xref: /petsc/src/ts/interface/ts.c (revision 2fb8446c541684a316151fd601c81003e751a50f)
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_monitor - print information at each timestep
76 .  -ts_monitor_lg_timestep - Monitor timestep size graphically
77 .  -ts_monitor_lg_solution - Monitor solution graphically
78 .  -ts_monitor_lg_error - Monitor error graphically
79 .  -ts_monitor_lg_snes_iterations - Monitor number nonlinear iterations for each timestep graphically
80 .  -ts_monitor_lg_ksp_iterations - Monitor number nonlinear iterations for each timestep graphically
81 .  -ts_monitor_sp_eig - Monitor eigenvalues of linearized operator graphically
82 .  -ts_monitor_draw_solution - Monitor solution graphically
83 .  -ts_monitor_draw_solution_phase - Monitor solution graphically with phase diagram
84 .  -ts_monitor_draw_error - Monitor error graphically
85 .  -ts_monitor_solution_binary <filename> - Save each solution to a binary file
86 -  -ts_monitor_solution_vtk <filename.vts> - Save each time step to a binary file, use filename-%%03D.vts
87 
88    Developer Note: We should unify all the -ts_monitor options in the way that -xxx_view has been unified
89 
90    Level: beginner
91 
92 .keywords: TS, timestep, set, options, database
93 
94 .seealso: TSGetType()
95 @*/
96 PetscErrorCode  TSSetFromOptions(TS ts)
97 {
98   PetscBool              opt,flg;
99   PetscErrorCode         ierr;
100   PetscViewer            monviewer;
101   char                   monfilename[PETSC_MAX_PATH_LEN];
102   SNES                   snes;
103   TSAdapt                adapt;
104   PetscReal              time_step;
105   TSExactFinalTimeOption eftopt;
106   char                   dir[16];
107 
108   PetscFunctionBegin;
109   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
110   ierr = PetscObjectOptionsBegin((PetscObject)ts);CHKERRQ(ierr);
111   /* Handle TS type options */
112   ierr = TSSetTypeFromOptions(ts);CHKERRQ(ierr);
113 
114   /* Handle generic TS options */
115   ierr = PetscOptionsInt("-ts_max_steps","Maximum number of time steps","TSSetDuration",ts->max_steps,&ts->max_steps,NULL);CHKERRQ(ierr);
116   ierr = PetscOptionsReal("-ts_final_time","Time to run to","TSSetDuration",ts->max_time,&ts->max_time,NULL);CHKERRQ(ierr);
117   ierr = PetscOptionsReal("-ts_init_time","Initial time","TSSetTime",ts->ptime,&ts->ptime,NULL);CHKERRQ(ierr);
118   ierr = PetscOptionsReal("-ts_dt","Initial time step","TSSetTimeStep",ts->time_step,&time_step,&flg);CHKERRQ(ierr);
119   if (flg) {
120     ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
121   }
122   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);
123   if (flg) {ierr = TSSetExactFinalTime(ts,eftopt);CHKERRQ(ierr);}
124   ierr = PetscOptionsInt("-ts_max_snes_failures","Maximum number of nonlinear solve failures","TSSetMaxSNESFailures",ts->max_snes_failures,&ts->max_snes_failures,NULL);CHKERRQ(ierr);
125   ierr = PetscOptionsInt("-ts_max_reject","Maximum number of step rejections before step fails","TSSetMaxStepRejections",ts->max_reject,&ts->max_reject,NULL);CHKERRQ(ierr);
126   ierr = PetscOptionsBool("-ts_error_if_step_fails","Error if no step succeeds","TSSetErrorIfStepFails",ts->errorifstepfailed,&ts->errorifstepfailed,NULL);CHKERRQ(ierr);
127   ierr = PetscOptionsReal("-ts_rtol","Relative tolerance for local truncation error","TSSetTolerances",ts->rtol,&ts->rtol,NULL);CHKERRQ(ierr);
128   ierr = PetscOptionsReal("-ts_atol","Absolute tolerance for local truncation error","TSSetTolerances",ts->atol,&ts->atol,NULL);CHKERRQ(ierr);
129 
130 #if defined(PETSC_HAVE_SAWS)
131   {
132   PetscBool set;
133   flg  = PETSC_FALSE;
134   ierr = PetscOptionsBool("-ts_saws_block","Block for SAWs memory snooper at end of TSSolve","PetscObjectSAWsBlock",((PetscObject)ts)->amspublishblock,&flg,&set);CHKERRQ(ierr);
135   if (set) {
136     ierr = PetscObjectSAWsSetBlock((PetscObject)ts,flg);CHKERRQ(ierr);
137   }
138   }
139 #endif
140 
141   /* Monitor options */
142   ierr = PetscOptionsString("-ts_monitor","Monitor timestep size","TSMonitorDefault","stdout",monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
143   if (flg) {
144     ierr = PetscViewerASCIIOpen(PetscObjectComm((PetscObject)ts),monfilename,&monviewer);CHKERRQ(ierr);
145     ierr = TSMonitorSet(ts,TSMonitorDefault,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
146   }
147   ierr = PetscOptionsString("-ts_monitor_python","Use Python function","TSMonitorSet",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
148   if (flg) {ierr = PetscPythonMonitorSet((PetscObject)ts,monfilename);CHKERRQ(ierr);}
149 
150   ierr = PetscOptionsName("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",&opt);CHKERRQ(ierr);
151   if (opt) {
152     TSMonitorLGCtx ctx;
153     PetscInt       howoften = 1;
154 
155     ierr = PetscOptionsInt("-ts_monitor_lg_timestep","Monitor timestep size graphically","TSMonitorLGTimeStep",howoften,&howoften,NULL);CHKERRQ(ierr);
156     ierr = TSMonitorLGCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
157     ierr = TSMonitorSet(ts,TSMonitorLGTimeStep,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
158   }
159   ierr = PetscOptionsName("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",&opt);CHKERRQ(ierr);
160   if (opt) {
161     TSMonitorLGCtx ctx;
162     PetscInt       howoften = 1;
163 
164     ierr = PetscOptionsInt("-ts_monitor_lg_solution","Monitor solution graphically","TSMonitorLGSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
165     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
166     ierr = TSMonitorSet(ts,TSMonitorLGSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
167   }
168   ierr = PetscOptionsName("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",&opt);CHKERRQ(ierr);
169   if (opt) {
170     TSMonitorLGCtx ctx;
171     PetscInt       howoften = 1;
172 
173     ierr = PetscOptionsInt("-ts_monitor_lg_error","Monitor error graphically","TSMonitorLGError",howoften,&howoften,NULL);CHKERRQ(ierr);
174     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
175     ierr = TSMonitorSet(ts,TSMonitorLGError,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
176   }
177   ierr = PetscOptionsName("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",&opt);CHKERRQ(ierr);
178   if (opt) {
179     TSMonitorLGCtx ctx;
180     PetscInt       howoften = 1;
181 
182     ierr = PetscOptionsInt("-ts_monitor_lg_snes_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGSNESIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
183     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
184     ierr = TSMonitorSet(ts,TSMonitorLGSNESIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
185   }
186   ierr = PetscOptionsName("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",&opt);CHKERRQ(ierr);
187   if (opt) {
188     TSMonitorLGCtx ctx;
189     PetscInt       howoften = 1;
190 
191     ierr = PetscOptionsInt("-ts_monitor_lg_ksp_iterations","Monitor number nonlinear iterations for each timestep graphically","TSMonitorLGKSPIterations",howoften,&howoften,NULL);CHKERRQ(ierr);
192     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,howoften,&ctx);CHKERRQ(ierr);
193     ierr = TSMonitorSet(ts,TSMonitorLGKSPIterations,ctx,(PetscErrorCode (*)(void**))TSMonitorLGCtxDestroy);CHKERRQ(ierr);
194   }
195   ierr = PetscOptionsName("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",&opt);CHKERRQ(ierr);
196   if (opt) {
197     TSMonitorSPEigCtx ctx;
198     PetscInt          howoften = 1;
199 
200     ierr = PetscOptionsInt("-ts_monitor_sp_eig","Monitor eigenvalues of linearized operator graphically","TSMonitorSPEig",howoften,&howoften,NULL);CHKERRQ(ierr);
201     ierr = TSMonitorSPEigCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
202     ierr = TSMonitorSet(ts,TSMonitorSPEig,ctx,(PetscErrorCode (*)(void**))TSMonitorSPEigCtxDestroy);CHKERRQ(ierr);
203   }
204   opt  = PETSC_FALSE;
205   ierr = PetscOptionsName("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",&opt);CHKERRQ(ierr);
206   if (opt) {
207     TSMonitorDrawCtx ctx;
208     PetscInt         howoften = 1;
209 
210     ierr = PetscOptionsInt("-ts_monitor_draw_solution","Monitor solution graphically","TSMonitorDrawSolution",howoften,&howoften,NULL);CHKERRQ(ierr);
211     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
212     ierr = TSMonitorSet(ts,TSMonitorDrawSolution,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
213   }
214   opt  = PETSC_FALSE;
215   ierr = PetscOptionsName("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",&opt);CHKERRQ(ierr);
216   if (opt) {
217     TSMonitorDrawCtx ctx;
218     PetscReal        bounds[4];
219     PetscInt         n = 4;
220     PetscDraw        draw;
221 
222     ierr = PetscOptionsRealArray("-ts_monitor_draw_solution_phase","Monitor solution graphically","TSMonitorDrawSolutionPhase",bounds,&n,NULL);CHKERRQ(ierr);
223     if (n != 4) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Must provide bounding box of phase field");
224     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,1,&ctx);CHKERRQ(ierr);
225     ierr = PetscViewerDrawGetDraw(ctx->viewer,0,&draw);CHKERRQ(ierr);
226     ierr = PetscDrawClear(draw);CHKERRQ(ierr);
227     ierr = PetscDrawAxisCreate(draw,&ctx->axis);CHKERRQ(ierr);
228     ierr = PetscDrawAxisSetLimits(ctx->axis,bounds[0],bounds[2],bounds[1],bounds[3]);CHKERRQ(ierr);
229     ierr = PetscDrawAxisSetLabels(ctx->axis,"Phase Diagram","Variable 1","Variable 2");CHKERRQ(ierr);
230     ierr = PetscDrawAxisDraw(ctx->axis);CHKERRQ(ierr);
231     /* ierr = PetscDrawSetCoordinates(draw,bounds[0],bounds[1],bounds[2],bounds[3]);CHKERRQ(ierr); */
232     ierr = TSMonitorSet(ts,TSMonitorDrawSolutionPhase,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
233   }
234   opt  = PETSC_FALSE;
235   ierr = PetscOptionsName("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",&opt);CHKERRQ(ierr);
236   if (opt) {
237     TSMonitorDrawCtx ctx;
238     PetscInt         howoften = 1;
239 
240     ierr = PetscOptionsInt("-ts_monitor_draw_error","Monitor error graphically","TSMonitorDrawError",howoften,&howoften,NULL);CHKERRQ(ierr);
241     ierr = TSMonitorDrawCtxCreate(PetscObjectComm((PetscObject)ts),0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&ctx);CHKERRQ(ierr);
242     ierr = TSMonitorSet(ts,TSMonitorDrawError,ctx,(PetscErrorCode (*)(void**))TSMonitorDrawCtxDestroy);CHKERRQ(ierr);
243   }
244   opt  = PETSC_FALSE;
245   ierr = PetscOptionsString("-ts_monitor_solution_binary","Save each solution to a binary file","TSMonitorSolutionBinary",0,monfilename,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
246   if (flg) {
247     PetscViewer ctx;
248     if (monfilename[0]) {
249       ierr = PetscViewerBinaryOpen(PetscObjectComm((PetscObject)ts),monfilename,FILE_MODE_WRITE,&ctx);CHKERRQ(ierr);
250       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))PetscViewerDestroy);CHKERRQ(ierr);
251     } else {
252       ctx = PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)ts));
253       ierr = TSMonitorSet(ts,TSMonitorSolutionBinary,ctx,(PetscErrorCode (*)(void**))NULL);CHKERRQ(ierr);
254     }
255   }
256   opt  = PETSC_FALSE;
257   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);
258   if (flg) {
259     const char *ptr,*ptr2;
260     char       *filetemplate;
261     if (!monfilename[0]) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
262     /* Do some cursory validation of the input. */
263     ierr = PetscStrstr(monfilename,"%",(char**)&ptr);CHKERRQ(ierr);
264     if (!ptr) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"-ts_monitor_solution_vtk requires a file template, e.g. filename-%%03D.vts");
265     for (ptr++; ptr && *ptr; ptr++) {
266       ierr = PetscStrchr("DdiouxX",*ptr,(char**)&ptr2);CHKERRQ(ierr);
267       if (!ptr2 && (*ptr < '0' || '9' < *ptr)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Invalid file template argument to -ts_monitor_solution_vtk, should look like filename-%%03D.vts");
268       if (ptr2) break;
269     }
270     ierr = PetscStrallocpy(monfilename,&filetemplate);CHKERRQ(ierr);
271     ierr = TSMonitorSet(ts,TSMonitorSolutionVTK,filetemplate,(PetscErrorCode (*)(void**))TSMonitorSolutionVTKDestroy);CHKERRQ(ierr);
272   }
273 
274   ierr = PetscOptionsString("-ts_monitor_dmda_ray","Display a ray of the solution","None","y=0",dir,16,&flg);CHKERRQ(ierr);
275   if (flg) {
276     TSMonitorDMDARayCtx *rayctx;
277     int                  ray = 0;
278     DMDADirection        ddir;
279     DM                   da;
280     PetscMPIInt          rank;
281 
282     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
283     if (dir[0] == 'x') ddir = DMDA_X;
284     else if (dir[0] == 'y') ddir = DMDA_Y;
285     else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Unknown ray %s",dir);
286     sscanf(dir+2,"%d",&ray);
287 
288     ierr = PetscInfo2(((PetscObject)ts),"Displaying DMDA ray %c = %D\n",dir[0],ray);CHKERRQ(ierr);
289     ierr = PetscNew(&rayctx);CHKERRQ(ierr);
290     ierr = TSGetDM(ts,&da);CHKERRQ(ierr);
291     ierr = DMDAGetRay(da,ddir,ray,&rayctx->ray,&rayctx->scatter);CHKERRQ(ierr);
292     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)ts),&rank);CHKERRQ(ierr);
293     if (!rank) {
294       ierr = PetscViewerDrawOpen(PETSC_COMM_SELF,0,0,0,0,600,300,&rayctx->viewer);CHKERRQ(ierr);
295     }
296     rayctx->lgctx = NULL;
297     ierr = TSMonitorSet(ts,TSMonitorDMDARay,rayctx,TSMonitorDMDARayDestroy);CHKERRQ(ierr);
298   }
299   ierr = PetscOptionsString("-ts_monitor_lg_dmda_ray","Display a ray of the solution","None","x=0",dir,16,&flg);CHKERRQ(ierr);
300   if (flg) {
301     TSMonitorDMDARayCtx *rayctx;
302     int                 ray = 0;
303     DMDADirection       ddir;
304     DM                  da;
305     PetscInt            howoften = 1;
306 
307     if (dir[1] != '=') SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Malformed ray %s", dir);
308     if      (dir[0] == 'x') ddir = DMDA_X;
309     else if (dir[0] == 'y') ddir = DMDA_Y;
310     else SETERRQ1(PetscObjectComm((PetscObject) ts), PETSC_ERR_ARG_WRONG, "Unknown ray direction %s", dir);
311     sscanf(dir+2, "%d", &ray);
312 
313     ierr = PetscInfo2(((PetscObject) ts),"Displaying LG DMDA ray %c = %D\n", dir[0], ray);CHKERRQ(ierr);
314     ierr = PetscNew(&rayctx);CHKERRQ(ierr);
315     ierr = TSGetDM(ts, &da);CHKERRQ(ierr);
316     ierr = DMDAGetRay(da, ddir, ray, &rayctx->ray, &rayctx->scatter);CHKERRQ(ierr);
317     ierr = TSMonitorLGCtxCreate(PETSC_COMM_SELF,0,0,PETSC_DECIDE,PETSC_DECIDE,600,400,howoften,&rayctx->lgctx);CHKERRQ(ierr);
318     ierr = TSMonitorSet(ts, TSMonitorLGDMDARay, rayctx, TSMonitorDMDARayDestroy);CHKERRQ(ierr);
319   }
320 
321   /*
322      This code is all wrong. One is creating objects inside the TSSetFromOptions() so if run with the options gui
323      will bleed memory. Also one is using a PetscOptionsBegin() inside a PetscOptionsBegin()
324   */
325   ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
326   ierr = TSAdaptSetFromOptions(adapt);CHKERRQ(ierr);
327 
328   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
329   if (ts->problem_type == TS_LINEAR) {ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);}
330 
331   /* Handle specific TS options */
332   if (ts->ops->setfromoptions) {
333     ierr = (*ts->ops->setfromoptions)(ts);CHKERRQ(ierr);
334   }
335 
336   /* process any options handlers added with PetscObjectAddOptionsHandler() */
337   ierr = PetscObjectProcessOptionsHandlers((PetscObject)ts);CHKERRQ(ierr);
338   ierr = PetscOptionsEnd();CHKERRQ(ierr);
339   PetscFunctionReturn(0);
340 }
341 
342 #undef __FUNCT__
343 #undef __FUNCT__
344 #define __FUNCT__ "TSComputeRHSJacobian"
345 /*@
346    TSComputeRHSJacobian - Computes the Jacobian matrix that has been
347       set with TSSetRHSJacobian().
348 
349    Collective on TS and Vec
350 
351    Input Parameters:
352 +  ts - the TS context
353 .  t - current timestep
354 -  U - input vector
355 
356    Output Parameters:
357 +  A - Jacobian matrix
358 .  B - optional preconditioning matrix
359 -  flag - flag indicating matrix structure
360 
361    Notes:
362    Most users should not need to explicitly call this routine, as it
363    is used internally within the nonlinear solvers.
364 
365    See KSPSetOperators() for important information about setting the
366    flag parameter.
367 
368    Level: developer
369 
370 .keywords: SNES, compute, Jacobian, matrix
371 
372 .seealso:  TSSetRHSJacobian(), KSPSetOperators()
373 @*/
374 PetscErrorCode  TSComputeRHSJacobian(TS ts,PetscReal t,Vec U,Mat A,Mat B)
375 {
376   PetscErrorCode ierr;
377   PetscObjectState Ustate;
378   DM             dm;
379   DMTS           tsdm;
380   TSRHSJacobian  rhsjacobianfunc;
381   void           *ctx;
382   TSIJacobian    ijacobianfunc;
383 
384   PetscFunctionBegin;
385   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
386   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
387   PetscCheckSameComm(ts,1,U,3);
388   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
389   ierr = DMGetDMTS(dm,&tsdm);CHKERRQ(ierr);
390   ierr = DMTSGetRHSJacobian(dm,&rhsjacobianfunc,&ctx);CHKERRQ(ierr);
391   ierr = DMTSGetIJacobian(dm,&ijacobianfunc,NULL);CHKERRQ(ierr);
392   ierr = PetscObjectStateGet((PetscObject)U,&Ustate);CHKERRQ(ierr);
393   if (ts->rhsjacobian.time == t && (ts->problem_type == TS_LINEAR || (ts->rhsjacobian.X == U && ts->rhsjacobian.Xstate == Ustate))) {
394     PetscFunctionReturn(0);
395   }
396 
397   if (!rhsjacobianfunc && !ijacobianfunc) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
398 
399   if (ts->rhsjacobian.reuse) {
400     ierr = MatShift(A,-ts->rhsjacobian.shift);CHKERRQ(ierr);
401     ierr = MatScale(A,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
402     if (A != B) {
403       ierr = MatShift(B,-ts->rhsjacobian.shift);CHKERRQ(ierr);
404       ierr = MatScale(B,1./ts->rhsjacobian.scale);CHKERRQ(ierr);
405     }
406     ts->rhsjacobian.shift = 0;
407     ts->rhsjacobian.scale = 1.;
408   }
409 
410   if (rhsjacobianfunc) {
411     ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
412     PetscStackPush("TS user Jacobian function");
413     ierr = (*rhsjacobianfunc)(ts,t,U,A,B,ctx);CHKERRQ(ierr);
414     PetscStackPop;
415     ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
416     /* make sure user returned a correct Jacobian and preconditioner */
417     PetscValidHeaderSpecific(A,MAT_CLASSID,4);
418     PetscValidHeaderSpecific(B,MAT_CLASSID,5);
419   } else {
420     ierr = MatZeroEntries(A);CHKERRQ(ierr);
421     if (A != B) {ierr = MatZeroEntries(B);CHKERRQ(ierr);}
422   }
423   ts->rhsjacobian.time       = t;
424   ts->rhsjacobian.X          = U;
425   ierr                       = PetscObjectStateGet((PetscObject)U,&ts->rhsjacobian.Xstate);CHKERRQ(ierr);
426   PetscFunctionReturn(0);
427 }
428 
429 #undef __FUNCT__
430 #define __FUNCT__ "TSComputeRHSFunction"
431 /*@
432    TSComputeRHSFunction - Evaluates the right-hand-side function.
433 
434    Collective on TS and Vec
435 
436    Input Parameters:
437 +  ts - the TS context
438 .  t - current time
439 -  U - state vector
440 
441    Output Parameter:
442 .  y - right hand side
443 
444    Note:
445    Most users should not need to explicitly call this routine, as it
446    is used internally within the nonlinear solvers.
447 
448    Level: developer
449 
450 .keywords: TS, compute
451 
452 .seealso: TSSetRHSFunction(), TSComputeIFunction()
453 @*/
454 PetscErrorCode TSComputeRHSFunction(TS ts,PetscReal t,Vec U,Vec y)
455 {
456   PetscErrorCode ierr;
457   TSRHSFunction  rhsfunction;
458   TSIFunction    ifunction;
459   void           *ctx;
460   DM             dm;
461 
462   PetscFunctionBegin;
463   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
464   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
465   PetscValidHeaderSpecific(y,VEC_CLASSID,4);
466   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
467   ierr = DMTSGetRHSFunction(dm,&rhsfunction,&ctx);CHKERRQ(ierr);
468   ierr = DMTSGetIFunction(dm,&ifunction,NULL);CHKERRQ(ierr);
469 
470   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
471 
472   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
473   if (rhsfunction) {
474     PetscStackPush("TS user right-hand-side function");
475     ierr = (*rhsfunction)(ts,t,U,y,ctx);CHKERRQ(ierr);
476     PetscStackPop;
477   } else {
478     ierr = VecZeroEntries(y);CHKERRQ(ierr);
479   }
480 
481   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,y,0);CHKERRQ(ierr);
482   PetscFunctionReturn(0);
483 }
484 
485 #undef __FUNCT__
486 #define __FUNCT__ "TSComputeSolutionFunction"
487 /*@
488    TSComputeSolutionFunction - Evaluates the solution function.
489 
490    Collective on TS and Vec
491 
492    Input Parameters:
493 +  ts - the TS context
494 -  t - current time
495 
496    Output Parameter:
497 .  U - the solution
498 
499    Note:
500    Most users should not need to explicitly call this routine, as it
501    is used internally within the nonlinear solvers.
502 
503    Level: developer
504 
505 .keywords: TS, compute
506 
507 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
508 @*/
509 PetscErrorCode TSComputeSolutionFunction(TS ts,PetscReal t,Vec U)
510 {
511   PetscErrorCode     ierr;
512   TSSolutionFunction solutionfunction;
513   void               *ctx;
514   DM                 dm;
515 
516   PetscFunctionBegin;
517   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
518   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
519   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
520   ierr = DMTSGetSolutionFunction(dm,&solutionfunction,&ctx);CHKERRQ(ierr);
521 
522   if (solutionfunction) {
523     PetscStackPush("TS user solution function");
524     ierr = (*solutionfunction)(ts,t,U,ctx);CHKERRQ(ierr);
525     PetscStackPop;
526   }
527   PetscFunctionReturn(0);
528 }
529 #undef __FUNCT__
530 #define __FUNCT__ "TSComputeForcingFunction"
531 /*@
532    TSComputeForcingFunction - Evaluates the forcing function.
533 
534    Collective on TS and Vec
535 
536    Input Parameters:
537 +  ts - the TS context
538 -  t - current time
539 
540    Output Parameter:
541 .  U - the function value
542 
543    Note:
544    Most users should not need to explicitly call this routine, as it
545    is used internally within the nonlinear solvers.
546 
547    Level: developer
548 
549 .keywords: TS, compute
550 
551 .seealso: TSSetSolutionFunction(), TSSetRHSFunction(), TSComputeIFunction()
552 @*/
553 PetscErrorCode TSComputeForcingFunction(TS ts,PetscReal t,Vec U)
554 {
555   PetscErrorCode     ierr, (*forcing)(TS,PetscReal,Vec,void*);
556   void               *ctx;
557   DM                 dm;
558 
559   PetscFunctionBegin;
560   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
561   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
562   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
563   ierr = DMTSGetForcingFunction(dm,&forcing,&ctx);CHKERRQ(ierr);
564 
565   if (forcing) {
566     PetscStackPush("TS user forcing function");
567     ierr = (*forcing)(ts,t,U,ctx);CHKERRQ(ierr);
568     PetscStackPop;
569   }
570   PetscFunctionReturn(0);
571 }
572 
573 #undef __FUNCT__
574 #define __FUNCT__ "TSGetRHSVec_Private"
575 static PetscErrorCode TSGetRHSVec_Private(TS ts,Vec *Frhs)
576 {
577   Vec            F;
578   PetscErrorCode ierr;
579 
580   PetscFunctionBegin;
581   *Frhs = NULL;
582   ierr  = TSGetIFunction(ts,&F,NULL,NULL);CHKERRQ(ierr);
583   if (!ts->Frhs) {
584     ierr = VecDuplicate(F,&ts->Frhs);CHKERRQ(ierr);
585   }
586   *Frhs = ts->Frhs;
587   PetscFunctionReturn(0);
588 }
589 
590 #undef __FUNCT__
591 #define __FUNCT__ "TSGetRHSMats_Private"
592 static PetscErrorCode TSGetRHSMats_Private(TS ts,Mat *Arhs,Mat *Brhs)
593 {
594   Mat            A,B;
595   PetscErrorCode ierr;
596 
597   PetscFunctionBegin;
598   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
599   if (Arhs) {
600     if (!ts->Arhs) {
601       ierr = MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&ts->Arhs);CHKERRQ(ierr);
602     }
603     *Arhs = ts->Arhs;
604   }
605   if (Brhs) {
606     if (!ts->Brhs) {
607       if (A != B) {
608         ierr = MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&ts->Brhs);CHKERRQ(ierr);
609       } else {
610         ts->Brhs = ts->Arhs;
611         ierr = PetscObjectReference((PetscObject)ts->Arhs);CHKERRQ(ierr);
612       }
613     }
614     *Brhs = ts->Brhs;
615   }
616   PetscFunctionReturn(0);
617 }
618 
619 #undef __FUNCT__
620 #define __FUNCT__ "TSComputeIFunction"
621 /*@
622    TSComputeIFunction - Evaluates the DAE residual written in implicit form F(t,U,Udot)=0
623 
624    Collective on TS and Vec
625 
626    Input Parameters:
627 +  ts - the TS context
628 .  t - current time
629 .  U - state vector
630 .  Udot - time derivative of state vector
631 -  imex - flag indicates if the method is IMEX so that the RHSFunction should be kept separate
632 
633    Output Parameter:
634 .  Y - right hand side
635 
636    Note:
637    Most users should not need to explicitly call this routine, as it
638    is used internally within the nonlinear solvers.
639 
640    If the user did did not write their equations in implicit form, this
641    function recasts them in implicit form.
642 
643    Level: developer
644 
645 .keywords: TS, compute
646 
647 .seealso: TSSetIFunction(), TSComputeRHSFunction()
648 @*/
649 PetscErrorCode TSComputeIFunction(TS ts,PetscReal t,Vec U,Vec Udot,Vec Y,PetscBool imex)
650 {
651   PetscErrorCode ierr;
652   TSIFunction    ifunction;
653   TSRHSFunction  rhsfunction;
654   void           *ctx;
655   DM             dm;
656 
657   PetscFunctionBegin;
658   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
659   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
660   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
661   PetscValidHeaderSpecific(Y,VEC_CLASSID,5);
662 
663   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
664   ierr = DMTSGetIFunction(dm,&ifunction,&ctx);CHKERRQ(ierr);
665   ierr = DMTSGetRHSFunction(dm,&rhsfunction,NULL);CHKERRQ(ierr);
666 
667   if (!rhsfunction && !ifunction) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSFunction() and / or TSSetIFunction()");
668 
669   ierr = PetscLogEventBegin(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
670   if (ifunction) {
671     PetscStackPush("TS user implicit function");
672     ierr = (*ifunction)(ts,t,U,Udot,Y,ctx);CHKERRQ(ierr);
673     PetscStackPop;
674   }
675   if (imex) {
676     if (!ifunction) {
677       ierr = VecCopy(Udot,Y);CHKERRQ(ierr);
678     }
679   } else if (rhsfunction) {
680     if (ifunction) {
681       Vec Frhs;
682       ierr = TSGetRHSVec_Private(ts,&Frhs);CHKERRQ(ierr);
683       ierr = TSComputeRHSFunction(ts,t,U,Frhs);CHKERRQ(ierr);
684       ierr = VecAXPY(Y,-1,Frhs);CHKERRQ(ierr);
685     } else {
686       ierr = TSComputeRHSFunction(ts,t,U,Y);CHKERRQ(ierr);
687       ierr = VecAYPX(Y,-1,Udot);CHKERRQ(ierr);
688     }
689   }
690   ierr = PetscLogEventEnd(TS_FunctionEval,ts,U,Udot,Y);CHKERRQ(ierr);
691   PetscFunctionReturn(0);
692 }
693 
694 #undef __FUNCT__
695 #define __FUNCT__ "TSComputeIJacobian"
696 /*@
697    TSComputeIJacobian - Evaluates the Jacobian of the DAE
698 
699    Collective on TS and Vec
700 
701    Input
702       Input Parameters:
703 +  ts - the TS context
704 .  t - current timestep
705 .  U - state vector
706 .  Udot - time derivative of state vector
707 .  shift - shift to apply, see note below
708 -  imex - flag indicates if the method is IMEX so that the RHSJacobian should be kept separate
709 
710    Output Parameters:
711 +  A - Jacobian matrix
712 .  B - optional preconditioning matrix
713 -  flag - flag indicating matrix structure
714 
715    Notes:
716    If F(t,U,Udot)=0 is the DAE, the required Jacobian is
717 
718    dF/dU + shift*dF/dUdot
719 
720    Most users should not need to explicitly call this routine, as it
721    is used internally within the nonlinear solvers.
722 
723    Level: developer
724 
725 .keywords: TS, compute, Jacobian, matrix
726 
727 .seealso:  TSSetIJacobian()
728 @*/
729 PetscErrorCode TSComputeIJacobian(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,PetscBool imex)
730 {
731   PetscErrorCode ierr;
732   TSIJacobian    ijacobian;
733   TSRHSJacobian  rhsjacobian;
734   DM             dm;
735   void           *ctx;
736 
737   PetscFunctionBegin;
738   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
739   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
740   PetscValidHeaderSpecific(Udot,VEC_CLASSID,4);
741   PetscValidPointer(A,6);
742   PetscValidHeaderSpecific(A,MAT_CLASSID,6);
743   PetscValidPointer(B,7);
744   PetscValidHeaderSpecific(B,MAT_CLASSID,7);
745 
746   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
747   ierr = DMTSGetIJacobian(dm,&ijacobian,&ctx);CHKERRQ(ierr);
748   ierr = DMTSGetRHSJacobian(dm,&rhsjacobian,NULL);CHKERRQ(ierr);
749 
750   if (!rhsjacobian && !ijacobian) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_USER,"Must call TSSetRHSJacobian() and / or TSSetIJacobian()");
751 
752   ierr = PetscLogEventBegin(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
753   if (ijacobian) {
754     PetscStackPush("TS user implicit Jacobian");
755     ierr = (*ijacobian)(ts,t,U,Udot,shift,A,B,ctx);CHKERRQ(ierr);
756     PetscStackPop;
757     /* make sure user returned a correct Jacobian and preconditioner */
758     PetscValidHeaderSpecific(A,MAT_CLASSID,4);
759     PetscValidHeaderSpecific(B,MAT_CLASSID,5);
760   }
761   if (imex) {
762     if (!ijacobian) {  /* system was written as Udot = G(t,U) */
763       ierr = MatZeroEntries(A);CHKERRQ(ierr);
764       ierr = MatShift(A,shift);CHKERRQ(ierr);
765       if (A != B) {
766         ierr = MatZeroEntries(B);CHKERRQ(ierr);
767         ierr = MatShift(B,shift);CHKERRQ(ierr);
768       }
769     }
770   } else {
771     Mat Arhs = NULL,Brhs = NULL;
772     if (rhsjacobian) {
773       if (ijacobian) {
774         ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
775       } else {
776         ierr = TSGetIJacobian(ts,&Arhs,&Brhs,NULL,NULL);CHKERRQ(ierr);
777       }
778       ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
779     }
780     if (Arhs == A) {           /* No IJacobian, so we only have the RHS matrix */
781       ts->rhsjacobian.scale = -1;
782       ts->rhsjacobian.shift = shift;
783       ierr = MatScale(A,-1);CHKERRQ(ierr);
784       ierr = MatShift(A,shift);CHKERRQ(ierr);
785       if (A != B) {
786         ierr = MatScale(B,-1);CHKERRQ(ierr);
787         ierr = MatShift(B,shift);CHKERRQ(ierr);
788       }
789     } else if (Arhs) {          /* Both IJacobian and RHSJacobian */
790       MatStructure axpy = DIFFERENT_NONZERO_PATTERN;
791       if (!ijacobian) {         /* No IJacobian provided, but we have a separate RHS matrix */
792         ierr = MatZeroEntries(A);CHKERRQ(ierr);
793         ierr = MatShift(A,shift);CHKERRQ(ierr);
794         if (A != B) {
795           ierr = MatZeroEntries(B);CHKERRQ(ierr);
796           ierr = MatShift(B,shift);CHKERRQ(ierr);
797         }
798       }
799       ierr = MatAXPY(A,-1,Arhs,axpy);CHKERRQ(ierr);
800       if (A != B) {
801         ierr = MatAXPY(B,-1,Brhs,axpy);CHKERRQ(ierr);
802       }
803     }
804   }
805   ierr = PetscLogEventEnd(TS_JacobianEval,ts,U,A,B);CHKERRQ(ierr);
806   PetscFunctionReturn(0);
807 }
808 
809 #undef __FUNCT__
810 #define __FUNCT__ "TSSetRHSFunction"
811 /*@C
812     TSSetRHSFunction - Sets the routine for evaluating the function,
813     where U_t = G(t,u).
814 
815     Logically Collective on TS
816 
817     Input Parameters:
818 +   ts - the TS context obtained from TSCreate()
819 .   r - vector to put the computed right hand side (or NULL to have it created)
820 .   f - routine for evaluating the right-hand-side function
821 -   ctx - [optional] user-defined context for private data for the
822           function evaluation routine (may be NULL)
823 
824     Calling sequence of func:
825 $     func (TS ts,PetscReal t,Vec u,Vec F,void *ctx);
826 
827 +   t - current timestep
828 .   u - input vector
829 .   F - function vector
830 -   ctx - [optional] user-defined function context
831 
832     Level: beginner
833 
834 .keywords: TS, timestep, set, right-hand-side, function
835 
836 .seealso: TSSetRHSJacobian(), TSSetIJacobian()
837 @*/
838 PetscErrorCode  TSSetRHSFunction(TS ts,Vec r,PetscErrorCode (*f)(TS,PetscReal,Vec,Vec,void*),void *ctx)
839 {
840   PetscErrorCode ierr;
841   SNES           snes;
842   Vec            ralloc = NULL;
843   DM             dm;
844 
845   PetscFunctionBegin;
846   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
847   if (r) PetscValidHeaderSpecific(r,VEC_CLASSID,2);
848 
849   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
850   ierr = DMTSSetRHSFunction(dm,f,ctx);CHKERRQ(ierr);
851   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
852   if (!r && !ts->dm && ts->vec_sol) {
853     ierr = VecDuplicate(ts->vec_sol,&ralloc);CHKERRQ(ierr);
854     r    = ralloc;
855   }
856   ierr = SNESSetFunction(snes,r,SNESTSFormFunction,ts);CHKERRQ(ierr);
857   ierr = VecDestroy(&ralloc);CHKERRQ(ierr);
858   PetscFunctionReturn(0);
859 }
860 
861 #undef __FUNCT__
862 #define __FUNCT__ "TSSetSolutionFunction"
863 /*@C
864     TSSetSolutionFunction - Provide a function that computes the solution of the ODE or DAE
865 
866     Logically Collective on TS
867 
868     Input Parameters:
869 +   ts - the TS context obtained from TSCreate()
870 .   f - routine for evaluating the solution
871 -   ctx - [optional] user-defined context for private data for the
872           function evaluation routine (may be NULL)
873 
874     Calling sequence of func:
875 $     func (TS ts,PetscReal t,Vec u,void *ctx);
876 
877 +   t - current timestep
878 .   u - output vector
879 -   ctx - [optional] user-defined function context
880 
881     Notes:
882     This routine is used for testing accuracy of time integration schemes when you already know the solution.
883     If analytic solutions are not known for your system, consider using the Method of Manufactured Solutions to
884     create closed-form solutions with non-physical forcing terms.
885 
886     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
887 
888     Level: beginner
889 
890 .keywords: TS, timestep, set, right-hand-side, function
891 
892 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetForcingFunction()
893 @*/
894 PetscErrorCode  TSSetSolutionFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
895 {
896   PetscErrorCode ierr;
897   DM             dm;
898 
899   PetscFunctionBegin;
900   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
901   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
902   ierr = DMTSSetSolutionFunction(dm,f,ctx);CHKERRQ(ierr);
903   PetscFunctionReturn(0);
904 }
905 
906 #undef __FUNCT__
907 #define __FUNCT__ "TSSetForcingFunction"
908 /*@C
909     TSSetForcingFunction - Provide a function that computes a forcing term for a ODE or PDE
910 
911     Logically Collective on TS
912 
913     Input Parameters:
914 +   ts - the TS context obtained from TSCreate()
915 .   f - routine for evaluating the forcing function
916 -   ctx - [optional] user-defined context for private data for the
917           function evaluation routine (may be NULL)
918 
919     Calling sequence of func:
920 $     func (TS ts,PetscReal t,Vec u,void *ctx);
921 
922 +   t - current timestep
923 .   u - output vector
924 -   ctx - [optional] user-defined function context
925 
926     Notes:
927     This routine is useful for testing accuracy of time integration schemes when using the Method of Manufactured Solutions to
928     create closed-form solutions with a non-physical forcing term.
929 
930     For low-dimensional problems solved in serial, such as small discrete systems, TSMonitorLGError() can be used to monitor the error history.
931 
932     Level: beginner
933 
934 .keywords: TS, timestep, set, right-hand-side, function
935 
936 .seealso: TSSetRHSJacobian(), TSSetIJacobian(), TSComputeSolutionFunction(), TSSetSolutionFunction()
937 @*/
938 PetscErrorCode  TSSetForcingFunction(TS ts,PetscErrorCode (*f)(TS,PetscReal,Vec,void*),void *ctx)
939 {
940   PetscErrorCode ierr;
941   DM             dm;
942 
943   PetscFunctionBegin;
944   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
945   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
946   ierr = DMTSSetForcingFunction(dm,f,ctx);CHKERRQ(ierr);
947   PetscFunctionReturn(0);
948 }
949 
950 #undef __FUNCT__
951 #define __FUNCT__ "TSSetRHSJacobian"
952 /*@C
953    TSSetRHSJacobian - Sets the function to compute the Jacobian of F,
954    where U_t = G(U,t), as well as the location to store the matrix.
955 
956    Logically Collective on TS
957 
958    Input Parameters:
959 +  ts  - the TS context obtained from TSCreate()
960 .  Amat - (approximate) Jacobian matrix
961 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
962 .  f   - the Jacobian evaluation routine
963 -  ctx - [optional] user-defined context for private data for the
964          Jacobian evaluation routine (may be NULL)
965 
966    Calling sequence of func:
967 $     func (TS ts,PetscReal t,Vec u,Mat *A,Mat *B,MatStructure *flag,void *ctx);
968 
969 +  t - current timestep
970 .  u - input vector
971 .  Amat - (approximate) Jacobian matrix
972 .  Pmat - matrix from which preconditioner is to be constructed (usually the same as Amat)
973 .  flag - flag indicating information about the preconditioner matrix
974           structure (same as flag in KSPSetOperators())
975 -  ctx - [optional] user-defined context for matrix evaluation routine
976 
977    Notes:
978    See KSPSetOperators() for important information about setting the flag
979    output parameter in the routine func().  Be sure to read this information!
980 
981    The routine func() takes Mat * as the matrix arguments rather than Mat.
982    This allows the matrix evaluation routine to replace A and/or B with a
983    completely new matrix structure (not just different matrix elements)
984    when appropriate, for instance, if the nonzero structure is changing
985    throughout the global iterations.
986 
987    Level: beginner
988 
989 .keywords: TS, timestep, set, right-hand-side, Jacobian
990 
991 .seealso: SNESComputeJacobianDefaultColor(), TSSetRHSFunction(), TSRHSJacobianSetReuse()
992 
993 @*/
994 PetscErrorCode  TSSetRHSJacobian(TS ts,Mat Amat,Mat Pmat,TSRHSJacobian f,void *ctx)
995 {
996   PetscErrorCode ierr;
997   SNES           snes;
998   DM             dm;
999   TSIJacobian    ijacobian;
1000 
1001   PetscFunctionBegin;
1002   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1003   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1004   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1005   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1006   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1007 
1008   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1009   ierr = DMTSSetRHSJacobian(dm,f,ctx);CHKERRQ(ierr);
1010   if (f == TSComputeRHSJacobianConstant) {
1011     /* Handle this case automatically for the user; otherwise user should call themselves. */
1012     ierr = TSRHSJacobianSetReuse(ts,PETSC_TRUE);CHKERRQ(ierr);
1013   }
1014   ierr = DMTSGetIJacobian(dm,&ijacobian,NULL);CHKERRQ(ierr);
1015   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1016   if (!ijacobian) {
1017     ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1018   }
1019   if (Amat) {
1020     ierr = PetscObjectReference((PetscObject)Amat);CHKERRQ(ierr);
1021     ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1022 
1023     ts->Arhs = Amat;
1024   }
1025   if (Pmat) {
1026     ierr = PetscObjectReference((PetscObject)Pmat);CHKERRQ(ierr);
1027     ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1028 
1029     ts->Brhs = Pmat;
1030   }
1031   PetscFunctionReturn(0);
1032 }
1033 
1034 
1035 #undef __FUNCT__
1036 #define __FUNCT__ "TSSetIFunction"
1037 /*@C
1038    TSSetIFunction - Set the function to compute F(t,U,U_t) where F() = 0 is the DAE to be solved.
1039 
1040    Logically Collective on TS
1041 
1042    Input Parameters:
1043 +  ts  - the TS context obtained from TSCreate()
1044 .  r   - vector to hold the residual (or NULL to have it created internally)
1045 .  f   - the function evaluation routine
1046 -  ctx - user-defined context for private data for the function evaluation routine (may be NULL)
1047 
1048    Calling sequence of f:
1049 $  f(TS ts,PetscReal t,Vec u,Vec u_t,Vec F,ctx);
1050 
1051 +  t   - time at step/stage being solved
1052 .  u   - state vector
1053 .  u_t - time derivative of state vector
1054 .  F   - function vector
1055 -  ctx - [optional] user-defined context for matrix evaluation routine
1056 
1057    Important:
1058    The user MUST call either this routine, TSSetRHSFunction().  This routine must be used when not solving an ODE, for example a DAE.
1059 
1060    Level: beginner
1061 
1062 .keywords: TS, timestep, set, DAE, Jacobian
1063 
1064 .seealso: TSSetRHSJacobian(), TSSetRHSFunction(), TSSetIJacobian()
1065 @*/
1066 PetscErrorCode  TSSetIFunction(TS ts,Vec res,TSIFunction f,void *ctx)
1067 {
1068   PetscErrorCode ierr;
1069   SNES           snes;
1070   Vec            resalloc = NULL;
1071   DM             dm;
1072 
1073   PetscFunctionBegin;
1074   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1075   if (res) PetscValidHeaderSpecific(res,VEC_CLASSID,2);
1076 
1077   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1078   ierr = DMTSSetIFunction(dm,f,ctx);CHKERRQ(ierr);
1079 
1080   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1081   if (!res && !ts->dm && ts->vec_sol) {
1082     ierr = VecDuplicate(ts->vec_sol,&resalloc);CHKERRQ(ierr);
1083     res  = resalloc;
1084   }
1085   ierr = SNESSetFunction(snes,res,SNESTSFormFunction,ts);CHKERRQ(ierr);
1086   ierr = VecDestroy(&resalloc);CHKERRQ(ierr);
1087   PetscFunctionReturn(0);
1088 }
1089 
1090 #undef __FUNCT__
1091 #define __FUNCT__ "TSGetIFunction"
1092 /*@C
1093    TSGetIFunction - Returns the vector where the implicit residual is stored and the function/contex to compute it.
1094 
1095    Not Collective
1096 
1097    Input Parameter:
1098 .  ts - the TS context
1099 
1100    Output Parameter:
1101 +  r - vector to hold residual (or NULL)
1102 .  func - the function to compute residual (or NULL)
1103 -  ctx - the function context (or NULL)
1104 
1105    Level: advanced
1106 
1107 .keywords: TS, nonlinear, get, function
1108 
1109 .seealso: TSSetIFunction(), SNESGetFunction()
1110 @*/
1111 PetscErrorCode TSGetIFunction(TS ts,Vec *r,TSIFunction *func,void **ctx)
1112 {
1113   PetscErrorCode ierr;
1114   SNES           snes;
1115   DM             dm;
1116 
1117   PetscFunctionBegin;
1118   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1119   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1120   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1121   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1122   ierr = DMTSGetIFunction(dm,func,ctx);CHKERRQ(ierr);
1123   PetscFunctionReturn(0);
1124 }
1125 
1126 #undef __FUNCT__
1127 #define __FUNCT__ "TSGetRHSFunction"
1128 /*@C
1129    TSGetRHSFunction - Returns the vector where the right hand side is stored and the function/context to compute it.
1130 
1131    Not Collective
1132 
1133    Input Parameter:
1134 .  ts - the TS context
1135 
1136    Output Parameter:
1137 +  r - vector to hold computed right hand side (or NULL)
1138 .  func - the function to compute right hand side (or NULL)
1139 -  ctx - the function context (or NULL)
1140 
1141    Level: advanced
1142 
1143 .keywords: TS, nonlinear, get, function
1144 
1145 .seealso: TSSetRhsfunction(), SNESGetFunction()
1146 @*/
1147 PetscErrorCode TSGetRHSFunction(TS ts,Vec *r,TSRHSFunction *func,void **ctx)
1148 {
1149   PetscErrorCode ierr;
1150   SNES           snes;
1151   DM             dm;
1152 
1153   PetscFunctionBegin;
1154   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1155   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1156   ierr = SNESGetFunction(snes,r,NULL,NULL);CHKERRQ(ierr);
1157   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1158   ierr = DMTSGetRHSFunction(dm,func,ctx);CHKERRQ(ierr);
1159   PetscFunctionReturn(0);
1160 }
1161 
1162 #undef __FUNCT__
1163 #define __FUNCT__ "TSSetIJacobian"
1164 /*@C
1165    TSSetIJacobian - Set the function to compute the matrix dF/dU + a*dF/dU_t where F(t,U,U_t) is the function
1166         you provided with TSSetIFunction().
1167 
1168    Logically Collective on TS
1169 
1170    Input Parameters:
1171 +  ts  - the TS context obtained from TSCreate()
1172 .  Amat - (approximate) Jacobian matrix
1173 .  Pmat - matrix used to compute preconditioner (usually the same as Amat)
1174 .  f   - the Jacobian evaluation routine
1175 -  ctx - user-defined context for private data for the Jacobian evaluation routine (may be NULL)
1176 
1177    Calling sequence of f:
1178 $  f(TS ts,PetscReal t,Vec U,Vec U_t,PetscReal a,Mat *Amat,Mat *Pmat,MatStructure *flag,void *ctx);
1179 
1180 +  t    - time at step/stage being solved
1181 .  U    - state vector
1182 .  U_t  - time derivative of state vector
1183 .  a    - shift
1184 .  Amat - (approximate) Jacobian of F(t,U,W+a*U), equivalent to dF/dU + a*dF/dU_t
1185 .  Pmat - matrix used for constructing preconditioner, usually the same as Amat
1186 .  flag - flag indicating information about the preconditioner matrix
1187           structure (same as flag in KSPSetOperators())
1188 -  ctx  - [optional] user-defined context for matrix evaluation routine
1189 
1190    Notes:
1191    The matrices Amat and Pmat are exactly the matrices that are used by SNES for the nonlinear solve.
1192 
1193    The matrix dF/dU + a*dF/dU_t you provide turns out to be
1194    the Jacobian of F(t,U,W+a*U) where F(t,U,U_t) = 0 is the DAE to be solved.
1195    The time integrator internally approximates U_t by W+a*U where the positive "shift"
1196    a and vector W depend on the integration method, step size, and past states. For example with
1197    the backward Euler method a = 1/dt and W = -a*U(previous timestep) so
1198    W + a*U = a*(U - U(previous timestep)) = (U - U(previous timestep))/dt
1199 
1200    Level: beginner
1201 
1202 .keywords: TS, timestep, DAE, Jacobian
1203 
1204 .seealso: TSSetIFunction(), TSSetRHSJacobian(), SNESComputeJacobianDefaultColor(), SNESComputeJacobianDefault()
1205 
1206 @*/
1207 PetscErrorCode  TSSetIJacobian(TS ts,Mat Amat,Mat Pmat,TSIJacobian f,void *ctx)
1208 {
1209   PetscErrorCode ierr;
1210   SNES           snes;
1211   DM             dm;
1212 
1213   PetscFunctionBegin;
1214   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1215   if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
1216   if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
1217   if (Amat) PetscCheckSameComm(ts,1,Amat,2);
1218   if (Pmat) PetscCheckSameComm(ts,1,Pmat,3);
1219 
1220   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1221   ierr = DMTSSetIJacobian(dm,f,ctx);CHKERRQ(ierr);
1222 
1223   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1224   ierr = SNESSetJacobian(snes,Amat,Pmat,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1225   PetscFunctionReturn(0);
1226 }
1227 
1228 #undef __FUNCT__
1229 #define __FUNCT__ "TSRHSJacobianSetReuse"
1230 /*@
1231    TSRHSJacobianSetReuse - restore RHS Jacobian before re-evaluating.  Without this flag, TS will change the sign and
1232    shift the RHS Jacobian for a finite-time-step implicit solve, in which case the user function will need to recompute
1233    the entire Jacobian.  The reuse flag must be set if the evaluation function will assume that the matrix entries have
1234    not been changed by the TS.
1235 
1236    Logically Collective
1237 
1238    Input Arguments:
1239 +  ts - TS context obtained from TSCreate()
1240 -  reuse - PETSC_TRUE if the RHS Jacobian
1241 
1242    Level: intermediate
1243 
1244 .seealso: TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
1245 @*/
1246 PetscErrorCode TSRHSJacobianSetReuse(TS ts,PetscBool reuse)
1247 {
1248   PetscFunctionBegin;
1249   ts->rhsjacobian.reuse = reuse;
1250   PetscFunctionReturn(0);
1251 }
1252 
1253 #undef __FUNCT__
1254 #define __FUNCT__ "TSLoad"
1255 /*@C
1256   TSLoad - Loads a KSP that has been stored in binary  with KSPView().
1257 
1258   Collective on PetscViewer
1259 
1260   Input Parameters:
1261 + newdm - the newly loaded TS, this needs to have been created with TSCreate() or
1262            some related function before a call to TSLoad().
1263 - viewer - binary file viewer, obtained from PetscViewerBinaryOpen()
1264 
1265    Level: intermediate
1266 
1267   Notes:
1268    The type is determined by the data in the file, any type set into the TS before this call is ignored.
1269 
1270   Notes for advanced users:
1271   Most users should not need to know the details of the binary storage
1272   format, since TSLoad() and TSView() completely hide these details.
1273   But for anyone who's interested, the standard binary matrix storage
1274   format is
1275 .vb
1276      has not yet been determined
1277 .ve
1278 
1279 .seealso: PetscViewerBinaryOpen(), TSView(), MatLoad(), VecLoad()
1280 @*/
1281 PetscErrorCode  TSLoad(TS ts, PetscViewer viewer)
1282 {
1283   PetscErrorCode ierr;
1284   PetscBool      isbinary;
1285   PetscInt       classid;
1286   char           type[256];
1287   DMTS           sdm;
1288   DM             dm;
1289 
1290   PetscFunctionBegin;
1291   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1292   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1293   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1294   if (!isbinary) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Invalid viewer; open viewer with PetscViewerBinaryOpen()");
1295 
1296   ierr = PetscViewerBinaryRead(viewer,&classid,1,PETSC_INT);CHKERRQ(ierr);
1297   if (classid != TS_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_ARG_WRONG,"Not TS next in file");
1298   ierr = PetscViewerBinaryRead(viewer,type,256,PETSC_CHAR);CHKERRQ(ierr);
1299   ierr = TSSetType(ts, type);CHKERRQ(ierr);
1300   if (ts->ops->load) {
1301     ierr = (*ts->ops->load)(ts,viewer);CHKERRQ(ierr);
1302   }
1303   ierr = DMCreate(PetscObjectComm((PetscObject)ts),&dm);CHKERRQ(ierr);
1304   ierr = DMLoad(dm,viewer);CHKERRQ(ierr);
1305   ierr = TSSetDM(ts,dm);CHKERRQ(ierr);
1306   ierr = DMCreateGlobalVector(ts->dm,&ts->vec_sol);CHKERRQ(ierr);
1307   ierr = VecLoad(ts->vec_sol,viewer);CHKERRQ(ierr);
1308   ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1309   ierr = DMTSLoad(sdm,viewer);CHKERRQ(ierr);
1310   PetscFunctionReturn(0);
1311 }
1312 
1313 #include <petscdraw.h>
1314 #if defined(PETSC_HAVE_SAWS)
1315 #include <petscviewersaws.h>
1316 #endif
1317 #undef __FUNCT__
1318 #define __FUNCT__ "TSView"
1319 /*@C
1320     TSView - Prints the TS data structure.
1321 
1322     Collective on TS
1323 
1324     Input Parameters:
1325 +   ts - the TS context obtained from TSCreate()
1326 -   viewer - visualization context
1327 
1328     Options Database Key:
1329 .   -ts_view - calls TSView() at end of TSStep()
1330 
1331     Notes:
1332     The available visualization contexts include
1333 +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
1334 -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
1335          output where only the first processor opens
1336          the file.  All other processors send their
1337          data to the first processor to print.
1338 
1339     The user can open an alternative visualization context with
1340     PetscViewerASCIIOpen() - output to a specified file.
1341 
1342     Level: beginner
1343 
1344 .keywords: TS, timestep, view
1345 
1346 .seealso: PetscViewerASCIIOpen()
1347 @*/
1348 PetscErrorCode  TSView(TS ts,PetscViewer viewer)
1349 {
1350   PetscErrorCode ierr;
1351   TSType         type;
1352   PetscBool      iascii,isstring,isundials,isbinary,isdraw;
1353   DMTS           sdm;
1354 #if defined(PETSC_HAVE_SAWS)
1355   PetscBool      isams;
1356 #endif
1357 
1358   PetscFunctionBegin;
1359   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1360   if (!viewer) {
1361     ierr = PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ts),&viewer);CHKERRQ(ierr);
1362   }
1363   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
1364   PetscCheckSameComm(ts,1,viewer,2);
1365 
1366   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1367   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
1368   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
1369   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
1370 #if defined(PETSC_HAVE_SAWS)
1371   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSAWS,&isams);CHKERRQ(ierr);
1372 #endif
1373   if (iascii) {
1374     ierr = PetscObjectPrintClassNamePrefixType((PetscObject)ts,viewer);CHKERRQ(ierr);
1375     ierr = PetscViewerASCIIPrintf(viewer,"  maximum steps=%D\n",ts->max_steps);CHKERRQ(ierr);
1376     ierr = PetscViewerASCIIPrintf(viewer,"  maximum time=%g\n",(double)ts->max_time);CHKERRQ(ierr);
1377     if (ts->problem_type == TS_NONLINEAR) {
1378       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solver iterations=%D\n",ts->snes_its);CHKERRQ(ierr);
1379       ierr = PetscViewerASCIIPrintf(viewer,"  total number of nonlinear solve failures=%D\n",ts->num_snes_failures);CHKERRQ(ierr);
1380     }
1381     ierr = PetscViewerASCIIPrintf(viewer,"  total number of linear solver iterations=%D\n",ts->ksp_its);CHKERRQ(ierr);
1382     ierr = PetscViewerASCIIPrintf(viewer,"  total number of rejected steps=%D\n",ts->reject);CHKERRQ(ierr);
1383     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1384     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1385     if (ts->ops->view) {
1386       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1387       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1388       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1389     }
1390   } else if (isstring) {
1391     ierr = TSGetType(ts,&type);CHKERRQ(ierr);
1392     ierr = PetscViewerStringSPrintf(viewer," %-7.7s",type);CHKERRQ(ierr);
1393   } else if (isbinary) {
1394     PetscInt    classid = TS_FILE_CLASSID;
1395     MPI_Comm    comm;
1396     PetscMPIInt rank;
1397     char        type[256];
1398 
1399     ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
1400     ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
1401     if (!rank) {
1402       ierr = PetscViewerBinaryWrite(viewer,&classid,1,PETSC_INT,PETSC_FALSE);CHKERRQ(ierr);
1403       ierr = PetscStrncpy(type,((PetscObject)ts)->type_name,256);CHKERRQ(ierr);
1404       ierr = PetscViewerBinaryWrite(viewer,type,256,PETSC_CHAR,PETSC_FALSE);CHKERRQ(ierr);
1405     }
1406     if (ts->ops->view) {
1407       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1408     }
1409     ierr = DMView(ts->dm,viewer);CHKERRQ(ierr);
1410     ierr = VecView(ts->vec_sol,viewer);CHKERRQ(ierr);
1411     ierr = DMGetDMTS(ts->dm,&sdm);CHKERRQ(ierr);
1412     ierr = DMTSView(sdm,viewer);CHKERRQ(ierr);
1413   } else if (isdraw) {
1414     PetscDraw draw;
1415     char      str[36];
1416     PetscReal x,y,bottom,h;
1417 
1418     ierr   = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
1419     ierr   = PetscDrawGetCurrentPoint(draw,&x,&y);CHKERRQ(ierr);
1420     ierr   = PetscStrcpy(str,"TS: ");CHKERRQ(ierr);
1421     ierr   = PetscStrcat(str,((PetscObject)ts)->type_name);CHKERRQ(ierr);
1422     ierr   = PetscDrawBoxedString(draw,x,y,PETSC_DRAW_BLACK,PETSC_DRAW_BLACK,str,NULL,&h);CHKERRQ(ierr);
1423     bottom = y - h;
1424     ierr   = PetscDrawPushCurrentPoint(draw,x,bottom);CHKERRQ(ierr);
1425     if (ts->ops->view) {
1426       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1427     }
1428     ierr = PetscDrawPopCurrentPoint(draw);CHKERRQ(ierr);
1429 #if defined(PETSC_HAVE_SAWS)
1430   } else if (isams) {
1431     PetscMPIInt rank;
1432     const char  *name;
1433 
1434     ierr = PetscObjectGetName((PetscObject)ts,&name);CHKERRQ(ierr);
1435     ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
1436     if (!((PetscObject)ts)->amsmem && !rank) {
1437       char       dir[1024];
1438 
1439       ierr = PetscObjectViewSAWs((PetscObject)ts,viewer);CHKERRQ(ierr);
1440       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time_step",name);CHKERRQ(ierr);
1441       PetscStackCallSAWs(SAWs_Register,(dir,&ts->steps,1,SAWs_READ,SAWs_INT));
1442       ierr = PetscSNPrintf(dir,1024,"/PETSc/Objects/%s/time",name);CHKERRQ(ierr);
1443       PetscStackCallSAWs(SAWs_Register,(dir,&ts->ptime,1,SAWs_READ,SAWs_DOUBLE));
1444     }
1445     if (ts->ops->view) {
1446       ierr = (*ts->ops->view)(ts,viewer);CHKERRQ(ierr);
1447     }
1448 #endif
1449   }
1450 
1451   ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
1452   ierr = PetscObjectTypeCompare((PetscObject)ts,TSSUNDIALS,&isundials);CHKERRQ(ierr);
1453   ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
1454   PetscFunctionReturn(0);
1455 }
1456 
1457 
1458 #undef __FUNCT__
1459 #define __FUNCT__ "TSSetApplicationContext"
1460 /*@
1461    TSSetApplicationContext - Sets an optional user-defined context for
1462    the timesteppers.
1463 
1464    Logically Collective on TS
1465 
1466    Input Parameters:
1467 +  ts - the TS context obtained from TSCreate()
1468 -  usrP - optional user context
1469 
1470    Level: intermediate
1471 
1472 .keywords: TS, timestep, set, application, context
1473 
1474 .seealso: TSGetApplicationContext()
1475 @*/
1476 PetscErrorCode  TSSetApplicationContext(TS ts,void *usrP)
1477 {
1478   PetscFunctionBegin;
1479   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1480   ts->user = usrP;
1481   PetscFunctionReturn(0);
1482 }
1483 
1484 #undef __FUNCT__
1485 #define __FUNCT__ "TSGetApplicationContext"
1486 /*@
1487     TSGetApplicationContext - Gets the user-defined context for the
1488     timestepper.
1489 
1490     Not Collective
1491 
1492     Input Parameter:
1493 .   ts - the TS context obtained from TSCreate()
1494 
1495     Output Parameter:
1496 .   usrP - user context
1497 
1498     Level: intermediate
1499 
1500 .keywords: TS, timestep, get, application, context
1501 
1502 .seealso: TSSetApplicationContext()
1503 @*/
1504 PetscErrorCode  TSGetApplicationContext(TS ts,void *usrP)
1505 {
1506   PetscFunctionBegin;
1507   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1508   *(void**)usrP = ts->user;
1509   PetscFunctionReturn(0);
1510 }
1511 
1512 #undef __FUNCT__
1513 #define __FUNCT__ "TSGetTimeStepNumber"
1514 /*@
1515    TSGetTimeStepNumber - Gets the number of time steps completed.
1516 
1517    Not Collective
1518 
1519    Input Parameter:
1520 .  ts - the TS context obtained from TSCreate()
1521 
1522    Output Parameter:
1523 .  iter - number of steps completed so far
1524 
1525    Level: intermediate
1526 
1527 .keywords: TS, timestep, get, iteration, number
1528 .seealso: TSGetTime(), TSGetTimeStep(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSSetPostStep()
1529 @*/
1530 PetscErrorCode  TSGetTimeStepNumber(TS ts,PetscInt *iter)
1531 {
1532   PetscFunctionBegin;
1533   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1534   PetscValidIntPointer(iter,2);
1535   *iter = ts->steps;
1536   PetscFunctionReturn(0);
1537 }
1538 
1539 #undef __FUNCT__
1540 #define __FUNCT__ "TSSetInitialTimeStep"
1541 /*@
1542    TSSetInitialTimeStep - Sets the initial timestep to be used,
1543    as well as the initial time.
1544 
1545    Logically Collective on TS
1546 
1547    Input Parameters:
1548 +  ts - the TS context obtained from TSCreate()
1549 .  initial_time - the initial time
1550 -  time_step - the size of the timestep
1551 
1552    Level: intermediate
1553 
1554 .seealso: TSSetTimeStep(), TSGetTimeStep()
1555 
1556 .keywords: TS, set, initial, timestep
1557 @*/
1558 PetscErrorCode  TSSetInitialTimeStep(TS ts,PetscReal initial_time,PetscReal time_step)
1559 {
1560   PetscErrorCode ierr;
1561 
1562   PetscFunctionBegin;
1563   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1564   ierr = TSSetTimeStep(ts,time_step);CHKERRQ(ierr);
1565   ierr = TSSetTime(ts,initial_time);CHKERRQ(ierr);
1566   PetscFunctionReturn(0);
1567 }
1568 
1569 #undef __FUNCT__
1570 #define __FUNCT__ "TSSetTimeStep"
1571 /*@
1572    TSSetTimeStep - Allows one to reset the timestep at any time,
1573    useful for simple pseudo-timestepping codes.
1574 
1575    Logically Collective on TS
1576 
1577    Input Parameters:
1578 +  ts - the TS context obtained from TSCreate()
1579 -  time_step - the size of the timestep
1580 
1581    Level: intermediate
1582 
1583 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1584 
1585 .keywords: TS, set, timestep
1586 @*/
1587 PetscErrorCode  TSSetTimeStep(TS ts,PetscReal time_step)
1588 {
1589   PetscFunctionBegin;
1590   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1591   PetscValidLogicalCollectiveReal(ts,time_step,2);
1592   ts->time_step      = time_step;
1593   ts->time_step_orig = time_step;
1594   PetscFunctionReturn(0);
1595 }
1596 
1597 #undef __FUNCT__
1598 #define __FUNCT__ "TSSetExactFinalTime"
1599 /*@
1600    TSSetExactFinalTime - Determines whether to adapt the final time step to
1601      match the exact final time, interpolate solution to the exact final time,
1602      or just return at the final time TS computed.
1603 
1604   Logically Collective on TS
1605 
1606    Input Parameter:
1607 +   ts - the time-step context
1608 -   eftopt - exact final time option
1609 
1610    Level: beginner
1611 
1612 .seealso: TSExactFinalTimeOption
1613 @*/
1614 PetscErrorCode  TSSetExactFinalTime(TS ts,TSExactFinalTimeOption eftopt)
1615 {
1616   PetscFunctionBegin;
1617   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1618   PetscValidLogicalCollectiveEnum(ts,eftopt,2);
1619   ts->exact_final_time = eftopt;
1620   PetscFunctionReturn(0);
1621 }
1622 
1623 #undef __FUNCT__
1624 #define __FUNCT__ "TSGetTimeStep"
1625 /*@
1626    TSGetTimeStep - Gets the current timestep size.
1627 
1628    Not Collective
1629 
1630    Input Parameter:
1631 .  ts - the TS context obtained from TSCreate()
1632 
1633    Output Parameter:
1634 .  dt - the current timestep size
1635 
1636    Level: intermediate
1637 
1638 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
1639 
1640 .keywords: TS, get, timestep
1641 @*/
1642 PetscErrorCode  TSGetTimeStep(TS ts,PetscReal *dt)
1643 {
1644   PetscFunctionBegin;
1645   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1646   PetscValidRealPointer(dt,2);
1647   *dt = ts->time_step;
1648   PetscFunctionReturn(0);
1649 }
1650 
1651 #undef __FUNCT__
1652 #define __FUNCT__ "TSGetSolution"
1653 /*@
1654    TSGetSolution - Returns the solution at the present timestep. It
1655    is valid to call this routine inside the function that you are evaluating
1656    in order to move to the new timestep. This vector not changed until
1657    the solution at the next timestep has been calculated.
1658 
1659    Not Collective, but Vec returned is parallel if TS is parallel
1660 
1661    Input Parameter:
1662 .  ts - the TS context obtained from TSCreate()
1663 
1664    Output Parameter:
1665 .  v - the vector containing the solution
1666 
1667    Level: intermediate
1668 
1669 .seealso: TSGetTimeStep()
1670 
1671 .keywords: TS, timestep, get, solution
1672 @*/
1673 PetscErrorCode  TSGetSolution(TS ts,Vec *v)
1674 {
1675   PetscFunctionBegin;
1676   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1677   PetscValidPointer(v,2);
1678   *v = ts->vec_sol;
1679   PetscFunctionReturn(0);
1680 }
1681 
1682 /* ----- Routines to initialize and destroy a timestepper ---- */
1683 #undef __FUNCT__
1684 #define __FUNCT__ "TSSetProblemType"
1685 /*@
1686   TSSetProblemType - Sets the type of problem to be solved.
1687 
1688   Not collective
1689 
1690   Input Parameters:
1691 + ts   - The TS
1692 - type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1693 .vb
1694          U_t - A U = 0      (linear)
1695          U_t - A(t) U = 0   (linear)
1696          F(t,U,U_t) = 0     (nonlinear)
1697 .ve
1698 
1699    Level: beginner
1700 
1701 .keywords: TS, problem type
1702 .seealso: TSSetUp(), TSProblemType, TS
1703 @*/
1704 PetscErrorCode  TSSetProblemType(TS ts, TSProblemType type)
1705 {
1706   PetscErrorCode ierr;
1707 
1708   PetscFunctionBegin;
1709   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1710   ts->problem_type = type;
1711   if (type == TS_LINEAR) {
1712     SNES snes;
1713     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1714     ierr = SNESSetType(snes,SNESKSPONLY);CHKERRQ(ierr);
1715   }
1716   PetscFunctionReturn(0);
1717 }
1718 
1719 #undef __FUNCT__
1720 #define __FUNCT__ "TSGetProblemType"
1721 /*@C
1722   TSGetProblemType - Gets the type of problem to be solved.
1723 
1724   Not collective
1725 
1726   Input Parameter:
1727 . ts   - The TS
1728 
1729   Output Parameter:
1730 . type - One of TS_LINEAR, TS_NONLINEAR where these types refer to problems of the forms
1731 .vb
1732          M U_t = A U
1733          M(t) U_t = A(t) U
1734          F(t,U,U_t)
1735 .ve
1736 
1737    Level: beginner
1738 
1739 .keywords: TS, problem type
1740 .seealso: TSSetUp(), TSProblemType, TS
1741 @*/
1742 PetscErrorCode  TSGetProblemType(TS ts, TSProblemType *type)
1743 {
1744   PetscFunctionBegin;
1745   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
1746   PetscValidIntPointer(type,2);
1747   *type = ts->problem_type;
1748   PetscFunctionReturn(0);
1749 }
1750 
1751 #undef __FUNCT__
1752 #define __FUNCT__ "TSSetUp"
1753 /*@
1754    TSSetUp - Sets up the internal data structures for the later use
1755    of a timestepper.
1756 
1757    Collective on TS
1758 
1759    Input Parameter:
1760 .  ts - the TS context obtained from TSCreate()
1761 
1762    Notes:
1763    For basic use of the TS solvers the user need not explicitly call
1764    TSSetUp(), since these actions will automatically occur during
1765    the call to TSStep().  However, if one wishes to control this
1766    phase separately, TSSetUp() should be called after TSCreate()
1767    and optional routines of the form TSSetXXX(), but before TSStep().
1768 
1769    Level: advanced
1770 
1771 .keywords: TS, timestep, setup
1772 
1773 .seealso: TSCreate(), TSStep(), TSDestroy()
1774 @*/
1775 PetscErrorCode  TSSetUp(TS ts)
1776 {
1777   PetscErrorCode ierr;
1778   DM             dm;
1779   PetscErrorCode (*func)(SNES,Vec,Vec,void*);
1780   PetscErrorCode (*jac)(SNES,Vec,Mat,Mat,void*);
1781   TSIJacobian    ijac;
1782   TSRHSJacobian  rhsjac;
1783 
1784   PetscFunctionBegin;
1785   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1786   if (ts->setupcalled) PetscFunctionReturn(0);
1787 
1788   if (!((PetscObject)ts)->type_name) {
1789     ierr = TSSetType(ts,TSEULER);CHKERRQ(ierr);
1790   }
1791 
1792   if (!ts->vec_sol) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Must call TSSetSolution() first");
1793 
1794   ierr = TSGetAdapt(ts,&ts->adapt);CHKERRQ(ierr);
1795 
1796   if (ts->rhsjacobian.reuse) {
1797     Mat Amat,Pmat;
1798     SNES snes;
1799     ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
1800     ierr = SNESGetJacobian(snes,&Amat,&Pmat,NULL,NULL);CHKERRQ(ierr);
1801     /* Matching matrices implies that an IJacobian is NOT set, because if it had been set, the IJacobian's matrix would
1802      * have displaced the RHS matrix */
1803     if (Amat == ts->Arhs) {
1804       ierr = MatDuplicate(ts->Arhs,MAT_DO_NOT_COPY_VALUES,&Amat);CHKERRQ(ierr);
1805       ierr = SNESSetJacobian(snes,Amat,NULL,NULL,NULL);CHKERRQ(ierr);
1806       ierr = MatDestroy(&Amat);CHKERRQ(ierr);
1807     }
1808     if (Pmat == ts->Brhs) {
1809       ierr = MatDuplicate(ts->Brhs,MAT_DO_NOT_COPY_VALUES,&Pmat);CHKERRQ(ierr);
1810       ierr = SNESSetJacobian(snes,NULL,Pmat,NULL,NULL);CHKERRQ(ierr);
1811       ierr = MatDestroy(&Pmat);CHKERRQ(ierr);
1812     }
1813   }
1814 
1815   if (ts->ops->setup) {
1816     ierr = (*ts->ops->setup)(ts);CHKERRQ(ierr);
1817   }
1818 
1819   /* in the case where we've set a DMTSFunction or what have you, we need the default SNESFunction
1820    to be set right but can't do it elsewhere due to the overreliance on ctx=ts.
1821    */
1822   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
1823   ierr = DMSNESGetFunction(dm,&func,NULL);CHKERRQ(ierr);
1824   if (!func) {
1825     ierr =DMSNESSetFunction(dm,SNESTSFormFunction,ts);CHKERRQ(ierr);
1826   }
1827   /* if the SNES doesn't have a jacobian set and the TS has an ijacobian or rhsjacobian set, set the SNES to use it.
1828      Otherwise, the SNES will use coloring internally to form the Jacobian.
1829    */
1830   ierr = DMSNESGetJacobian(dm,&jac,NULL);CHKERRQ(ierr);
1831   ierr = DMTSGetIJacobian(dm,&ijac,NULL);CHKERRQ(ierr);
1832   ierr = DMTSGetRHSJacobian(dm,&rhsjac,NULL);CHKERRQ(ierr);
1833   if (!jac && (ijac || rhsjac)) {
1834     ierr = DMSNESSetJacobian(dm,SNESTSFormJacobian,ts);CHKERRQ(ierr);
1835   }
1836   ts->setupcalled = PETSC_TRUE;
1837   PetscFunctionReturn(0);
1838 }
1839 
1840 #undef __FUNCT__
1841 #define __FUNCT__ "TSReset"
1842 /*@
1843    TSReset - Resets a TS context and removes any allocated Vecs and Mats.
1844 
1845    Collective on TS
1846 
1847    Input Parameter:
1848 .  ts - the TS context obtained from TSCreate()
1849 
1850    Level: beginner
1851 
1852 .keywords: TS, timestep, reset
1853 
1854 .seealso: TSCreate(), TSSetup(), TSDestroy()
1855 @*/
1856 PetscErrorCode  TSReset(TS ts)
1857 {
1858   PetscErrorCode ierr;
1859 
1860   PetscFunctionBegin;
1861   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1862   if (ts->ops->reset) {
1863     ierr = (*ts->ops->reset)(ts);CHKERRQ(ierr);
1864   }
1865   if (ts->snes) {ierr = SNESReset(ts->snes);CHKERRQ(ierr);}
1866 
1867   ierr = MatDestroy(&ts->Arhs);CHKERRQ(ierr);
1868   ierr = MatDestroy(&ts->Brhs);CHKERRQ(ierr);
1869   ierr = VecDestroy(&ts->Frhs);CHKERRQ(ierr);
1870   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
1871   ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
1872   ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
1873   ierr = VecDestroyVecs(ts->nwork,&ts->work);CHKERRQ(ierr);
1874 
1875   ts->setupcalled = PETSC_FALSE;
1876   PetscFunctionReturn(0);
1877 }
1878 
1879 #undef __FUNCT__
1880 #define __FUNCT__ "TSDestroy"
1881 /*@
1882    TSDestroy - Destroys the timestepper context that was created
1883    with TSCreate().
1884 
1885    Collective on TS
1886 
1887    Input Parameter:
1888 .  ts - the TS context obtained from TSCreate()
1889 
1890    Level: beginner
1891 
1892 .keywords: TS, timestepper, destroy
1893 
1894 .seealso: TSCreate(), TSSetUp(), TSSolve()
1895 @*/
1896 PetscErrorCode  TSDestroy(TS *ts)
1897 {
1898   PetscErrorCode ierr;
1899 
1900   PetscFunctionBegin;
1901   if (!*ts) PetscFunctionReturn(0);
1902   PetscValidHeaderSpecific((*ts),TS_CLASSID,1);
1903   if (--((PetscObject)(*ts))->refct > 0) {*ts = 0; PetscFunctionReturn(0);}
1904 
1905   ierr = TSReset((*ts));CHKERRQ(ierr);
1906 
1907   /* if memory was published with SAWs then destroy it */
1908   ierr = PetscObjectSAWsViewOff((PetscObject)*ts);CHKERRQ(ierr);
1909   if ((*ts)->ops->destroy) {ierr = (*(*ts)->ops->destroy)((*ts));CHKERRQ(ierr);}
1910 
1911   ierr = TSAdaptDestroy(&(*ts)->adapt);CHKERRQ(ierr);
1912   ierr = SNESDestroy(&(*ts)->snes);CHKERRQ(ierr);
1913   ierr = DMDestroy(&(*ts)->dm);CHKERRQ(ierr);
1914   ierr = TSMonitorCancel((*ts));CHKERRQ(ierr);
1915 
1916   ierr = PetscHeaderDestroy(ts);CHKERRQ(ierr);
1917   PetscFunctionReturn(0);
1918 }
1919 
1920 #undef __FUNCT__
1921 #define __FUNCT__ "TSGetSNES"
1922 /*@
1923    TSGetSNES - Returns the SNES (nonlinear solver) associated with
1924    a TS (timestepper) context. Valid only for nonlinear problems.
1925 
1926    Not Collective, but SNES is parallel if TS is parallel
1927 
1928    Input Parameter:
1929 .  ts - the TS context obtained from TSCreate()
1930 
1931    Output Parameter:
1932 .  snes - the nonlinear solver context
1933 
1934    Notes:
1935    The user can then directly manipulate the SNES context to set various
1936    options, etc.  Likewise, the user can then extract and manipulate the
1937    KSP, KSP, and PC contexts as well.
1938 
1939    TSGetSNES() does not work for integrators that do not use SNES; in
1940    this case TSGetSNES() returns NULL in snes.
1941 
1942    Level: beginner
1943 
1944 .keywords: timestep, get, SNES
1945 @*/
1946 PetscErrorCode  TSGetSNES(TS ts,SNES *snes)
1947 {
1948   PetscErrorCode ierr;
1949 
1950   PetscFunctionBegin;
1951   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1952   PetscValidPointer(snes,2);
1953   if (!ts->snes) {
1954     ierr = SNESCreate(PetscObjectComm((PetscObject)ts),&ts->snes);CHKERRQ(ierr);
1955     ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
1956     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->snes);CHKERRQ(ierr);
1957     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->snes,(PetscObject)ts,1);CHKERRQ(ierr);
1958     if (ts->dm) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
1959     if (ts->problem_type == TS_LINEAR) {
1960       ierr = SNESSetType(ts->snes,SNESKSPONLY);CHKERRQ(ierr);
1961     }
1962   }
1963   *snes = ts->snes;
1964   PetscFunctionReturn(0);
1965 }
1966 
1967 #undef __FUNCT__
1968 #define __FUNCT__ "TSSetSNES"
1969 /*@
1970    TSSetSNES - Set the SNES (nonlinear solver) to be used by the timestepping context
1971 
1972    Collective
1973 
1974    Input Parameter:
1975 +  ts - the TS context obtained from TSCreate()
1976 -  snes - the nonlinear solver context
1977 
1978    Notes:
1979    Most users should have the TS created by calling TSGetSNES()
1980 
1981    Level: developer
1982 
1983 .keywords: timestep, set, SNES
1984 @*/
1985 PetscErrorCode TSSetSNES(TS ts,SNES snes)
1986 {
1987   PetscErrorCode ierr;
1988   PetscErrorCode (*func)(SNES,Vec,Mat,Mat,void*);
1989 
1990   PetscFunctionBegin;
1991   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1992   PetscValidHeaderSpecific(snes,SNES_CLASSID,2);
1993   ierr = PetscObjectReference((PetscObject)snes);CHKERRQ(ierr);
1994   ierr = SNESDestroy(&ts->snes);CHKERRQ(ierr);
1995 
1996   ts->snes = snes;
1997 
1998   ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
1999   ierr = SNESGetJacobian(ts->snes,NULL,NULL,&func,NULL);CHKERRQ(ierr);
2000   if (func == SNESTSFormJacobian) {
2001     ierr = SNESSetJacobian(ts->snes,NULL,NULL,SNESTSFormJacobian,ts);CHKERRQ(ierr);
2002   }
2003   PetscFunctionReturn(0);
2004 }
2005 
2006 #undef __FUNCT__
2007 #define __FUNCT__ "TSGetKSP"
2008 /*@
2009    TSGetKSP - Returns the KSP (linear solver) associated with
2010    a TS (timestepper) context.
2011 
2012    Not Collective, but KSP is parallel if TS is parallel
2013 
2014    Input Parameter:
2015 .  ts - the TS context obtained from TSCreate()
2016 
2017    Output Parameter:
2018 .  ksp - the nonlinear solver context
2019 
2020    Notes:
2021    The user can then directly manipulate the KSP context to set various
2022    options, etc.  Likewise, the user can then extract and manipulate the
2023    KSP and PC contexts as well.
2024 
2025    TSGetKSP() does not work for integrators that do not use KSP;
2026    in this case TSGetKSP() returns NULL in ksp.
2027 
2028    Level: beginner
2029 
2030 .keywords: timestep, get, KSP
2031 @*/
2032 PetscErrorCode  TSGetKSP(TS ts,KSP *ksp)
2033 {
2034   PetscErrorCode ierr;
2035   SNES           snes;
2036 
2037   PetscFunctionBegin;
2038   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2039   PetscValidPointer(ksp,2);
2040   if (!((PetscObject)ts)->type_name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"KSP is not created yet. Call TSSetType() first");
2041   if (ts->problem_type != TS_LINEAR) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Linear only; use TSGetSNES()");
2042   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2043   ierr = SNESGetKSP(snes,ksp);CHKERRQ(ierr);
2044   PetscFunctionReturn(0);
2045 }
2046 
2047 /* ----------- Routines to set solver parameters ---------- */
2048 
2049 #undef __FUNCT__
2050 #define __FUNCT__ "TSGetDuration"
2051 /*@
2052    TSGetDuration - Gets the maximum number of timesteps to use and
2053    maximum time for iteration.
2054 
2055    Not Collective
2056 
2057    Input Parameters:
2058 +  ts       - the TS context obtained from TSCreate()
2059 .  maxsteps - maximum number of iterations to use, or NULL
2060 -  maxtime  - final time to iterate to, or NULL
2061 
2062    Level: intermediate
2063 
2064 .keywords: TS, timestep, get, maximum, iterations, time
2065 @*/
2066 PetscErrorCode  TSGetDuration(TS ts, PetscInt *maxsteps, PetscReal *maxtime)
2067 {
2068   PetscFunctionBegin;
2069   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2070   if (maxsteps) {
2071     PetscValidIntPointer(maxsteps,2);
2072     *maxsteps = ts->max_steps;
2073   }
2074   if (maxtime) {
2075     PetscValidScalarPointer(maxtime,3);
2076     *maxtime = ts->max_time;
2077   }
2078   PetscFunctionReturn(0);
2079 }
2080 
2081 #undef __FUNCT__
2082 #define __FUNCT__ "TSSetDuration"
2083 /*@
2084    TSSetDuration - Sets the maximum number of timesteps to use and
2085    maximum time for iteration.
2086 
2087    Logically Collective on TS
2088 
2089    Input Parameters:
2090 +  ts - the TS context obtained from TSCreate()
2091 .  maxsteps - maximum number of iterations to use
2092 -  maxtime - final time to iterate to
2093 
2094    Options Database Keys:
2095 .  -ts_max_steps <maxsteps> - Sets maxsteps
2096 .  -ts_final_time <maxtime> - Sets maxtime
2097 
2098    Notes:
2099    The default maximum number of iterations is 5000. Default time is 5.0
2100 
2101    Level: intermediate
2102 
2103 .keywords: TS, timestep, set, maximum, iterations
2104 
2105 .seealso: TSSetExactFinalTime()
2106 @*/
2107 PetscErrorCode  TSSetDuration(TS ts,PetscInt maxsteps,PetscReal maxtime)
2108 {
2109   PetscFunctionBegin;
2110   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2111   PetscValidLogicalCollectiveInt(ts,maxsteps,2);
2112   PetscValidLogicalCollectiveReal(ts,maxtime,2);
2113   if (maxsteps >= 0) ts->max_steps = maxsteps;
2114   if (maxtime != PETSC_DEFAULT) ts->max_time = maxtime;
2115   PetscFunctionReturn(0);
2116 }
2117 
2118 #undef __FUNCT__
2119 #define __FUNCT__ "TSSetSolution"
2120 /*@
2121    TSSetSolution - Sets the initial solution vector
2122    for use by the TS routines.
2123 
2124    Logically Collective on TS and Vec
2125 
2126    Input Parameters:
2127 +  ts - the TS context obtained from TSCreate()
2128 -  u - the solution vector
2129 
2130    Level: beginner
2131 
2132 .keywords: TS, timestep, set, solution, initial conditions
2133 @*/
2134 PetscErrorCode  TSSetSolution(TS ts,Vec u)
2135 {
2136   PetscErrorCode ierr;
2137   DM             dm;
2138 
2139   PetscFunctionBegin;
2140   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2141   PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2142   ierr = PetscObjectReference((PetscObject)u);CHKERRQ(ierr);
2143   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
2144 
2145   ts->vec_sol = u;
2146 
2147   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
2148   ierr = DMShellSetGlobalVector(dm,u);CHKERRQ(ierr);
2149   PetscFunctionReturn(0);
2150 }
2151 
2152 #undef __FUNCT__
2153 #define __FUNCT__ "TSSetPreStep"
2154 /*@C
2155   TSSetPreStep - Sets the general-purpose function
2156   called once at the beginning of each time step.
2157 
2158   Logically Collective on TS
2159 
2160   Input Parameters:
2161 + ts   - The TS context obtained from TSCreate()
2162 - func - The function
2163 
2164   Calling sequence of func:
2165 . func (TS ts);
2166 
2167   Level: intermediate
2168 
2169   Note:
2170   If a step is rejected, TSStep() will call this routine again before each attempt.
2171   The last completed time step number can be queried using TSGetTimeStepNumber(), the
2172   size of the step being attempted can be obtained using TSGetTimeStep().
2173 
2174 .keywords: TS, timestep
2175 .seealso: TSSetPreStage(), TSSetPostStage(), TSSetPostStep(), TSStep()
2176 @*/
2177 PetscErrorCode  TSSetPreStep(TS ts, PetscErrorCode (*func)(TS))
2178 {
2179   PetscFunctionBegin;
2180   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2181   ts->prestep = func;
2182   PetscFunctionReturn(0);
2183 }
2184 
2185 #undef __FUNCT__
2186 #define __FUNCT__ "TSPreStep"
2187 /*@
2188   TSPreStep - Runs the user-defined pre-step function.
2189 
2190   Collective on TS
2191 
2192   Input Parameters:
2193 . ts   - The TS context obtained from TSCreate()
2194 
2195   Notes:
2196   TSPreStep() is typically used within time stepping implementations,
2197   so most users would not generally call this routine themselves.
2198 
2199   Level: developer
2200 
2201 .keywords: TS, timestep
2202 .seealso: TSSetPreStep(), TSPreStage(), TSPostStage(), TSPostStep()
2203 @*/
2204 PetscErrorCode  TSPreStep(TS ts)
2205 {
2206   PetscErrorCode ierr;
2207 
2208   PetscFunctionBegin;
2209   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2210   if (ts->prestep) {
2211     PetscStackCallStandard((*ts->prestep),(ts));
2212   }
2213   PetscFunctionReturn(0);
2214 }
2215 
2216 #undef __FUNCT__
2217 #define __FUNCT__ "TSSetPreStage"
2218 /*@C
2219   TSSetPreStage - Sets the general-purpose function
2220   called once at the beginning of each stage.
2221 
2222   Logically Collective on TS
2223 
2224   Input Parameters:
2225 + ts   - The TS context obtained from TSCreate()
2226 - func - The function
2227 
2228   Calling sequence of func:
2229 . PetscErrorCode func(TS ts, PetscReal stagetime);
2230 
2231   Level: intermediate
2232 
2233   Note:
2234   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2235   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2236   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2237 
2238 .keywords: TS, timestep
2239 .seealso: TSSetPostStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2240 @*/
2241 PetscErrorCode  TSSetPreStage(TS ts, PetscErrorCode (*func)(TS,PetscReal))
2242 {
2243   PetscFunctionBegin;
2244   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2245   ts->prestage = func;
2246   PetscFunctionReturn(0);
2247 }
2248 
2249 #undef __FUNCT__
2250 #define __FUNCT__ "TSSetPostStage"
2251 /*@C
2252   TSSetPostStage - Sets the general-purpose function
2253   called once at the end of each stage.
2254 
2255   Logically Collective on TS
2256 
2257   Input Parameters:
2258 + ts   - The TS context obtained from TSCreate()
2259 - func - The function
2260 
2261   Calling sequence of func:
2262 . PetscErrorCode func(TS ts, PetscReal stagetime, PetscInt stageindex, Vec* Y);
2263 
2264   Level: intermediate
2265 
2266   Note:
2267   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2268   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2269   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2270 
2271 .keywords: TS, timestep
2272 .seealso: TSSetPreStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2273 @*/
2274 PetscErrorCode  TSSetPostStage(TS ts, PetscErrorCode (*func)(TS,PetscReal,PetscInt,Vec*))
2275 {
2276   PetscFunctionBegin;
2277   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2278   ts->poststage = func;
2279   PetscFunctionReturn(0);
2280 }
2281 
2282 #undef __FUNCT__
2283 #define __FUNCT__ "TSPreStage"
2284 /*@
2285   TSPreStage - Runs the user-defined pre-stage function set using TSSetPreStage()
2286 
2287   Collective on TS
2288 
2289   Input Parameters:
2290 . ts          - The TS context obtained from TSCreate()
2291   stagetime   - The absolute time of the current stage
2292 
2293   Notes:
2294   TSPreStage() is typically used within time stepping implementations,
2295   most users would not generally call this routine themselves.
2296 
2297   Level: developer
2298 
2299 .keywords: TS, timestep
2300 .seealso: TSPostStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2301 @*/
2302 PetscErrorCode  TSPreStage(TS ts, PetscReal stagetime)
2303 {
2304   PetscErrorCode ierr;
2305 
2306   PetscFunctionBegin;
2307   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2308   if (ts->prestage) {
2309     PetscStackCallStandard((*ts->prestage),(ts,stagetime));
2310   }
2311   PetscFunctionReturn(0);
2312 }
2313 
2314 #undef __FUNCT__
2315 #define __FUNCT__ "TSPostStage"
2316 /*@
2317   TSPostStage - Runs the user-defined post-stage function set using TSSetPostStage()
2318 
2319   Collective on TS
2320 
2321   Input Parameters:
2322 . ts          - The TS context obtained from TSCreate()
2323   stagetime   - The absolute time of the current stage
2324   stageindex  - Stage number
2325   Y           - Array of vectors (of size = total number
2326                 of stages) with the stage solutions
2327 
2328   Notes:
2329   TSPostStage() is typically used within time stepping implementations,
2330   most users would not generally call this routine themselves.
2331 
2332   Level: developer
2333 
2334 .keywords: TS, timestep
2335 .seealso: TSPreStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2336 @*/
2337 PetscErrorCode  TSPostStage(TS ts, PetscReal stagetime, PetscInt stageindex, Vec *Y)
2338 {
2339   PetscErrorCode ierr;
2340 
2341   PetscFunctionBegin;
2342   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2343   if (ts->prestage) {
2344     PetscStackCallStandard((*ts->poststage),(ts,stagetime,stageindex,Y));
2345   }
2346   PetscFunctionReturn(0);
2347 }
2348 
2349 #undef __FUNCT__
2350 #define __FUNCT__ "TSSetPostStep"
2351 /*@C
2352   TSSetPostStep - Sets the general-purpose function
2353   called once at the end of each time step.
2354 
2355   Logically Collective on TS
2356 
2357   Input Parameters:
2358 + ts   - The TS context obtained from TSCreate()
2359 - func - The function
2360 
2361   Calling sequence of func:
2362 $ func (TS ts);
2363 
2364   Level: intermediate
2365 
2366 .keywords: TS, timestep
2367 .seealso: TSSetPreStep(), TSSetPreStage(), TSGetTimeStep(), TSGetTimeStepNumber(), TSGetTime()
2368 @*/
2369 PetscErrorCode  TSSetPostStep(TS ts, PetscErrorCode (*func)(TS))
2370 {
2371   PetscFunctionBegin;
2372   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2373   ts->poststep = func;
2374   PetscFunctionReturn(0);
2375 }
2376 
2377 #undef __FUNCT__
2378 #define __FUNCT__ "TSPostStep"
2379 /*@
2380   TSPostStep - Runs the user-defined post-step function.
2381 
2382   Collective on TS
2383 
2384   Input Parameters:
2385 . ts   - The TS context obtained from TSCreate()
2386 
2387   Notes:
2388   TSPostStep() is typically used within time stepping implementations,
2389   so most users would not generally call this routine themselves.
2390 
2391   Level: developer
2392 
2393 .keywords: TS, timestep
2394 @*/
2395 PetscErrorCode  TSPostStep(TS ts)
2396 {
2397   PetscErrorCode ierr;
2398 
2399   PetscFunctionBegin;
2400   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2401   if (ts->poststep) {
2402     PetscStackCallStandard((*ts->poststep),(ts));
2403   }
2404   PetscFunctionReturn(0);
2405 }
2406 
2407 /* ------------ Routines to set performance monitoring options ----------- */
2408 
2409 #undef __FUNCT__
2410 #define __FUNCT__ "TSMonitorSet"
2411 /*@C
2412    TSMonitorSet - Sets an ADDITIONAL function that is to be used at every
2413    timestep to display the iteration's  progress.
2414 
2415    Logically Collective on TS
2416 
2417    Input Parameters:
2418 +  ts - the TS context obtained from TSCreate()
2419 .  monitor - monitoring routine
2420 .  mctx - [optional] user-defined context for private data for the
2421              monitor routine (use NULL if no context is desired)
2422 -  monitordestroy - [optional] routine that frees monitor context
2423           (may be NULL)
2424 
2425    Calling sequence of monitor:
2426 $    int monitor(TS ts,PetscInt steps,PetscReal time,Vec u,void *mctx)
2427 
2428 +    ts - the TS context
2429 .    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
2430                                been interpolated to)
2431 .    time - current time
2432 .    u - current iterate
2433 -    mctx - [optional] monitoring context
2434 
2435    Notes:
2436    This routine adds an additional monitor to the list of monitors that
2437    already has been loaded.
2438 
2439    Fortran notes: Only a single monitor function can be set for each TS object
2440 
2441    Level: intermediate
2442 
2443 .keywords: TS, timestep, set, monitor
2444 
2445 .seealso: TSMonitorDefault(), TSMonitorCancel()
2446 @*/
2447 PetscErrorCode  TSMonitorSet(TS ts,PetscErrorCode (*monitor)(TS,PetscInt,PetscReal,Vec,void*),void *mctx,PetscErrorCode (*mdestroy)(void**))
2448 {
2449   PetscFunctionBegin;
2450   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2451   if (ts->numbermonitors >= MAXTSMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
2452   ts->monitor[ts->numbermonitors]          = monitor;
2453   ts->monitordestroy[ts->numbermonitors]   = mdestroy;
2454   ts->monitorcontext[ts->numbermonitors++] = (void*)mctx;
2455   PetscFunctionReturn(0);
2456 }
2457 
2458 #undef __FUNCT__
2459 #define __FUNCT__ "TSMonitorCancel"
2460 /*@C
2461    TSMonitorCancel - Clears all the monitors that have been set on a time-step object.
2462 
2463    Logically Collective on TS
2464 
2465    Input Parameters:
2466 .  ts - the TS context obtained from TSCreate()
2467 
2468    Notes:
2469    There is no way to remove a single, specific monitor.
2470 
2471    Level: intermediate
2472 
2473 .keywords: TS, timestep, set, monitor
2474 
2475 .seealso: TSMonitorDefault(), TSMonitorSet()
2476 @*/
2477 PetscErrorCode  TSMonitorCancel(TS ts)
2478 {
2479   PetscErrorCode ierr;
2480   PetscInt       i;
2481 
2482   PetscFunctionBegin;
2483   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2484   for (i=0; i<ts->numbermonitors; i++) {
2485     if (ts->monitordestroy[i]) {
2486       ierr = (*ts->monitordestroy[i])(&ts->monitorcontext[i]);CHKERRQ(ierr);
2487     }
2488   }
2489   ts->numbermonitors = 0;
2490   PetscFunctionReturn(0);
2491 }
2492 
2493 #undef __FUNCT__
2494 #define __FUNCT__ "TSMonitorDefault"
2495 /*@
2496    TSMonitorDefault - Sets the Default monitor
2497 
2498    Level: intermediate
2499 
2500 .keywords: TS, set, monitor
2501 
2502 .seealso: TSMonitorDefault(), TSMonitorSet()
2503 @*/
2504 PetscErrorCode TSMonitorDefault(TS ts,PetscInt step,PetscReal ptime,Vec v,void *dummy)
2505 {
2506   PetscErrorCode ierr;
2507   PetscViewer    viewer = dummy ? (PetscViewer) dummy : PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)ts));
2508 
2509   PetscFunctionBegin;
2510   ierr = PetscViewerASCIIAddTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2511   ierr = PetscViewerASCIIPrintf(viewer,"%D TS dt %g time %g\n",step,(double)ts->time_step,(double)ptime);CHKERRQ(ierr);
2512   ierr = PetscViewerASCIISubtractTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2513   PetscFunctionReturn(0);
2514 }
2515 
2516 #undef __FUNCT__
2517 #define __FUNCT__ "TSSetRetainStages"
2518 /*@
2519    TSSetRetainStages - Request that all stages in the upcoming step be stored so that interpolation will be available.
2520 
2521    Logically Collective on TS
2522 
2523    Input Argument:
2524 .  ts - time stepping context
2525 
2526    Output Argument:
2527 .  flg - PETSC_TRUE or PETSC_FALSE
2528 
2529    Level: intermediate
2530 
2531 .keywords: TS, set
2532 
2533 .seealso: TSInterpolate(), TSSetPostStep()
2534 @*/
2535 PetscErrorCode TSSetRetainStages(TS ts,PetscBool flg)
2536 {
2537   PetscFunctionBegin;
2538   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2539   ts->retain_stages = flg;
2540   PetscFunctionReturn(0);
2541 }
2542 
2543 #undef __FUNCT__
2544 #define __FUNCT__ "TSInterpolate"
2545 /*@
2546    TSInterpolate - Interpolate the solution computed during the previous step to an arbitrary location in the interval
2547 
2548    Collective on TS
2549 
2550    Input Argument:
2551 +  ts - time stepping context
2552 -  t - time to interpolate to
2553 
2554    Output Argument:
2555 .  U - state at given time
2556 
2557    Notes:
2558    The user should call TSSetRetainStages() before taking a step in which interpolation will be requested.
2559 
2560    Level: intermediate
2561 
2562    Developer Notes:
2563    TSInterpolate() and the storing of previous steps/stages should be generalized to support delay differential equations and continuous adjoints.
2564 
2565 .keywords: TS, set
2566 
2567 .seealso: TSSetRetainStages(), TSSetPostStep()
2568 @*/
2569 PetscErrorCode TSInterpolate(TS ts,PetscReal t,Vec U)
2570 {
2571   PetscErrorCode ierr;
2572 
2573   PetscFunctionBegin;
2574   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2575   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2576   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);
2577   if (!ts->ops->interpolate) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"%s does not provide interpolation",((PetscObject)ts)->type_name);
2578   ierr = (*ts->ops->interpolate)(ts,t,U);CHKERRQ(ierr);
2579   PetscFunctionReturn(0);
2580 }
2581 
2582 #undef __FUNCT__
2583 #define __FUNCT__ "TSStep"
2584 /*@
2585    TSStep - Steps one time step
2586 
2587    Collective on TS
2588 
2589    Input Parameter:
2590 .  ts - the TS context obtained from TSCreate()
2591 
2592    Level: intermediate
2593 
2594    Notes:
2595    The hook set using TSSetPreStep() is called before each attempt to take the step. In general, the time step size may
2596    be changed due to adaptive error controller or solve failures. Note that steps may contain multiple stages.
2597 
2598    This may over-step the final time provided in TSSetDuration() depending on the time-step used. TSSolve() interpolates to exactly the
2599    time provided in TSSetDuration(). One can use TSInterpolate() to determine an interpolated solution within the final timestep.
2600 
2601 .keywords: TS, timestep, solve
2602 
2603 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSInterpolate()
2604 @*/
2605 PetscErrorCode  TSStep(TS ts)
2606 {
2607   DM               dm;
2608   PetscReal        ptime_prev;
2609   PetscErrorCode   ierr;
2610   static PetscBool cite = PETSC_FALSE;
2611 
2612   PetscFunctionBegin;
2613   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2614   ierr = PetscCitationsRegister("@techreport{tspaper,\n"
2615                                 "  title       = {{PETSc/TS}: A Modern Scalable {DAE/ODE} Solver Library},\n"
2616                                 "  author      = {Shrirang Abhyankar and Jed Brown and Emil Constantinescu and Debojyoti Ghosh and Barry F. Smith},\n"
2617                                 "  type        = {Preprint},\n"
2618                                 "  number      = {ANL/MCS-P5061-0114},\n"
2619                                 "  institution = {Argonne National Laboratory},\n"
2620                                 "  year        = {2014}\n}\n",&cite);
2621 
2622   ierr = TSGetDM(ts, &dm);CHKERRQ(ierr);
2623   ierr = TSSetUp(ts);CHKERRQ(ierr);
2624 
2625   ts->reason = TS_CONVERGED_ITERATING;
2626   ptime_prev = ts->ptime;
2627   ierr = DMSetOutputSequenceNumber(dm, ts->steps);CHKERRQ(ierr);
2628 
2629   ierr = PetscLogEventBegin(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2630   ierr = (*ts->ops->step)(ts);CHKERRQ(ierr);
2631   ierr = PetscLogEventEnd(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2632 
2633   ts->time_step_prev = ts->ptime - ptime_prev;
2634   ierr = DMSetOutputSequenceNumber(dm, ts->steps);CHKERRQ(ierr);
2635 
2636   if (ts->reason < 0) {
2637     if (ts->errorifstepfailed) {
2638       if (ts->reason == TS_DIVERGED_NONLINEAR_SOLVE) {
2639         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]);
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       ierr = TSPostStep(ts);CHKERRQ(ierr);
2749     }
2750     if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE && ts->ptime > ts->max_time) {
2751       ierr = TSInterpolate(ts,ts->max_time,u);CHKERRQ(ierr);
2752       ts->solvetime = ts->max_time;
2753       solution = u;
2754     } else {
2755       if (u) {ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);}
2756       ts->solvetime = ts->ptime;
2757       solution = ts->vec_sol;
2758     }
2759     ierr = TSMonitor(ts,ts->steps,ts->solvetime,solution);CHKERRQ(ierr);
2760   }
2761   ierr = TSViewFromOptions(ts,NULL,"-ts_view");CHKERRQ(ierr);
2762   ierr = PetscObjectSAWsBlock((PetscObject)ts);CHKERRQ(ierr);
2763   PetscFunctionReturn(0);
2764 }
2765 
2766 #undef __FUNCT__
2767 #define __FUNCT__ "TSMonitor"
2768 /*@
2769    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()
2770 
2771    Collective on TS
2772 
2773    Input Parameters:
2774 +  ts - time stepping context obtained from TSCreate()
2775 .  step - step number that has just completed
2776 .  ptime - model time of the state
2777 -  u - state at the current model time
2778 
2779    Notes:
2780    TSMonitor() is typically used within the time stepping implementations.
2781    Users might call this function when using the TSStep() interface instead of TSSolve().
2782 
2783    Level: advanced
2784 
2785 .keywords: TS, timestep
2786 @*/
2787 PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
2788 {
2789   PetscErrorCode ierr;
2790   PetscInt       i,n = ts->numbermonitors;
2791 
2792   PetscFunctionBegin;
2793   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2794   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
2795   for (i=0; i<n; i++) {
2796     ierr = (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);CHKERRQ(ierr);
2797   }
2798   PetscFunctionReturn(0);
2799 }
2800 
2801 /* ------------------------------------------------------------------------*/
2802 #undef __FUNCT__
2803 #define __FUNCT__ "TSMonitorLGCtxCreate"
2804 /*@C
2805    TSMonitorLGCtxCreate - Creates a line graph context for use with
2806    TS to monitor the solution process graphically in various ways
2807 
2808    Collective on TS
2809 
2810    Input Parameters:
2811 +  host - the X display to open, or null for the local machine
2812 .  label - the title to put in the title bar
2813 .  x, y - the screen coordinates of the upper left coordinate of the window
2814 .  m, n - the screen width and height in pixels
2815 -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time
2816 
2817    Output Parameter:
2818 .  ctx - the context
2819 
2820    Options Database Key:
2821 +  -ts_monitor_lg_timestep - automatically sets line graph monitor
2822 .  -ts_monitor_lg_solution -
2823 .  -ts_monitor_lg_error -
2824 .  -ts_monitor_lg_ksp_iterations -
2825 .  -ts_monitor_lg_snes_iterations -
2826 -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true
2827 
2828    Notes:
2829    Use TSMonitorLGCtxDestroy() to destroy.
2830 
2831    Level: intermediate
2832 
2833 .keywords: TS, monitor, line graph, residual, seealso
2834 
2835 .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()
2836 
2837 @*/
2838 PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
2839 {
2840   PetscDraw      win;
2841   PetscErrorCode ierr;
2842 
2843   PetscFunctionBegin;
2844   ierr = PetscNew(ctx);CHKERRQ(ierr);
2845   ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr);
2846   ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr);
2847   ierr = PetscDrawLGCreate(win,1,&(*ctx)->lg);CHKERRQ(ierr);
2848   ierr = PetscLogObjectParent((PetscObject)(*ctx)->lg,(PetscObject)win);CHKERRQ(ierr);
2849   ierr = PetscDrawLGIndicateDataPoints((*ctx)->lg,PETSC_TRUE);CHKERRQ(ierr);
2850   ierr = PetscDrawLGSetFromOptions((*ctx)->lg);CHKERRQ(ierr);
2851   (*ctx)->howoften = howoften;
2852   PetscFunctionReturn(0);
2853 }
2854 
2855 #undef __FUNCT__
2856 #define __FUNCT__ "TSMonitorLGTimeStep"
2857 PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx)
2858 {
2859   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
2860   PetscReal      x   = ptime,y;
2861   PetscErrorCode ierr;
2862 
2863   PetscFunctionBegin;
2864   if (!step) {
2865     PetscDrawAxis axis;
2866     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
2867     ierr = PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");CHKERRQ(ierr);
2868     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
2869     ierr = PetscDrawLGIndicateDataPoints(ctx->lg,PETSC_TRUE);CHKERRQ(ierr);
2870   }
2871   ierr = TSGetTimeStep(ts,&y);CHKERRQ(ierr);
2872   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
2873   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
2874     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
2875   }
2876   PetscFunctionReturn(0);
2877 }
2878 
2879 #undef __FUNCT__
2880 #define __FUNCT__ "TSMonitorLGCtxDestroy"
2881 /*@C
2882    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
2883    with TSMonitorLGCtxCreate().
2884 
2885    Collective on TSMonitorLGCtx
2886 
2887    Input Parameter:
2888 .  ctx - the monitor context
2889 
2890    Level: intermediate
2891 
2892 .keywords: TS, monitor, line graph, destroy
2893 
2894 .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
2895 @*/
2896 PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
2897 {
2898   PetscDraw      draw;
2899   PetscErrorCode ierr;
2900 
2901   PetscFunctionBegin;
2902   ierr = PetscDrawLGGetDraw((*ctx)->lg,&draw);CHKERRQ(ierr);
2903   ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
2904   ierr = PetscDrawLGDestroy(&(*ctx)->lg);CHKERRQ(ierr);
2905   ierr = PetscFree(*ctx);CHKERRQ(ierr);
2906   PetscFunctionReturn(0);
2907 }
2908 
2909 #undef __FUNCT__
2910 #define __FUNCT__ "TSGetTime"
2911 /*@
2912    TSGetTime - Gets the time of the most recently completed step.
2913 
2914    Not Collective
2915 
2916    Input Parameter:
2917 .  ts - the TS context obtained from TSCreate()
2918 
2919    Output Parameter:
2920 .  t  - the current time
2921 
2922    Level: beginner
2923 
2924    Note:
2925    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
2926    TSSetPreStage(), TSSetPostStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.
2927 
2928 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
2929 
2930 .keywords: TS, get, time
2931 @*/
2932 PetscErrorCode  TSGetTime(TS ts,PetscReal *t)
2933 {
2934   PetscFunctionBegin;
2935   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2936   PetscValidRealPointer(t,2);
2937   *t = ts->ptime;
2938   PetscFunctionReturn(0);
2939 }
2940 
2941 #undef __FUNCT__
2942 #define __FUNCT__ "TSSetTime"
2943 /*@
2944    TSSetTime - Allows one to reset the time.
2945 
2946    Logically Collective on TS
2947 
2948    Input Parameters:
2949 +  ts - the TS context obtained from TSCreate()
2950 -  time - the time
2951 
2952    Level: intermediate
2953 
2954 .seealso: TSGetTime(), TSSetDuration()
2955 
2956 .keywords: TS, set, time
2957 @*/
2958 PetscErrorCode  TSSetTime(TS ts, PetscReal t)
2959 {
2960   PetscFunctionBegin;
2961   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2962   PetscValidLogicalCollectiveReal(ts,t,2);
2963   ts->ptime = t;
2964   PetscFunctionReturn(0);
2965 }
2966 
2967 #undef __FUNCT__
2968 #define __FUNCT__ "TSSetOptionsPrefix"
2969 /*@C
2970    TSSetOptionsPrefix - Sets the prefix used for searching for all
2971    TS options in the database.
2972 
2973    Logically Collective on TS
2974 
2975    Input Parameter:
2976 +  ts     - The TS context
2977 -  prefix - The prefix to prepend to all option names
2978 
2979    Notes:
2980    A hyphen (-) must NOT be given at the beginning of the prefix name.
2981    The first character of all runtime options is AUTOMATICALLY the
2982    hyphen.
2983 
2984    Level: advanced
2985 
2986 .keywords: TS, set, options, prefix, database
2987 
2988 .seealso: TSSetFromOptions()
2989 
2990 @*/
2991 PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
2992 {
2993   PetscErrorCode ierr;
2994   SNES           snes;
2995 
2996   PetscFunctionBegin;
2997   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2998   ierr = PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
2999   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3000   ierr = SNESSetOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3001   PetscFunctionReturn(0);
3002 }
3003 
3004 
3005 #undef __FUNCT__
3006 #define __FUNCT__ "TSAppendOptionsPrefix"
3007 /*@C
3008    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
3009    TS options in the database.
3010 
3011    Logically Collective on TS
3012 
3013    Input Parameter:
3014 +  ts     - The TS context
3015 -  prefix - The prefix to prepend to all option names
3016 
3017    Notes:
3018    A hyphen (-) must NOT be given at the beginning of the prefix name.
3019    The first character of all runtime options is AUTOMATICALLY the
3020    hyphen.
3021 
3022    Level: advanced
3023 
3024 .keywords: TS, append, options, prefix, database
3025 
3026 .seealso: TSGetOptionsPrefix()
3027 
3028 @*/
3029 PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
3030 {
3031   PetscErrorCode ierr;
3032   SNES           snes;
3033 
3034   PetscFunctionBegin;
3035   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3036   ierr = PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3037   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3038   ierr = SNESAppendOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3039   PetscFunctionReturn(0);
3040 }
3041 
3042 #undef __FUNCT__
3043 #define __FUNCT__ "TSGetOptionsPrefix"
3044 /*@C
3045    TSGetOptionsPrefix - Sets the prefix used for searching for all
3046    TS options in the database.
3047 
3048    Not Collective
3049 
3050    Input Parameter:
3051 .  ts - The TS context
3052 
3053    Output Parameter:
3054 .  prefix - A pointer to the prefix string used
3055 
3056    Notes: On the fortran side, the user should pass in a string 'prifix' of
3057    sufficient length to hold the prefix.
3058 
3059    Level: intermediate
3060 
3061 .keywords: TS, get, options, prefix, database
3062 
3063 .seealso: TSAppendOptionsPrefix()
3064 @*/
3065 PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
3066 {
3067   PetscErrorCode ierr;
3068 
3069   PetscFunctionBegin;
3070   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3071   PetscValidPointer(prefix,2);
3072   ierr = PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3073   PetscFunctionReturn(0);
3074 }
3075 
3076 #undef __FUNCT__
3077 #define __FUNCT__ "TSGetRHSJacobian"
3078 /*@C
3079    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.
3080 
3081    Not Collective, but parallel objects are returned if TS is parallel
3082 
3083    Input Parameter:
3084 .  ts  - The TS context obtained from TSCreate()
3085 
3086    Output Parameters:
3087 +  Amat - The (approximate) Jacobian J of G, where U_t = G(U,t)  (or NULL)
3088 .  Pmat - The matrix from which the preconditioner is constructed, usually the same as Amat  (or NULL)
3089 .  func - Function to compute the Jacobian of the RHS  (or NULL)
3090 -  ctx - User-defined context for Jacobian evaluation routine  (or NULL)
3091 
3092    Notes: You can pass in NULL for any return argument you do not need.
3093 
3094    Level: intermediate
3095 
3096 .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3097 
3098 .keywords: TS, timestep, get, matrix, Jacobian
3099 @*/
3100 PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *Amat,Mat *Pmat,TSRHSJacobian *func,void **ctx)
3101 {
3102   PetscErrorCode ierr;
3103   SNES           snes;
3104   DM             dm;
3105 
3106   PetscFunctionBegin;
3107   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3108   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3109   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3110   ierr = DMTSGetRHSJacobian(dm,func,ctx);CHKERRQ(ierr);
3111   PetscFunctionReturn(0);
3112 }
3113 
3114 #undef __FUNCT__
3115 #define __FUNCT__ "TSGetIJacobian"
3116 /*@C
3117    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.
3118 
3119    Not Collective, but parallel objects are returned if TS is parallel
3120 
3121    Input Parameter:
3122 .  ts  - The TS context obtained from TSCreate()
3123 
3124    Output Parameters:
3125 +  Amat  - The (approximate) Jacobian of F(t,U,U_t)
3126 .  Pmat - The matrix from which the preconditioner is constructed, often the same as Amat
3127 .  f   - The function to compute the matrices
3128 - ctx - User-defined context for Jacobian evaluation routine
3129 
3130    Notes: You can pass in NULL for any return argument you do not need.
3131 
3132    Level: advanced
3133 
3134 .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3135 
3136 .keywords: TS, timestep, get, matrix, Jacobian
3137 @*/
3138 PetscErrorCode  TSGetIJacobian(TS ts,Mat *Amat,Mat *Pmat,TSIJacobian *f,void **ctx)
3139 {
3140   PetscErrorCode ierr;
3141   SNES           snes;
3142   DM             dm;
3143 
3144   PetscFunctionBegin;
3145   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3146   ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
3147   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3148   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3149   ierr = DMTSGetIJacobian(dm,f,ctx);CHKERRQ(ierr);
3150   PetscFunctionReturn(0);
3151 }
3152 
3153 
3154 #undef __FUNCT__
3155 #define __FUNCT__ "TSMonitorDrawSolution"
3156 /*@C
3157    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
3158    VecView() for the solution at each timestep
3159 
3160    Collective on TS
3161 
3162    Input Parameters:
3163 +  ts - the TS context
3164 .  step - current time-step
3165 .  ptime - current time
3166 -  dummy - either a viewer or NULL
3167 
3168    Options Database:
3169 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3170 
3171    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
3172        will look bad
3173 
3174    Level: intermediate
3175 
3176 .keywords: TS,  vector, monitor, view
3177 
3178 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3179 @*/
3180 PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3181 {
3182   PetscErrorCode   ierr;
3183   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
3184   PetscDraw        draw;
3185 
3186   PetscFunctionBegin;
3187   if (!step && ictx->showinitial) {
3188     if (!ictx->initialsolution) {
3189       ierr = VecDuplicate(u,&ictx->initialsolution);CHKERRQ(ierr);
3190     }
3191     ierr = VecCopy(u,ictx->initialsolution);CHKERRQ(ierr);
3192   }
3193   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften))) || ((ictx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3194 
3195   if (ictx->showinitial) {
3196     PetscReal pause;
3197     ierr = PetscViewerDrawGetPause(ictx->viewer,&pause);CHKERRQ(ierr);
3198     ierr = PetscViewerDrawSetPause(ictx->viewer,0.0);CHKERRQ(ierr);
3199     ierr = VecView(ictx->initialsolution,ictx->viewer);CHKERRQ(ierr);
3200     ierr = PetscViewerDrawSetPause(ictx->viewer,pause);CHKERRQ(ierr);
3201     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);CHKERRQ(ierr);
3202   }
3203   ierr = VecView(u,ictx->viewer);CHKERRQ(ierr);
3204   if (ictx->showtimestepandtime) {
3205     PetscReal xl,yl,xr,yr,tw,w,h;
3206     char      time[32];
3207     size_t    len;
3208 
3209     ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3210     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3211     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3212     ierr =  PetscStrlen(time,&len);CHKERRQ(ierr);
3213     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3214     w    = xl + .5*(xr - xl) - .5*len*tw;
3215     h    = yl + .95*(yr - yl);
3216     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3217     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3218   }
3219 
3220   if (ictx->showinitial) {
3221     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);CHKERRQ(ierr);
3222   }
3223   PetscFunctionReturn(0);
3224 }
3225 
3226 #undef __FUNCT__
3227 #define __FUNCT__ "TSMonitorDrawSolutionPhase"
3228 /*@C
3229    TSMonitorDrawSolutionPhase - Monitors progress of the TS solvers by plotting the solution as a phase diagram
3230 
3231    Collective on TS
3232 
3233    Input Parameters:
3234 +  ts - the TS context
3235 .  step - current time-step
3236 .  ptime - current time
3237 -  dummy - either a viewer or NULL
3238 
3239    Level: intermediate
3240 
3241 .keywords: TS,  vector, monitor, view
3242 
3243 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3244 @*/
3245 PetscErrorCode  TSMonitorDrawSolutionPhase(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3246 {
3247   PetscErrorCode    ierr;
3248   TSMonitorDrawCtx  ictx = (TSMonitorDrawCtx)dummy;
3249   PetscDraw         draw;
3250   MPI_Comm          comm;
3251   PetscInt          n;
3252   PetscMPIInt       size;
3253   PetscReal         xl,yl,xr,yr,tw,w,h;
3254   char              time[32];
3255   size_t            len;
3256   const PetscScalar *U;
3257 
3258   PetscFunctionBegin;
3259   ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
3260   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3261   if (size != 1) SETERRQ(comm,PETSC_ERR_SUP,"Only allowed for sequential runs");
3262   ierr = VecGetSize(u,&n);CHKERRQ(ierr);
3263   if (n != 2) SETERRQ(comm,PETSC_ERR_SUP,"Only for ODEs with two unknowns");
3264 
3265   ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3266 
3267   ierr = VecGetArrayRead(u,&U);CHKERRQ(ierr);
3268   ierr = PetscDrawAxisGetLimits(ictx->axis,&xl,&xr,&yl,&yr);CHKERRQ(ierr);
3269   if ((PetscRealPart(U[0]) < xl) || (PetscRealPart(U[1]) < yl) || (PetscRealPart(U[0]) > xr) || (PetscRealPart(U[1]) > yr)) {
3270       ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3271       PetscFunctionReturn(0);
3272   }
3273   if (!step) ictx->color++;
3274   ierr = PetscDrawPoint(draw,PetscRealPart(U[0]),PetscRealPart(U[1]),ictx->color);CHKERRQ(ierr);
3275   ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3276 
3277   if (ictx->showtimestepandtime) {
3278     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3279     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3280     ierr = PetscStrlen(time,&len);CHKERRQ(ierr);
3281     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3282     w    = xl + .5*(xr - xl) - .5*len*tw;
3283     h    = yl + .95*(yr - yl);
3284     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3285   }
3286   ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3287   PetscFunctionReturn(0);
3288 }
3289 
3290 
3291 #undef __FUNCT__
3292 #define __FUNCT__ "TSMonitorDrawCtxDestroy"
3293 /*@C
3294    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()
3295 
3296    Collective on TS
3297 
3298    Input Parameters:
3299 .    ctx - the monitor context
3300 
3301    Level: intermediate
3302 
3303 .keywords: TS,  vector, monitor, view
3304 
3305 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
3306 @*/
3307 PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
3308 {
3309   PetscErrorCode ierr;
3310 
3311   PetscFunctionBegin;
3312   ierr = PetscDrawAxisDestroy(&(*ictx)->axis);CHKERRQ(ierr);
3313   ierr = PetscViewerDestroy(&(*ictx)->viewer);CHKERRQ(ierr);
3314   ierr = VecDestroy(&(*ictx)->initialsolution);CHKERRQ(ierr);
3315   ierr = PetscFree(*ictx);CHKERRQ(ierr);
3316   PetscFunctionReturn(0);
3317 }
3318 
3319 #undef __FUNCT__
3320 #define __FUNCT__ "TSMonitorDrawCtxCreate"
3321 /*@C
3322    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx
3323 
3324    Collective on TS
3325 
3326    Input Parameter:
3327 .    ts - time-step context
3328 
3329    Output Patameter:
3330 .    ctx - the monitor context
3331 
3332    Options Database:
3333 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3334 
3335    Level: intermediate
3336 
3337 .keywords: TS,  vector, monitor, view
3338 
3339 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
3340 @*/
3341 PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
3342 {
3343   PetscErrorCode   ierr;
3344 
3345   PetscFunctionBegin;
3346   ierr = PetscNew(ctx);CHKERRQ(ierr);
3347   ierr = PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);CHKERRQ(ierr);
3348   ierr = PetscViewerSetFromOptions((*ctx)->viewer);CHKERRQ(ierr);
3349 
3350   (*ctx)->howoften    = howoften;
3351   (*ctx)->showinitial = PETSC_FALSE;
3352   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,NULL);CHKERRQ(ierr);
3353 
3354   (*ctx)->showtimestepandtime = PETSC_FALSE;
3355   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_show_time",&(*ctx)->showtimestepandtime,NULL);CHKERRQ(ierr);
3356   (*ctx)->color = PETSC_DRAW_WHITE;
3357   PetscFunctionReturn(0);
3358 }
3359 
3360 #undef __FUNCT__
3361 #define __FUNCT__ "TSMonitorDrawError"
3362 /*@C
3363    TSMonitorDrawError - Monitors progress of the TS solvers by calling
3364    VecView() for the error at each timestep
3365 
3366    Collective on TS
3367 
3368    Input Parameters:
3369 +  ts - the TS context
3370 .  step - current time-step
3371 .  ptime - current time
3372 -  dummy - either a viewer or NULL
3373 
3374    Level: intermediate
3375 
3376 .keywords: TS,  vector, monitor, view
3377 
3378 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3379 @*/
3380 PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3381 {
3382   PetscErrorCode   ierr;
3383   TSMonitorDrawCtx ctx    = (TSMonitorDrawCtx)dummy;
3384   PetscViewer      viewer = ctx->viewer;
3385   Vec              work;
3386 
3387   PetscFunctionBegin;
3388   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3389   ierr = VecDuplicate(u,&work);CHKERRQ(ierr);
3390   ierr = TSComputeSolutionFunction(ts,ptime,work);CHKERRQ(ierr);
3391   ierr = VecAXPY(work,-1.0,u);CHKERRQ(ierr);
3392   ierr = VecView(work,viewer);CHKERRQ(ierr);
3393   ierr = VecDestroy(&work);CHKERRQ(ierr);
3394   PetscFunctionReturn(0);
3395 }
3396 
3397 #include <petsc-private/dmimpl.h>
3398 #undef __FUNCT__
3399 #define __FUNCT__ "TSSetDM"
3400 /*@
3401    TSSetDM - Sets the DM that may be used by some preconditioners
3402 
3403    Logically Collective on TS and DM
3404 
3405    Input Parameters:
3406 +  ts - the preconditioner context
3407 -  dm - the dm
3408 
3409    Level: intermediate
3410 
3411 
3412 .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
3413 @*/
3414 PetscErrorCode  TSSetDM(TS ts,DM dm)
3415 {
3416   PetscErrorCode ierr;
3417   SNES           snes;
3418   DMTS           tsdm;
3419 
3420   PetscFunctionBegin;
3421   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3422   ierr = PetscObjectReference((PetscObject)dm);CHKERRQ(ierr);
3423   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
3424     if (ts->dm->dmts && !dm->dmts) {
3425       ierr = DMCopyDMTS(ts->dm,dm);CHKERRQ(ierr);
3426       ierr = DMGetDMTS(ts->dm,&tsdm);CHKERRQ(ierr);
3427       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
3428         tsdm->originaldm = dm;
3429       }
3430     }
3431     ierr = DMDestroy(&ts->dm);CHKERRQ(ierr);
3432   }
3433   ts->dm = dm;
3434 
3435   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3436   ierr = SNESSetDM(snes,dm);CHKERRQ(ierr);
3437   PetscFunctionReturn(0);
3438 }
3439 
3440 #undef __FUNCT__
3441 #define __FUNCT__ "TSGetDM"
3442 /*@
3443    TSGetDM - Gets the DM that may be used by some preconditioners
3444 
3445    Not Collective
3446 
3447    Input Parameter:
3448 . ts - the preconditioner context
3449 
3450    Output Parameter:
3451 .  dm - the dm
3452 
3453    Level: intermediate
3454 
3455 
3456 .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
3457 @*/
3458 PetscErrorCode  TSGetDM(TS ts,DM *dm)
3459 {
3460   PetscErrorCode ierr;
3461 
3462   PetscFunctionBegin;
3463   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3464   if (!ts->dm) {
3465     ierr = DMShellCreate(PetscObjectComm((PetscObject)ts),&ts->dm);CHKERRQ(ierr);
3466     if (ts->snes) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
3467   }
3468   *dm = ts->dm;
3469   PetscFunctionReturn(0);
3470 }
3471 
3472 #undef __FUNCT__
3473 #define __FUNCT__ "SNESTSFormFunction"
3474 /*@
3475    SNESTSFormFunction - Function to evaluate nonlinear residual
3476 
3477    Logically Collective on SNES
3478 
3479    Input Parameter:
3480 + snes - nonlinear solver
3481 . U - the current state at which to evaluate the residual
3482 - ctx - user context, must be a TS
3483 
3484    Output Parameter:
3485 . F - the nonlinear residual
3486 
3487    Notes:
3488    This function is not normally called by users and is automatically registered with the SNES used by TS.
3489    It is most frequently passed to MatFDColoringSetFunction().
3490 
3491    Level: advanced
3492 
3493 .seealso: SNESSetFunction(), MatFDColoringSetFunction()
3494 @*/
3495 PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
3496 {
3497   TS             ts = (TS)ctx;
3498   PetscErrorCode ierr;
3499 
3500   PetscFunctionBegin;
3501   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3502   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3503   PetscValidHeaderSpecific(F,VEC_CLASSID,3);
3504   PetscValidHeaderSpecific(ts,TS_CLASSID,4);
3505   ierr = (ts->ops->snesfunction)(snes,U,F,ts);CHKERRQ(ierr);
3506   PetscFunctionReturn(0);
3507 }
3508 
3509 #undef __FUNCT__
3510 #define __FUNCT__ "SNESTSFormJacobian"
3511 /*@
3512    SNESTSFormJacobian - Function to evaluate the Jacobian
3513 
3514    Collective on SNES
3515 
3516    Input Parameter:
3517 + snes - nonlinear solver
3518 . U - the current state at which to evaluate the residual
3519 - ctx - user context, must be a TS
3520 
3521    Output Parameter:
3522 + A - the Jacobian
3523 . B - the preconditioning matrix (may be the same as A)
3524 - flag - indicates any structure change in the matrix
3525 
3526    Notes:
3527    This function is not normally called by users and is automatically registered with the SNES used by TS.
3528 
3529    Level: developer
3530 
3531 .seealso: SNESSetJacobian()
3532 @*/
3533 PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat A,Mat B,void *ctx)
3534 {
3535   TS             ts = (TS)ctx;
3536   PetscErrorCode ierr;
3537 
3538   PetscFunctionBegin;
3539   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3540   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3541   PetscValidPointer(A,3);
3542   PetscValidHeaderSpecific(A,MAT_CLASSID,3);
3543   PetscValidPointer(B,4);
3544   PetscValidHeaderSpecific(B,MAT_CLASSID,4);
3545   PetscValidHeaderSpecific(ts,TS_CLASSID,6);
3546   ierr = (ts->ops->snesjacobian)(snes,U,A,B,ts);CHKERRQ(ierr);
3547   PetscFunctionReturn(0);
3548 }
3549 
3550 #undef __FUNCT__
3551 #define __FUNCT__ "TSComputeRHSFunctionLinear"
3552 /*@C
3553    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only
3554 
3555    Collective on TS
3556 
3557    Input Arguments:
3558 +  ts - time stepping context
3559 .  t - time at which to evaluate
3560 .  U - state at which to evaluate
3561 -  ctx - context
3562 
3563    Output Arguments:
3564 .  F - right hand side
3565 
3566    Level: intermediate
3567 
3568    Notes:
3569    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
3570    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().
3571 
3572 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
3573 @*/
3574 PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
3575 {
3576   PetscErrorCode ierr;
3577   Mat            Arhs,Brhs;
3578 
3579   PetscFunctionBegin;
3580   ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
3581   ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
3582   ierr = MatMult(Arhs,U,F);CHKERRQ(ierr);
3583   PetscFunctionReturn(0);
3584 }
3585 
3586 #undef __FUNCT__
3587 #define __FUNCT__ "TSComputeRHSJacobianConstant"
3588 /*@C
3589    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.
3590 
3591    Collective on TS
3592 
3593    Input Arguments:
3594 +  ts - time stepping context
3595 .  t - time at which to evaluate
3596 .  U - state at which to evaluate
3597 -  ctx - context
3598 
3599    Output Arguments:
3600 +  A - pointer to operator
3601 .  B - pointer to preconditioning matrix
3602 -  flg - matrix structure flag
3603 
3604    Level: intermediate
3605 
3606    Notes:
3607    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.
3608 
3609 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
3610 @*/
3611 PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat A,Mat B,void *ctx)
3612 {
3613   PetscFunctionBegin;
3614   PetscFunctionReturn(0);
3615 }
3616 
3617 #undef __FUNCT__
3618 #define __FUNCT__ "TSComputeIFunctionLinear"
3619 /*@C
3620    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only
3621 
3622    Collective on TS
3623 
3624    Input Arguments:
3625 +  ts - time stepping context
3626 .  t - time at which to evaluate
3627 .  U - state at which to evaluate
3628 .  Udot - time derivative of state vector
3629 -  ctx - context
3630 
3631    Output Arguments:
3632 .  F - left hand side
3633 
3634    Level: intermediate
3635 
3636    Notes:
3637    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
3638    user is required to write their own TSComputeIFunction.
3639    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
3640    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().
3641 
3642 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
3643 @*/
3644 PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
3645 {
3646   PetscErrorCode ierr;
3647   Mat            A,B;
3648 
3649   PetscFunctionBegin;
3650   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
3651   ierr = TSComputeIJacobian(ts,t,U,Udot,1.0,A,B,PETSC_TRUE);CHKERRQ(ierr);
3652   ierr = MatMult(A,Udot,F);CHKERRQ(ierr);
3653   PetscFunctionReturn(0);
3654 }
3655 
3656 #undef __FUNCT__
3657 #define __FUNCT__ "TSComputeIJacobianConstant"
3658 /*@C
3659    TSComputeIJacobianConstant - Reuses a time-independent for a semi-implicit DAE or ODE
3660 
3661    Collective on TS
3662 
3663    Input Arguments:
3664 +  ts - time stepping context
3665 .  t - time at which to evaluate
3666 .  U - state at which to evaluate
3667 .  Udot - time derivative of state vector
3668 .  shift - shift to apply
3669 -  ctx - context
3670 
3671    Output Arguments:
3672 +  A - pointer to operator
3673 .  B - pointer to preconditioning matrix
3674 -  flg - matrix structure flag
3675 
3676    Level: advanced
3677 
3678    Notes:
3679    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.
3680 
3681    It is only appropriate for problems of the form
3682 
3683 $     M Udot = F(U,t)
3684 
3685   where M is constant and F is non-stiff.  The user must pass M to TSSetIJacobian().  The current implementation only
3686   works with IMEX time integration methods such as TSROSW and TSARKIMEX, since there is no support for de-constructing
3687   an implicit operator of the form
3688 
3689 $    shift*M + J
3690 
3691   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
3692   a copy of M or reassemble it when requested.
3693 
3694 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
3695 @*/
3696 PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,void *ctx)
3697 {
3698   PetscErrorCode ierr;
3699 
3700   PetscFunctionBegin;
3701   ierr = MatScale(A, shift / ts->ijacobian.shift);CHKERRQ(ierr);
3702   ts->ijacobian.shift = shift;
3703   PetscFunctionReturn(0);
3704 }
3705 
3706 #undef __FUNCT__
3707 #define __FUNCT__ "TSGetEquationType"
3708 /*@
3709    TSGetEquationType - Gets the type of the equation that TS is solving.
3710 
3711    Not Collective
3712 
3713    Input Parameter:
3714 .  ts - the TS context
3715 
3716    Output Parameter:
3717 .  equation_type - see TSEquationType
3718 
3719    Level: beginner
3720 
3721 .keywords: TS, equation type
3722 
3723 .seealso: TSSetEquationType(), TSEquationType
3724 @*/
3725 PetscErrorCode  TSGetEquationType(TS ts,TSEquationType *equation_type)
3726 {
3727   PetscFunctionBegin;
3728   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3729   PetscValidPointer(equation_type,2);
3730   *equation_type = ts->equation_type;
3731   PetscFunctionReturn(0);
3732 }
3733 
3734 #undef __FUNCT__
3735 #define __FUNCT__ "TSSetEquationType"
3736 /*@
3737    TSSetEquationType - Sets the type of the equation that TS is solving.
3738 
3739    Not Collective
3740 
3741    Input Parameter:
3742 +  ts - the TS context
3743 .  equation_type - see TSEquationType
3744 
3745    Level: advanced
3746 
3747 .keywords: TS, equation type
3748 
3749 .seealso: TSGetEquationType(), TSEquationType
3750 @*/
3751 PetscErrorCode  TSSetEquationType(TS ts,TSEquationType equation_type)
3752 {
3753   PetscFunctionBegin;
3754   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3755   ts->equation_type = equation_type;
3756   PetscFunctionReturn(0);
3757 }
3758 
3759 #undef __FUNCT__
3760 #define __FUNCT__ "TSGetConvergedReason"
3761 /*@
3762    TSGetConvergedReason - Gets the reason the TS iteration was stopped.
3763 
3764    Not Collective
3765 
3766    Input Parameter:
3767 .  ts - the TS context
3768 
3769    Output Parameter:
3770 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3771             manual pages for the individual convergence tests for complete lists
3772 
3773    Level: beginner
3774 
3775    Notes:
3776    Can only be called after the call to TSSolve() is complete.
3777 
3778 .keywords: TS, nonlinear, set, convergence, test
3779 
3780 .seealso: TSSetConvergenceTest(), TSConvergedReason
3781 @*/
3782 PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
3783 {
3784   PetscFunctionBegin;
3785   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3786   PetscValidPointer(reason,2);
3787   *reason = ts->reason;
3788   PetscFunctionReturn(0);
3789 }
3790 
3791 #undef __FUNCT__
3792 #define __FUNCT__ "TSSetConvergedReason"
3793 /*@
3794    TSSetConvergedReason - Sets the reason for handling the convergence of TSSolve.
3795 
3796    Not Collective
3797 
3798    Input Parameter:
3799 +  ts - the TS context
3800 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3801             manual pages for the individual convergence tests for complete lists
3802 
3803    Level: advanced
3804 
3805    Notes:
3806    Can only be called during TSSolve() is active.
3807 
3808 .keywords: TS, nonlinear, set, convergence, test
3809 
3810 .seealso: TSConvergedReason
3811 @*/
3812 PetscErrorCode  TSSetConvergedReason(TS ts,TSConvergedReason reason)
3813 {
3814   PetscFunctionBegin;
3815   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3816   ts->reason = reason;
3817   PetscFunctionReturn(0);
3818 }
3819 
3820 #undef __FUNCT__
3821 #define __FUNCT__ "TSGetSolveTime"
3822 /*@
3823    TSGetSolveTime - Gets the time after a call to TSSolve()
3824 
3825    Not Collective
3826 
3827    Input Parameter:
3828 .  ts - the TS context
3829 
3830    Output Parameter:
3831 .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()
3832 
3833    Level: beginner
3834 
3835    Notes:
3836    Can only be called after the call to TSSolve() is complete.
3837 
3838 .keywords: TS, nonlinear, set, convergence, test
3839 
3840 .seealso: TSSetConvergenceTest(), TSConvergedReason
3841 @*/
3842 PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
3843 {
3844   PetscFunctionBegin;
3845   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3846   PetscValidPointer(ftime,2);
3847   *ftime = ts->solvetime;
3848   PetscFunctionReturn(0);
3849 }
3850 
3851 #undef __FUNCT__
3852 #define __FUNCT__ "TSGetSNESIterations"
3853 /*@
3854    TSGetSNESIterations - Gets the total number of nonlinear iterations
3855    used by the time integrator.
3856 
3857    Not Collective
3858 
3859    Input Parameter:
3860 .  ts - TS context
3861 
3862    Output Parameter:
3863 .  nits - number of nonlinear iterations
3864 
3865    Notes:
3866    This counter is reset to zero for each successive call to TSSolve().
3867 
3868    Level: intermediate
3869 
3870 .keywords: TS, get, number, nonlinear, iterations
3871 
3872 .seealso:  TSGetKSPIterations()
3873 @*/
3874 PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
3875 {
3876   PetscFunctionBegin;
3877   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3878   PetscValidIntPointer(nits,2);
3879   *nits = ts->snes_its;
3880   PetscFunctionReturn(0);
3881 }
3882 
3883 #undef __FUNCT__
3884 #define __FUNCT__ "TSGetKSPIterations"
3885 /*@
3886    TSGetKSPIterations - Gets the total number of linear iterations
3887    used by the time integrator.
3888 
3889    Not Collective
3890 
3891    Input Parameter:
3892 .  ts - TS context
3893 
3894    Output Parameter:
3895 .  lits - number of linear iterations
3896 
3897    Notes:
3898    This counter is reset to zero for each successive call to TSSolve().
3899 
3900    Level: intermediate
3901 
3902 .keywords: TS, get, number, linear, iterations
3903 
3904 .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
3905 @*/
3906 PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
3907 {
3908   PetscFunctionBegin;
3909   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3910   PetscValidIntPointer(lits,2);
3911   *lits = ts->ksp_its;
3912   PetscFunctionReturn(0);
3913 }
3914 
3915 #undef __FUNCT__
3916 #define __FUNCT__ "TSGetStepRejections"
3917 /*@
3918    TSGetStepRejections - Gets the total number of rejected steps.
3919 
3920    Not Collective
3921 
3922    Input Parameter:
3923 .  ts - TS context
3924 
3925    Output Parameter:
3926 .  rejects - number of steps rejected
3927 
3928    Notes:
3929    This counter is reset to zero for each successive call to TSSolve().
3930 
3931    Level: intermediate
3932 
3933 .keywords: TS, get, number
3934 
3935 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
3936 @*/
3937 PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
3938 {
3939   PetscFunctionBegin;
3940   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3941   PetscValidIntPointer(rejects,2);
3942   *rejects = ts->reject;
3943   PetscFunctionReturn(0);
3944 }
3945 
3946 #undef __FUNCT__
3947 #define __FUNCT__ "TSGetSNESFailures"
3948 /*@
3949    TSGetSNESFailures - Gets the total number of failed SNES solves
3950 
3951    Not Collective
3952 
3953    Input Parameter:
3954 .  ts - TS context
3955 
3956    Output Parameter:
3957 .  fails - number of failed nonlinear solves
3958 
3959    Notes:
3960    This counter is reset to zero for each successive call to TSSolve().
3961 
3962    Level: intermediate
3963 
3964 .keywords: TS, get, number
3965 
3966 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
3967 @*/
3968 PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
3969 {
3970   PetscFunctionBegin;
3971   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3972   PetscValidIntPointer(fails,2);
3973   *fails = ts->num_snes_failures;
3974   PetscFunctionReturn(0);
3975 }
3976 
3977 #undef __FUNCT__
3978 #define __FUNCT__ "TSSetMaxStepRejections"
3979 /*@
3980    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails
3981 
3982    Not Collective
3983 
3984    Input Parameter:
3985 +  ts - TS context
3986 -  rejects - maximum number of rejected steps, pass -1 for unlimited
3987 
3988    Notes:
3989    The counter is reset to zero for each step
3990 
3991    Options Database Key:
3992  .  -ts_max_reject - Maximum number of step rejections before a step fails
3993 
3994    Level: intermediate
3995 
3996 .keywords: TS, set, maximum, number
3997 
3998 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
3999 @*/
4000 PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
4001 {
4002   PetscFunctionBegin;
4003   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4004   ts->max_reject = rejects;
4005   PetscFunctionReturn(0);
4006 }
4007 
4008 #undef __FUNCT__
4009 #define __FUNCT__ "TSSetMaxSNESFailures"
4010 /*@
4011    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves
4012 
4013    Not Collective
4014 
4015    Input Parameter:
4016 +  ts - TS context
4017 -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited
4018 
4019    Notes:
4020    The counter is reset to zero for each successive call to TSSolve().
4021 
4022    Options Database Key:
4023  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures
4024 
4025    Level: intermediate
4026 
4027 .keywords: TS, set, maximum, number
4028 
4029 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
4030 @*/
4031 PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
4032 {
4033   PetscFunctionBegin;
4034   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4035   ts->max_snes_failures = fails;
4036   PetscFunctionReturn(0);
4037 }
4038 
4039 #undef __FUNCT__
4040 #define __FUNCT__ "TSSetErrorIfStepFails"
4041 /*@
4042    TSSetErrorIfStepFails - Error if no step succeeds
4043 
4044    Not Collective
4045 
4046    Input Parameter:
4047 +  ts - TS context
4048 -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure
4049 
4050    Options Database Key:
4051  .  -ts_error_if_step_fails - Error if no step succeeds
4052 
4053    Level: intermediate
4054 
4055 .keywords: TS, set, error
4056 
4057 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4058 @*/
4059 PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
4060 {
4061   PetscFunctionBegin;
4062   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4063   ts->errorifstepfailed = err;
4064   PetscFunctionReturn(0);
4065 }
4066 
4067 #undef __FUNCT__
4068 #define __FUNCT__ "TSMonitorSolutionBinary"
4069 /*@C
4070    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file
4071 
4072    Collective on TS
4073 
4074    Input Parameters:
4075 +  ts - the TS context
4076 .  step - current time-step
4077 .  ptime - current time
4078 .  u - current state
4079 -  viewer - binary viewer
4080 
4081    Level: intermediate
4082 
4083 .keywords: TS,  vector, monitor, view
4084 
4085 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4086 @*/
4087 PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
4088 {
4089   PetscErrorCode ierr;
4090   PetscViewer    v = (PetscViewer)viewer;
4091 
4092   PetscFunctionBegin;
4093   ierr = VecView(u,v);CHKERRQ(ierr);
4094   PetscFunctionReturn(0);
4095 }
4096 
4097 #undef __FUNCT__
4098 #define __FUNCT__ "TSMonitorSolutionVTK"
4099 /*@C
4100    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.
4101 
4102    Collective on TS
4103 
4104    Input Parameters:
4105 +  ts - the TS context
4106 .  step - current time-step
4107 .  ptime - current time
4108 .  u - current state
4109 -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4110 
4111    Level: intermediate
4112 
4113    Notes:
4114    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.
4115    These are named according to the file name template.
4116 
4117    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().
4118 
4119 .keywords: TS,  vector, monitor, view
4120 
4121 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4122 @*/
4123 PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
4124 {
4125   PetscErrorCode ierr;
4126   char           filename[PETSC_MAX_PATH_LEN];
4127   PetscViewer    viewer;
4128 
4129   PetscFunctionBegin;
4130   ierr = PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);CHKERRQ(ierr);
4131   ierr = PetscViewerVTKOpen(PetscObjectComm((PetscObject)ts),filename,FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
4132   ierr = VecView(u,viewer);CHKERRQ(ierr);
4133   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
4134   PetscFunctionReturn(0);
4135 }
4136 
4137 #undef __FUNCT__
4138 #define __FUNCT__ "TSMonitorSolutionVTKDestroy"
4139 /*@C
4140    TSMonitorSolutionVTKDestroy - Destroy context for monitoring
4141 
4142    Collective on TS
4143 
4144    Input Parameters:
4145 .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4146 
4147    Level: intermediate
4148 
4149    Note:
4150    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().
4151 
4152 .keywords: TS,  vector, monitor, view
4153 
4154 .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
4155 @*/
4156 PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
4157 {
4158   PetscErrorCode ierr;
4159 
4160   PetscFunctionBegin;
4161   ierr = PetscFree(*(char**)filenametemplate);CHKERRQ(ierr);
4162   PetscFunctionReturn(0);
4163 }
4164 
4165 #undef __FUNCT__
4166 #define __FUNCT__ "TSGetAdapt"
4167 /*@
4168    TSGetAdapt - Get the adaptive controller context for the current method
4169 
4170    Collective on TS if controller has not been created yet
4171 
4172    Input Arguments:
4173 .  ts - time stepping context
4174 
4175    Output Arguments:
4176 .  adapt - adaptive controller
4177 
4178    Level: intermediate
4179 
4180 .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
4181 @*/
4182 PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
4183 {
4184   PetscErrorCode ierr;
4185 
4186   PetscFunctionBegin;
4187   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4188   PetscValidPointer(adapt,2);
4189   if (!ts->adapt) {
4190     ierr = TSAdaptCreate(PetscObjectComm((PetscObject)ts),&ts->adapt);CHKERRQ(ierr);
4191     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->adapt);CHKERRQ(ierr);
4192     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);CHKERRQ(ierr);
4193   }
4194   *adapt = ts->adapt;
4195   PetscFunctionReturn(0);
4196 }
4197 
4198 #undef __FUNCT__
4199 #define __FUNCT__ "TSSetTolerances"
4200 /*@
4201    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller
4202 
4203    Logically Collective
4204 
4205    Input Arguments:
4206 +  ts - time integration context
4207 .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
4208 .  vatol - vector of absolute tolerances or NULL, used in preference to atol if present
4209 .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
4210 -  vrtol - vector of relative tolerances or NULL, used in preference to atol if present
4211 
4212    Level: beginner
4213 
4214 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
4215 @*/
4216 PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
4217 {
4218   PetscErrorCode ierr;
4219 
4220   PetscFunctionBegin;
4221   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
4222   if (vatol) {
4223     ierr = PetscObjectReference((PetscObject)vatol);CHKERRQ(ierr);
4224     ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
4225 
4226     ts->vatol = vatol;
4227   }
4228   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
4229   if (vrtol) {
4230     ierr = PetscObjectReference((PetscObject)vrtol);CHKERRQ(ierr);
4231     ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
4232 
4233     ts->vrtol = vrtol;
4234   }
4235   PetscFunctionReturn(0);
4236 }
4237 
4238 #undef __FUNCT__
4239 #define __FUNCT__ "TSGetTolerances"
4240 /*@
4241    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller
4242 
4243    Logically Collective
4244 
4245    Input Arguments:
4246 .  ts - time integration context
4247 
4248    Output Arguments:
4249 +  atol - scalar absolute tolerances, NULL to ignore
4250 .  vatol - vector of absolute tolerances, NULL to ignore
4251 .  rtol - scalar relative tolerances, NULL to ignore
4252 -  vrtol - vector of relative tolerances, NULL to ignore
4253 
4254    Level: beginner
4255 
4256 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
4257 @*/
4258 PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
4259 {
4260   PetscFunctionBegin;
4261   if (atol)  *atol  = ts->atol;
4262   if (vatol) *vatol = ts->vatol;
4263   if (rtol)  *rtol  = ts->rtol;
4264   if (vrtol) *vrtol = ts->vrtol;
4265   PetscFunctionReturn(0);
4266 }
4267 
4268 #undef __FUNCT__
4269 #define __FUNCT__ "TSErrorNormWRMS"
4270 /*@
4271    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state
4272 
4273    Collective on TS
4274 
4275    Input Arguments:
4276 +  ts - time stepping context
4277 -  Y - state vector to be compared to ts->vec_sol
4278 
4279    Output Arguments:
4280 .  norm - weighted norm, a value of 1.0 is considered small
4281 
4282    Level: developer
4283 
4284 .seealso: TSSetTolerances()
4285 @*/
4286 PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
4287 {
4288   PetscErrorCode    ierr;
4289   PetscInt          i,n,N;
4290   const PetscScalar *u,*y;
4291   Vec               U;
4292   PetscReal         sum,gsum;
4293 
4294   PetscFunctionBegin;
4295   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4296   PetscValidHeaderSpecific(Y,VEC_CLASSID,2);
4297   PetscValidPointer(norm,3);
4298   U = ts->vec_sol;
4299   PetscCheckSameTypeAndComm(U,1,Y,2);
4300   if (U == Y) SETERRQ(PetscObjectComm((PetscObject)U),PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");
4301 
4302   ierr = VecGetSize(U,&N);CHKERRQ(ierr);
4303   ierr = VecGetLocalSize(U,&n);CHKERRQ(ierr);
4304   ierr = VecGetArrayRead(U,&u);CHKERRQ(ierr);
4305   ierr = VecGetArrayRead(Y,&y);CHKERRQ(ierr);
4306   sum  = 0.;
4307   if (ts->vatol && ts->vrtol) {
4308     const PetscScalar *atol,*rtol;
4309     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4310     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4311     for (i=0; i<n; i++) {
4312       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4313       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4314     }
4315     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4316     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4317   } else if (ts->vatol) {       /* vector atol, scalar rtol */
4318     const PetscScalar *atol;
4319     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4320     for (i=0; i<n; i++) {
4321       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4322       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4323     }
4324     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4325   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
4326     const PetscScalar *rtol;
4327     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4328     for (i=0; i<n; i++) {
4329       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4330       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4331     }
4332     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4333   } else {                      /* scalar atol, scalar rtol */
4334     for (i=0; i<n; i++) {
4335       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4336       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4337     }
4338   }
4339   ierr = VecRestoreArrayRead(U,&u);CHKERRQ(ierr);
4340   ierr = VecRestoreArrayRead(Y,&y);CHKERRQ(ierr);
4341 
4342   ierr  = MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4343   *norm = PetscSqrtReal(gsum / N);
4344   if (PetscIsInfOrNanScalar(*norm)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
4345   PetscFunctionReturn(0);
4346 }
4347 
4348 #undef __FUNCT__
4349 #define __FUNCT__ "TSSetCFLTimeLocal"
4350 /*@
4351    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler
4352 
4353    Logically Collective on TS
4354 
4355    Input Arguments:
4356 +  ts - time stepping context
4357 -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)
4358 
4359    Note:
4360    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()
4361 
4362    Level: intermediate
4363 
4364 .seealso: TSGetCFLTime(), TSADAPTCFL
4365 @*/
4366 PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
4367 {
4368   PetscFunctionBegin;
4369   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4370   ts->cfltime_local = cfltime;
4371   ts->cfltime       = -1.;
4372   PetscFunctionReturn(0);
4373 }
4374 
4375 #undef __FUNCT__
4376 #define __FUNCT__ "TSGetCFLTime"
4377 /*@
4378    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler
4379 
4380    Collective on TS
4381 
4382    Input Arguments:
4383 .  ts - time stepping context
4384 
4385    Output Arguments:
4386 .  cfltime - maximum stable time step for forward Euler
4387 
4388    Level: advanced
4389 
4390 .seealso: TSSetCFLTimeLocal()
4391 @*/
4392 PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
4393 {
4394   PetscErrorCode ierr;
4395 
4396   PetscFunctionBegin;
4397   if (ts->cfltime < 0) {
4398     ierr = MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4399   }
4400   *cfltime = ts->cfltime;
4401   PetscFunctionReturn(0);
4402 }
4403 
4404 #undef __FUNCT__
4405 #define __FUNCT__ "TSVISetVariableBounds"
4406 /*@
4407    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu
4408 
4409    Input Parameters:
4410 .  ts   - the TS context.
4411 .  xl   - lower bound.
4412 .  xu   - upper bound.
4413 
4414    Notes:
4415    If this routine is not called then the lower and upper bounds are set to
4416    PETSC_NINFINITY and PETSC_INFINITY respectively during SNESSetUp().
4417 
4418    Level: advanced
4419 
4420 @*/
4421 PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
4422 {
4423   PetscErrorCode ierr;
4424   SNES           snes;
4425 
4426   PetscFunctionBegin;
4427   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
4428   ierr = SNESVISetVariableBounds(snes,xl,xu);CHKERRQ(ierr);
4429   PetscFunctionReturn(0);
4430 }
4431 
4432 #if defined(PETSC_HAVE_MATLAB_ENGINE)
4433 #include <mex.h>
4434 
4435 typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;
4436 
4437 #undef __FUNCT__
4438 #define __FUNCT__ "TSComputeFunction_Matlab"
4439 /*
4440    TSComputeFunction_Matlab - Calls the function that has been set with
4441                          TSSetFunctionMatlab().
4442 
4443    Collective on TS
4444 
4445    Input Parameters:
4446 +  snes - the TS context
4447 -  u - input vector
4448 
4449    Output Parameter:
4450 .  y - function vector, as set by TSSetFunction()
4451 
4452    Notes:
4453    TSComputeFunction() is typically used within nonlinear solvers
4454    implementations, so most users would not generally call this routine
4455    themselves.
4456 
4457    Level: developer
4458 
4459 .keywords: TS, nonlinear, compute, function
4460 
4461 .seealso: TSSetFunction(), TSGetFunction()
4462 */
4463 PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
4464 {
4465   PetscErrorCode  ierr;
4466   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4467   int             nlhs  = 1,nrhs = 7;
4468   mxArray         *plhs[1],*prhs[7];
4469   long long int   lx = 0,lxdot = 0,ly = 0,ls = 0;
4470 
4471   PetscFunctionBegin;
4472   PetscValidHeaderSpecific(snes,TS_CLASSID,1);
4473   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4474   PetscValidHeaderSpecific(udot,VEC_CLASSID,4);
4475   PetscValidHeaderSpecific(y,VEC_CLASSID,5);
4476   PetscCheckSameComm(snes,1,u,3);
4477   PetscCheckSameComm(snes,1,y,5);
4478 
4479   ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr);
4480   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4481   ierr = PetscMemcpy(&lxdot,&udot,sizeof(udot));CHKERRQ(ierr);
4482   ierr = PetscMemcpy(&ly,&y,sizeof(u));CHKERRQ(ierr);
4483 
4484   prhs[0] =  mxCreateDoubleScalar((double)ls);
4485   prhs[1] =  mxCreateDoubleScalar(time);
4486   prhs[2] =  mxCreateDoubleScalar((double)lx);
4487   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4488   prhs[4] =  mxCreateDoubleScalar((double)ly);
4489   prhs[5] =  mxCreateString(sctx->funcname);
4490   prhs[6] =  sctx->ctx;
4491   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");CHKERRQ(ierr);
4492   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4493   mxDestroyArray(prhs[0]);
4494   mxDestroyArray(prhs[1]);
4495   mxDestroyArray(prhs[2]);
4496   mxDestroyArray(prhs[3]);
4497   mxDestroyArray(prhs[4]);
4498   mxDestroyArray(prhs[5]);
4499   mxDestroyArray(plhs[0]);
4500   PetscFunctionReturn(0);
4501 }
4502 
4503 
4504 #undef __FUNCT__
4505 #define __FUNCT__ "TSSetFunctionMatlab"
4506 /*
4507    TSSetFunctionMatlab - Sets the function evaluation routine and function
4508    vector for use by the TS routines in solving ODEs
4509    equations from MATLAB. Here the function is a string containing the name of a MATLAB function
4510 
4511    Logically Collective on TS
4512 
4513    Input Parameters:
4514 +  ts - the TS context
4515 -  func - function evaluation routine
4516 
4517    Calling sequence of func:
4518 $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);
4519 
4520    Level: beginner
4521 
4522 .keywords: TS, nonlinear, set, function
4523 
4524 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4525 */
4526 PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
4527 {
4528   PetscErrorCode  ierr;
4529   TSMatlabContext *sctx;
4530 
4531   PetscFunctionBegin;
4532   /* currently sctx is memory bleed */
4533   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4534   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4535   /*
4536      This should work, but it doesn't
4537   sctx->ctx = ctx;
4538   mexMakeArrayPersistent(sctx->ctx);
4539   */
4540   sctx->ctx = mxDuplicateArray(ctx);
4541 
4542   ierr = TSSetIFunction(ts,NULL,TSComputeFunction_Matlab,sctx);CHKERRQ(ierr);
4543   PetscFunctionReturn(0);
4544 }
4545 
4546 #undef __FUNCT__
4547 #define __FUNCT__ "TSComputeJacobian_Matlab"
4548 /*
4549    TSComputeJacobian_Matlab - Calls the function that has been set with
4550                          TSSetJacobianMatlab().
4551 
4552    Collective on TS
4553 
4554    Input Parameters:
4555 +  ts - the TS context
4556 .  u - input vector
4557 .  A, B - the matrices
4558 -  ctx - user context
4559 
4560    Output Parameter:
4561 .  flag - structure of the matrix
4562 
4563    Level: developer
4564 
4565 .keywords: TS, nonlinear, compute, function
4566 
4567 .seealso: TSSetFunction(), TSGetFunction()
4568 @*/
4569 PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flag, void *ctx)
4570 {
4571   PetscErrorCode  ierr;
4572   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4573   int             nlhs  = 2,nrhs = 9;
4574   mxArray         *plhs[2],*prhs[9];
4575   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;
4576 
4577   PetscFunctionBegin;
4578   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4579   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4580 
4581   /* call Matlab function in ctx with arguments u and y */
4582 
4583   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4584   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4585   ierr = PetscMemcpy(&lxdot,&udot,sizeof(u));CHKERRQ(ierr);
4586   ierr = PetscMemcpy(&lA,A,sizeof(u));CHKERRQ(ierr);
4587   ierr = PetscMemcpy(&lB,B,sizeof(u));CHKERRQ(ierr);
4588 
4589   prhs[0] =  mxCreateDoubleScalar((double)ls);
4590   prhs[1] =  mxCreateDoubleScalar((double)time);
4591   prhs[2] =  mxCreateDoubleScalar((double)lx);
4592   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4593   prhs[4] =  mxCreateDoubleScalar((double)shift);
4594   prhs[5] =  mxCreateDoubleScalar((double)lA);
4595   prhs[6] =  mxCreateDoubleScalar((double)lB);
4596   prhs[7] =  mxCreateString(sctx->funcname);
4597   prhs[8] =  sctx->ctx;
4598   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");CHKERRQ(ierr);
4599   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4600   *flag   =  (MatStructure) mxGetScalar(plhs[1]);CHKERRQ(ierr);
4601   mxDestroyArray(prhs[0]);
4602   mxDestroyArray(prhs[1]);
4603   mxDestroyArray(prhs[2]);
4604   mxDestroyArray(prhs[3]);
4605   mxDestroyArray(prhs[4]);
4606   mxDestroyArray(prhs[5]);
4607   mxDestroyArray(prhs[6]);
4608   mxDestroyArray(prhs[7]);
4609   mxDestroyArray(plhs[0]);
4610   mxDestroyArray(plhs[1]);
4611   PetscFunctionReturn(0);
4612 }
4613 
4614 
4615 #undef __FUNCT__
4616 #define __FUNCT__ "TSSetJacobianMatlab"
4617 /*
4618    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
4619    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
4620 
4621    Logically Collective on TS
4622 
4623    Input Parameters:
4624 +  ts - the TS context
4625 .  A,B - Jacobian matrices
4626 .  func - function evaluation routine
4627 -  ctx - user context
4628 
4629    Calling sequence of func:
4630 $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);
4631 
4632 
4633    Level: developer
4634 
4635 .keywords: TS, nonlinear, set, function
4636 
4637 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4638 */
4639 PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
4640 {
4641   PetscErrorCode  ierr;
4642   TSMatlabContext *sctx;
4643 
4644   PetscFunctionBegin;
4645   /* currently sctx is memory bleed */
4646   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4647   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4648   /*
4649      This should work, but it doesn't
4650   sctx->ctx = ctx;
4651   mexMakeArrayPersistent(sctx->ctx);
4652   */
4653   sctx->ctx = mxDuplicateArray(ctx);
4654 
4655   ierr = TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);CHKERRQ(ierr);
4656   PetscFunctionReturn(0);
4657 }
4658 
4659 #undef __FUNCT__
4660 #define __FUNCT__ "TSMonitor_Matlab"
4661 /*
4662    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().
4663 
4664    Collective on TS
4665 
4666 .seealso: TSSetFunction(), TSGetFunction()
4667 @*/
4668 PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
4669 {
4670   PetscErrorCode  ierr;
4671   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4672   int             nlhs  = 1,nrhs = 6;
4673   mxArray         *plhs[1],*prhs[6];
4674   long long int   lx = 0,ls = 0;
4675 
4676   PetscFunctionBegin;
4677   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4678   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
4679 
4680   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4681   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4682 
4683   prhs[0] =  mxCreateDoubleScalar((double)ls);
4684   prhs[1] =  mxCreateDoubleScalar((double)it);
4685   prhs[2] =  mxCreateDoubleScalar((double)time);
4686   prhs[3] =  mxCreateDoubleScalar((double)lx);
4687   prhs[4] =  mxCreateString(sctx->funcname);
4688   prhs[5] =  sctx->ctx;
4689   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");CHKERRQ(ierr);
4690   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4691   mxDestroyArray(prhs[0]);
4692   mxDestroyArray(prhs[1]);
4693   mxDestroyArray(prhs[2]);
4694   mxDestroyArray(prhs[3]);
4695   mxDestroyArray(prhs[4]);
4696   mxDestroyArray(plhs[0]);
4697   PetscFunctionReturn(0);
4698 }
4699 
4700 
4701 #undef __FUNCT__
4702 #define __FUNCT__ "TSMonitorSetMatlab"
4703 /*
4704    TSMonitorSetMatlab - Sets the monitor function from Matlab
4705 
4706    Level: developer
4707 
4708 .keywords: TS, nonlinear, set, function
4709 
4710 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4711 */
4712 PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
4713 {
4714   PetscErrorCode  ierr;
4715   TSMatlabContext *sctx;
4716 
4717   PetscFunctionBegin;
4718   /* currently sctx is memory bleed */
4719   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4720   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4721   /*
4722      This should work, but it doesn't
4723   sctx->ctx = ctx;
4724   mexMakeArrayPersistent(sctx->ctx);
4725   */
4726   sctx->ctx = mxDuplicateArray(ctx);
4727 
4728   ierr = TSMonitorSet(ts,TSMonitor_Matlab,sctx,NULL);CHKERRQ(ierr);
4729   PetscFunctionReturn(0);
4730 }
4731 #endif
4732 
4733 
4734 
4735 #undef __FUNCT__
4736 #define __FUNCT__ "TSMonitorLGSolution"
4737 /*@C
4738    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
4739        in a time based line graph
4740 
4741    Collective on TS
4742 
4743    Input Parameters:
4744 +  ts - the TS context
4745 .  step - current time-step
4746 .  ptime - current time
4747 -  lg - a line graph object
4748 
4749    Level: intermediate
4750 
4751     Notes: each process in a parallel run displays its component solutions in a separate window
4752 
4753 .keywords: TS,  vector, monitor, view
4754 
4755 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4756 @*/
4757 PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4758 {
4759   PetscErrorCode    ierr;
4760   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4761   const PetscScalar *yy;
4762   PetscInt          dim;
4763 
4764   PetscFunctionBegin;
4765   if (!step) {
4766     PetscDrawAxis axis;
4767     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4768     ierr = PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");CHKERRQ(ierr);
4769     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4770     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4771     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4772   }
4773   ierr = VecGetArrayRead(u,&yy);CHKERRQ(ierr);
4774 #if defined(PETSC_USE_COMPLEX)
4775   {
4776     PetscReal *yreal;
4777     PetscInt  i,n;
4778     ierr = VecGetLocalSize(u,&n);CHKERRQ(ierr);
4779     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4780     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4781     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4782     ierr = PetscFree(yreal);CHKERRQ(ierr);
4783   }
4784 #else
4785   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4786 #endif
4787   ierr = VecRestoreArrayRead(u,&yy);CHKERRQ(ierr);
4788   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4789     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4790   }
4791   PetscFunctionReturn(0);
4792 }
4793 
4794 #undef __FUNCT__
4795 #define __FUNCT__ "TSMonitorLGError"
4796 /*@C
4797    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
4798        in a time based line graph
4799 
4800    Collective on TS
4801 
4802    Input Parameters:
4803 +  ts - the TS context
4804 .  step - current time-step
4805 .  ptime - current time
4806 -  lg - a line graph object
4807 
4808    Level: intermediate
4809 
4810    Notes:
4811    Only for sequential solves.
4812 
4813    The user must provide the solution using TSSetSolutionFunction() to use this monitor.
4814 
4815    Options Database Keys:
4816 .  -ts_monitor_lg_error - create a graphical monitor of error history
4817 
4818 .keywords: TS,  vector, monitor, view
4819 
4820 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
4821 @*/
4822 PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4823 {
4824   PetscErrorCode    ierr;
4825   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4826   const PetscScalar *yy;
4827   Vec               y;
4828   PetscInt          dim;
4829 
4830   PetscFunctionBegin;
4831   if (!step) {
4832     PetscDrawAxis axis;
4833     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4834     ierr = PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");CHKERRQ(ierr);
4835     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4836     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4837     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4838   }
4839   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
4840   ierr = TSComputeSolutionFunction(ts,ptime,y);CHKERRQ(ierr);
4841   ierr = VecAXPY(y,-1.0,u);CHKERRQ(ierr);
4842   ierr = VecGetArrayRead(y,&yy);CHKERRQ(ierr);
4843 #if defined(PETSC_USE_COMPLEX)
4844   {
4845     PetscReal *yreal;
4846     PetscInt  i,n;
4847     ierr = VecGetLocalSize(y,&n);CHKERRQ(ierr);
4848     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4849     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4850     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4851     ierr = PetscFree(yreal);CHKERRQ(ierr);
4852   }
4853 #else
4854   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4855 #endif
4856   ierr = VecRestoreArrayRead(y,&yy);CHKERRQ(ierr);
4857   ierr = VecDestroy(&y);CHKERRQ(ierr);
4858   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4859     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4860   }
4861   PetscFunctionReturn(0);
4862 }
4863 
4864 #undef __FUNCT__
4865 #define __FUNCT__ "TSMonitorLGSNESIterations"
4866 PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4867 {
4868   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4869   PetscReal      x   = ptime,y;
4870   PetscErrorCode ierr;
4871   PetscInt       its;
4872 
4873   PetscFunctionBegin;
4874   if (!n) {
4875     PetscDrawAxis axis;
4876 
4877     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4878     ierr = PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");CHKERRQ(ierr);
4879     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4880 
4881     ctx->snes_its = 0;
4882   }
4883   ierr = TSGetSNESIterations(ts,&its);CHKERRQ(ierr);
4884   y    = its - ctx->snes_its;
4885   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4886   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4887     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4888   }
4889   ctx->snes_its = its;
4890   PetscFunctionReturn(0);
4891 }
4892 
4893 #undef __FUNCT__
4894 #define __FUNCT__ "TSMonitorLGKSPIterations"
4895 PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4896 {
4897   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4898   PetscReal      x   = ptime,y;
4899   PetscErrorCode ierr;
4900   PetscInt       its;
4901 
4902   PetscFunctionBegin;
4903   if (!n) {
4904     PetscDrawAxis axis;
4905 
4906     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4907     ierr = PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");CHKERRQ(ierr);
4908     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4909 
4910     ctx->ksp_its = 0;
4911   }
4912   ierr = TSGetKSPIterations(ts,&its);CHKERRQ(ierr);
4913   y    = its - ctx->ksp_its;
4914   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4915   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4916     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4917   }
4918   ctx->ksp_its = its;
4919   PetscFunctionReturn(0);
4920 }
4921 
4922 #undef __FUNCT__
4923 #define __FUNCT__ "TSComputeLinearStability"
4924 /*@
4925    TSComputeLinearStability - computes the linear stability function at a point
4926 
4927    Collective on TS and Vec
4928 
4929    Input Parameters:
4930 +  ts - the TS context
4931 -  xr,xi - real and imaginary part of input arguments
4932 
4933    Output Parameters:
4934 .  yr,yi - real and imaginary part of function value
4935 
4936    Level: developer
4937 
4938 .keywords: TS, compute
4939 
4940 .seealso: TSSetRHSFunction(), TSComputeIFunction()
4941 @*/
4942 PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
4943 {
4944   PetscErrorCode ierr;
4945 
4946   PetscFunctionBegin;
4947   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4948   if (!ts->ops->linearstability) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"Linearized stability function not provided for this method");
4949   ierr = (*ts->ops->linearstability)(ts,xr,xi,yr,yi);CHKERRQ(ierr);
4950   PetscFunctionReturn(0);
4951 }
4952