xref: /petsc/src/ts/interface/ts.c (revision 48c19aef3ec706a6e55cfad78edf49c6be5514da)
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->poststage) {
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 if (ts->reason == TS_DIVERGED_STEP_REJECTED) {
2639         SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s, increase -ts_max_reject or make negative to attempt recovery",TSConvergedReasons[ts->reason]);
2640       } else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s",TSConvergedReasons[ts->reason]);
2641     }
2642   } else if (!ts->reason) {
2643     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2644     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2645   }
2646   PetscFunctionReturn(0);
2647 }
2648 
2649 #undef __FUNCT__
2650 #define __FUNCT__ "TSEvaluateStep"
2651 /*@
2652    TSEvaluateStep - Evaluate the solution at the end of a time step with a given order of accuracy.
2653 
2654    Collective on TS
2655 
2656    Input Arguments:
2657 +  ts - time stepping context
2658 .  order - desired order of accuracy
2659 -  done - whether the step was evaluated at this order (pass NULL to generate an error if not available)
2660 
2661    Output Arguments:
2662 .  U - state at the end of the current step
2663 
2664    Level: advanced
2665 
2666    Notes:
2667    This function cannot be called until all stages have been evaluated.
2668    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.
2669 
2670 .seealso: TSStep(), TSAdapt
2671 @*/
2672 PetscErrorCode TSEvaluateStep(TS ts,PetscInt order,Vec U,PetscBool *done)
2673 {
2674   PetscErrorCode ierr;
2675 
2676   PetscFunctionBegin;
2677   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2678   PetscValidType(ts,1);
2679   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2680   if (!ts->ops->evaluatestep) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSEvaluateStep not implemented for type '%s'",((PetscObject)ts)->type_name);
2681   ierr = (*ts->ops->evaluatestep)(ts,order,U,done);CHKERRQ(ierr);
2682   PetscFunctionReturn(0);
2683 }
2684 
2685 #undef __FUNCT__
2686 #define __FUNCT__ "TSSolve"
2687 /*@
2688    TSSolve - Steps the requested number of timesteps.
2689 
2690    Collective on TS
2691 
2692    Input Parameter:
2693 +  ts - the TS context obtained from TSCreate()
2694 -  u - the solution vector  (can be null if TSSetSolution() was used, otherwise must contain the initial conditions)
2695 
2696    Level: beginner
2697 
2698    Notes:
2699    The final time returned by this function may be different from the time of the internally
2700    held state accessible by TSGetSolution() and TSGetTime() because the method may have
2701    stepped over the final time.
2702 
2703 .keywords: TS, timestep, solve
2704 
2705 .seealso: TSCreate(), TSSetSolution(), TSStep()
2706 @*/
2707 PetscErrorCode TSSolve(TS ts,Vec u)
2708 {
2709   Vec               solution;
2710   PetscErrorCode    ierr;
2711 
2712   PetscFunctionBegin;
2713   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2714   if (u) PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2715   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 */
2716     PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2717     if (!ts->vec_sol || u == ts->vec_sol) {
2718       ierr = VecDuplicate(u,&solution);CHKERRQ(ierr);
2719       ierr = TSSetSolution(ts,solution);CHKERRQ(ierr);
2720       ierr = VecDestroy(&solution);CHKERRQ(ierr); /* grant ownership */
2721     }
2722     ierr = VecCopy(u,ts->vec_sol);CHKERRQ(ierr);
2723   } else if (u) {
2724     ierr = TSSetSolution(ts,u);CHKERRQ(ierr);
2725   }
2726   ierr = TSSetUp(ts);CHKERRQ(ierr);
2727   /* reset time step and iteration counters */
2728   ts->steps             = 0;
2729   ts->ksp_its           = 0;
2730   ts->snes_its          = 0;
2731   ts->num_snes_failures = 0;
2732   ts->reject            = 0;
2733   ts->reason            = TS_CONVERGED_ITERATING;
2734 
2735   ierr = TSViewFromOptions(ts,NULL,"-ts_view_pre");CHKERRQ(ierr);
2736 
2737   if (ts->ops->solve) {         /* This private interface is transitional and should be removed when all implementations are updated. */
2738     ierr = (*ts->ops->solve)(ts);CHKERRQ(ierr);
2739     ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);
2740     ts->solvetime = ts->ptime;
2741   } else {
2742     /* steps the requested number of timesteps. */
2743     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2744     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2745     while (!ts->reason) {
2746       ierr = TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
2747       ierr = TSStep(ts);CHKERRQ(ierr);
2748       if (ts->event) {
2749 	ierr = TSEventMonitor(ts);CHKERRQ(ierr);
2750 	if (ts->event->status != TSEVENT_PROCESSING) {
2751 	  ierr = TSPostStep(ts);CHKERRQ(ierr);
2752 	}
2753       } else {
2754 	ierr = TSPostStep(ts);CHKERRQ(ierr);
2755       }
2756     }
2757     if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE && ts->ptime > ts->max_time) {
2758       ierr = TSInterpolate(ts,ts->max_time,u);CHKERRQ(ierr);
2759       ts->solvetime = ts->max_time;
2760       solution = u;
2761     } else {
2762       if (u) {ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);}
2763       ts->solvetime = ts->ptime;
2764       solution = ts->vec_sol;
2765     }
2766     ierr = TSMonitor(ts,ts->steps,ts->solvetime,solution);CHKERRQ(ierr);
2767     ierr = VecViewFromOptions(u, ((PetscObject) ts)->prefix, "-ts_view_solution");CHKERRQ(ierr);
2768   }
2769   ierr = TSViewFromOptions(ts,NULL,"-ts_view");CHKERRQ(ierr);
2770   ierr = PetscObjectSAWsBlock((PetscObject)ts);CHKERRQ(ierr);
2771   PetscFunctionReturn(0);
2772 }
2773 
2774 #undef __FUNCT__
2775 #define __FUNCT__ "TSMonitor"
2776 /*@
2777    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()
2778 
2779    Collective on TS
2780 
2781    Input Parameters:
2782 +  ts - time stepping context obtained from TSCreate()
2783 .  step - step number that has just completed
2784 .  ptime - model time of the state
2785 -  u - state at the current model time
2786 
2787    Notes:
2788    TSMonitor() is typically used within the time stepping implementations.
2789    Users might call this function when using the TSStep() interface instead of TSSolve().
2790 
2791    Level: advanced
2792 
2793 .keywords: TS, timestep
2794 @*/
2795 PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
2796 {
2797   PetscErrorCode ierr;
2798   PetscInt       i,n = ts->numbermonitors;
2799 
2800   PetscFunctionBegin;
2801   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2802   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
2803   for (i=0; i<n; i++) {
2804     ierr = (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);CHKERRQ(ierr);
2805   }
2806   PetscFunctionReturn(0);
2807 }
2808 
2809 /* ------------------------------------------------------------------------*/
2810 #undef __FUNCT__
2811 #define __FUNCT__ "TSMonitorLGCtxCreate"
2812 /*@C
2813    TSMonitorLGCtxCreate - Creates a line graph context for use with
2814    TS to monitor the solution process graphically in various ways
2815 
2816    Collective on TS
2817 
2818    Input Parameters:
2819 +  host - the X display to open, or null for the local machine
2820 .  label - the title to put in the title bar
2821 .  x, y - the screen coordinates of the upper left coordinate of the window
2822 .  m, n - the screen width and height in pixels
2823 -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time
2824 
2825    Output Parameter:
2826 .  ctx - the context
2827 
2828    Options Database Key:
2829 +  -ts_monitor_lg_timestep - automatically sets line graph monitor
2830 .  -ts_monitor_lg_solution -
2831 .  -ts_monitor_lg_error -
2832 .  -ts_monitor_lg_ksp_iterations -
2833 .  -ts_monitor_lg_snes_iterations -
2834 -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true
2835 
2836    Notes:
2837    Use TSMonitorLGCtxDestroy() to destroy.
2838 
2839    Level: intermediate
2840 
2841 .keywords: TS, monitor, line graph, residual, seealso
2842 
2843 .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()
2844 
2845 @*/
2846 PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
2847 {
2848   PetscDraw      win;
2849   PetscErrorCode ierr;
2850 
2851   PetscFunctionBegin;
2852   ierr = PetscNew(ctx);CHKERRQ(ierr);
2853   ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr);
2854   ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr);
2855   ierr = PetscDrawLGCreate(win,1,&(*ctx)->lg);CHKERRQ(ierr);
2856   ierr = PetscLogObjectParent((PetscObject)(*ctx)->lg,(PetscObject)win);CHKERRQ(ierr);
2857   ierr = PetscDrawLGIndicateDataPoints((*ctx)->lg,PETSC_TRUE);CHKERRQ(ierr);
2858   ierr = PetscDrawLGSetFromOptions((*ctx)->lg);CHKERRQ(ierr);
2859   (*ctx)->howoften = howoften;
2860   PetscFunctionReturn(0);
2861 }
2862 
2863 #undef __FUNCT__
2864 #define __FUNCT__ "TSMonitorLGTimeStep"
2865 PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx)
2866 {
2867   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
2868   PetscReal      x   = ptime,y;
2869   PetscErrorCode ierr;
2870 
2871   PetscFunctionBegin;
2872   if (!step) {
2873     PetscDrawAxis axis;
2874     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
2875     ierr = PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");CHKERRQ(ierr);
2876     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
2877     ierr = PetscDrawLGIndicateDataPoints(ctx->lg,PETSC_TRUE);CHKERRQ(ierr);
2878   }
2879   ierr = TSGetTimeStep(ts,&y);CHKERRQ(ierr);
2880   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
2881   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
2882     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
2883   }
2884   PetscFunctionReturn(0);
2885 }
2886 
2887 #undef __FUNCT__
2888 #define __FUNCT__ "TSMonitorLGCtxDestroy"
2889 /*@C
2890    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
2891    with TSMonitorLGCtxCreate().
2892 
2893    Collective on TSMonitorLGCtx
2894 
2895    Input Parameter:
2896 .  ctx - the monitor context
2897 
2898    Level: intermediate
2899 
2900 .keywords: TS, monitor, line graph, destroy
2901 
2902 .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
2903 @*/
2904 PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
2905 {
2906   PetscDraw      draw;
2907   PetscErrorCode ierr;
2908 
2909   PetscFunctionBegin;
2910   ierr = PetscDrawLGGetDraw((*ctx)->lg,&draw);CHKERRQ(ierr);
2911   ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
2912   ierr = PetscDrawLGDestroy(&(*ctx)->lg);CHKERRQ(ierr);
2913   ierr = PetscFree(*ctx);CHKERRQ(ierr);
2914   PetscFunctionReturn(0);
2915 }
2916 
2917 #undef __FUNCT__
2918 #define __FUNCT__ "TSGetTime"
2919 /*@
2920    TSGetTime - Gets the time of the most recently completed step.
2921 
2922    Not Collective
2923 
2924    Input Parameter:
2925 .  ts - the TS context obtained from TSCreate()
2926 
2927    Output Parameter:
2928 .  t  - the current time
2929 
2930    Level: beginner
2931 
2932    Note:
2933    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
2934    TSSetPreStage(), TSSetPostStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.
2935 
2936 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
2937 
2938 .keywords: TS, get, time
2939 @*/
2940 PetscErrorCode  TSGetTime(TS ts,PetscReal *t)
2941 {
2942   PetscFunctionBegin;
2943   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2944   PetscValidRealPointer(t,2);
2945   *t = ts->ptime;
2946   PetscFunctionReturn(0);
2947 }
2948 
2949 #undef __FUNCT__
2950 #define __FUNCT__ "TSSetTime"
2951 /*@
2952    TSSetTime - Allows one to reset the time.
2953 
2954    Logically Collective on TS
2955 
2956    Input Parameters:
2957 +  ts - the TS context obtained from TSCreate()
2958 -  time - the time
2959 
2960    Level: intermediate
2961 
2962 .seealso: TSGetTime(), TSSetDuration()
2963 
2964 .keywords: TS, set, time
2965 @*/
2966 PetscErrorCode  TSSetTime(TS ts, PetscReal t)
2967 {
2968   PetscFunctionBegin;
2969   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2970   PetscValidLogicalCollectiveReal(ts,t,2);
2971   ts->ptime = t;
2972   PetscFunctionReturn(0);
2973 }
2974 
2975 #undef __FUNCT__
2976 #define __FUNCT__ "TSSetOptionsPrefix"
2977 /*@C
2978    TSSetOptionsPrefix - Sets the prefix used for searching for all
2979    TS options in the database.
2980 
2981    Logically Collective on TS
2982 
2983    Input Parameter:
2984 +  ts     - The TS context
2985 -  prefix - The prefix to prepend to all option names
2986 
2987    Notes:
2988    A hyphen (-) must NOT be given at the beginning of the prefix name.
2989    The first character of all runtime options is AUTOMATICALLY the
2990    hyphen.
2991 
2992    Level: advanced
2993 
2994 .keywords: TS, set, options, prefix, database
2995 
2996 .seealso: TSSetFromOptions()
2997 
2998 @*/
2999 PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
3000 {
3001   PetscErrorCode ierr;
3002   SNES           snes;
3003 
3004   PetscFunctionBegin;
3005   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3006   ierr = PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3007   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3008   ierr = SNESSetOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3009   PetscFunctionReturn(0);
3010 }
3011 
3012 
3013 #undef __FUNCT__
3014 #define __FUNCT__ "TSAppendOptionsPrefix"
3015 /*@C
3016    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
3017    TS options in the database.
3018 
3019    Logically Collective on TS
3020 
3021    Input Parameter:
3022 +  ts     - The TS context
3023 -  prefix - The prefix to prepend to all option names
3024 
3025    Notes:
3026    A hyphen (-) must NOT be given at the beginning of the prefix name.
3027    The first character of all runtime options is AUTOMATICALLY the
3028    hyphen.
3029 
3030    Level: advanced
3031 
3032 .keywords: TS, append, options, prefix, database
3033 
3034 .seealso: TSGetOptionsPrefix()
3035 
3036 @*/
3037 PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
3038 {
3039   PetscErrorCode ierr;
3040   SNES           snes;
3041 
3042   PetscFunctionBegin;
3043   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3044   ierr = PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3045   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3046   ierr = SNESAppendOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3047   PetscFunctionReturn(0);
3048 }
3049 
3050 #undef __FUNCT__
3051 #define __FUNCT__ "TSGetOptionsPrefix"
3052 /*@C
3053    TSGetOptionsPrefix - Sets the prefix used for searching for all
3054    TS options in the database.
3055 
3056    Not Collective
3057 
3058    Input Parameter:
3059 .  ts - The TS context
3060 
3061    Output Parameter:
3062 .  prefix - A pointer to the prefix string used
3063 
3064    Notes: On the fortran side, the user should pass in a string 'prifix' of
3065    sufficient length to hold the prefix.
3066 
3067    Level: intermediate
3068 
3069 .keywords: TS, get, options, prefix, database
3070 
3071 .seealso: TSAppendOptionsPrefix()
3072 @*/
3073 PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
3074 {
3075   PetscErrorCode ierr;
3076 
3077   PetscFunctionBegin;
3078   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3079   PetscValidPointer(prefix,2);
3080   ierr = PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3081   PetscFunctionReturn(0);
3082 }
3083 
3084 #undef __FUNCT__
3085 #define __FUNCT__ "TSGetRHSJacobian"
3086 /*@C
3087    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.
3088 
3089    Not Collective, but parallel objects are returned if TS is parallel
3090 
3091    Input Parameter:
3092 .  ts  - The TS context obtained from TSCreate()
3093 
3094    Output Parameters:
3095 +  Amat - The (approximate) Jacobian J of G, where U_t = G(U,t)  (or NULL)
3096 .  Pmat - The matrix from which the preconditioner is constructed, usually the same as Amat  (or NULL)
3097 .  func - Function to compute the Jacobian of the RHS  (or NULL)
3098 -  ctx - User-defined context for Jacobian evaluation routine  (or NULL)
3099 
3100    Notes: You can pass in NULL for any return argument you do not need.
3101 
3102    Level: intermediate
3103 
3104 .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3105 
3106 .keywords: TS, timestep, get, matrix, Jacobian
3107 @*/
3108 PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *Amat,Mat *Pmat,TSRHSJacobian *func,void **ctx)
3109 {
3110   PetscErrorCode ierr;
3111   SNES           snes;
3112   DM             dm;
3113 
3114   PetscFunctionBegin;
3115   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3116   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3117   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3118   ierr = DMTSGetRHSJacobian(dm,func,ctx);CHKERRQ(ierr);
3119   PetscFunctionReturn(0);
3120 }
3121 
3122 #undef __FUNCT__
3123 #define __FUNCT__ "TSGetIJacobian"
3124 /*@C
3125    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.
3126 
3127    Not Collective, but parallel objects are returned if TS is parallel
3128 
3129    Input Parameter:
3130 .  ts  - The TS context obtained from TSCreate()
3131 
3132    Output Parameters:
3133 +  Amat  - The (approximate) Jacobian of F(t,U,U_t)
3134 .  Pmat - The matrix from which the preconditioner is constructed, often the same as Amat
3135 .  f   - The function to compute the matrices
3136 - ctx - User-defined context for Jacobian evaluation routine
3137 
3138    Notes: You can pass in NULL for any return argument you do not need.
3139 
3140    Level: advanced
3141 
3142 .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3143 
3144 .keywords: TS, timestep, get, matrix, Jacobian
3145 @*/
3146 PetscErrorCode  TSGetIJacobian(TS ts,Mat *Amat,Mat *Pmat,TSIJacobian *f,void **ctx)
3147 {
3148   PetscErrorCode ierr;
3149   SNES           snes;
3150   DM             dm;
3151 
3152   PetscFunctionBegin;
3153   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3154   ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
3155   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3156   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3157   ierr = DMTSGetIJacobian(dm,f,ctx);CHKERRQ(ierr);
3158   PetscFunctionReturn(0);
3159 }
3160 
3161 
3162 #undef __FUNCT__
3163 #define __FUNCT__ "TSMonitorDrawSolution"
3164 /*@C
3165    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
3166    VecView() for the solution at each timestep
3167 
3168    Collective on TS
3169 
3170    Input Parameters:
3171 +  ts - the TS context
3172 .  step - current time-step
3173 .  ptime - current time
3174 -  dummy - either a viewer or NULL
3175 
3176    Options Database:
3177 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3178 
3179    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
3180        will look bad
3181 
3182    Level: intermediate
3183 
3184 .keywords: TS,  vector, monitor, view
3185 
3186 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3187 @*/
3188 PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3189 {
3190   PetscErrorCode   ierr;
3191   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
3192   PetscDraw        draw;
3193 
3194   PetscFunctionBegin;
3195   if (!step && ictx->showinitial) {
3196     if (!ictx->initialsolution) {
3197       ierr = VecDuplicate(u,&ictx->initialsolution);CHKERRQ(ierr);
3198     }
3199     ierr = VecCopy(u,ictx->initialsolution);CHKERRQ(ierr);
3200   }
3201   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften))) || ((ictx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3202 
3203   if (ictx->showinitial) {
3204     PetscReal pause;
3205     ierr = PetscViewerDrawGetPause(ictx->viewer,&pause);CHKERRQ(ierr);
3206     ierr = PetscViewerDrawSetPause(ictx->viewer,0.0);CHKERRQ(ierr);
3207     ierr = VecView(ictx->initialsolution,ictx->viewer);CHKERRQ(ierr);
3208     ierr = PetscViewerDrawSetPause(ictx->viewer,pause);CHKERRQ(ierr);
3209     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);CHKERRQ(ierr);
3210   }
3211   ierr = VecView(u,ictx->viewer);CHKERRQ(ierr);
3212   if (ictx->showtimestepandtime) {
3213     PetscReal xl,yl,xr,yr,tw,w,h;
3214     char      time[32];
3215     size_t    len;
3216 
3217     ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3218     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3219     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3220     ierr =  PetscStrlen(time,&len);CHKERRQ(ierr);
3221     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3222     w    = xl + .5*(xr - xl) - .5*len*tw;
3223     h    = yl + .95*(yr - yl);
3224     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3225     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3226   }
3227 
3228   if (ictx->showinitial) {
3229     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);CHKERRQ(ierr);
3230   }
3231   PetscFunctionReturn(0);
3232 }
3233 
3234 #undef __FUNCT__
3235 #define __FUNCT__ "TSMonitorDrawSolutionPhase"
3236 /*@C
3237    TSMonitorDrawSolutionPhase - Monitors progress of the TS solvers by plotting the solution as a phase diagram
3238 
3239    Collective on TS
3240 
3241    Input Parameters:
3242 +  ts - the TS context
3243 .  step - current time-step
3244 .  ptime - current time
3245 -  dummy - either a viewer or NULL
3246 
3247    Level: intermediate
3248 
3249 .keywords: TS,  vector, monitor, view
3250 
3251 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3252 @*/
3253 PetscErrorCode  TSMonitorDrawSolutionPhase(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3254 {
3255   PetscErrorCode    ierr;
3256   TSMonitorDrawCtx  ictx = (TSMonitorDrawCtx)dummy;
3257   PetscDraw         draw;
3258   MPI_Comm          comm;
3259   PetscInt          n;
3260   PetscMPIInt       size;
3261   PetscReal         xl,yl,xr,yr,tw,w,h;
3262   char              time[32];
3263   size_t            len;
3264   const PetscScalar *U;
3265 
3266   PetscFunctionBegin;
3267   ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
3268   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3269   if (size != 1) SETERRQ(comm,PETSC_ERR_SUP,"Only allowed for sequential runs");
3270   ierr = VecGetSize(u,&n);CHKERRQ(ierr);
3271   if (n != 2) SETERRQ(comm,PETSC_ERR_SUP,"Only for ODEs with two unknowns");
3272 
3273   ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3274 
3275   ierr = VecGetArrayRead(u,&U);CHKERRQ(ierr);
3276   ierr = PetscDrawAxisGetLimits(ictx->axis,&xl,&xr,&yl,&yr);CHKERRQ(ierr);
3277   if ((PetscRealPart(U[0]) < xl) || (PetscRealPart(U[1]) < yl) || (PetscRealPart(U[0]) > xr) || (PetscRealPart(U[1]) > yr)) {
3278       ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3279       PetscFunctionReturn(0);
3280   }
3281   if (!step) ictx->color++;
3282   ierr = PetscDrawPoint(draw,PetscRealPart(U[0]),PetscRealPart(U[1]),ictx->color);CHKERRQ(ierr);
3283   ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3284 
3285   if (ictx->showtimestepandtime) {
3286     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3287     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3288     ierr = PetscStrlen(time,&len);CHKERRQ(ierr);
3289     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3290     w    = xl + .5*(xr - xl) - .5*len*tw;
3291     h    = yl + .95*(yr - yl);
3292     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3293   }
3294   ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3295   PetscFunctionReturn(0);
3296 }
3297 
3298 
3299 #undef __FUNCT__
3300 #define __FUNCT__ "TSMonitorDrawCtxDestroy"
3301 /*@C
3302    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()
3303 
3304    Collective on TS
3305 
3306    Input Parameters:
3307 .    ctx - the monitor context
3308 
3309    Level: intermediate
3310 
3311 .keywords: TS,  vector, monitor, view
3312 
3313 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
3314 @*/
3315 PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
3316 {
3317   PetscErrorCode ierr;
3318 
3319   PetscFunctionBegin;
3320   ierr = PetscDrawAxisDestroy(&(*ictx)->axis);CHKERRQ(ierr);
3321   ierr = PetscViewerDestroy(&(*ictx)->viewer);CHKERRQ(ierr);
3322   ierr = VecDestroy(&(*ictx)->initialsolution);CHKERRQ(ierr);
3323   ierr = PetscFree(*ictx);CHKERRQ(ierr);
3324   PetscFunctionReturn(0);
3325 }
3326 
3327 #undef __FUNCT__
3328 #define __FUNCT__ "TSMonitorDrawCtxCreate"
3329 /*@C
3330    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx
3331 
3332    Collective on TS
3333 
3334    Input Parameter:
3335 .    ts - time-step context
3336 
3337    Output Patameter:
3338 .    ctx - the monitor context
3339 
3340    Options Database:
3341 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3342 
3343    Level: intermediate
3344 
3345 .keywords: TS,  vector, monitor, view
3346 
3347 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
3348 @*/
3349 PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
3350 {
3351   PetscErrorCode   ierr;
3352 
3353   PetscFunctionBegin;
3354   ierr = PetscNew(ctx);CHKERRQ(ierr);
3355   ierr = PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);CHKERRQ(ierr);
3356   ierr = PetscViewerSetFromOptions((*ctx)->viewer);CHKERRQ(ierr);
3357 
3358   (*ctx)->howoften    = howoften;
3359   (*ctx)->showinitial = PETSC_FALSE;
3360   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,NULL);CHKERRQ(ierr);
3361 
3362   (*ctx)->showtimestepandtime = PETSC_FALSE;
3363   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_show_time",&(*ctx)->showtimestepandtime,NULL);CHKERRQ(ierr);
3364   (*ctx)->color = PETSC_DRAW_WHITE;
3365   PetscFunctionReturn(0);
3366 }
3367 
3368 #undef __FUNCT__
3369 #define __FUNCT__ "TSMonitorDrawError"
3370 /*@C
3371    TSMonitorDrawError - Monitors progress of the TS solvers by calling
3372    VecView() for the error at each timestep
3373 
3374    Collective on TS
3375 
3376    Input Parameters:
3377 +  ts - the TS context
3378 .  step - current time-step
3379 .  ptime - current time
3380 -  dummy - either a viewer or NULL
3381 
3382    Level: intermediate
3383 
3384 .keywords: TS,  vector, monitor, view
3385 
3386 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3387 @*/
3388 PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3389 {
3390   PetscErrorCode   ierr;
3391   TSMonitorDrawCtx ctx    = (TSMonitorDrawCtx)dummy;
3392   PetscViewer      viewer = ctx->viewer;
3393   Vec              work;
3394 
3395   PetscFunctionBegin;
3396   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3397   ierr = VecDuplicate(u,&work);CHKERRQ(ierr);
3398   ierr = TSComputeSolutionFunction(ts,ptime,work);CHKERRQ(ierr);
3399   ierr = VecAXPY(work,-1.0,u);CHKERRQ(ierr);
3400   ierr = VecView(work,viewer);CHKERRQ(ierr);
3401   ierr = VecDestroy(&work);CHKERRQ(ierr);
3402   PetscFunctionReturn(0);
3403 }
3404 
3405 #include <petsc-private/dmimpl.h>
3406 #undef __FUNCT__
3407 #define __FUNCT__ "TSSetDM"
3408 /*@
3409    TSSetDM - Sets the DM that may be used by some preconditioners
3410 
3411    Logically Collective on TS and DM
3412 
3413    Input Parameters:
3414 +  ts - the preconditioner context
3415 -  dm - the dm
3416 
3417    Level: intermediate
3418 
3419 
3420 .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
3421 @*/
3422 PetscErrorCode  TSSetDM(TS ts,DM dm)
3423 {
3424   PetscErrorCode ierr;
3425   SNES           snes;
3426   DMTS           tsdm;
3427 
3428   PetscFunctionBegin;
3429   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3430   ierr = PetscObjectReference((PetscObject)dm);CHKERRQ(ierr);
3431   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
3432     if (ts->dm->dmts && !dm->dmts) {
3433       ierr = DMCopyDMTS(ts->dm,dm);CHKERRQ(ierr);
3434       ierr = DMGetDMTS(ts->dm,&tsdm);CHKERRQ(ierr);
3435       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
3436         tsdm->originaldm = dm;
3437       }
3438     }
3439     ierr = DMDestroy(&ts->dm);CHKERRQ(ierr);
3440   }
3441   ts->dm = dm;
3442 
3443   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3444   ierr = SNESSetDM(snes,dm);CHKERRQ(ierr);
3445   PetscFunctionReturn(0);
3446 }
3447 
3448 #undef __FUNCT__
3449 #define __FUNCT__ "TSGetDM"
3450 /*@
3451    TSGetDM - Gets the DM that may be used by some preconditioners
3452 
3453    Not Collective
3454 
3455    Input Parameter:
3456 . ts - the preconditioner context
3457 
3458    Output Parameter:
3459 .  dm - the dm
3460 
3461    Level: intermediate
3462 
3463 
3464 .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
3465 @*/
3466 PetscErrorCode  TSGetDM(TS ts,DM *dm)
3467 {
3468   PetscErrorCode ierr;
3469 
3470   PetscFunctionBegin;
3471   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3472   if (!ts->dm) {
3473     ierr = DMShellCreate(PetscObjectComm((PetscObject)ts),&ts->dm);CHKERRQ(ierr);
3474     if (ts->snes) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
3475   }
3476   *dm = ts->dm;
3477   PetscFunctionReturn(0);
3478 }
3479 
3480 #undef __FUNCT__
3481 #define __FUNCT__ "SNESTSFormFunction"
3482 /*@
3483    SNESTSFormFunction - Function to evaluate nonlinear residual
3484 
3485    Logically Collective on SNES
3486 
3487    Input Parameter:
3488 + snes - nonlinear solver
3489 . U - the current state at which to evaluate the residual
3490 - ctx - user context, must be a TS
3491 
3492    Output Parameter:
3493 . F - the nonlinear residual
3494 
3495    Notes:
3496    This function is not normally called by users and is automatically registered with the SNES used by TS.
3497    It is most frequently passed to MatFDColoringSetFunction().
3498 
3499    Level: advanced
3500 
3501 .seealso: SNESSetFunction(), MatFDColoringSetFunction()
3502 @*/
3503 PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
3504 {
3505   TS             ts = (TS)ctx;
3506   PetscErrorCode ierr;
3507 
3508   PetscFunctionBegin;
3509   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3510   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3511   PetscValidHeaderSpecific(F,VEC_CLASSID,3);
3512   PetscValidHeaderSpecific(ts,TS_CLASSID,4);
3513   ierr = (ts->ops->snesfunction)(snes,U,F,ts);CHKERRQ(ierr);
3514   PetscFunctionReturn(0);
3515 }
3516 
3517 #undef __FUNCT__
3518 #define __FUNCT__ "SNESTSFormJacobian"
3519 /*@
3520    SNESTSFormJacobian - Function to evaluate the Jacobian
3521 
3522    Collective on SNES
3523 
3524    Input Parameter:
3525 + snes - nonlinear solver
3526 . U - the current state at which to evaluate the residual
3527 - ctx - user context, must be a TS
3528 
3529    Output Parameter:
3530 + A - the Jacobian
3531 . B - the preconditioning matrix (may be the same as A)
3532 - flag - indicates any structure change in the matrix
3533 
3534    Notes:
3535    This function is not normally called by users and is automatically registered with the SNES used by TS.
3536 
3537    Level: developer
3538 
3539 .seealso: SNESSetJacobian()
3540 @*/
3541 PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat A,Mat B,void *ctx)
3542 {
3543   TS             ts = (TS)ctx;
3544   PetscErrorCode ierr;
3545 
3546   PetscFunctionBegin;
3547   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3548   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3549   PetscValidPointer(A,3);
3550   PetscValidHeaderSpecific(A,MAT_CLASSID,3);
3551   PetscValidPointer(B,4);
3552   PetscValidHeaderSpecific(B,MAT_CLASSID,4);
3553   PetscValidHeaderSpecific(ts,TS_CLASSID,6);
3554   ierr = (ts->ops->snesjacobian)(snes,U,A,B,ts);CHKERRQ(ierr);
3555   PetscFunctionReturn(0);
3556 }
3557 
3558 #undef __FUNCT__
3559 #define __FUNCT__ "TSComputeRHSFunctionLinear"
3560 /*@C
3561    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only
3562 
3563    Collective on TS
3564 
3565    Input Arguments:
3566 +  ts - time stepping context
3567 .  t - time at which to evaluate
3568 .  U - state at which to evaluate
3569 -  ctx - context
3570 
3571    Output Arguments:
3572 .  F - right hand side
3573 
3574    Level: intermediate
3575 
3576    Notes:
3577    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
3578    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().
3579 
3580 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
3581 @*/
3582 PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
3583 {
3584   PetscErrorCode ierr;
3585   Mat            Arhs,Brhs;
3586 
3587   PetscFunctionBegin;
3588   ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
3589   ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
3590   ierr = MatMult(Arhs,U,F);CHKERRQ(ierr);
3591   PetscFunctionReturn(0);
3592 }
3593 
3594 #undef __FUNCT__
3595 #define __FUNCT__ "TSComputeRHSJacobianConstant"
3596 /*@C
3597    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.
3598 
3599    Collective on TS
3600 
3601    Input Arguments:
3602 +  ts - time stepping context
3603 .  t - time at which to evaluate
3604 .  U - state at which to evaluate
3605 -  ctx - context
3606 
3607    Output Arguments:
3608 +  A - pointer to operator
3609 .  B - pointer to preconditioning matrix
3610 -  flg - matrix structure flag
3611 
3612    Level: intermediate
3613 
3614    Notes:
3615    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.
3616 
3617 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
3618 @*/
3619 PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat A,Mat B,void *ctx)
3620 {
3621   PetscFunctionBegin;
3622   PetscFunctionReturn(0);
3623 }
3624 
3625 #undef __FUNCT__
3626 #define __FUNCT__ "TSComputeIFunctionLinear"
3627 /*@C
3628    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only
3629 
3630    Collective on TS
3631 
3632    Input Arguments:
3633 +  ts - time stepping context
3634 .  t - time at which to evaluate
3635 .  U - state at which to evaluate
3636 .  Udot - time derivative of state vector
3637 -  ctx - context
3638 
3639    Output Arguments:
3640 .  F - left hand side
3641 
3642    Level: intermediate
3643 
3644    Notes:
3645    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
3646    user is required to write their own TSComputeIFunction.
3647    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
3648    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().
3649 
3650 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
3651 @*/
3652 PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
3653 {
3654   PetscErrorCode ierr;
3655   Mat            A,B;
3656 
3657   PetscFunctionBegin;
3658   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
3659   ierr = TSComputeIJacobian(ts,t,U,Udot,1.0,A,B,PETSC_TRUE);CHKERRQ(ierr);
3660   ierr = MatMult(A,Udot,F);CHKERRQ(ierr);
3661   PetscFunctionReturn(0);
3662 }
3663 
3664 #undef __FUNCT__
3665 #define __FUNCT__ "TSComputeIJacobianConstant"
3666 /*@C
3667    TSComputeIJacobianConstant - Reuses a time-independent for a semi-implicit DAE or ODE
3668 
3669    Collective on TS
3670 
3671    Input Arguments:
3672 +  ts - time stepping context
3673 .  t - time at which to evaluate
3674 .  U - state at which to evaluate
3675 .  Udot - time derivative of state vector
3676 .  shift - shift to apply
3677 -  ctx - context
3678 
3679    Output Arguments:
3680 +  A - pointer to operator
3681 .  B - pointer to preconditioning matrix
3682 -  flg - matrix structure flag
3683 
3684    Level: advanced
3685 
3686    Notes:
3687    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.
3688 
3689    It is only appropriate for problems of the form
3690 
3691 $     M Udot = F(U,t)
3692 
3693   where M is constant and F is non-stiff.  The user must pass M to TSSetIJacobian().  The current implementation only
3694   works with IMEX time integration methods such as TSROSW and TSARKIMEX, since there is no support for de-constructing
3695   an implicit operator of the form
3696 
3697 $    shift*M + J
3698 
3699   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
3700   a copy of M or reassemble it when requested.
3701 
3702 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
3703 @*/
3704 PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,void *ctx)
3705 {
3706   PetscErrorCode ierr;
3707 
3708   PetscFunctionBegin;
3709   ierr = MatScale(A, shift / ts->ijacobian.shift);CHKERRQ(ierr);
3710   ts->ijacobian.shift = shift;
3711   PetscFunctionReturn(0);
3712 }
3713 
3714 #undef __FUNCT__
3715 #define __FUNCT__ "TSGetEquationType"
3716 /*@
3717    TSGetEquationType - Gets the type of the equation that TS is solving.
3718 
3719    Not Collective
3720 
3721    Input Parameter:
3722 .  ts - the TS context
3723 
3724    Output Parameter:
3725 .  equation_type - see TSEquationType
3726 
3727    Level: beginner
3728 
3729 .keywords: TS, equation type
3730 
3731 .seealso: TSSetEquationType(), TSEquationType
3732 @*/
3733 PetscErrorCode  TSGetEquationType(TS ts,TSEquationType *equation_type)
3734 {
3735   PetscFunctionBegin;
3736   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3737   PetscValidPointer(equation_type,2);
3738   *equation_type = ts->equation_type;
3739   PetscFunctionReturn(0);
3740 }
3741 
3742 #undef __FUNCT__
3743 #define __FUNCT__ "TSSetEquationType"
3744 /*@
3745    TSSetEquationType - Sets the type of the equation that TS is solving.
3746 
3747    Not Collective
3748 
3749    Input Parameter:
3750 +  ts - the TS context
3751 .  equation_type - see TSEquationType
3752 
3753    Level: advanced
3754 
3755 .keywords: TS, equation type
3756 
3757 .seealso: TSGetEquationType(), TSEquationType
3758 @*/
3759 PetscErrorCode  TSSetEquationType(TS ts,TSEquationType equation_type)
3760 {
3761   PetscFunctionBegin;
3762   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3763   ts->equation_type = equation_type;
3764   PetscFunctionReturn(0);
3765 }
3766 
3767 #undef __FUNCT__
3768 #define __FUNCT__ "TSGetConvergedReason"
3769 /*@
3770    TSGetConvergedReason - Gets the reason the TS iteration was stopped.
3771 
3772    Not Collective
3773 
3774    Input Parameter:
3775 .  ts - the TS context
3776 
3777    Output Parameter:
3778 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3779             manual pages for the individual convergence tests for complete lists
3780 
3781    Level: beginner
3782 
3783    Notes:
3784    Can only be called after the call to TSSolve() is complete.
3785 
3786 .keywords: TS, nonlinear, set, convergence, test
3787 
3788 .seealso: TSSetConvergenceTest(), TSConvergedReason
3789 @*/
3790 PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
3791 {
3792   PetscFunctionBegin;
3793   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3794   PetscValidPointer(reason,2);
3795   *reason = ts->reason;
3796   PetscFunctionReturn(0);
3797 }
3798 
3799 #undef __FUNCT__
3800 #define __FUNCT__ "TSSetConvergedReason"
3801 /*@
3802    TSSetConvergedReason - Sets the reason for handling the convergence of TSSolve.
3803 
3804    Not Collective
3805 
3806    Input Parameter:
3807 +  ts - the TS context
3808 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3809             manual pages for the individual convergence tests for complete lists
3810 
3811    Level: advanced
3812 
3813    Notes:
3814    Can only be called during TSSolve() is active.
3815 
3816 .keywords: TS, nonlinear, set, convergence, test
3817 
3818 .seealso: TSConvergedReason
3819 @*/
3820 PetscErrorCode  TSSetConvergedReason(TS ts,TSConvergedReason reason)
3821 {
3822   PetscFunctionBegin;
3823   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3824   ts->reason = reason;
3825   PetscFunctionReturn(0);
3826 }
3827 
3828 #undef __FUNCT__
3829 #define __FUNCT__ "TSGetSolveTime"
3830 /*@
3831    TSGetSolveTime - Gets the time after a call to TSSolve()
3832 
3833    Not Collective
3834 
3835    Input Parameter:
3836 .  ts - the TS context
3837 
3838    Output Parameter:
3839 .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()
3840 
3841    Level: beginner
3842 
3843    Notes:
3844    Can only be called after the call to TSSolve() is complete.
3845 
3846 .keywords: TS, nonlinear, set, convergence, test
3847 
3848 .seealso: TSSetConvergenceTest(), TSConvergedReason
3849 @*/
3850 PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
3851 {
3852   PetscFunctionBegin;
3853   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3854   PetscValidPointer(ftime,2);
3855   *ftime = ts->solvetime;
3856   PetscFunctionReturn(0);
3857 }
3858 
3859 #undef __FUNCT__
3860 #define __FUNCT__ "TSGetSNESIterations"
3861 /*@
3862    TSGetSNESIterations - Gets the total number of nonlinear iterations
3863    used by the time integrator.
3864 
3865    Not Collective
3866 
3867    Input Parameter:
3868 .  ts - TS context
3869 
3870    Output Parameter:
3871 .  nits - number of nonlinear iterations
3872 
3873    Notes:
3874    This counter is reset to zero for each successive call to TSSolve().
3875 
3876    Level: intermediate
3877 
3878 .keywords: TS, get, number, nonlinear, iterations
3879 
3880 .seealso:  TSGetKSPIterations()
3881 @*/
3882 PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
3883 {
3884   PetscFunctionBegin;
3885   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3886   PetscValidIntPointer(nits,2);
3887   *nits = ts->snes_its;
3888   PetscFunctionReturn(0);
3889 }
3890 
3891 #undef __FUNCT__
3892 #define __FUNCT__ "TSGetKSPIterations"
3893 /*@
3894    TSGetKSPIterations - Gets the total number of linear iterations
3895    used by the time integrator.
3896 
3897    Not Collective
3898 
3899    Input Parameter:
3900 .  ts - TS context
3901 
3902    Output Parameter:
3903 .  lits - number of linear iterations
3904 
3905    Notes:
3906    This counter is reset to zero for each successive call to TSSolve().
3907 
3908    Level: intermediate
3909 
3910 .keywords: TS, get, number, linear, iterations
3911 
3912 .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
3913 @*/
3914 PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
3915 {
3916   PetscFunctionBegin;
3917   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3918   PetscValidIntPointer(lits,2);
3919   *lits = ts->ksp_its;
3920   PetscFunctionReturn(0);
3921 }
3922 
3923 #undef __FUNCT__
3924 #define __FUNCT__ "TSGetStepRejections"
3925 /*@
3926    TSGetStepRejections - Gets the total number of rejected steps.
3927 
3928    Not Collective
3929 
3930    Input Parameter:
3931 .  ts - TS context
3932 
3933    Output Parameter:
3934 .  rejects - number of steps rejected
3935 
3936    Notes:
3937    This counter is reset to zero for each successive call to TSSolve().
3938 
3939    Level: intermediate
3940 
3941 .keywords: TS, get, number
3942 
3943 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
3944 @*/
3945 PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
3946 {
3947   PetscFunctionBegin;
3948   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3949   PetscValidIntPointer(rejects,2);
3950   *rejects = ts->reject;
3951   PetscFunctionReturn(0);
3952 }
3953 
3954 #undef __FUNCT__
3955 #define __FUNCT__ "TSGetSNESFailures"
3956 /*@
3957    TSGetSNESFailures - Gets the total number of failed SNES solves
3958 
3959    Not Collective
3960 
3961    Input Parameter:
3962 .  ts - TS context
3963 
3964    Output Parameter:
3965 .  fails - number of failed nonlinear solves
3966 
3967    Notes:
3968    This counter is reset to zero for each successive call to TSSolve().
3969 
3970    Level: intermediate
3971 
3972 .keywords: TS, get, number
3973 
3974 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
3975 @*/
3976 PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
3977 {
3978   PetscFunctionBegin;
3979   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3980   PetscValidIntPointer(fails,2);
3981   *fails = ts->num_snes_failures;
3982   PetscFunctionReturn(0);
3983 }
3984 
3985 #undef __FUNCT__
3986 #define __FUNCT__ "TSSetMaxStepRejections"
3987 /*@
3988    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails
3989 
3990    Not Collective
3991 
3992    Input Parameter:
3993 +  ts - TS context
3994 -  rejects - maximum number of rejected steps, pass -1 for unlimited
3995 
3996    Notes:
3997    The counter is reset to zero for each step
3998 
3999    Options Database Key:
4000  .  -ts_max_reject - Maximum number of step rejections before a step fails
4001 
4002    Level: intermediate
4003 
4004 .keywords: TS, set, maximum, number
4005 
4006 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4007 @*/
4008 PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
4009 {
4010   PetscFunctionBegin;
4011   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4012   ts->max_reject = rejects;
4013   PetscFunctionReturn(0);
4014 }
4015 
4016 #undef __FUNCT__
4017 #define __FUNCT__ "TSSetMaxSNESFailures"
4018 /*@
4019    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves
4020 
4021    Not Collective
4022 
4023    Input Parameter:
4024 +  ts - TS context
4025 -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited
4026 
4027    Notes:
4028    The counter is reset to zero for each successive call to TSSolve().
4029 
4030    Options Database Key:
4031  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures
4032 
4033    Level: intermediate
4034 
4035 .keywords: TS, set, maximum, number
4036 
4037 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
4038 @*/
4039 PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
4040 {
4041   PetscFunctionBegin;
4042   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4043   ts->max_snes_failures = fails;
4044   PetscFunctionReturn(0);
4045 }
4046 
4047 #undef __FUNCT__
4048 #define __FUNCT__ "TSSetErrorIfStepFails"
4049 /*@
4050    TSSetErrorIfStepFails - Error if no step succeeds
4051 
4052    Not Collective
4053 
4054    Input Parameter:
4055 +  ts - TS context
4056 -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure
4057 
4058    Options Database Key:
4059  .  -ts_error_if_step_fails - Error if no step succeeds
4060 
4061    Level: intermediate
4062 
4063 .keywords: TS, set, error
4064 
4065 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4066 @*/
4067 PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
4068 {
4069   PetscFunctionBegin;
4070   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4071   ts->errorifstepfailed = err;
4072   PetscFunctionReturn(0);
4073 }
4074 
4075 #undef __FUNCT__
4076 #define __FUNCT__ "TSMonitorSolutionBinary"
4077 /*@C
4078    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file
4079 
4080    Collective on TS
4081 
4082    Input Parameters:
4083 +  ts - the TS context
4084 .  step - current time-step
4085 .  ptime - current time
4086 .  u - current state
4087 -  viewer - binary viewer
4088 
4089    Level: intermediate
4090 
4091 .keywords: TS,  vector, monitor, view
4092 
4093 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4094 @*/
4095 PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
4096 {
4097   PetscErrorCode ierr;
4098   PetscViewer    v = (PetscViewer)viewer;
4099 
4100   PetscFunctionBegin;
4101   ierr = VecView(u,v);CHKERRQ(ierr);
4102   PetscFunctionReturn(0);
4103 }
4104 
4105 #undef __FUNCT__
4106 #define __FUNCT__ "TSMonitorSolutionVTK"
4107 /*@C
4108    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.
4109 
4110    Collective on TS
4111 
4112    Input Parameters:
4113 +  ts - the TS context
4114 .  step - current time-step
4115 .  ptime - current time
4116 .  u - current state
4117 -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4118 
4119    Level: intermediate
4120 
4121    Notes:
4122    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.
4123    These are named according to the file name template.
4124 
4125    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().
4126 
4127 .keywords: TS,  vector, monitor, view
4128 
4129 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4130 @*/
4131 PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
4132 {
4133   PetscErrorCode ierr;
4134   char           filename[PETSC_MAX_PATH_LEN];
4135   PetscViewer    viewer;
4136 
4137   PetscFunctionBegin;
4138   ierr = PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);CHKERRQ(ierr);
4139   ierr = PetscViewerVTKOpen(PetscObjectComm((PetscObject)ts),filename,FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
4140   ierr = VecView(u,viewer);CHKERRQ(ierr);
4141   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
4142   PetscFunctionReturn(0);
4143 }
4144 
4145 #undef __FUNCT__
4146 #define __FUNCT__ "TSMonitorSolutionVTKDestroy"
4147 /*@C
4148    TSMonitorSolutionVTKDestroy - Destroy context for monitoring
4149 
4150    Collective on TS
4151 
4152    Input Parameters:
4153 .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4154 
4155    Level: intermediate
4156 
4157    Note:
4158    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().
4159 
4160 .keywords: TS,  vector, monitor, view
4161 
4162 .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
4163 @*/
4164 PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
4165 {
4166   PetscErrorCode ierr;
4167 
4168   PetscFunctionBegin;
4169   ierr = PetscFree(*(char**)filenametemplate);CHKERRQ(ierr);
4170   PetscFunctionReturn(0);
4171 }
4172 
4173 #undef __FUNCT__
4174 #define __FUNCT__ "TSGetAdapt"
4175 /*@
4176    TSGetAdapt - Get the adaptive controller context for the current method
4177 
4178    Collective on TS if controller has not been created yet
4179 
4180    Input Arguments:
4181 .  ts - time stepping context
4182 
4183    Output Arguments:
4184 .  adapt - adaptive controller
4185 
4186    Level: intermediate
4187 
4188 .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
4189 @*/
4190 PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
4191 {
4192   PetscErrorCode ierr;
4193 
4194   PetscFunctionBegin;
4195   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4196   PetscValidPointer(adapt,2);
4197   if (!ts->adapt) {
4198     ierr = TSAdaptCreate(PetscObjectComm((PetscObject)ts),&ts->adapt);CHKERRQ(ierr);
4199     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->adapt);CHKERRQ(ierr);
4200     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);CHKERRQ(ierr);
4201   }
4202   *adapt = ts->adapt;
4203   PetscFunctionReturn(0);
4204 }
4205 
4206 #undef __FUNCT__
4207 #define __FUNCT__ "TSSetTolerances"
4208 /*@
4209    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller
4210 
4211    Logically Collective
4212 
4213    Input Arguments:
4214 +  ts - time integration context
4215 .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
4216 .  vatol - vector of absolute tolerances or NULL, used in preference to atol if present
4217 .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
4218 -  vrtol - vector of relative tolerances or NULL, used in preference to atol if present
4219 
4220    Options Database keys:
4221 +  -ts_rtol <rtol> - relative tolerance for local truncation error
4222 -  -ts_atol <atol> Absolute tolerance for local truncation error
4223 
4224    Level: beginner
4225 
4226 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
4227 @*/
4228 PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
4229 {
4230   PetscErrorCode ierr;
4231 
4232   PetscFunctionBegin;
4233   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
4234   if (vatol) {
4235     ierr = PetscObjectReference((PetscObject)vatol);CHKERRQ(ierr);
4236     ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
4237 
4238     ts->vatol = vatol;
4239   }
4240   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
4241   if (vrtol) {
4242     ierr = PetscObjectReference((PetscObject)vrtol);CHKERRQ(ierr);
4243     ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
4244 
4245     ts->vrtol = vrtol;
4246   }
4247   PetscFunctionReturn(0);
4248 }
4249 
4250 #undef __FUNCT__
4251 #define __FUNCT__ "TSGetTolerances"
4252 /*@
4253    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller
4254 
4255    Logically Collective
4256 
4257    Input Arguments:
4258 .  ts - time integration context
4259 
4260    Output Arguments:
4261 +  atol - scalar absolute tolerances, NULL to ignore
4262 .  vatol - vector of absolute tolerances, NULL to ignore
4263 .  rtol - scalar relative tolerances, NULL to ignore
4264 -  vrtol - vector of relative tolerances, NULL to ignore
4265 
4266    Level: beginner
4267 
4268 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
4269 @*/
4270 PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
4271 {
4272   PetscFunctionBegin;
4273   if (atol)  *atol  = ts->atol;
4274   if (vatol) *vatol = ts->vatol;
4275   if (rtol)  *rtol  = ts->rtol;
4276   if (vrtol) *vrtol = ts->vrtol;
4277   PetscFunctionReturn(0);
4278 }
4279 
4280 #undef __FUNCT__
4281 #define __FUNCT__ "TSErrorNormWRMS"
4282 /*@
4283    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state
4284 
4285    Collective on TS
4286 
4287    Input Arguments:
4288 +  ts - time stepping context
4289 -  Y - state vector to be compared to ts->vec_sol
4290 
4291    Output Arguments:
4292 .  norm - weighted norm, a value of 1.0 is considered small
4293 
4294    Level: developer
4295 
4296 .seealso: TSSetTolerances()
4297 @*/
4298 PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
4299 {
4300   PetscErrorCode    ierr;
4301   PetscInt          i,n,N;
4302   const PetscScalar *u,*y;
4303   Vec               U;
4304   PetscReal         sum,gsum;
4305 
4306   PetscFunctionBegin;
4307   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4308   PetscValidHeaderSpecific(Y,VEC_CLASSID,2);
4309   PetscValidPointer(norm,3);
4310   U = ts->vec_sol;
4311   PetscCheckSameTypeAndComm(U,1,Y,2);
4312   if (U == Y) SETERRQ(PetscObjectComm((PetscObject)U),PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");
4313 
4314   ierr = VecGetSize(U,&N);CHKERRQ(ierr);
4315   ierr = VecGetLocalSize(U,&n);CHKERRQ(ierr);
4316   ierr = VecGetArrayRead(U,&u);CHKERRQ(ierr);
4317   ierr = VecGetArrayRead(Y,&y);CHKERRQ(ierr);
4318   sum  = 0.;
4319   if (ts->vatol && ts->vrtol) {
4320     const PetscScalar *atol,*rtol;
4321     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4322     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4323     for (i=0; i<n; i++) {
4324       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4325       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4326     }
4327     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4328     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4329   } else if (ts->vatol) {       /* vector atol, scalar rtol */
4330     const PetscScalar *atol;
4331     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4332     for (i=0; i<n; i++) {
4333       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4334       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4335     }
4336     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4337   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
4338     const PetscScalar *rtol;
4339     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4340     for (i=0; i<n; i++) {
4341       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4342       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4343     }
4344     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4345   } else {                      /* scalar atol, scalar rtol */
4346     for (i=0; i<n; i++) {
4347       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4348       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4349     }
4350   }
4351   ierr = VecRestoreArrayRead(U,&u);CHKERRQ(ierr);
4352   ierr = VecRestoreArrayRead(Y,&y);CHKERRQ(ierr);
4353 
4354   ierr  = MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4355   *norm = PetscSqrtReal(gsum / N);
4356   if (PetscIsInfOrNanScalar(*norm)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
4357   PetscFunctionReturn(0);
4358 }
4359 
4360 #undef __FUNCT__
4361 #define __FUNCT__ "TSSetCFLTimeLocal"
4362 /*@
4363    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler
4364 
4365    Logically Collective on TS
4366 
4367    Input Arguments:
4368 +  ts - time stepping context
4369 -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)
4370 
4371    Note:
4372    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()
4373 
4374    Level: intermediate
4375 
4376 .seealso: TSGetCFLTime(), TSADAPTCFL
4377 @*/
4378 PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
4379 {
4380   PetscFunctionBegin;
4381   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4382   ts->cfltime_local = cfltime;
4383   ts->cfltime       = -1.;
4384   PetscFunctionReturn(0);
4385 }
4386 
4387 #undef __FUNCT__
4388 #define __FUNCT__ "TSGetCFLTime"
4389 /*@
4390    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler
4391 
4392    Collective on TS
4393 
4394    Input Arguments:
4395 .  ts - time stepping context
4396 
4397    Output Arguments:
4398 .  cfltime - maximum stable time step for forward Euler
4399 
4400    Level: advanced
4401 
4402 .seealso: TSSetCFLTimeLocal()
4403 @*/
4404 PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
4405 {
4406   PetscErrorCode ierr;
4407 
4408   PetscFunctionBegin;
4409   if (ts->cfltime < 0) {
4410     ierr = MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4411   }
4412   *cfltime = ts->cfltime;
4413   PetscFunctionReturn(0);
4414 }
4415 
4416 #undef __FUNCT__
4417 #define __FUNCT__ "TSVISetVariableBounds"
4418 /*@
4419    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu
4420 
4421    Input Parameters:
4422 .  ts   - the TS context.
4423 .  xl   - lower bound.
4424 .  xu   - upper bound.
4425 
4426    Notes:
4427    If this routine is not called then the lower and upper bounds are set to
4428    PETSC_NINFINITY and PETSC_INFINITY respectively during SNESSetUp().
4429 
4430    Level: advanced
4431 
4432 @*/
4433 PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
4434 {
4435   PetscErrorCode ierr;
4436   SNES           snes;
4437 
4438   PetscFunctionBegin;
4439   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
4440   ierr = SNESVISetVariableBounds(snes,xl,xu);CHKERRQ(ierr);
4441   PetscFunctionReturn(0);
4442 }
4443 
4444 #if defined(PETSC_HAVE_MATLAB_ENGINE)
4445 #include <mex.h>
4446 
4447 typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;
4448 
4449 #undef __FUNCT__
4450 #define __FUNCT__ "TSComputeFunction_Matlab"
4451 /*
4452    TSComputeFunction_Matlab - Calls the function that has been set with
4453                          TSSetFunctionMatlab().
4454 
4455    Collective on TS
4456 
4457    Input Parameters:
4458 +  snes - the TS context
4459 -  u - input vector
4460 
4461    Output Parameter:
4462 .  y - function vector, as set by TSSetFunction()
4463 
4464    Notes:
4465    TSComputeFunction() is typically used within nonlinear solvers
4466    implementations, so most users would not generally call this routine
4467    themselves.
4468 
4469    Level: developer
4470 
4471 .keywords: TS, nonlinear, compute, function
4472 
4473 .seealso: TSSetFunction(), TSGetFunction()
4474 */
4475 PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
4476 {
4477   PetscErrorCode  ierr;
4478   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4479   int             nlhs  = 1,nrhs = 7;
4480   mxArray         *plhs[1],*prhs[7];
4481   long long int   lx = 0,lxdot = 0,ly = 0,ls = 0;
4482 
4483   PetscFunctionBegin;
4484   PetscValidHeaderSpecific(snes,TS_CLASSID,1);
4485   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4486   PetscValidHeaderSpecific(udot,VEC_CLASSID,4);
4487   PetscValidHeaderSpecific(y,VEC_CLASSID,5);
4488   PetscCheckSameComm(snes,1,u,3);
4489   PetscCheckSameComm(snes,1,y,5);
4490 
4491   ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr);
4492   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4493   ierr = PetscMemcpy(&lxdot,&udot,sizeof(udot));CHKERRQ(ierr);
4494   ierr = PetscMemcpy(&ly,&y,sizeof(u));CHKERRQ(ierr);
4495 
4496   prhs[0] =  mxCreateDoubleScalar((double)ls);
4497   prhs[1] =  mxCreateDoubleScalar(time);
4498   prhs[2] =  mxCreateDoubleScalar((double)lx);
4499   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4500   prhs[4] =  mxCreateDoubleScalar((double)ly);
4501   prhs[5] =  mxCreateString(sctx->funcname);
4502   prhs[6] =  sctx->ctx;
4503   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");CHKERRQ(ierr);
4504   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4505   mxDestroyArray(prhs[0]);
4506   mxDestroyArray(prhs[1]);
4507   mxDestroyArray(prhs[2]);
4508   mxDestroyArray(prhs[3]);
4509   mxDestroyArray(prhs[4]);
4510   mxDestroyArray(prhs[5]);
4511   mxDestroyArray(plhs[0]);
4512   PetscFunctionReturn(0);
4513 }
4514 
4515 
4516 #undef __FUNCT__
4517 #define __FUNCT__ "TSSetFunctionMatlab"
4518 /*
4519    TSSetFunctionMatlab - Sets the function evaluation routine and function
4520    vector for use by the TS routines in solving ODEs
4521    equations from MATLAB. Here the function is a string containing the name of a MATLAB function
4522 
4523    Logically Collective on TS
4524 
4525    Input Parameters:
4526 +  ts - the TS context
4527 -  func - function evaluation routine
4528 
4529    Calling sequence of func:
4530 $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);
4531 
4532    Level: beginner
4533 
4534 .keywords: TS, nonlinear, set, function
4535 
4536 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4537 */
4538 PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
4539 {
4540   PetscErrorCode  ierr;
4541   TSMatlabContext *sctx;
4542 
4543   PetscFunctionBegin;
4544   /* currently sctx is memory bleed */
4545   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4546   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4547   /*
4548      This should work, but it doesn't
4549   sctx->ctx = ctx;
4550   mexMakeArrayPersistent(sctx->ctx);
4551   */
4552   sctx->ctx = mxDuplicateArray(ctx);
4553 
4554   ierr = TSSetIFunction(ts,NULL,TSComputeFunction_Matlab,sctx);CHKERRQ(ierr);
4555   PetscFunctionReturn(0);
4556 }
4557 
4558 #undef __FUNCT__
4559 #define __FUNCT__ "TSComputeJacobian_Matlab"
4560 /*
4561    TSComputeJacobian_Matlab - Calls the function that has been set with
4562                          TSSetJacobianMatlab().
4563 
4564    Collective on TS
4565 
4566    Input Parameters:
4567 +  ts - the TS context
4568 .  u - input vector
4569 .  A, B - the matrices
4570 -  ctx - user context
4571 
4572    Level: developer
4573 
4574 .keywords: TS, nonlinear, compute, function
4575 
4576 .seealso: TSSetFunction(), TSGetFunction()
4577 @*/
4578 PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat A,Mat B,void *ctx)
4579 {
4580   PetscErrorCode  ierr;
4581   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4582   int             nlhs  = 2,nrhs = 9;
4583   mxArray         *plhs[2],*prhs[9];
4584   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;
4585 
4586   PetscFunctionBegin;
4587   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4588   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4589 
4590   /* call Matlab function in ctx with arguments u and y */
4591 
4592   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4593   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4594   ierr = PetscMemcpy(&lxdot,&udot,sizeof(u));CHKERRQ(ierr);
4595   ierr = PetscMemcpy(&lA,A,sizeof(u));CHKERRQ(ierr);
4596   ierr = PetscMemcpy(&lB,B,sizeof(u));CHKERRQ(ierr);
4597 
4598   prhs[0] =  mxCreateDoubleScalar((double)ls);
4599   prhs[1] =  mxCreateDoubleScalar((double)time);
4600   prhs[2] =  mxCreateDoubleScalar((double)lx);
4601   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4602   prhs[4] =  mxCreateDoubleScalar((double)shift);
4603   prhs[5] =  mxCreateDoubleScalar((double)lA);
4604   prhs[6] =  mxCreateDoubleScalar((double)lB);
4605   prhs[7] =  mxCreateString(sctx->funcname);
4606   prhs[8] =  sctx->ctx;
4607   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");CHKERRQ(ierr);
4608   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4609   mxDestroyArray(prhs[0]);
4610   mxDestroyArray(prhs[1]);
4611   mxDestroyArray(prhs[2]);
4612   mxDestroyArray(prhs[3]);
4613   mxDestroyArray(prhs[4]);
4614   mxDestroyArray(prhs[5]);
4615   mxDestroyArray(prhs[6]);
4616   mxDestroyArray(prhs[7]);
4617   mxDestroyArray(plhs[0]);
4618   mxDestroyArray(plhs[1]);
4619   PetscFunctionReturn(0);
4620 }
4621 
4622 
4623 #undef __FUNCT__
4624 #define __FUNCT__ "TSSetJacobianMatlab"
4625 /*
4626    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
4627    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
4628 
4629    Logically Collective on TS
4630 
4631    Input Parameters:
4632 +  ts - the TS context
4633 .  A,B - Jacobian matrices
4634 .  func - function evaluation routine
4635 -  ctx - user context
4636 
4637    Calling sequence of func:
4638 $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);
4639 
4640 
4641    Level: developer
4642 
4643 .keywords: TS, nonlinear, set, function
4644 
4645 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4646 */
4647 PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
4648 {
4649   PetscErrorCode  ierr;
4650   TSMatlabContext *sctx;
4651 
4652   PetscFunctionBegin;
4653   /* currently sctx is memory bleed */
4654   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4655   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4656   /*
4657      This should work, but it doesn't
4658   sctx->ctx = ctx;
4659   mexMakeArrayPersistent(sctx->ctx);
4660   */
4661   sctx->ctx = mxDuplicateArray(ctx);
4662 
4663   ierr = TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);CHKERRQ(ierr);
4664   PetscFunctionReturn(0);
4665 }
4666 
4667 #undef __FUNCT__
4668 #define __FUNCT__ "TSMonitor_Matlab"
4669 /*
4670    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().
4671 
4672    Collective on TS
4673 
4674 .seealso: TSSetFunction(), TSGetFunction()
4675 @*/
4676 PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
4677 {
4678   PetscErrorCode  ierr;
4679   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4680   int             nlhs  = 1,nrhs = 6;
4681   mxArray         *plhs[1],*prhs[6];
4682   long long int   lx = 0,ls = 0;
4683 
4684   PetscFunctionBegin;
4685   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4686   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
4687 
4688   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4689   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4690 
4691   prhs[0] =  mxCreateDoubleScalar((double)ls);
4692   prhs[1] =  mxCreateDoubleScalar((double)it);
4693   prhs[2] =  mxCreateDoubleScalar((double)time);
4694   prhs[3] =  mxCreateDoubleScalar((double)lx);
4695   prhs[4] =  mxCreateString(sctx->funcname);
4696   prhs[5] =  sctx->ctx;
4697   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");CHKERRQ(ierr);
4698   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4699   mxDestroyArray(prhs[0]);
4700   mxDestroyArray(prhs[1]);
4701   mxDestroyArray(prhs[2]);
4702   mxDestroyArray(prhs[3]);
4703   mxDestroyArray(prhs[4]);
4704   mxDestroyArray(plhs[0]);
4705   PetscFunctionReturn(0);
4706 }
4707 
4708 
4709 #undef __FUNCT__
4710 #define __FUNCT__ "TSMonitorSetMatlab"
4711 /*
4712    TSMonitorSetMatlab - Sets the monitor function from Matlab
4713 
4714    Level: developer
4715 
4716 .keywords: TS, nonlinear, set, function
4717 
4718 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4719 */
4720 PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
4721 {
4722   PetscErrorCode  ierr;
4723   TSMatlabContext *sctx;
4724 
4725   PetscFunctionBegin;
4726   /* currently sctx is memory bleed */
4727   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4728   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4729   /*
4730      This should work, but it doesn't
4731   sctx->ctx = ctx;
4732   mexMakeArrayPersistent(sctx->ctx);
4733   */
4734   sctx->ctx = mxDuplicateArray(ctx);
4735 
4736   ierr = TSMonitorSet(ts,TSMonitor_Matlab,sctx,NULL);CHKERRQ(ierr);
4737   PetscFunctionReturn(0);
4738 }
4739 #endif
4740 
4741 
4742 
4743 #undef __FUNCT__
4744 #define __FUNCT__ "TSMonitorLGSolution"
4745 /*@C
4746    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
4747        in a time based line graph
4748 
4749    Collective on TS
4750 
4751    Input Parameters:
4752 +  ts - the TS context
4753 .  step - current time-step
4754 .  ptime - current time
4755 -  lg - a line graph object
4756 
4757    Level: intermediate
4758 
4759     Notes: each process in a parallel run displays its component solutions in a separate window
4760 
4761 .keywords: TS,  vector, monitor, view
4762 
4763 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4764 @*/
4765 PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4766 {
4767   PetscErrorCode    ierr;
4768   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4769   const PetscScalar *yy;
4770   PetscInt          dim;
4771 
4772   PetscFunctionBegin;
4773   if (!step) {
4774     PetscDrawAxis axis;
4775     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4776     ierr = PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");CHKERRQ(ierr);
4777     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4778     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4779     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4780   }
4781   ierr = VecGetArrayRead(u,&yy);CHKERRQ(ierr);
4782 #if defined(PETSC_USE_COMPLEX)
4783   {
4784     PetscReal *yreal;
4785     PetscInt  i,n;
4786     ierr = VecGetLocalSize(u,&n);CHKERRQ(ierr);
4787     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4788     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4789     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4790     ierr = PetscFree(yreal);CHKERRQ(ierr);
4791   }
4792 #else
4793   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4794 #endif
4795   ierr = VecRestoreArrayRead(u,&yy);CHKERRQ(ierr);
4796   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4797     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4798   }
4799   PetscFunctionReturn(0);
4800 }
4801 
4802 #undef __FUNCT__
4803 #define __FUNCT__ "TSMonitorLGError"
4804 /*@C
4805    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
4806        in a time based line graph
4807 
4808    Collective on TS
4809 
4810    Input Parameters:
4811 +  ts - the TS context
4812 .  step - current time-step
4813 .  ptime - current time
4814 -  lg - a line graph object
4815 
4816    Level: intermediate
4817 
4818    Notes:
4819    Only for sequential solves.
4820 
4821    The user must provide the solution using TSSetSolutionFunction() to use this monitor.
4822 
4823    Options Database Keys:
4824 .  -ts_monitor_lg_error - create a graphical monitor of error history
4825 
4826 .keywords: TS,  vector, monitor, view
4827 
4828 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
4829 @*/
4830 PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4831 {
4832   PetscErrorCode    ierr;
4833   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4834   const PetscScalar *yy;
4835   Vec               y;
4836   PetscInt          dim;
4837 
4838   PetscFunctionBegin;
4839   if (!step) {
4840     PetscDrawAxis axis;
4841     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4842     ierr = PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");CHKERRQ(ierr);
4843     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4844     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4845     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4846   }
4847   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
4848   ierr = TSComputeSolutionFunction(ts,ptime,y);CHKERRQ(ierr);
4849   ierr = VecAXPY(y,-1.0,u);CHKERRQ(ierr);
4850   ierr = VecGetArrayRead(y,&yy);CHKERRQ(ierr);
4851 #if defined(PETSC_USE_COMPLEX)
4852   {
4853     PetscReal *yreal;
4854     PetscInt  i,n;
4855     ierr = VecGetLocalSize(y,&n);CHKERRQ(ierr);
4856     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4857     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4858     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4859     ierr = PetscFree(yreal);CHKERRQ(ierr);
4860   }
4861 #else
4862   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4863 #endif
4864   ierr = VecRestoreArrayRead(y,&yy);CHKERRQ(ierr);
4865   ierr = VecDestroy(&y);CHKERRQ(ierr);
4866   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4867     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4868   }
4869   PetscFunctionReturn(0);
4870 }
4871 
4872 #undef __FUNCT__
4873 #define __FUNCT__ "TSMonitorLGSNESIterations"
4874 PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4875 {
4876   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4877   PetscReal      x   = ptime,y;
4878   PetscErrorCode ierr;
4879   PetscInt       its;
4880 
4881   PetscFunctionBegin;
4882   if (!n) {
4883     PetscDrawAxis axis;
4884 
4885     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4886     ierr = PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");CHKERRQ(ierr);
4887     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4888 
4889     ctx->snes_its = 0;
4890   }
4891   ierr = TSGetSNESIterations(ts,&its);CHKERRQ(ierr);
4892   y    = its - ctx->snes_its;
4893   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4894   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4895     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4896   }
4897   ctx->snes_its = its;
4898   PetscFunctionReturn(0);
4899 }
4900 
4901 #undef __FUNCT__
4902 #define __FUNCT__ "TSMonitorLGKSPIterations"
4903 PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4904 {
4905   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4906   PetscReal      x   = ptime,y;
4907   PetscErrorCode ierr;
4908   PetscInt       its;
4909 
4910   PetscFunctionBegin;
4911   if (!n) {
4912     PetscDrawAxis axis;
4913 
4914     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4915     ierr = PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");CHKERRQ(ierr);
4916     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4917 
4918     ctx->ksp_its = 0;
4919   }
4920   ierr = TSGetKSPIterations(ts,&its);CHKERRQ(ierr);
4921   y    = its - ctx->ksp_its;
4922   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4923   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4924     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4925   }
4926   ctx->ksp_its = its;
4927   PetscFunctionReturn(0);
4928 }
4929 
4930 #undef __FUNCT__
4931 #define __FUNCT__ "TSComputeLinearStability"
4932 /*@
4933    TSComputeLinearStability - computes the linear stability function at a point
4934 
4935    Collective on TS and Vec
4936 
4937    Input Parameters:
4938 +  ts - the TS context
4939 -  xr,xi - real and imaginary part of input arguments
4940 
4941    Output Parameters:
4942 .  yr,yi - real and imaginary part of function value
4943 
4944    Level: developer
4945 
4946 .keywords: TS, compute
4947 
4948 .seealso: TSSetRHSFunction(), TSComputeIFunction()
4949 @*/
4950 PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
4951 {
4952   PetscErrorCode ierr;
4953 
4954   PetscFunctionBegin;
4955   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4956   if (!ts->ops->linearstability) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"Linearized stability function not provided for this method");
4957   ierr = (*ts->ops->linearstability)(ts,xr,xi,yr,yi);CHKERRQ(ierr);
4958   PetscFunctionReturn(0);
4959 }
4960 
4961 #undef __FUNCT__
4962 #define __FUNCT__ "TSRollBack"
4963 /*@
4964    TSRollBack - Rolls back one time step
4965 
4966    Collective on TS
4967 
4968    Input Parameter:
4969 .  ts - the TS context obtained from TSCreate()
4970 
4971    Level: advanced
4972 
4973 .keywords: TS, timestep, rollback
4974 
4975 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSInterpolate()
4976 @*/
4977 PetscErrorCode  TSRollBack(TS ts)
4978 {
4979   PetscErrorCode ierr;
4980 
4981   PetscFunctionBegin;
4982   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
4983 
4984   if (!ts->ops->rollback) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSRollBack not implemented for type '%s'",((PetscObject)ts)->type_name);
4985   ierr = (*ts->ops->rollback)(ts);CHKERRQ(ierr);
4986   ts->time_step = ts->ptime - ts->ptime_prev;
4987   ts->ptime = ts->ptime_prev;
4988   PetscFunctionReturn(0);
4989 }
4990 
4991