3439   ts->dm = dm;
3440 
3441   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3442   ierr = SNESSetDM(snes,dm);CHKERRQ(ierr);
3443   PetscFunctionReturn(0);
3444 }
3445 
3446 #undef __FUNCT__
3447 #define __FUNCT__ "TSGetDM"
3448 /*@
3449    TSGetDM - Gets the DM that may be used by some preconditioners
3450 
3451    Not Collective
3452 
3453    Input Parameter:
3454 . ts - the preconditioner context
3455 
3456    Output Parameter:
3457 .  dm - the dm
3458 
3459    Level: intermediate
3460 
3461 
3462 .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
3463 @*/
3464 PetscErrorCode  TSGetDM(TS ts,DM *dm)
3465 {
3466   PetscErrorCode ierr;
3467 
3468   PetscFunctionBegin;
3469   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3470   if (!ts->dm) {
3471     ierr = DMShellCreate(PetscObjectComm((PetscObject)ts),&ts->dm);CHKERRQ(ierr);
3472     if (ts->snes) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
3473   }
3474   *dm = ts->dm;
3475   PetscFunctionReturn(0);
3476 }
3477 
3478 #undef __FUNCT__
3479 #define __FUNCT__ "SNESTSFormFunction"
3480 /*@
3481    SNESTSFormFunction - Function to evaluate nonlinear residual
3482 
3483    Logically Collective on SNES
3484 
3485    Input Parameter:
3486 + snes - nonlinear solver
3487 . U - the current state at which to evaluate the residual
3488 - ctx - user context, must be a TS
3489 
3490    Output Parameter:
3491 . F - the nonlinear residual
3492 
3493    Notes:
3494    This function is not normally called by users and is automatically registered with the SNES used by TS.
3495    It is most frequently passed to MatFDColoringSetFunction().
3496 
3497    Level: advanced
3498 
3499 .seealso: SNESSetFunction(), MatFDColoringSetFunction()
3500 @*/
3501 PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
3502 {
3503   TS             ts = (TS)ctx;
3504   PetscErrorCode ierr;
3505 
3506   PetscFunctionBegin;
3507   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3508   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3509   PetscValidHeaderSpecific(F,VEC_CLASSID,3);
3510   PetscValidHeaderSpecific(ts,TS_CLASSID,4);
3511   ierr = (ts->ops->snesfunction)(snes,U,F,ts);CHKERRQ(ierr);
3512   PetscFunctionReturn(0);
3513 }
3514 
3515 #undef __FUNCT__
3516 #define __FUNCT__ "SNESTSFormJacobian"
3517 /*@
3518    SNESTSFormJacobian - Function to evaluate the Jacobian
3519 
3520    Collective on SNES
3521 
3522    Input Parameter:
3523 + snes - nonlinear solver
3524 . U - the current state at which to evaluate the residual
3525 - ctx - user context, must be a TS
3526 
3527    Output Parameter:
3528 + A - the Jacobian
3529 . B - the preconditioning matrix (may be the same as A)
3530 - flag - indicates any structure change in the matrix
3531 
3532    Notes:
3533    This function is not normally called by users and is automatically registered with the SNES used by TS.
3534 
3535    Level: developer
3536 
3537 .seealso: SNESSetJacobian()
3538 @*/
3539 PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat A,Mat B,void *ctx)
3540 {
3541   TS             ts = (TS)ctx;
3542   PetscErrorCode ierr;
3543 
3544   PetscFunctionBegin;
3545   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3546   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3547   PetscValidPointer(A,3);
3548   PetscValidHeaderSpecific(A,MAT_CLASSID,3);
3549   PetscValidPointer(B,4);
3550   PetscValidHeaderSpecific(B,MAT_CLASSID,4);
3551   PetscValidHeaderSpecific(ts,TS_CLASSID,6);
3552   ierr = (ts->ops->snesjacobian)(snes,U,A,B,ts);CHKERRQ(ierr);
3553   PetscFunctionReturn(0);
3554 }
3555 
3556 #undef __FUNCT__
3557 #define __FUNCT__ "TSComputeRHSFunctionLinear"
3558 /*@C
3559    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only
3560 
3561    Collective on TS
3562 
3563    Input Arguments:
3564 +  ts - time stepping context
3565 .  t - time at which to evaluate
3566 .  U - state at which to evaluate
3567 -  ctx - context
3568 
3569    Output Arguments:
3570 .  F - right hand side
3571 
3572    Level: intermediate
3573 
3574    Notes:
3575    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
3576    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().
3577 
3578 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
3579 @*/
3580 PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
3581 {
3582   PetscErrorCode ierr;
3583   Mat            Arhs,Brhs;
3584 
3585   PetscFunctionBegin;
3586   ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
3587   ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
3588   ierr = MatMult(Arhs,U,F);CHKERRQ(ierr);
3589   PetscFunctionReturn(0);
3590 }
3591 
3592 #undef __FUNCT__
3593 #define __FUNCT__ "TSComputeRHSJacobianConstant"
3594 /*@C
3595    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.
3596 
3597    Collective on TS
3598 
3599    Input Arguments:
3600 +  ts - time stepping context
3601 .  t - time at which to evaluate
3602 .  U - state at which to evaluate
3603 -  ctx - context
3604 
3605    Output Arguments:
3606 +  A - pointer to operator
3607 .  B - pointer to preconditioning matrix
3608 -  flg - matrix structure flag
3609 
3610    Level: intermediate
3611 
3612    Notes:
3613    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.
3614 
3615 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
3616 @*/
3617 PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat A,Mat B,void *ctx)
3618 {
3619   PetscFunctionBegin;
3620   PetscFunctionReturn(0);
3621 }
3622 
3623 #undef __FUNCT__
3624 #define __FUNCT__ "TSComputeIFunctionLinear"
3625 /*@C
3626    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only
3627 
3628    Collective on TS
3629 
3630    Input Arguments:
3631 +  ts - time stepping context
3632 .  t - time at which to evaluate
3633 .  U - state at which to evaluate
3634 .  Udot - time derivative of state vector
3635 -  ctx - context
3636 
3637    Output Arguments:
3638 .  F - left hand side
3639 
3640    Level: intermediate
3641 
3642    Notes:
3643    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
3644    user is required to write their own TSComputeIFunction.
3645    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
3646    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().
3647 
3648 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
3649 @*/
3650 PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
3651 {
3652   PetscErrorCode ierr;
3653   Mat            A,B;
3654 
3655   PetscFunctionBegin;
3656   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
3657   ierr = TSComputeIJacobian(ts,t,U,Udot,1.0,A,B,PETSC_TRUE);CHKERRQ(ierr);
3658   ierr = MatMult(A,Udot,F);CHKERRQ(ierr);
3659   PetscFunctionReturn(0);
3660 }
3661 
3662 #undef __FUNCT__
3663 #define __FUNCT__ "TSComputeIJacobianConstant"
3664 /*@C
3665    TSComputeIJacobianConstant - Reuses a time-independent for a semi-implicit DAE or ODE
3666 
3667    Collective on TS
3668 
3669    Input Arguments:
3670 +  ts - time stepping context
3671 .  t - time at which to evaluate
3672 .  U - state at which to evaluate
3673 .  Udot - time derivative of state vector
3674 .  shift - shift to apply
3675 -  ctx - context
3676 
3677    Output Arguments:
3678 +  A - pointer to operator
3679 .  B - pointer to preconditioning matrix
3680 -  flg - matrix structure flag
3681 
3682    Level: advanced
3683 
3684    Notes:
3685    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.
3686 
3687    It is only appropriate for problems of the form
3688 
3689 $     M Udot = F(U,t)
3690 
3691   where M is constant and F is non-stiff.  The user must pass M to TSSetIJacobian().  The current implementation only
3692   works with IMEX time integration methods such as TSROSW and TSARKIMEX, since there is no support for de-constructing
3693   an implicit operator of the form
3694 
3695 $    shift*M + J
3696 
3697   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
3698   a copy of M or reassemble it when requested.
3699 
3700 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
3701 @*/
3702 PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,void *ctx)
3703 {
3704   PetscErrorCode ierr;
3705 
3706   PetscFunctionBegin;
3707   ierr = MatScale(A, shift / ts->ijacobian.shift);CHKERRQ(ierr);
3708   ts->ijacobian.shift = shift;
3709   PetscFunctionReturn(0);
3710 }
3711 
3712 #undef __FUNCT__
3713 #define __FUNCT__ "TSGetEquationType"
3714 /*@
3715    TSGetEquationType - Gets the type of the equation that TS is solving.
3716 
3717    Not Collective
3718 
3719    Input Parameter:
3720 .  ts - the TS context
3721 
3722    Output Parameter:
3723 .  equation_type - see TSEquationType
3724 
3725    Level: beginner
3726 
3727 .keywords: TS, equation type
3728 
3729 .seealso: TSSetEquationType(), TSEquationType
3730 @*/
3731 PetscErrorCode  TSGetEquationType(TS ts,TSEquationType *equation_type)
3732 {
3733   PetscFunctionBegin;
3734   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3735   PetscValidPointer(equation_type,2);
3736   *equation_type = ts->equation_type;
3737   PetscFunctionReturn(0);
3738 }
3739 
3740 #undef __FUNCT__
3741 #define __FUNCT__ "TSSetEquationType"
3742 /*@
3743    TSSetEquationType - Sets the type of the equation that TS is solving.
3744 
3745    Not Collective
3746 
3747    Input Parameter:
3748 +  ts - the TS context
3749 .  equation_type - see TSEquationType
3750 
3751    Level: advanced
3752 
3753 .keywords: TS, equation type
3754 
3755 .seealso: TSGetEquationType(), TSEquationType
3756 @*/
3757 PetscErrorCode  TSSetEquationType(TS ts,TSEquationType equation_type)
3758 {
3759   PetscFunctionBegin;
3760   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3761   ts->equation_type = equation_type;
3762   PetscFunctionReturn(0);
3763 }
3764 
3765 #undef __FUNCT__
3766 #define __FUNCT__ "TSGetConvergedReason"
3767 /*@
3768    TSGetConvergedReason - Gets the reason the TS iteration was stopped.
3769 
3770    Not Collective
3771 
3772    Input Parameter:
3773 .  ts - the TS context
3774 
3775    Output Parameter:
3776 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3777             manual pages for the individual convergence tests for complete lists
3778 
3779    Level: beginner
3780 
3781    Notes:
3782    Can only be called after the call to TSSolve() is complete.
3783 
3784 .keywords: TS, nonlinear, set, convergence, test
3785 
3786 .seealso: TSSetConvergenceTest(), TSConvergedReason
3787 @*/
3788 PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
3789 {
3790   PetscFunctionBegin;
3791   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3792   PetscValidPointer(reason,2);
3793   *reason = ts->reason;
3794   PetscFunctionReturn(0);
3795 }
3796 
3797 #undef __FUNCT__
3798 #define __FUNCT__ "TSSetConvergedReason"
3799 /*@
3800    TSSetConvergedReason - Sets the reason for handling the convergence of TSSolve.
3801 
3802    Not Collective
3803 
3804    Input Parameter:
3805 +  ts - the TS context
3806 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3807             manual pages for the individual convergence tests for complete lists
3808 
3809    Level: advanced
3810 
3811    Notes:
3812    Can only be called during TSSolve() is active.
3813 
3814 .keywords: TS, nonlinear, set, convergence, test
3815 
3816 .seealso: TSConvergedReason
3817 @*/
3818 PetscErrorCode  TSSetConvergedReason(TS ts,TSConvergedReason reason)
3819 {
3820   PetscFunctionBegin;
3821   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3822   ts->reason = reason;
3823   PetscFunctionReturn(0);
3824 }
3825 
3826 #undef __FUNCT__
3827 #define __FUNCT__ "TSGetSolveTime"
3828 /*@
3829    TSGetSolveTime - Gets the time after a call to TSSolve()
3830 
3831    Not Collective
3832 
3833    Input Parameter:
3834 .  ts - the TS context
3835 
3836    Output Parameter:
3837 .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()
3838 
3839    Level: beginner
3840 
3841    Notes:
3842    Can only be called after the call to TSSolve() is complete.
3843 
3844 .keywords: TS, nonlinear, set, convergence, test
3845 
3846 .seealso: TSSetConvergenceTest(), TSConvergedReason
3847 @*/
3848 PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
3849 {
3850   PetscFunctionBegin;
3851   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3852   PetscValidPointer(ftime,2);
3853   *ftime = ts->solvetime;
3854   PetscFunctionReturn(0);
3855 }
3856 
3857 #undef __FUNCT__
3858 #define __FUNCT__ "TSGetSNESIterations"
3859 /*@
3860    TSGetSNESIterations - Gets the total number of nonlinear iterations
3861    used by the time integrator.
3862 
3863    Not Collective
3864 
3865    Input Parameter:
3866 .  ts - TS context
3867 
3868    Output Parameter:
3869 .  nits - number of nonlinear iterations
3870 
3871    Notes:
3872    This counter is reset to zero for each successive call to TSSolve().
3873 
3874    Level: intermediate
3875 
3876 .keywords: TS, get, number, nonlinear, iterations
3877 
3878 .seealso:  TSGetKSPIterations()
3879 @*/
3880 PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
3881 {
3882   PetscFunctionBegin;
3883   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3884   PetscValidIntPointer(nits,2);
3885   *nits = ts->snes_its;
3886   PetscFunctionReturn(0);
3887 }
3888 
3889 #undef __FUNCT__
3890 #define __FUNCT__ "TSGetKSPIterations"
3891 /*@
3892    TSGetKSPIterations - Gets the total number of linear iterations
3893    used by the time integrator.
3894 
3895    Not Collective
3896 
3897    Input Parameter:
3898 .  ts - TS context
3899 
3900    Output Parameter:
3901 .  lits - number of linear iterations
3902 
3903    Notes:
3904    This counter is reset to zero for each successive call to TSSolve().
3905 
3906    Level: intermediate
3907 
3908 .keywords: TS, get, number, linear, iterations
3909 
3910 .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
3911 @*/
3912 PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
3913 {
3914   PetscFunctionBegin;
3915   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3916   PetscValidIntPointer(lits,2);
3917   *lits = ts->ksp_its;
3918   PetscFunctionReturn(0);
3919 }
3920 
3921 #undef __FUNCT__
3922 #define __FUNCT__ "TSGetStepRejections"
3923 /*@
3924    TSGetStepRejections - Gets the total number of rejected steps.
3925 
3926    Not Collective
3927 
3928    Input Parameter:
3929 .  ts - TS context
3930 
3931    Output Parameter:
3932 .  rejects - number of steps rejected
3933 
3934    Notes:
3935    This counter is reset to zero for each successive call to TSSolve().
3936 
3937    Level: intermediate
3938 
3939 .keywords: TS, get, number
3940 
3941 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
3942 @*/
3943 PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
3944 {
3945   PetscFunctionBegin;
3946   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3947   PetscValidIntPointer(rejects,2);
3948   *rejects = ts->reject;
3949   PetscFunctionReturn(0);
3950 }
3951 
3952 #undef __FUNCT__
3953 #define __FUNCT__ "TSGetSNESFailures"
3954 /*@
3955    TSGetSNESFailures - Gets the total number of failed SNES solves
3956 
3957    Not Collective
3958 
3959    Input Parameter:
3960 .  ts - TS context
3961 
3962    Output Parameter:
3963 .  fails - number of failed nonlinear solves
3964 
3965    Notes:
3966    This counter is reset to zero for each successive call to TSSolve().
3967 
3968    Level: intermediate
3969 
3970 .keywords: TS, get, number
3971 
3972 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
3973 @*/
3974 PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
3975 {
3976   PetscFunctionBegin;
3977   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3978   PetscValidIntPointer(fails,2);
3979   *fails = ts->num_snes_failures;
3980   PetscFunctionReturn(0);
3981 }
3982 
3983 #undef __FUNCT__
3984 #define __FUNCT__ "TSSetMaxStepRejections"
3985 /*@
3986    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails
3987 
3988    Not Collective
3989 
3990    Input Parameter:
3991 +  ts - TS context
3992 -  rejects - maximum number of rejected steps, pass -1 for unlimited
3993 
3994    Notes:
3995    The counter is reset to zero for each step
3996 
3997    Options Database Key:
3998  .  -ts_max_reject - Maximum number of step rejections before a step fails
3999 
4000    Level: intermediate
4001 
4002 .keywords: TS, set, maximum, number
4003 
4004 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4005 @*/
4006 PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
4007 {
4008   PetscFunctionBegin;
4009   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4010   ts->max_reject = rejects;
4011   PetscFunctionReturn(0);
4012 }
4013 
4014 #undef __FUNCT__
4015 #define __FUNCT__ "TSSetMaxSNESFailures"
4016 /*@
4017    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves
4018 
4019    Not Collective
4020 
4021    Input Parameter:
4022 +  ts - TS context
4023 -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited
4024 
4025    Notes:
4026    The counter is reset to zero for each successive call to TSSolve().
4027 
4028    Options Database Key:
4029  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures
4030 
4031    Level: intermediate
4032 
4033 .keywords: TS, set, maximum, number
4034 
4035 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
4036 @*/
4037 PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
4038 {
4039   PetscFunctionBegin;
4040   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4041   ts->max_snes_failures = fails;
4042   PetscFunctionReturn(0);
4043 }
4044 
4045 #undef __FUNCT__
4046 #define __FUNCT__ "TSSetErrorIfStepFails"
4047 /*@
4048    TSSetErrorIfStepFails - Error if no step succeeds
4049 
4050    Not Collective
4051 
4052    Input Parameter:
4053 +  ts - TS context
4054 -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure
4055 
4056    Options Database Key:
4057  .  -ts_error_if_step_fails - Error if no step succeeds
4058 
4059    Level: intermediate
4060 
4061 .keywords: TS, set, error
4062 
4063 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4064 @*/
4065 PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
4066 {
4067   PetscFunctionBegin;
4068   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4069   ts->errorifstepfailed = err;
4070   PetscFunctionReturn(0);
4071 }
4072 
4073 #undef __FUNCT__
4074 #define __FUNCT__ "TSMonitorSolutionBinary"
4075 /*@C
4076    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file
4077 
4078    Collective on TS
4079 
4080    Input Parameters:
4081 +  ts - the TS context
4082 .  step - current time-step
4083 .  ptime - current time
4084 .  u - current state
4085 -  viewer - binary viewer
4086 
4087    Level: intermediate
4088 
4089 .keywords: TS,  vector, monitor, view
4090 
4091 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4092 @*/
4093 PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
4094 {
4095   PetscErrorCode ierr;
4096   PetscViewer    v = (PetscViewer)viewer;
4097 
4098   PetscFunctionBegin;
4099   ierr = VecView(u,v);CHKERRQ(ierr);
4100   PetscFunctionReturn(0);
4101 }
4102 
4103 #undef __FUNCT__
4104 #define __FUNCT__ "TSMonitorSolutionVTK"
4105 /*@C
4106    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.
4107 
4108    Collective on TS
4109 
4110    Input Parameters:
4111 +  ts - the TS context
4112 .  step - current time-step
4113 .  ptime - current time
4114 .  u - current state
4115 -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4116 
4117    Level: intermediate
4118 
4119    Notes:
4120    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.
4121    These are named according to the file name template.
4122 
4123    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().
4124 
4125 .keywords: TS,  vector, monitor, view
4126 
4127 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4128 @*/
4129 PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
4130 {
4131   PetscErrorCode ierr;
4132   char           filename[PETSC_MAX_PATH_LEN];
4133   PetscViewer    viewer;
4134 
4135   PetscFunctionBegin;
4136   ierr = PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);CHKERRQ(ierr);
4137   ierr = PetscViewerVTKOpen(PetscObjectComm((PetscObject)ts),filename,FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
4138   ierr = VecView(u,viewer);CHKERRQ(ierr);
4139   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
4140   PetscFunctionReturn(0);
4141 }
4142 
4143 #undef __FUNCT__
4144 #define __FUNCT__ "TSMonitorSolutionVTKDestroy"
4145 /*@C
4146    TSMonitorSolutionVTKDestroy - Destroy context for monitoring
4147 
4148    Collective on TS
4149 
4150    Input Parameters:
4151 .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4152 
4153    Level: intermediate
4154 
4155    Note:
4156    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().
4157 
4158 .keywords: TS,  vector, monitor, view
4159 
4160 .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
4161 @*/
4162 PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
4163 {
4164   PetscErrorCode ierr;
4165 
4166   PetscFunctionBegin;
4167   ierr = PetscFree(*(char**)filenametemplate);CHKERRQ(ierr);
4168   PetscFunctionReturn(0);
4169 }
4170 
4171 #undef __FUNCT__
4172 #define __FUNCT__ "TSGetAdapt"
4173 /*@
4174    TSGetAdapt - Get the adaptive controller context for the current method
4175 
4176    Collective on TS if controller has not been created yet
4177 
4178    Input Arguments:
4179 .  ts - time stepping context
4180 
4181    Output Arguments:
4182 .  adapt - adaptive controller
4183 
4184    Level: intermediate
4185 
4186 .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
4187 @*/
4188 PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
4189 {
4190   PetscErrorCode ierr;
4191 
4192   PetscFunctionBegin;
4193   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4194   PetscValidPointer(adapt,2);
4195   if (!ts->adapt) {
4196     ierr = TSAdaptCreate(PetscObjectComm((PetscObject)ts),&ts->adapt);CHKERRQ(ierr);
4197     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->adapt);CHKERRQ(ierr);
4198     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);CHKERRQ(ierr);
4199   }
4200   *adapt = ts->adapt;
4201   PetscFunctionReturn(0);
4202 }
4203 
4204 #undef __FUNCT__
4205 #define __FUNCT__ "TSSetTolerances"
4206 /*@
4207    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller
4208 
4209    Logically Collective
4210 
4211    Input Arguments:
4212 +  ts - time integration context
4213 .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
4214 .  vatol - vector of absolute tolerances or NULL, used in preference to atol if present
4215 .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
4216 -  vrtol - vector of relative tolerances or NULL, used in preference to atol if present
4217 
4218    Options Database keys:
4219 +  -ts_rtol <rtol> - relative tolerance for local truncation error
4220 -  -ts_atol <atol> Absolute tolerance for local truncation error
4221 
4222    Level: beginner
4223 
4224 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
4225 @*/
4226 PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
4227 {
4228   PetscErrorCode ierr;
4229 
4230   PetscFunctionBegin;
4231   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
4232   if (vatol) {
4233     ierr = PetscObjectReference((PetscObject)vatol);CHKERRQ(ierr);
4234     ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
4235 
4236     ts->vatol = vatol;
4237   }
4238   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
4239   if (vrtol) {
4240     ierr = PetscObjectReference((PetscObject)vrtol);CHKERRQ(ierr);
4241     ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
4242 
4243     ts->vrtol = vrtol;
4244   }
4245   PetscFunctionReturn(0);
4246 }
4247 
4248 #undef __FUNCT__
4249 #define __FUNCT__ "TSGetTolerances"
4250 /*@
4251    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller
4252 
4253    Logically Collective
4254 
4255    Input Arguments:
4256 .  ts - time integration context
4257 
4258    Output Arguments:
4259 +  atol - scalar absolute tolerances, NULL to ignore
4260 .  vatol - vector of absolute tolerances, NULL to ignore
4261 .  rtol - scalar relative tolerances, NULL to ignore
4262 -  vrtol - vector of relative tolerances, NULL to ignore
4263 
4264    Level: beginner
4265 
4266 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
4267 @*/
4268 PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
4269 {
4270   PetscFunctionBegin;
4271   if (atol)  *atol  = ts->atol;
4272   if (vatol) *vatol = ts->vatol;
4273   if (rtol)  *rtol  = ts->rtol;
4274   if (vrtol) *vrtol = ts->vrtol;
4275   PetscFunctionReturn(0);
4276 }
4277 
4278 #undef __FUNCT__
4279 #define __FUNCT__ "TSErrorNormWRMS"
4280 /*@
4281    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state
4282 
4283    Collective on TS
4284 
4285    Input Arguments:
4286 +  ts - time stepping context
4287 -  Y - state vector to be compared to ts->vec_sol
4288 
4289    Output Arguments:
4290 .  norm - weighted norm, a value of 1.0 is considered small
4291 
4292    Level: developer
4293 
4294 .seealso: TSSetTolerances()
4295 @*/
4296 PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
4297 {
4298   PetscErrorCode    ierr;
4299   PetscInt          i,n,N;
4300   const PetscScalar *u,*y;
4301   Vec               U;
4302   PetscReal         sum,gsum;
4303 
4304   PetscFunctionBegin;
4305   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4306   PetscValidHeaderSpecific(Y,VEC_CLASSID,2);
4307   PetscValidPointer(norm,3);
4308   U = ts->vec_sol;
4309   PetscCheckSameTypeAndComm(U,1,Y,2);
4310   if (U == Y) SETERRQ(PetscObjectComm((PetscObject)U),PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");
4311 
4312   ierr = VecGetSize(U,&N);CHKERRQ(ierr);
4313   ierr = VecGetLocalSize(U,&n);CHKERRQ(ierr);
4314   ierr = VecGetArrayRead(U,&u);CHKERRQ(ierr);
4315   ierr = VecGetArrayRead(Y,&y);CHKERRQ(ierr);
4316   sum  = 0.;
4317   if (ts->vatol && ts->vrtol) {
4318     const PetscScalar *atol,*rtol;
4319     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4320     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4321     for (i=0; i<n; i++) {
4322       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4323       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4324     }
4325     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4326     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4327   } else if (ts->vatol) {       /* vector atol, scalar rtol */
4328     const PetscScalar *atol;
4329     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4330     for (i=0; i<n; i++) {
4331       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4332       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4333     }
4334     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4335   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
4336     const PetscScalar *rtol;
4337     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4338     for (i=0; i<n; i++) {
4339       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4340       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4341     }
4342     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4343   } else {                      /* scalar atol, scalar rtol */
4344     for (i=0; i<n; i++) {
4345       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4346       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4347     }
4348   }
4349   ierr = VecRestoreArrayRead(U,&u);CHKERRQ(ierr);
4350   ierr = VecRestoreArrayRead(Y,&y);CHKERRQ(ierr);
4351 
4352   ierr  = MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4353   *norm = PetscSqrtReal(gsum / N);
4354   if (PetscIsInfOrNanScalar(*norm)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
4355   PetscFunctionReturn(0);
4356 }
4357 
4358 #undef __FUNCT__
4359 #define __FUNCT__ "TSSetCFLTimeLocal"
4360 /*@
4361    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler
4362 
4363    Logically Collective on TS
4364 
4365    Input Arguments:
4366 +  ts - time stepping context
4367 -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)
4368 
4369    Note:
4370    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()
4371 
4372    Level: intermediate
4373 
4374 .seealso: TSGetCFLTime(), TSADAPTCFL
4375 @*/
4376 PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
4377 {
4378   PetscFunctionBegin;
4379   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4380   ts->cfltime_local = cfltime;
4381   ts->cfltime       = -1.;
4382   PetscFunctionReturn(0);
4383 }
4384 
4385 #undef __FUNCT__
4386 #define __FUNCT__ "TSGetCFLTime"
4387 /*@
4388    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler
4389 
4390    Collective on TS
4391 
4392    Input Arguments:
4393 .  ts - time stepping context
4394 
4395    Output Arguments:
4396 .  cfltime - maximum stable time step for forward Euler
4397 
4398    Level: advanced
4399 
4400 .seealso: TSSetCFLTimeLocal()
4401 @*/
4402 PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
4403 {
4404   PetscErrorCode ierr;
4405 
4406   PetscFunctionBegin;
4407   if (ts->cfltime < 0) {
4408     ierr = MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4409   }
4410   *cfltime = ts->cfltime;
4411   PetscFunctionReturn(0);
4412 }
4413 
4414 #undef __FUNCT__
4415 #define __FUNCT__ "TSVISetVariableBounds"
4416 /*@
4417    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu
4418 
4419    Input Parameters:
4420 .  ts   - the TS context.
4421 .  xl   - lower bound.
4422 .  xu   - upper bound.
4423 
4424    Notes:
4425    If this routine is not called then the lower and upper bounds are set to
4426    PETSC_NINFINITY and PETSC_INFINITY respectively during SNESSetUp().
4427 
4428    Level: advanced
4429 
4430 @*/
4431 PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
4432 {
4433   PetscErrorCode ierr;
4434   SNES           snes;
4435 
4436   PetscFunctionBegin;
4437   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
4438   ierr = SNESVISetVariableBounds(snes,xl,xu);CHKERRQ(ierr);
4439   PetscFunctionReturn(0);
4440 }
4441 
4442 #if defined(PETSC_HAVE_MATLAB_ENGINE)
4443 #include <mex.h>
4444 
4445 typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;
4446 
4447 #undef __FUNCT__
4448 #define __FUNCT__ "TSComputeFunction_Matlab"
4449 /*
4450    TSComputeFunction_Matlab - Calls the function that has been set with
4451                          TSSetFunctionMatlab().
4452 
4453    Collective on TS
4454 
4455    Input Parameters:
4456 +  snes - the TS context
4457 -  u - input vector
4458 
4459    Output Parameter:
4460 .  y - function vector, as set by TSSetFunction()
4461 
4462    Notes:
4463    TSComputeFunction() is typically used within nonlinear solvers
4464    implementations, so most users would not generally call this routine
4465    themselves.
4466 
4467    Level: developer
4468 
4469 .keywords: TS, nonlinear, compute, function
4470 
4471 .seealso: TSSetFunction(), TSGetFunction()
4472 */
4473 PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
4474 {
4475   PetscErrorCode  ierr;
4476   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4477   int             nlhs  = 1,nrhs = 7;
4478   mxArray         *plhs[1],*prhs[7];
4479   long long int   lx = 0,lxdot = 0,ly = 0,ls = 0;
4480 
4481   PetscFunctionBegin;
4482   PetscValidHeaderSpecific(snes,TS_CLASSID,1);
4483   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4484   PetscValidHeaderSpecific(udot,VEC_CLASSID,4);
4485   PetscValidHeaderSpecific(y,VEC_CLASSID,5);
4486   PetscCheckSameComm(snes,1,u,3);
4487   PetscCheckSameComm(snes,1,y,5);
4488 
4489   ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr);
4490   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4491   ierr = PetscMemcpy(&lxdot,&udot,sizeof(udot));CHKERRQ(ierr);
4492   ierr = PetscMemcpy(&ly,&y,sizeof(u));CHKERRQ(ierr);
4493 
4494   prhs[0] =  mxCreateDoubleScalar((double)ls);
4495   prhs[1] =  mxCreateDoubleScalar(time);
4496   prhs[2] =  mxCreateDoubleScalar((double)lx);
4497   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4498   prhs[4] =  mxCreateDoubleScalar((double)ly);
4499   prhs[5] =  mxCreateString(sctx->funcname);
4500   prhs[6] =  sctx->ctx;
4501   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");CHKERRQ(ierr);
4502   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4503   mxDestroyArray(prhs[0]);
4504   mxDestroyArray(prhs[1]);
4505   mxDestroyArray(prhs[2]);
4506   mxDestroyArray(prhs[3]);
4507   mxDestroyArray(prhs[4]);
4508   mxDestroyArray(prhs[5]);
4509   mxDestroyArray(plhs[0]);
4510   PetscFunctionReturn(0);
4511 }
4512 
4513 
4514 #undef __FUNCT__
4515 #define __FUNCT__ "TSSetFunctionMatlab"
4516 /*
4517    TSSetFunctionMatlab - Sets the function evaluation routine and function
4518    vector for use by the TS routines in solving ODEs
4519    equations from MATLAB. Here the function is a string containing the name of a MATLAB function
4520 
4521    Logically Collective on TS
4522 
4523    Input Parameters:
4524 +  ts - the TS context
4525 -  func - function evaluation routine
4526 
4527    Calling sequence of func:
4528 $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);
4529 
4530    Level: beginner
4531 
4532 .keywords: TS, nonlinear, set, function
4533 
4534 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4535 */
4536 PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
4537 {
4538   PetscErrorCode  ierr;
4539   TSMatlabContext *sctx;
4540 
4541   PetscFunctionBegin;
4542   /* currently sctx is memory bleed */
4543   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4544   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4545   /*
4546      This should work, but it doesn't
4547   sctx->ctx = ctx;
4548   mexMakeArrayPersistent(sctx->ctx);
4549   */
4550   sctx->ctx = mxDuplicateArray(ctx);
4551 
4552   ierr = TSSetIFunction(ts,NULL,TSComputeFunction_Matlab,sctx);CHKERRQ(ierr);
4553   PetscFunctionReturn(0);
4554 }
4555 
4556 #undef __FUNCT__
4557 #define __FUNCT__ "TSComputeJacobian_Matlab"
4558 /*
4559    TSComputeJacobian_Matlab - Calls the function that has been set with
4560                          TSSetJacobianMatlab().
4561 
4562    Collective on TS
4563 
4564    Input Parameters:
4565 +  ts - the TS context
4566 .  u - input vector
4567 .  A, B - the matrices
4568 -  ctx - user context
4569 
4570    Level: developer
4571 
4572 .keywords: TS, nonlinear, compute, function
4573 
4574 .seealso: TSSetFunction(), TSGetFunction()
4575 @*/
4576 PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat A,Mat B,void *ctx)
4577 {
4578   PetscErrorCode  ierr;
4579   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4580   int             nlhs  = 2,nrhs = 9;
4581   mxArray         *plhs[2],*prhs[9];
4582   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;
4583 
4584   PetscFunctionBegin;
4585   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4586   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4587 
4588   /* call Matlab function in ctx with arguments u and y */
4589 
4590   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4591   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4592   ierr = PetscMemcpy(&lxdot,&udot,sizeof(u));CHKERRQ(ierr);
4593   ierr = PetscMemcpy(&lA,A,sizeof(u));CHKERRQ(ierr);
4594   ierr = PetscMemcpy(&lB,B,sizeof(u));CHKERRQ(ierr);
4595 
4596   prhs[0] =  mxCreateDoubleScalar((double)ls);
4597   prhs[1] =  mxCreateDoubleScalar((double)time);
4598   prhs[2] =  mxCreateDoubleScalar((double)lx);
4599   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4600   prhs[4] =  mxCreateDoubleScalar((double)shift);
4601   prhs[5] =  mxCreateDoubleScalar((double)lA);
4602   prhs[6] =  mxCreateDoubleScalar((double)lB);
4603   prhs[7] =  mxCreateString(sctx->funcname);
4604   prhs[8] =  sctx->ctx;
4605   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");CHKERRQ(ierr);
4606   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4607   mxDestroyArray(prhs[0]);
4608   mxDestroyArray(prhs[1]);
4609   mxDestroyArray(prhs[2]);
4610   mxDestroyArray(prhs[3]);
4611   mxDestroyArray(prhs[4]);
4612   mxDestroyArray(prhs[5]);
4613   mxDestroyArray(prhs[6]);
4614   mxDestroyArray(prhs[7]);
4615   mxDestroyArray(plhs[0]);
4616   mxDestroyArray(plhs[1]);
4617   PetscFunctionReturn(0);
4618 }
4619 
4620 
4621 #undef __FUNCT__
4622 #define __FUNCT__ "TSSetJacobianMatlab"
4623 /*
4624    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
4625    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
4626 
4627    Logically Collective on TS
4628 
4629    Input Parameters:
4630 +  ts - the TS context
4631 .  A,B - Jacobian matrices
4632 .  func - function evaluation routine
4633 -  ctx - user context
4634 
4635    Calling sequence of func:
4636 $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);
4637 
4638 
4639    Level: developer
4640 
4641 .keywords: TS, nonlinear, set, function
4642 
4643 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4644 */
4645 PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
4646 {
4647   PetscErrorCode  ierr;
4648   TSMatlabContext *sctx;
4649 
4650   PetscFunctionBegin;
4651   /* currently sctx is memory bleed */
4652   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4653   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4654   /*
4655      This should work, but it doesn't
4656   sctx->ctx = ctx;
4657   mexMakeArrayPersistent(sctx->ctx);
4658   */
4659   sctx->ctx = mxDuplicateArray(ctx);
4660 
4661   ierr = TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);CHKERRQ(ierr);
4662   PetscFunctionReturn(0);
4663 }
4664 
4665 #undef __FUNCT__
4666 #define __FUNCT__ "TSMonitor_Matlab"
4667 /*
4668    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().
4669 
4670    Collective on TS
4671 
4672 .seealso: TSSetFunction(), TSGetFunction()
4673 @*/
4674 PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
4675 {
4676   PetscErrorCode  ierr;
4677   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4678   int             nlhs  = 1,nrhs = 6;
4679   mxArray         *plhs[1],*prhs[6];
4680   long long int   lx = 0,ls = 0;
4681 
4682   PetscFunctionBegin;
4683   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4684   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
4685 
4686   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4687   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4688 
4689   prhs[0] =  mxCreateDoubleScalar((double)ls);
4690   prhs[1] =  mxCreateDoubleScalar((double)it);
4691   prhs[2] =  mxCreateDoubleScalar((double)time);
4692   prhs[3] =  mxCreateDoubleScalar((double)lx);
4693   prhs[4] =  mxCreateString(sctx->funcname);
4694   prhs[5] =  sctx->ctx;
4695   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");CHKERRQ(ierr);
4696   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4697   mxDestroyArray(prhs[0]);
4698   mxDestroyArray(prhs[1]);
4699   mxDestroyArray(prhs[2]);
4700   mxDestroyArray(prhs[3]);
4701   mxDestroyArray(prhs[4]);
4702   mxDestroyArray(plhs[0]);
4703   PetscFunctionReturn(0);
4704 }
4705 
4706 
4707 #undef __FUNCT__
4708 #define __FUNCT__ "TSMonitorSetMatlab"
4709 /*
4710    TSMonitorSetMatlab - Sets the monitor function from Matlab
4711 
4712    Level: developer
4713 
4714 .keywords: TS, nonlinear, set, function
4715 
4716 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4717 */
4718 PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
4719 {
4720   PetscErrorCode  ierr;
4721   TSMatlabContext *sctx;
4722 
4723   PetscFunctionBegin;
4724   /* currently sctx is memory bleed */
4725   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4726   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4727   /*
4728      This should work, but it doesn't
4729   sctx->ctx = ctx;
4730   mexMakeArrayPersistent(sctx->ctx);
4731   */
4732   sctx->ctx = mxDuplicateArray(ctx);
4733 
4734   ierr = TSMonitorSet(ts,TSMonitor_Matlab,sctx,NULL);CHKERRQ(ierr);
4735   PetscFunctionReturn(0);
4736 }
4737 #endif
4738 
4739 
4740 
4741 #undef __FUNCT__
4742 #define __FUNCT__ "TSMonitorLGSolution"
4743 /*@C
4744    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
4745        in a time based line graph
4746 
4747    Collective on TS
4748 
4749    Input Parameters:
4750 +  ts - the TS context
4751 .  step - current time-step
4752 .  ptime - current time
4753 -  lg - a line graph object
4754 
4755    Level: intermediate
4756 
4757     Notes: each process in a parallel run displays its component solutions in a separate window
4758 
4759 .keywords: TS,  vector, monitor, view
4760 
4761 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4762 @*/
4763 PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4764 {
4765   PetscErrorCode    ierr;
4766   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4767   const PetscScalar *yy;
4768   PetscInt          dim;
4769 
4770   PetscFunctionBegin;
4771   if (!step) {
4772     PetscDrawAxis axis;
4773     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4774     ierr = PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");CHKERRQ(ierr);
4775     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4776     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4777     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4778   }
4779   ierr = VecGetArrayRead(u,&yy);CHKERRQ(ierr);
4780 #if defined(PETSC_USE_COMPLEX)
4781   {
4782     PetscReal *yreal;
4783     PetscInt  i,n;
4784     ierr = VecGetLocalSize(u,&n);CHKERRQ(ierr);
4785     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4786     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4787     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4788     ierr = PetscFree(yreal);CHKERRQ(ierr);
4789   }
4790 #else
4791   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4792 #endif
4793   ierr = VecRestoreArrayRead(u,&yy);CHKERRQ(ierr);
4794   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4795     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4796   }
4797   PetscFunctionReturn(0);
4798 }
4799 
4800 #undef __FUNCT__
4801 #define __FUNCT__ "TSMonitorLGError"
4802 /*@C
4803    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
4804        in a time based line graph
4805 
4806    Collective on TS
4807 
4808    Input Parameters:
4809 +  ts - the TS context
4810 .  step - current time-step
4811 .  ptime - current time
4812 -  lg - a line graph object
4813 
4814    Level: intermediate
4815 
4816    Notes:
4817    Only for sequential solves.
4818 
4819    The user must provide the solution using TSSetSolutionFunction() to use this monitor.
4820 
4821    Options Database Keys:
4822 .  -ts_monitor_lg_error - create a graphical monitor of error history
4823 
4824 .keywords: TS,  vector, monitor, view
4825 
4826 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
4827 @*/
4828 PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4829 {
4830   PetscErrorCode    ierr;
4831   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4832   const PetscScalar *yy;
4833   Vec               y;
4834   PetscInt          dim;
4835 
4836   PetscFunctionBegin;
4837   if (!step) {
4838     PetscDrawAxis axis;
4839     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4840     ierr = PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");CHKERRQ(ierr);
4841     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4842     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4843     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4844   }
4845   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
4846   ierr = TSComputeSolutionFunction(ts,ptime,y);CHKERRQ(ierr);
4847   ierr = VecAXPY(y,-1.0,u);CHKERRQ(ierr);
4848   ierr = VecGetArrayRead(y,&yy);CHKERRQ(ierr);
4849 #if defined(PETSC_USE_COMPLEX)
4850   {
4851     PetscReal *yreal;
4852     PetscInt  i,n;
4853     ierr = VecGetLocalSize(y,&n);CHKERRQ(ierr);
4854     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4855     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4856     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4857     ierr = PetscFree(yreal);CHKERRQ(ierr);
4858   }
4859 #else
4860   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4861 #endif
4862   ierr = VecRestoreArrayRead(y,&yy);CHKERRQ(ierr);
4863   ierr = VecDestroy(&y);CHKERRQ(ierr);
4864   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4865     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4866   }
4867   PetscFunctionReturn(0);
4868 }
4869 
4870 #undef __FUNCT__
4871 #define __FUNCT__ "TSMonitorLGSNESIterations"
4872 PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4873 {
4874   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4875   PetscReal      x   = ptime,y;
4876   PetscErrorCode ierr;
4877   PetscInt       its;
4878 
4879   PetscFunctionBegin;
4880   if (!n) {
4881     PetscDrawAxis axis;
4882 
4883     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4884     ierr = PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");CHKERRQ(ierr);
4885     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4886 
4887     ctx->snes_its = 0;
4888   }
4889   ierr = TSGetSNESIterations(ts,&its);CHKERRQ(ierr);
4890   y    = its - ctx->snes_its;
4891   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4892   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4893     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4894   }
4895   ctx->snes_its = its;
4896   PetscFunctionReturn(0);
4897 }
4898 
4899 #undef __FUNCT__
4900 #define __FUNCT__ "TSMonitorLGKSPIterations"
4901 PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4902 {
4903   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4904   PetscReal      x   = ptime,y;
4905   PetscErrorCode ierr;
4906   PetscInt       its;
4907 
4908   PetscFunctionBegin;
4909   if (!n) {
4910     PetscDrawAxis axis;
4911 
4912     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4913     ierr = PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");CHKERRQ(ierr);
4914     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4915 
4916     ctx->ksp_its = 0;
4917   }
4918   ierr = TSGetKSPIterations(ts,&its);CHKERRQ(ierr);
4919   y    = its - ctx->ksp_its;
4920   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4921   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4922     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4923   }
4924   ctx->ksp_its = its;
4925   PetscFunctionReturn(0);
4926 }
4927 
4928 #undef __FUNCT__
4929 #define __FUNCT__ "TSComputeLinearStability"
4930 /*@
4931    TSComputeLinearStability - computes the linear stability function at a point
4932 
4933    Collective on TS and Vec
4934 
4935    Input Parameters:
4936 +  ts - the TS context
4937 -  xr,xi - real and imaginary part of input arguments
4938 
4939    Output Parameters:
4940 .  yr,yi - real and imaginary part of function value
4941 
4942    Level: developer
4943 
4944 .keywords: TS, compute
4945 
4946 .seealso: TSSetRHSFunction(), TSComputeIFunction()
4947 @*/
4948 PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
4949 {
4950   PetscErrorCode ierr;
4951 
4952   PetscFunctionBegin;
4953   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4954   if (!ts->ops->linearstability) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"Linearized stability function not provided for this method");
4955   ierr = (*ts->ops->linearstability)(ts,xr,xi,yr,yi);CHKERRQ(ierr);
4956   PetscFunctionReturn(0);
4957 }
4958 
4959 #undef __FUNCT__
4960 #define __FUNCT__ "TSRollBack"
4961 /*@
4962    TSRollBack - Rolls back one time step
4963 
4964    Collective on TS
4965 
4966    Input Parameter:
4967 .  ts - the TS context obtained from TSCreate()
4968 
4969    Level: advanced
4970 
4971 .keywords: TS, timestep, rollback
4972 
4973 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSInterpolate()
4974 @*/
4975 PetscErrorCode  TSRollBack(TS ts)
4976 {
4977   PetscErrorCode ierr;
4978 
4979   PetscFunctionBegin;
4980   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
4981 
4982   if (!ts->ops->rollback) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSRollBack not implemented for type '%s'",((PetscObject)ts)->type_name);
4983   ierr = (*ts->ops->rollback)(ts);CHKERRQ(ierr);
4984   ts->time_step = ts->ptime - ts->ptime_prev;
4985   ts->ptime = ts->ptime_prev;
4986   PetscFunctionReturn(0);
4987 }
4988 
4989