xref: /petsc/src/ts/interface/ts.c (revision f15a11d28b36f01875e426cb22da92fd19b081e4)
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   if ((*ts)->event) {
1913     ierr = TSEventMonitorDestroy(&(*ts)->event);CHKERRQ(ierr);
1914   }
1915   ierr = SNESDestroy(&(*ts)->snes);CHKERRQ(ierr);
1916   ierr = DMDestroy(&(*ts)->dm);CHKERRQ(ierr);
1917   ierr = TSMonitorCancel((*ts));CHKERRQ(ierr);
1918 
1919   ierr = PetscHeaderDestroy(ts);CHKERRQ(ierr);
1920   PetscFunctionReturn(0);
1921 }
1922 
1923 #undef __FUNCT__
1924 #define __FUNCT__ "TSGetSNES"
1925 /*@
1926    TSGetSNES - Returns the SNES (nonlinear solver) associated with
1927    a TS (timestepper) context. Valid only for nonlinear problems.
1928 
1929    Not Collective, but SNES is parallel if TS is parallel
1930 
1931    Input Parameter:
1932 .  ts - the TS context obtained from TSCreate()
1933 
1934    Output Parameter:
1935 .  snes - the nonlinear solver context
1936 
1937    Notes:
1938    The user can then directly manipulate the SNES context to set various
1939    options, etc.  Likewise, the user can then extract and manipulate the
1940    KSP, KSP, and PC contexts as well.
1941 
1942    TSGetSNES() does not work for integrators that do not use SNES; in
1943    this case TSGetSNES() returns NULL in snes.
1944 
1945    Level: beginner
1946 
1947 .keywords: timestep, get, SNES
1948 @*/
1949 PetscErrorCode  TSGetSNES(TS ts,SNES *snes)
1950 {
1951   PetscErrorCode ierr;
1952 
1953   PetscFunctionBegin;
1954   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1955   PetscValidPointer(snes,2);
1956   if (!ts->snes) {
1957     ierr = SNESCreate(PetscObjectComm((PetscObject)ts),&ts->snes);CHKERRQ(ierr);
1958     ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
1959     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->snes);CHKERRQ(ierr);
1960     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->snes,(PetscObject)ts,1);CHKERRQ(ierr);
1961     if (ts->dm) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
1962     if (ts->problem_type == TS_LINEAR) {
1963       ierr = SNESSetType(ts->snes,SNESKSPONLY);CHKERRQ(ierr);
1964     }
1965   }
1966   *snes = ts->snes;
1967   PetscFunctionReturn(0);
1968 }
1969 
1970 #undef __FUNCT__
1971 #define __FUNCT__ "TSSetSNES"
1972 /*@
1973    TSSetSNES - Set the SNES (nonlinear solver) to be used by the timestepping context
1974 
1975    Collective
1976 
1977    Input Parameter:
1978 +  ts - the TS context obtained from TSCreate()
1979 -  snes - the nonlinear solver context
1980 
1981    Notes:
1982    Most users should have the TS created by calling TSGetSNES()
1983 
1984    Level: developer
1985 
1986 .keywords: timestep, set, SNES
1987 @*/
1988 PetscErrorCode TSSetSNES(TS ts,SNES snes)
1989 {
1990   PetscErrorCode ierr;
1991   PetscErrorCode (*func)(SNES,Vec,Mat,Mat,void*);
1992 
1993   PetscFunctionBegin;
1994   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
1995   PetscValidHeaderSpecific(snes,SNES_CLASSID,2);
1996   ierr = PetscObjectReference((PetscObject)snes);CHKERRQ(ierr);
1997   ierr = SNESDestroy(&ts->snes);CHKERRQ(ierr);
1998 
1999   ts->snes = snes;
2000 
2001   ierr = SNESSetFunction(ts->snes,NULL,SNESTSFormFunction,ts);CHKERRQ(ierr);
2002   ierr = SNESGetJacobian(ts->snes,NULL,NULL,&func,NULL);CHKERRQ(ierr);
2003   if (func == SNESTSFormJacobian) {
2004     ierr = SNESSetJacobian(ts->snes,NULL,NULL,SNESTSFormJacobian,ts);CHKERRQ(ierr);
2005   }
2006   PetscFunctionReturn(0);
2007 }
2008 
2009 #undef __FUNCT__
2010 #define __FUNCT__ "TSGetKSP"
2011 /*@
2012    TSGetKSP - Returns the KSP (linear solver) associated with
2013    a TS (timestepper) context.
2014 
2015    Not Collective, but KSP is parallel if TS is parallel
2016 
2017    Input Parameter:
2018 .  ts - the TS context obtained from TSCreate()
2019 
2020    Output Parameter:
2021 .  ksp - the nonlinear solver context
2022 
2023    Notes:
2024    The user can then directly manipulate the KSP context to set various
2025    options, etc.  Likewise, the user can then extract and manipulate the
2026    KSP and PC contexts as well.
2027 
2028    TSGetKSP() does not work for integrators that do not use KSP;
2029    in this case TSGetKSP() returns NULL in ksp.
2030 
2031    Level: beginner
2032 
2033 .keywords: timestep, get, KSP
2034 @*/
2035 PetscErrorCode  TSGetKSP(TS ts,KSP *ksp)
2036 {
2037   PetscErrorCode ierr;
2038   SNES           snes;
2039 
2040   PetscFunctionBegin;
2041   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2042   PetscValidPointer(ksp,2);
2043   if (!((PetscObject)ts)->type_name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"KSP is not created yet. Call TSSetType() first");
2044   if (ts->problem_type != TS_LINEAR) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Linear only; use TSGetSNES()");
2045   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
2046   ierr = SNESGetKSP(snes,ksp);CHKERRQ(ierr);
2047   PetscFunctionReturn(0);
2048 }
2049 
2050 /* ----------- Routines to set solver parameters ---------- */
2051 
2052 #undef __FUNCT__
2053 #define __FUNCT__ "TSGetDuration"
2054 /*@
2055    TSGetDuration - Gets the maximum number of timesteps to use and
2056    maximum time for iteration.
2057 
2058    Not Collective
2059 
2060    Input Parameters:
2061 +  ts       - the TS context obtained from TSCreate()
2062 .  maxsteps - maximum number of iterations to use, or NULL
2063 -  maxtime  - final time to iterate to, or NULL
2064 
2065    Level: intermediate
2066 
2067 .keywords: TS, timestep, get, maximum, iterations, time
2068 @*/
2069 PetscErrorCode  TSGetDuration(TS ts, PetscInt *maxsteps, PetscReal *maxtime)
2070 {
2071   PetscFunctionBegin;
2072   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2073   if (maxsteps) {
2074     PetscValidIntPointer(maxsteps,2);
2075     *maxsteps = ts->max_steps;
2076   }
2077   if (maxtime) {
2078     PetscValidScalarPointer(maxtime,3);
2079     *maxtime = ts->max_time;
2080   }
2081   PetscFunctionReturn(0);
2082 }
2083 
2084 #undef __FUNCT__
2085 #define __FUNCT__ "TSSetDuration"
2086 /*@
2087    TSSetDuration - Sets the maximum number of timesteps to use and
2088    maximum time for iteration.
2089 
2090    Logically Collective on TS
2091 
2092    Input Parameters:
2093 +  ts - the TS context obtained from TSCreate()
2094 .  maxsteps - maximum number of iterations to use
2095 -  maxtime - final time to iterate to
2096 
2097    Options Database Keys:
2098 .  -ts_max_steps <maxsteps> - Sets maxsteps
2099 .  -ts_final_time <maxtime> - Sets maxtime
2100 
2101    Notes:
2102    The default maximum number of iterations is 5000. Default time is 5.0
2103 
2104    Level: intermediate
2105 
2106 .keywords: TS, timestep, set, maximum, iterations
2107 
2108 .seealso: TSSetExactFinalTime()
2109 @*/
2110 PetscErrorCode  TSSetDuration(TS ts,PetscInt maxsteps,PetscReal maxtime)
2111 {
2112   PetscFunctionBegin;
2113   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2114   PetscValidLogicalCollectiveInt(ts,maxsteps,2);
2115   PetscValidLogicalCollectiveReal(ts,maxtime,2);
2116   if (maxsteps >= 0) ts->max_steps = maxsteps;
2117   if (maxtime != PETSC_DEFAULT) ts->max_time = maxtime;
2118   PetscFunctionReturn(0);
2119 }
2120 
2121 #undef __FUNCT__
2122 #define __FUNCT__ "TSSetSolution"
2123 /*@
2124    TSSetSolution - Sets the initial solution vector
2125    for use by the TS routines.
2126 
2127    Logically Collective on TS and Vec
2128 
2129    Input Parameters:
2130 +  ts - the TS context obtained from TSCreate()
2131 -  u - the solution vector
2132 
2133    Level: beginner
2134 
2135 .keywords: TS, timestep, set, solution, initial conditions
2136 @*/
2137 PetscErrorCode  TSSetSolution(TS ts,Vec u)
2138 {
2139   PetscErrorCode ierr;
2140   DM             dm;
2141 
2142   PetscFunctionBegin;
2143   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2144   PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2145   ierr = PetscObjectReference((PetscObject)u);CHKERRQ(ierr);
2146   ierr = VecDestroy(&ts->vec_sol);CHKERRQ(ierr);
2147 
2148   ts->vec_sol = u;
2149 
2150   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
2151   ierr = DMShellSetGlobalVector(dm,u);CHKERRQ(ierr);
2152   PetscFunctionReturn(0);
2153 }
2154 
2155 #undef __FUNCT__
2156 #define __FUNCT__ "TSSetPreStep"
2157 /*@C
2158   TSSetPreStep - Sets the general-purpose function
2159   called once at the beginning of each time step.
2160 
2161   Logically Collective on TS
2162 
2163   Input Parameters:
2164 + ts   - The TS context obtained from TSCreate()
2165 - func - The function
2166 
2167   Calling sequence of func:
2168 . func (TS ts);
2169 
2170   Level: intermediate
2171 
2172   Note:
2173   If a step is rejected, TSStep() will call this routine again before each attempt.
2174   The last completed time step number can be queried using TSGetTimeStepNumber(), the
2175   size of the step being attempted can be obtained using TSGetTimeStep().
2176 
2177 .keywords: TS, timestep
2178 .seealso: TSSetPreStage(), TSSetPostStage(), TSSetPostStep(), TSStep()
2179 @*/
2180 PetscErrorCode  TSSetPreStep(TS ts, PetscErrorCode (*func)(TS))
2181 {
2182   PetscFunctionBegin;
2183   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2184   ts->prestep = func;
2185   PetscFunctionReturn(0);
2186 }
2187 
2188 #undef __FUNCT__
2189 #define __FUNCT__ "TSPreStep"
2190 /*@
2191   TSPreStep - Runs the user-defined pre-step function.
2192 
2193   Collective on TS
2194 
2195   Input Parameters:
2196 . ts   - The TS context obtained from TSCreate()
2197 
2198   Notes:
2199   TSPreStep() is typically used within time stepping implementations,
2200   so most users would not generally call this routine themselves.
2201 
2202   Level: developer
2203 
2204 .keywords: TS, timestep
2205 .seealso: TSSetPreStep(), TSPreStage(), TSPostStage(), TSPostStep()
2206 @*/
2207 PetscErrorCode  TSPreStep(TS ts)
2208 {
2209   PetscErrorCode ierr;
2210 
2211   PetscFunctionBegin;
2212   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2213   if (ts->prestep) {
2214     PetscStackCallStandard((*ts->prestep),(ts));
2215   }
2216   PetscFunctionReturn(0);
2217 }
2218 
2219 #undef __FUNCT__
2220 #define __FUNCT__ "TSSetPreStage"
2221 /*@C
2222   TSSetPreStage - Sets the general-purpose function
2223   called once at the beginning of each stage.
2224 
2225   Logically Collective on TS
2226 
2227   Input Parameters:
2228 + ts   - The TS context obtained from TSCreate()
2229 - func - The function
2230 
2231   Calling sequence of func:
2232 . PetscErrorCode func(TS ts, PetscReal stagetime);
2233 
2234   Level: intermediate
2235 
2236   Note:
2237   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2238   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2239   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2240 
2241 .keywords: TS, timestep
2242 .seealso: TSSetPostStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2243 @*/
2244 PetscErrorCode  TSSetPreStage(TS ts, PetscErrorCode (*func)(TS,PetscReal))
2245 {
2246   PetscFunctionBegin;
2247   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2248   ts->prestage = func;
2249   PetscFunctionReturn(0);
2250 }
2251 
2252 #undef __FUNCT__
2253 #define __FUNCT__ "TSSetPostStage"
2254 /*@C
2255   TSSetPostStage - Sets the general-purpose function
2256   called once at the end of each stage.
2257 
2258   Logically Collective on TS
2259 
2260   Input Parameters:
2261 + ts   - The TS context obtained from TSCreate()
2262 - func - The function
2263 
2264   Calling sequence of func:
2265 . PetscErrorCode func(TS ts, PetscReal stagetime, PetscInt stageindex, Vec* Y);
2266 
2267   Level: intermediate
2268 
2269   Note:
2270   There may be several stages per time step. If the solve for a given stage fails, the step may be rejected and retried.
2271   The time step number being computed can be queried using TSGetTimeStepNumber() and the total size of the step being
2272   attempted can be obtained using TSGetTimeStep(). The time at the start of the step is available via TSGetTime().
2273 
2274 .keywords: TS, timestep
2275 .seealso: TSSetPreStage(), TSSetPreStep(), TSSetPostStep(), TSGetApplicationContext()
2276 @*/
2277 PetscErrorCode  TSSetPostStage(TS ts, PetscErrorCode (*func)(TS,PetscReal,PetscInt,Vec*))
2278 {
2279   PetscFunctionBegin;
2280   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2281   ts->poststage = func;
2282   PetscFunctionReturn(0);
2283 }
2284 
2285 #undef __FUNCT__
2286 #define __FUNCT__ "TSPreStage"
2287 /*@
2288   TSPreStage - Runs the user-defined pre-stage function set using TSSetPreStage()
2289 
2290   Collective on TS
2291 
2292   Input Parameters:
2293 . ts          - The TS context obtained from TSCreate()
2294   stagetime   - The absolute time of the current stage
2295 
2296   Notes:
2297   TSPreStage() is typically used within time stepping implementations,
2298   most users would not generally call this routine themselves.
2299 
2300   Level: developer
2301 
2302 .keywords: TS, timestep
2303 .seealso: TSPostStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2304 @*/
2305 PetscErrorCode  TSPreStage(TS ts, PetscReal stagetime)
2306 {
2307   PetscErrorCode ierr;
2308 
2309   PetscFunctionBegin;
2310   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2311   if (ts->prestage) {
2312     PetscStackCallStandard((*ts->prestage),(ts,stagetime));
2313   }
2314   PetscFunctionReturn(0);
2315 }
2316 
2317 #undef __FUNCT__
2318 #define __FUNCT__ "TSPostStage"
2319 /*@
2320   TSPostStage - Runs the user-defined post-stage function set using TSSetPostStage()
2321 
2322   Collective on TS
2323 
2324   Input Parameters:
2325 . ts          - The TS context obtained from TSCreate()
2326   stagetime   - The absolute time of the current stage
2327   stageindex  - Stage number
2328   Y           - Array of vectors (of size = total number
2329                 of stages) with the stage solutions
2330 
2331   Notes:
2332   TSPostStage() is typically used within time stepping implementations,
2333   most users would not generally call this routine themselves.
2334 
2335   Level: developer
2336 
2337 .keywords: TS, timestep
2338 .seealso: TSPreStage(), TSSetPreStep(), TSPreStep(), TSPostStep()
2339 @*/
2340 PetscErrorCode  TSPostStage(TS ts, PetscReal stagetime, PetscInt stageindex, Vec *Y)
2341 {
2342   PetscErrorCode ierr;
2343 
2344   PetscFunctionBegin;
2345   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2346   if (ts->prestage) {
2347     PetscStackCallStandard((*ts->poststage),(ts,stagetime,stageindex,Y));
2348   }
2349   PetscFunctionReturn(0);
2350 }
2351 
2352 #undef __FUNCT__
2353 #define __FUNCT__ "TSSetPostStep"
2354 /*@C
2355   TSSetPostStep - Sets the general-purpose function
2356   called once at the end of each time step.
2357 
2358   Logically Collective on TS
2359 
2360   Input Parameters:
2361 + ts   - The TS context obtained from TSCreate()
2362 - func - The function
2363 
2364   Calling sequence of func:
2365 $ func (TS ts);
2366 
2367   Level: intermediate
2368 
2369 .keywords: TS, timestep
2370 .seealso: TSSetPreStep(), TSSetPreStage(), TSGetTimeStep(), TSGetTimeStepNumber(), TSGetTime()
2371 @*/
2372 PetscErrorCode  TSSetPostStep(TS ts, PetscErrorCode (*func)(TS))
2373 {
2374   PetscFunctionBegin;
2375   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2376   ts->poststep = func;
2377   PetscFunctionReturn(0);
2378 }
2379 
2380 #undef __FUNCT__
2381 #define __FUNCT__ "TSPostStep"
2382 /*@
2383   TSPostStep - Runs the user-defined post-step function.
2384 
2385   Collective on TS
2386 
2387   Input Parameters:
2388 . ts   - The TS context obtained from TSCreate()
2389 
2390   Notes:
2391   TSPostStep() is typically used within time stepping implementations,
2392   so most users would not generally call this routine themselves.
2393 
2394   Level: developer
2395 
2396 .keywords: TS, timestep
2397 @*/
2398 PetscErrorCode  TSPostStep(TS ts)
2399 {
2400   PetscErrorCode ierr;
2401 
2402   PetscFunctionBegin;
2403   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2404   if (ts->poststep) {
2405     PetscStackCallStandard((*ts->poststep),(ts));
2406   }
2407   PetscFunctionReturn(0);
2408 }
2409 
2410 /* ------------ Routines to set performance monitoring options ----------- */
2411 
2412 #undef __FUNCT__
2413 #define __FUNCT__ "TSMonitorSet"
2414 /*@C
2415    TSMonitorSet - Sets an ADDITIONAL function that is to be used at every
2416    timestep to display the iteration's  progress.
2417 
2418    Logically Collective on TS
2419 
2420    Input Parameters:
2421 +  ts - the TS context obtained from TSCreate()
2422 .  monitor - monitoring routine
2423 .  mctx - [optional] user-defined context for private data for the
2424              monitor routine (use NULL if no context is desired)
2425 -  monitordestroy - [optional] routine that frees monitor context
2426           (may be NULL)
2427 
2428    Calling sequence of monitor:
2429 $    int monitor(TS ts,PetscInt steps,PetscReal time,Vec u,void *mctx)
2430 
2431 +    ts - the TS context
2432 .    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
2433                                been interpolated to)
2434 .    time - current time
2435 .    u - current iterate
2436 -    mctx - [optional] monitoring context
2437 
2438    Notes:
2439    This routine adds an additional monitor to the list of monitors that
2440    already has been loaded.
2441 
2442    Fortran notes: Only a single monitor function can be set for each TS object
2443 
2444    Level: intermediate
2445 
2446 .keywords: TS, timestep, set, monitor
2447 
2448 .seealso: TSMonitorDefault(), TSMonitorCancel()
2449 @*/
2450 PetscErrorCode  TSMonitorSet(TS ts,PetscErrorCode (*monitor)(TS,PetscInt,PetscReal,Vec,void*),void *mctx,PetscErrorCode (*mdestroy)(void**))
2451 {
2452   PetscFunctionBegin;
2453   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2454   if (ts->numbermonitors >= MAXTSMONITORS) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many monitors set");
2455   ts->monitor[ts->numbermonitors]          = monitor;
2456   ts->monitordestroy[ts->numbermonitors]   = mdestroy;
2457   ts->monitorcontext[ts->numbermonitors++] = (void*)mctx;
2458   PetscFunctionReturn(0);
2459 }
2460 
2461 #undef __FUNCT__
2462 #define __FUNCT__ "TSMonitorCancel"
2463 /*@C
2464    TSMonitorCancel - Clears all the monitors that have been set on a time-step object.
2465 
2466    Logically Collective on TS
2467 
2468    Input Parameters:
2469 .  ts - the TS context obtained from TSCreate()
2470 
2471    Notes:
2472    There is no way to remove a single, specific monitor.
2473 
2474    Level: intermediate
2475 
2476 .keywords: TS, timestep, set, monitor
2477 
2478 .seealso: TSMonitorDefault(), TSMonitorSet()
2479 @*/
2480 PetscErrorCode  TSMonitorCancel(TS ts)
2481 {
2482   PetscErrorCode ierr;
2483   PetscInt       i;
2484 
2485   PetscFunctionBegin;
2486   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2487   for (i=0; i<ts->numbermonitors; i++) {
2488     if (ts->monitordestroy[i]) {
2489       ierr = (*ts->monitordestroy[i])(&ts->monitorcontext[i]);CHKERRQ(ierr);
2490     }
2491   }
2492   ts->numbermonitors = 0;
2493   PetscFunctionReturn(0);
2494 }
2495 
2496 #undef __FUNCT__
2497 #define __FUNCT__ "TSMonitorDefault"
2498 /*@
2499    TSMonitorDefault - Sets the Default monitor
2500 
2501    Level: intermediate
2502 
2503 .keywords: TS, set, monitor
2504 
2505 .seealso: TSMonitorDefault(), TSMonitorSet()
2506 @*/
2507 PetscErrorCode TSMonitorDefault(TS ts,PetscInt step,PetscReal ptime,Vec v,void *dummy)
2508 {
2509   PetscErrorCode ierr;
2510   PetscViewer    viewer = dummy ? (PetscViewer) dummy : PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)ts));
2511 
2512   PetscFunctionBegin;
2513   ierr = PetscViewerASCIIAddTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2514   ierr = PetscViewerASCIIPrintf(viewer,"%D TS dt %g time %g\n",step,(double)ts->time_step,(double)ptime);CHKERRQ(ierr);
2515   ierr = PetscViewerASCIISubtractTab(viewer,((PetscObject)ts)->tablevel);CHKERRQ(ierr);
2516   PetscFunctionReturn(0);
2517 }
2518 
2519 #undef __FUNCT__
2520 #define __FUNCT__ "TSSetRetainStages"
2521 /*@
2522    TSSetRetainStages - Request that all stages in the upcoming step be stored so that interpolation will be available.
2523 
2524    Logically Collective on TS
2525 
2526    Input Argument:
2527 .  ts - time stepping context
2528 
2529    Output Argument:
2530 .  flg - PETSC_TRUE or PETSC_FALSE
2531 
2532    Level: intermediate
2533 
2534 .keywords: TS, set
2535 
2536 .seealso: TSInterpolate(), TSSetPostStep()
2537 @*/
2538 PetscErrorCode TSSetRetainStages(TS ts,PetscBool flg)
2539 {
2540   PetscFunctionBegin;
2541   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2542   ts->retain_stages = flg;
2543   PetscFunctionReturn(0);
2544 }
2545 
2546 #undef __FUNCT__
2547 #define __FUNCT__ "TSInterpolate"
2548 /*@
2549    TSInterpolate - Interpolate the solution computed during the previous step to an arbitrary location in the interval
2550 
2551    Collective on TS
2552 
2553    Input Argument:
2554 +  ts - time stepping context
2555 -  t - time to interpolate to
2556 
2557    Output Argument:
2558 .  U - state at given time
2559 
2560    Notes:
2561    The user should call TSSetRetainStages() before taking a step in which interpolation will be requested.
2562 
2563    Level: intermediate
2564 
2565    Developer Notes:
2566    TSInterpolate() and the storing of previous steps/stages should be generalized to support delay differential equations and continuous adjoints.
2567 
2568 .keywords: TS, set
2569 
2570 .seealso: TSSetRetainStages(), TSSetPostStep()
2571 @*/
2572 PetscErrorCode TSInterpolate(TS ts,PetscReal t,Vec U)
2573 {
2574   PetscErrorCode ierr;
2575 
2576   PetscFunctionBegin;
2577   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2578   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2579   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);
2580   if (!ts->ops->interpolate) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"%s does not provide interpolation",((PetscObject)ts)->type_name);
2581   ierr = (*ts->ops->interpolate)(ts,t,U);CHKERRQ(ierr);
2582   PetscFunctionReturn(0);
2583 }
2584 
2585 #undef __FUNCT__
2586 #define __FUNCT__ "TSStep"
2587 /*@
2588    TSStep - Steps one time step
2589 
2590    Collective on TS
2591 
2592    Input Parameter:
2593 .  ts - the TS context obtained from TSCreate()
2594 
2595    Level: intermediate
2596 
2597    Notes:
2598    The hook set using TSSetPreStep() is called before each attempt to take the step. In general, the time step size may
2599    be changed due to adaptive error controller or solve failures. Note that steps may contain multiple stages.
2600 
2601    This may over-step the final time provided in TSSetDuration() depending on the time-step used. TSSolve() interpolates to exactly the
2602    time provided in TSSetDuration(). One can use TSInterpolate() to determine an interpolated solution within the final timestep.
2603 
2604 .keywords: TS, timestep, solve
2605 
2606 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSSetPostStage(), TSInterpolate()
2607 @*/
2608 PetscErrorCode  TSStep(TS ts)
2609 {
2610   PetscErrorCode   ierr;
2611   static PetscBool cite = PETSC_FALSE;
2612 
2613   PetscFunctionBegin;
2614   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
2615   ierr = PetscCitationsRegister("@techreport{tspaper,\n"
2616                                 "  title       = {{PETSc/TS}: A Modern Scalable {DAE/ODE} Solver Library},\n"
2617                                 "  author      = {Shrirang Abhyankar and Jed Brown and Emil Constantinescu and Debojyoti Ghosh and Barry F. Smith},\n"
2618                                 "  type        = {Preprint},\n"
2619                                 "  number      = {ANL/MCS-P5061-0114},\n"
2620                                 "  institution = {Argonne National Laboratory},\n"
2621                                 "  year        = {2014}\n}\n",&cite);
2622 
2623   ierr = TSSetUp(ts);CHKERRQ(ierr);
2624 
2625   ts->reason = TS_CONVERGED_ITERATING;
2626   ts->ptime_prev = ts->ptime;
2627 
2628   ierr = PetscLogEventBegin(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2629   ierr = (*ts->ops->step)(ts);CHKERRQ(ierr);
2630   ierr = PetscLogEventEnd(TS_Step,ts,0,0,0);CHKERRQ(ierr);
2631 
2632   ts->time_step_prev = ts->ptime - ts->ptime_prev;
2633 
2634   if (ts->reason < 0) {
2635     if (ts->errorifstepfailed) {
2636       if (ts->reason == TS_DIVERGED_NONLINEAR_SOLVE) {
2637         SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s, increase -ts_max_snes_failures or make negative to attempt recovery",TSConvergedReasons[ts->reason]);
2638       } else SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_NOT_CONVERGED,"TSStep has failed due to %s",TSConvergedReasons[ts->reason]);
2639     }
2640   } else if (!ts->reason) {
2641     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2642     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2643   }
2644   PetscFunctionReturn(0);
2645 }
2646 
2647 #undef __FUNCT__
2648 #define __FUNCT__ "TSEvaluateStep"
2649 /*@
2650    TSEvaluateStep - Evaluate the solution at the end of a time step with a given order of accuracy.
2651 
2652    Collective on TS
2653 
2654    Input Arguments:
2655 +  ts - time stepping context
2656 .  order - desired order of accuracy
2657 -  done - whether the step was evaluated at this order (pass NULL to generate an error if not available)
2658 
2659    Output Arguments:
2660 .  U - state at the end of the current step
2661 
2662    Level: advanced
2663 
2664    Notes:
2665    This function cannot be called until all stages have been evaluated.
2666    It is normally called by adaptive controllers before a step has been accepted and may also be called by the user after TSStep() has returned.
2667 
2668 .seealso: TSStep(), TSAdapt
2669 @*/
2670 PetscErrorCode TSEvaluateStep(TS ts,PetscInt order,Vec U,PetscBool *done)
2671 {
2672   PetscErrorCode ierr;
2673 
2674   PetscFunctionBegin;
2675   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2676   PetscValidType(ts,1);
2677   PetscValidHeaderSpecific(U,VEC_CLASSID,3);
2678   if (!ts->ops->evaluatestep) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSEvaluateStep not implemented for type '%s'",((PetscObject)ts)->type_name);
2679   ierr = (*ts->ops->evaluatestep)(ts,order,U,done);CHKERRQ(ierr);
2680   PetscFunctionReturn(0);
2681 }
2682 
2683 #undef __FUNCT__
2684 #define __FUNCT__ "TSSolve"
2685 /*@
2686    TSSolve - Steps the requested number of timesteps.
2687 
2688    Collective on TS
2689 
2690    Input Parameter:
2691 +  ts - the TS context obtained from TSCreate()
2692 -  u - the solution vector  (can be null if TSSetSolution() was used, otherwise must contain the initial conditions)
2693 
2694    Level: beginner
2695 
2696    Notes:
2697    The final time returned by this function may be different from the time of the internally
2698    held state accessible by TSGetSolution() and TSGetTime() because the method may have
2699    stepped over the final time.
2700 
2701 .keywords: TS, timestep, solve
2702 
2703 .seealso: TSCreate(), TSSetSolution(), TSStep()
2704 @*/
2705 PetscErrorCode TSSolve(TS ts,Vec u)
2706 {
2707   Vec               solution;
2708   PetscErrorCode    ierr;
2709 
2710   PetscFunctionBegin;
2711   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2712   if (u) PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2713   if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE) {   /* Need ts->vec_sol to be distinct so it is not overwritten when we interpolate at the end */
2714     PetscValidHeaderSpecific(u,VEC_CLASSID,2);
2715     if (!ts->vec_sol || u == ts->vec_sol) {
2716       ierr = VecDuplicate(u,&solution);CHKERRQ(ierr);
2717       ierr = TSSetSolution(ts,solution);CHKERRQ(ierr);
2718       ierr = VecDestroy(&solution);CHKERRQ(ierr); /* grant ownership */
2719     }
2720     ierr = VecCopy(u,ts->vec_sol);CHKERRQ(ierr);
2721   } else if (u) {
2722     ierr = TSSetSolution(ts,u);CHKERRQ(ierr);
2723   }
2724   ierr = TSSetUp(ts);CHKERRQ(ierr);
2725   /* reset time step and iteration counters */
2726   ts->steps             = 0;
2727   ts->ksp_its           = 0;
2728   ts->snes_its          = 0;
2729   ts->num_snes_failures = 0;
2730   ts->reject            = 0;
2731   ts->reason            = TS_CONVERGED_ITERATING;
2732 
2733   ierr = TSViewFromOptions(ts,NULL,"-ts_view_pre");CHKERRQ(ierr);
2734 
2735   if (ts->ops->solve) {         /* This private interface is transitional and should be removed when all implementations are updated. */
2736     ierr = (*ts->ops->solve)(ts);CHKERRQ(ierr);
2737     ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);
2738     ts->solvetime = ts->ptime;
2739   } else {
2740     /* steps the requested number of timesteps. */
2741     if (ts->steps >= ts->max_steps)     ts->reason = TS_CONVERGED_ITS;
2742     else if (ts->ptime >= ts->max_time) ts->reason = TS_CONVERGED_TIME;
2743     while (!ts->reason) {
2744       ierr = TSMonitor(ts,ts->steps,ts->ptime,ts->vec_sol);CHKERRQ(ierr);
2745       ierr = TSStep(ts);CHKERRQ(ierr);
2746       ierr = TSPostStep(ts);CHKERRQ(ierr);
2747       if (ts->event) {
2748 	ierr = TSEventMonitor(ts);CHKERRQ(ierr);
2749       }
2750     }
2751     if (ts->exact_final_time == TS_EXACTFINALTIME_INTERPOLATE && ts->ptime > ts->max_time) {
2752       ierr = TSInterpolate(ts,ts->max_time,u);CHKERRQ(ierr);
2753       ts->solvetime = ts->max_time;
2754       solution = u;
2755     } else {
2756       if (u) {ierr = VecCopy(ts->vec_sol,u);CHKERRQ(ierr);}
2757       ts->solvetime = ts->ptime;
2758       solution = ts->vec_sol;
2759     }
2760     ierr = TSMonitor(ts,ts->steps,ts->solvetime,solution);CHKERRQ(ierr);
2761   }
2762   ierr = TSViewFromOptions(ts,NULL,"-ts_view");CHKERRQ(ierr);
2763   ierr = PetscObjectSAWsBlock((PetscObject)ts);CHKERRQ(ierr);
2764   PetscFunctionReturn(0);
2765 }
2766 
2767 #undef __FUNCT__
2768 #define __FUNCT__ "TSMonitor"
2769 /*@
2770    TSMonitor - Runs all user-provided monitor routines set using TSMonitorSet()
2771 
2772    Collective on TS
2773 
2774    Input Parameters:
2775 +  ts - time stepping context obtained from TSCreate()
2776 .  step - step number that has just completed
2777 .  ptime - model time of the state
2778 -  u - state at the current model time
2779 
2780    Notes:
2781    TSMonitor() is typically used within the time stepping implementations.
2782    Users might call this function when using the TSStep() interface instead of TSSolve().
2783 
2784    Level: advanced
2785 
2786 .keywords: TS, timestep
2787 @*/
2788 PetscErrorCode TSMonitor(TS ts,PetscInt step,PetscReal ptime,Vec u)
2789 {
2790   PetscErrorCode ierr;
2791   PetscInt       i,n = ts->numbermonitors;
2792 
2793   PetscFunctionBegin;
2794   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2795   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
2796   for (i=0; i<n; i++) {
2797     ierr = (*ts->monitor[i])(ts,step,ptime,u,ts->monitorcontext[i]);CHKERRQ(ierr);
2798   }
2799   PetscFunctionReturn(0);
2800 }
2801 
2802 /* ------------------------------------------------------------------------*/
2803 #undef __FUNCT__
2804 #define __FUNCT__ "TSMonitorLGCtxCreate"
2805 /*@C
2806    TSMonitorLGCtxCreate - Creates a line graph context for use with
2807    TS to monitor the solution process graphically in various ways
2808 
2809    Collective on TS
2810 
2811    Input Parameters:
2812 +  host - the X display to open, or null for the local machine
2813 .  label - the title to put in the title bar
2814 .  x, y - the screen coordinates of the upper left coordinate of the window
2815 .  m, n - the screen width and height in pixels
2816 -  howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time
2817 
2818    Output Parameter:
2819 .  ctx - the context
2820 
2821    Options Database Key:
2822 +  -ts_monitor_lg_timestep - automatically sets line graph monitor
2823 .  -ts_monitor_lg_solution -
2824 .  -ts_monitor_lg_error -
2825 .  -ts_monitor_lg_ksp_iterations -
2826 .  -ts_monitor_lg_snes_iterations -
2827 -  -lg_indicate_data_points <true,false> - indicate the data points (at each time step) on the plot; default is true
2828 
2829    Notes:
2830    Use TSMonitorLGCtxDestroy() to destroy.
2831 
2832    Level: intermediate
2833 
2834 .keywords: TS, monitor, line graph, residual, seealso
2835 
2836 .seealso: TSMonitorLGTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError()
2837 
2838 @*/
2839 PetscErrorCode  TSMonitorLGCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorLGCtx *ctx)
2840 {
2841   PetscDraw      win;
2842   PetscErrorCode ierr;
2843 
2844   PetscFunctionBegin;
2845   ierr = PetscNew(ctx);CHKERRQ(ierr);
2846   ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr);
2847   ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr);
2848   ierr = PetscDrawLGCreate(win,1,&(*ctx)->lg);CHKERRQ(ierr);
2849   ierr = PetscLogObjectParent((PetscObject)(*ctx)->lg,(PetscObject)win);CHKERRQ(ierr);
2850   ierr = PetscDrawLGIndicateDataPoints((*ctx)->lg,PETSC_TRUE);CHKERRQ(ierr);
2851   ierr = PetscDrawLGSetFromOptions((*ctx)->lg);CHKERRQ(ierr);
2852   (*ctx)->howoften = howoften;
2853   PetscFunctionReturn(0);
2854 }
2855 
2856 #undef __FUNCT__
2857 #define __FUNCT__ "TSMonitorLGTimeStep"
2858 PetscErrorCode TSMonitorLGTimeStep(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx)
2859 {
2860   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
2861   PetscReal      x   = ptime,y;
2862   PetscErrorCode ierr;
2863 
2864   PetscFunctionBegin;
2865   if (!step) {
2866     PetscDrawAxis axis;
2867     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
2868     ierr = PetscDrawAxisSetLabels(axis,"Timestep as function of time","Time","Time step");CHKERRQ(ierr);
2869     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
2870     ierr = PetscDrawLGIndicateDataPoints(ctx->lg,PETSC_TRUE);CHKERRQ(ierr);
2871   }
2872   ierr = TSGetTimeStep(ts,&y);CHKERRQ(ierr);
2873   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
2874   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
2875     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
2876   }
2877   PetscFunctionReturn(0);
2878 }
2879 
2880 #undef __FUNCT__
2881 #define __FUNCT__ "TSMonitorLGCtxDestroy"
2882 /*@C
2883    TSMonitorLGCtxDestroy - Destroys a line graph context that was created
2884    with TSMonitorLGCtxCreate().
2885 
2886    Collective on TSMonitorLGCtx
2887 
2888    Input Parameter:
2889 .  ctx - the monitor context
2890 
2891    Level: intermediate
2892 
2893 .keywords: TS, monitor, line graph, destroy
2894 
2895 .seealso: TSMonitorLGCtxCreate(),  TSMonitorSet(), TSMonitorLGTimeStep();
2896 @*/
2897 PetscErrorCode  TSMonitorLGCtxDestroy(TSMonitorLGCtx *ctx)
2898 {
2899   PetscDraw      draw;
2900   PetscErrorCode ierr;
2901 
2902   PetscFunctionBegin;
2903   ierr = PetscDrawLGGetDraw((*ctx)->lg,&draw);CHKERRQ(ierr);
2904   ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
2905   ierr = PetscDrawLGDestroy(&(*ctx)->lg);CHKERRQ(ierr);
2906   ierr = PetscFree(*ctx);CHKERRQ(ierr);
2907   PetscFunctionReturn(0);
2908 }
2909 
2910 #undef __FUNCT__
2911 #define __FUNCT__ "TSGetTime"
2912 /*@
2913    TSGetTime - Gets the time of the most recently completed step.
2914 
2915    Not Collective
2916 
2917    Input Parameter:
2918 .  ts - the TS context obtained from TSCreate()
2919 
2920    Output Parameter:
2921 .  t  - the current time
2922 
2923    Level: beginner
2924 
2925    Note:
2926    When called during time step evaluation (e.g. during residual evaluation or via hooks set using TSSetPreStep(),
2927    TSSetPreStage(), TSSetPostStage(), or TSSetPostStep()), the time is the time at the start of the step being evaluated.
2928 
2929 .seealso: TSSetInitialTimeStep(), TSGetTimeStep()
2930 
2931 .keywords: TS, get, time
2932 @*/
2933 PetscErrorCode  TSGetTime(TS ts,PetscReal *t)
2934 {
2935   PetscFunctionBegin;
2936   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2937   PetscValidRealPointer(t,2);
2938   *t = ts->ptime;
2939   PetscFunctionReturn(0);
2940 }
2941 
2942 #undef __FUNCT__
2943 #define __FUNCT__ "TSSetTime"
2944 /*@
2945    TSSetTime - Allows one to reset the time.
2946 
2947    Logically Collective on TS
2948 
2949    Input Parameters:
2950 +  ts - the TS context obtained from TSCreate()
2951 -  time - the time
2952 
2953    Level: intermediate
2954 
2955 .seealso: TSGetTime(), TSSetDuration()
2956 
2957 .keywords: TS, set, time
2958 @*/
2959 PetscErrorCode  TSSetTime(TS ts, PetscReal t)
2960 {
2961   PetscFunctionBegin;
2962   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2963   PetscValidLogicalCollectiveReal(ts,t,2);
2964   ts->ptime = t;
2965   PetscFunctionReturn(0);
2966 }
2967 
2968 #undef __FUNCT__
2969 #define __FUNCT__ "TSSetOptionsPrefix"
2970 /*@C
2971    TSSetOptionsPrefix - Sets the prefix used for searching for all
2972    TS options in the database.
2973 
2974    Logically Collective on TS
2975 
2976    Input Parameter:
2977 +  ts     - The TS context
2978 -  prefix - The prefix to prepend to all option names
2979 
2980    Notes:
2981    A hyphen (-) must NOT be given at the beginning of the prefix name.
2982    The first character of all runtime options is AUTOMATICALLY the
2983    hyphen.
2984 
2985    Level: advanced
2986 
2987 .keywords: TS, set, options, prefix, database
2988 
2989 .seealso: TSSetFromOptions()
2990 
2991 @*/
2992 PetscErrorCode  TSSetOptionsPrefix(TS ts,const char prefix[])
2993 {
2994   PetscErrorCode ierr;
2995   SNES           snes;
2996 
2997   PetscFunctionBegin;
2998   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
2999   ierr = PetscObjectSetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3000   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3001   ierr = SNESSetOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3002   PetscFunctionReturn(0);
3003 }
3004 
3005 
3006 #undef __FUNCT__
3007 #define __FUNCT__ "TSAppendOptionsPrefix"
3008 /*@C
3009    TSAppendOptionsPrefix - Appends to the prefix used for searching for all
3010    TS options in the database.
3011 
3012    Logically Collective on TS
3013 
3014    Input Parameter:
3015 +  ts     - The TS context
3016 -  prefix - The prefix to prepend to all option names
3017 
3018    Notes:
3019    A hyphen (-) must NOT be given at the beginning of the prefix name.
3020    The first character of all runtime options is AUTOMATICALLY the
3021    hyphen.
3022 
3023    Level: advanced
3024 
3025 .keywords: TS, append, options, prefix, database
3026 
3027 .seealso: TSGetOptionsPrefix()
3028 
3029 @*/
3030 PetscErrorCode  TSAppendOptionsPrefix(TS ts,const char prefix[])
3031 {
3032   PetscErrorCode ierr;
3033   SNES           snes;
3034 
3035   PetscFunctionBegin;
3036   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3037   ierr = PetscObjectAppendOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3038   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3039   ierr = SNESAppendOptionsPrefix(snes,prefix);CHKERRQ(ierr);
3040   PetscFunctionReturn(0);
3041 }
3042 
3043 #undef __FUNCT__
3044 #define __FUNCT__ "TSGetOptionsPrefix"
3045 /*@C
3046    TSGetOptionsPrefix - Sets the prefix used for searching for all
3047    TS options in the database.
3048 
3049    Not Collective
3050 
3051    Input Parameter:
3052 .  ts - The TS context
3053 
3054    Output Parameter:
3055 .  prefix - A pointer to the prefix string used
3056 
3057    Notes: On the fortran side, the user should pass in a string 'prifix' of
3058    sufficient length to hold the prefix.
3059 
3060    Level: intermediate
3061 
3062 .keywords: TS, get, options, prefix, database
3063 
3064 .seealso: TSAppendOptionsPrefix()
3065 @*/
3066 PetscErrorCode  TSGetOptionsPrefix(TS ts,const char *prefix[])
3067 {
3068   PetscErrorCode ierr;
3069 
3070   PetscFunctionBegin;
3071   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3072   PetscValidPointer(prefix,2);
3073   ierr = PetscObjectGetOptionsPrefix((PetscObject)ts,prefix);CHKERRQ(ierr);
3074   PetscFunctionReturn(0);
3075 }
3076 
3077 #undef __FUNCT__
3078 #define __FUNCT__ "TSGetRHSJacobian"
3079 /*@C
3080    TSGetRHSJacobian - Returns the Jacobian J at the present timestep.
3081 
3082    Not Collective, but parallel objects are returned if TS is parallel
3083 
3084    Input Parameter:
3085 .  ts  - The TS context obtained from TSCreate()
3086 
3087    Output Parameters:
3088 +  Amat - The (approximate) Jacobian J of G, where U_t = G(U,t)  (or NULL)
3089 .  Pmat - The matrix from which the preconditioner is constructed, usually the same as Amat  (or NULL)
3090 .  func - Function to compute the Jacobian of the RHS  (or NULL)
3091 -  ctx - User-defined context for Jacobian evaluation routine  (or NULL)
3092 
3093    Notes: You can pass in NULL for any return argument you do not need.
3094 
3095    Level: intermediate
3096 
3097 .seealso: TSGetTimeStep(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3098 
3099 .keywords: TS, timestep, get, matrix, Jacobian
3100 @*/
3101 PetscErrorCode  TSGetRHSJacobian(TS ts,Mat *Amat,Mat *Pmat,TSRHSJacobian *func,void **ctx)
3102 {
3103   PetscErrorCode ierr;
3104   SNES           snes;
3105   DM             dm;
3106 
3107   PetscFunctionBegin;
3108   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3109   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3110   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3111   ierr = DMTSGetRHSJacobian(dm,func,ctx);CHKERRQ(ierr);
3112   PetscFunctionReturn(0);
3113 }
3114 
3115 #undef __FUNCT__
3116 #define __FUNCT__ "TSGetIJacobian"
3117 /*@C
3118    TSGetIJacobian - Returns the implicit Jacobian at the present timestep.
3119 
3120    Not Collective, but parallel objects are returned if TS is parallel
3121 
3122    Input Parameter:
3123 .  ts  - The TS context obtained from TSCreate()
3124 
3125    Output Parameters:
3126 +  Amat  - The (approximate) Jacobian of F(t,U,U_t)
3127 .  Pmat - The matrix from which the preconditioner is constructed, often the same as Amat
3128 .  f   - The function to compute the matrices
3129 - ctx - User-defined context for Jacobian evaluation routine
3130 
3131    Notes: You can pass in NULL for any return argument you do not need.
3132 
3133    Level: advanced
3134 
3135 .seealso: TSGetTimeStep(), TSGetRHSJacobian(), TSGetMatrices(), TSGetTime(), TSGetTimeStepNumber()
3136 
3137 .keywords: TS, timestep, get, matrix, Jacobian
3138 @*/
3139 PetscErrorCode  TSGetIJacobian(TS ts,Mat *Amat,Mat *Pmat,TSIJacobian *f,void **ctx)
3140 {
3141   PetscErrorCode ierr;
3142   SNES           snes;
3143   DM             dm;
3144 
3145   PetscFunctionBegin;
3146   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3147   ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);
3148   ierr = SNESGetJacobian(snes,Amat,Pmat,NULL,NULL);CHKERRQ(ierr);
3149   ierr = TSGetDM(ts,&dm);CHKERRQ(ierr);
3150   ierr = DMTSGetIJacobian(dm,f,ctx);CHKERRQ(ierr);
3151   PetscFunctionReturn(0);
3152 }
3153 
3154 
3155 #undef __FUNCT__
3156 #define __FUNCT__ "TSMonitorDrawSolution"
3157 /*@C
3158    TSMonitorDrawSolution - Monitors progress of the TS solvers by calling
3159    VecView() for the solution at each timestep
3160 
3161    Collective on TS
3162 
3163    Input Parameters:
3164 +  ts - the TS context
3165 .  step - current time-step
3166 .  ptime - current time
3167 -  dummy - either a viewer or NULL
3168 
3169    Options Database:
3170 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3171 
3172    Notes: the initial solution and current solution are not displayed with a common axis scaling so generally the option -ts_monitor_draw_solution_initial
3173        will look bad
3174 
3175    Level: intermediate
3176 
3177 .keywords: TS,  vector, monitor, view
3178 
3179 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3180 @*/
3181 PetscErrorCode  TSMonitorDrawSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3182 {
3183   PetscErrorCode   ierr;
3184   TSMonitorDrawCtx ictx = (TSMonitorDrawCtx)dummy;
3185   PetscDraw        draw;
3186 
3187   PetscFunctionBegin;
3188   if (!step && ictx->showinitial) {
3189     if (!ictx->initialsolution) {
3190       ierr = VecDuplicate(u,&ictx->initialsolution);CHKERRQ(ierr);
3191     }
3192     ierr = VecCopy(u,ictx->initialsolution);CHKERRQ(ierr);
3193   }
3194   if (!(((ictx->howoften > 0) && (!(step % ictx->howoften))) || ((ictx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3195 
3196   if (ictx->showinitial) {
3197     PetscReal pause;
3198     ierr = PetscViewerDrawGetPause(ictx->viewer,&pause);CHKERRQ(ierr);
3199     ierr = PetscViewerDrawSetPause(ictx->viewer,0.0);CHKERRQ(ierr);
3200     ierr = VecView(ictx->initialsolution,ictx->viewer);CHKERRQ(ierr);
3201     ierr = PetscViewerDrawSetPause(ictx->viewer,pause);CHKERRQ(ierr);
3202     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_TRUE);CHKERRQ(ierr);
3203   }
3204   ierr = VecView(u,ictx->viewer);CHKERRQ(ierr);
3205   if (ictx->showtimestepandtime) {
3206     PetscReal xl,yl,xr,yr,tw,w,h;
3207     char      time[32];
3208     size_t    len;
3209 
3210     ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3211     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3212     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3213     ierr =  PetscStrlen(time,&len);CHKERRQ(ierr);
3214     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3215     w    = xl + .5*(xr - xl) - .5*len*tw;
3216     h    = yl + .95*(yr - yl);
3217     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3218     ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3219   }
3220 
3221   if (ictx->showinitial) {
3222     ierr = PetscViewerDrawSetHold(ictx->viewer,PETSC_FALSE);CHKERRQ(ierr);
3223   }
3224   PetscFunctionReturn(0);
3225 }
3226 
3227 #undef __FUNCT__
3228 #define __FUNCT__ "TSMonitorDrawSolutionPhase"
3229 /*@C
3230    TSMonitorDrawSolutionPhase - Monitors progress of the TS solvers by plotting the solution as a phase diagram
3231 
3232    Collective on TS
3233 
3234    Input Parameters:
3235 +  ts - the TS context
3236 .  step - current time-step
3237 .  ptime - current time
3238 -  dummy - either a viewer or NULL
3239 
3240    Level: intermediate
3241 
3242 .keywords: TS,  vector, monitor, view
3243 
3244 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3245 @*/
3246 PetscErrorCode  TSMonitorDrawSolutionPhase(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3247 {
3248   PetscErrorCode    ierr;
3249   TSMonitorDrawCtx  ictx = (TSMonitorDrawCtx)dummy;
3250   PetscDraw         draw;
3251   MPI_Comm          comm;
3252   PetscInt          n;
3253   PetscMPIInt       size;
3254   PetscReal         xl,yl,xr,yr,tw,w,h;
3255   char              time[32];
3256   size_t            len;
3257   const PetscScalar *U;
3258 
3259   PetscFunctionBegin;
3260   ierr = PetscObjectGetComm((PetscObject)ts,&comm);CHKERRQ(ierr);
3261   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
3262   if (size != 1) SETERRQ(comm,PETSC_ERR_SUP,"Only allowed for sequential runs");
3263   ierr = VecGetSize(u,&n);CHKERRQ(ierr);
3264   if (n != 2) SETERRQ(comm,PETSC_ERR_SUP,"Only for ODEs with two unknowns");
3265 
3266   ierr = PetscViewerDrawGetDraw(ictx->viewer,0,&draw);CHKERRQ(ierr);
3267 
3268   ierr = VecGetArrayRead(u,&U);CHKERRQ(ierr);
3269   ierr = PetscDrawAxisGetLimits(ictx->axis,&xl,&xr,&yl,&yr);CHKERRQ(ierr);
3270   if ((PetscRealPart(U[0]) < xl) || (PetscRealPart(U[1]) < yl) || (PetscRealPart(U[0]) > xr) || (PetscRealPart(U[1]) > yr)) {
3271       ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3272       PetscFunctionReturn(0);
3273   }
3274   if (!step) ictx->color++;
3275   ierr = PetscDrawPoint(draw,PetscRealPart(U[0]),PetscRealPart(U[1]),ictx->color);CHKERRQ(ierr);
3276   ierr = VecRestoreArrayRead(u,&U);CHKERRQ(ierr);
3277 
3278   if (ictx->showtimestepandtime) {
3279     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
3280     ierr = PetscSNPrintf(time,32,"Timestep %d Time %f",(int)step,(double)ptime);CHKERRQ(ierr);
3281     ierr = PetscStrlen(time,&len);CHKERRQ(ierr);
3282     ierr = PetscDrawStringGetSize(draw,&tw,NULL);CHKERRQ(ierr);
3283     w    = xl + .5*(xr - xl) - .5*len*tw;
3284     h    = yl + .95*(yr - yl);
3285     ierr = PetscDrawString(draw,w,h,PETSC_DRAW_BLACK,time);CHKERRQ(ierr);
3286   }
3287   ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
3288   PetscFunctionReturn(0);
3289 }
3290 
3291 
3292 #undef __FUNCT__
3293 #define __FUNCT__ "TSMonitorDrawCtxDestroy"
3294 /*@C
3295    TSMonitorDrawCtxDestroy - Destroys the monitor context for TSMonitorDrawSolution()
3296 
3297    Collective on TS
3298 
3299    Input Parameters:
3300 .    ctx - the monitor context
3301 
3302    Level: intermediate
3303 
3304 .keywords: TS,  vector, monitor, view
3305 
3306 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawSolution(), TSMonitorDrawError()
3307 @*/
3308 PetscErrorCode  TSMonitorDrawCtxDestroy(TSMonitorDrawCtx *ictx)
3309 {
3310   PetscErrorCode ierr;
3311 
3312   PetscFunctionBegin;
3313   ierr = PetscDrawAxisDestroy(&(*ictx)->axis);CHKERRQ(ierr);
3314   ierr = PetscViewerDestroy(&(*ictx)->viewer);CHKERRQ(ierr);
3315   ierr = VecDestroy(&(*ictx)->initialsolution);CHKERRQ(ierr);
3316   ierr = PetscFree(*ictx);CHKERRQ(ierr);
3317   PetscFunctionReturn(0);
3318 }
3319 
3320 #undef __FUNCT__
3321 #define __FUNCT__ "TSMonitorDrawCtxCreate"
3322 /*@C
3323    TSMonitorDrawCtxCreate - Creates the monitor context for TSMonitorDrawCtx
3324 
3325    Collective on TS
3326 
3327    Input Parameter:
3328 .    ts - time-step context
3329 
3330    Output Patameter:
3331 .    ctx - the monitor context
3332 
3333    Options Database:
3334 .   -ts_monitor_draw_solution_initial - show initial solution as well as current solution
3335 
3336    Level: intermediate
3337 
3338 .keywords: TS,  vector, monitor, view
3339 
3340 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSMonitorDrawCtx()
3341 @*/
3342 PetscErrorCode  TSMonitorDrawCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorDrawCtx *ctx)
3343 {
3344   PetscErrorCode   ierr;
3345 
3346   PetscFunctionBegin;
3347   ierr = PetscNew(ctx);CHKERRQ(ierr);
3348   ierr = PetscViewerDrawOpen(comm,host,label,x,y,m,n,&(*ctx)->viewer);CHKERRQ(ierr);
3349   ierr = PetscViewerSetFromOptions((*ctx)->viewer);CHKERRQ(ierr);
3350 
3351   (*ctx)->howoften    = howoften;
3352   (*ctx)->showinitial = PETSC_FALSE;
3353   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_initial",&(*ctx)->showinitial,NULL);CHKERRQ(ierr);
3354 
3355   (*ctx)->showtimestepandtime = PETSC_FALSE;
3356   ierr = PetscOptionsGetBool(NULL,"-ts_monitor_draw_solution_show_time",&(*ctx)->showtimestepandtime,NULL);CHKERRQ(ierr);
3357   (*ctx)->color = PETSC_DRAW_WHITE;
3358   PetscFunctionReturn(0);
3359 }
3360 
3361 #undef __FUNCT__
3362 #define __FUNCT__ "TSMonitorDrawError"
3363 /*@C
3364    TSMonitorDrawError - Monitors progress of the TS solvers by calling
3365    VecView() for the error at each timestep
3366 
3367    Collective on TS
3368 
3369    Input Parameters:
3370 +  ts - the TS context
3371 .  step - current time-step
3372 .  ptime - current time
3373 -  dummy - either a viewer or NULL
3374 
3375    Level: intermediate
3376 
3377 .keywords: TS,  vector, monitor, view
3378 
3379 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
3380 @*/
3381 PetscErrorCode  TSMonitorDrawError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
3382 {
3383   PetscErrorCode   ierr;
3384   TSMonitorDrawCtx ctx    = (TSMonitorDrawCtx)dummy;
3385   PetscViewer      viewer = ctx->viewer;
3386   Vec              work;
3387 
3388   PetscFunctionBegin;
3389   if (!(((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason))) PetscFunctionReturn(0);
3390   ierr = VecDuplicate(u,&work);CHKERRQ(ierr);
3391   ierr = TSComputeSolutionFunction(ts,ptime,work);CHKERRQ(ierr);
3392   ierr = VecAXPY(work,-1.0,u);CHKERRQ(ierr);
3393   ierr = VecView(work,viewer);CHKERRQ(ierr);
3394   ierr = VecDestroy(&work);CHKERRQ(ierr);
3395   PetscFunctionReturn(0);
3396 }
3397 
3398 #include <petsc-private/dmimpl.h>
3399 #undef __FUNCT__
3400 #define __FUNCT__ "TSSetDM"
3401 /*@
3402    TSSetDM - Sets the DM that may be used by some preconditioners
3403 
3404    Logically Collective on TS and DM
3405 
3406    Input Parameters:
3407 +  ts - the preconditioner context
3408 -  dm - the dm
3409 
3410    Level: intermediate
3411 
3412 
3413 .seealso: TSGetDM(), SNESSetDM(), SNESGetDM()
3414 @*/
3415 PetscErrorCode  TSSetDM(TS ts,DM dm)
3416 {
3417   PetscErrorCode ierr;
3418   SNES           snes;
3419   DMTS           tsdm;
3420 
3421   PetscFunctionBegin;
3422   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3423   ierr = PetscObjectReference((PetscObject)dm);CHKERRQ(ierr);
3424   if (ts->dm) {               /* Move the DMTS context over to the new DM unless the new DM already has one */
3425     if (ts->dm->dmts && !dm->dmts) {
3426       ierr = DMCopyDMTS(ts->dm,dm);CHKERRQ(ierr);
3427       ierr = DMGetDMTS(ts->dm,&tsdm);CHKERRQ(ierr);
3428       if (tsdm->originaldm == ts->dm) { /* Grant write privileges to the replacement DM */
3429         tsdm->originaldm = dm;
3430       }
3431     }
3432     ierr = DMDestroy(&ts->dm);CHKERRQ(ierr);
3433   }
3434   ts->dm = dm;
3435 
3436   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
3437   ierr = SNESSetDM(snes,dm);CHKERRQ(ierr);
3438   PetscFunctionReturn(0);
3439 }
3440 
3441 #undef __FUNCT__
3442 #define __FUNCT__ "TSGetDM"
3443 /*@
3444    TSGetDM - Gets the DM that may be used by some preconditioners
3445 
3446    Not Collective
3447 
3448    Input Parameter:
3449 . ts - the preconditioner context
3450 
3451    Output Parameter:
3452 .  dm - the dm
3453 
3454    Level: intermediate
3455 
3456 
3457 .seealso: TSSetDM(), SNESSetDM(), SNESGetDM()
3458 @*/
3459 PetscErrorCode  TSGetDM(TS ts,DM *dm)
3460 {
3461   PetscErrorCode ierr;
3462 
3463   PetscFunctionBegin;
3464   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3465   if (!ts->dm) {
3466     ierr = DMShellCreate(PetscObjectComm((PetscObject)ts),&ts->dm);CHKERRQ(ierr);
3467     if (ts->snes) {ierr = SNESSetDM(ts->snes,ts->dm);CHKERRQ(ierr);}
3468   }
3469   *dm = ts->dm;
3470   PetscFunctionReturn(0);
3471 }
3472 
3473 #undef __FUNCT__
3474 #define __FUNCT__ "SNESTSFormFunction"
3475 /*@
3476    SNESTSFormFunction - Function to evaluate nonlinear residual
3477 
3478    Logically Collective on SNES
3479 
3480    Input Parameter:
3481 + snes - nonlinear solver
3482 . U - the current state at which to evaluate the residual
3483 - ctx - user context, must be a TS
3484 
3485    Output Parameter:
3486 . F - the nonlinear residual
3487 
3488    Notes:
3489    This function is not normally called by users and is automatically registered with the SNES used by TS.
3490    It is most frequently passed to MatFDColoringSetFunction().
3491 
3492    Level: advanced
3493 
3494 .seealso: SNESSetFunction(), MatFDColoringSetFunction()
3495 @*/
3496 PetscErrorCode  SNESTSFormFunction(SNES snes,Vec U,Vec F,void *ctx)
3497 {
3498   TS             ts = (TS)ctx;
3499   PetscErrorCode ierr;
3500 
3501   PetscFunctionBegin;
3502   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3503   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3504   PetscValidHeaderSpecific(F,VEC_CLASSID,3);
3505   PetscValidHeaderSpecific(ts,TS_CLASSID,4);
3506   ierr = (ts->ops->snesfunction)(snes,U,F,ts);CHKERRQ(ierr);
3507   PetscFunctionReturn(0);
3508 }
3509 
3510 #undef __FUNCT__
3511 #define __FUNCT__ "SNESTSFormJacobian"
3512 /*@
3513    SNESTSFormJacobian - Function to evaluate the Jacobian
3514 
3515    Collective on SNES
3516 
3517    Input Parameter:
3518 + snes - nonlinear solver
3519 . U - the current state at which to evaluate the residual
3520 - ctx - user context, must be a TS
3521 
3522    Output Parameter:
3523 + A - the Jacobian
3524 . B - the preconditioning matrix (may be the same as A)
3525 - flag - indicates any structure change in the matrix
3526 
3527    Notes:
3528    This function is not normally called by users and is automatically registered with the SNES used by TS.
3529 
3530    Level: developer
3531 
3532 .seealso: SNESSetJacobian()
3533 @*/
3534 PetscErrorCode  SNESTSFormJacobian(SNES snes,Vec U,Mat A,Mat B,void *ctx)
3535 {
3536   TS             ts = (TS)ctx;
3537   PetscErrorCode ierr;
3538 
3539   PetscFunctionBegin;
3540   PetscValidHeaderSpecific(snes,SNES_CLASSID,1);
3541   PetscValidHeaderSpecific(U,VEC_CLASSID,2);
3542   PetscValidPointer(A,3);
3543   PetscValidHeaderSpecific(A,MAT_CLASSID,3);
3544   PetscValidPointer(B,4);
3545   PetscValidHeaderSpecific(B,MAT_CLASSID,4);
3546   PetscValidHeaderSpecific(ts,TS_CLASSID,6);
3547   ierr = (ts->ops->snesjacobian)(snes,U,A,B,ts);CHKERRQ(ierr);
3548   PetscFunctionReturn(0);
3549 }
3550 
3551 #undef __FUNCT__
3552 #define __FUNCT__ "TSComputeRHSFunctionLinear"
3553 /*@C
3554    TSComputeRHSFunctionLinear - Evaluate the right hand side via the user-provided Jacobian, for linear problems only
3555 
3556    Collective on TS
3557 
3558    Input Arguments:
3559 +  ts - time stepping context
3560 .  t - time at which to evaluate
3561 .  U - state at which to evaluate
3562 -  ctx - context
3563 
3564    Output Arguments:
3565 .  F - right hand side
3566 
3567    Level: intermediate
3568 
3569    Notes:
3570    This function is intended to be passed to TSSetRHSFunction() to evaluate the right hand side for linear problems.
3571    The matrix (and optionally the evaluation context) should be passed to TSSetRHSJacobian().
3572 
3573 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSJacobianConstant()
3574 @*/
3575 PetscErrorCode TSComputeRHSFunctionLinear(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
3576 {
3577   PetscErrorCode ierr;
3578   Mat            Arhs,Brhs;
3579 
3580   PetscFunctionBegin;
3581   ierr = TSGetRHSMats_Private(ts,&Arhs,&Brhs);CHKERRQ(ierr);
3582   ierr = TSComputeRHSJacobian(ts,t,U,Arhs,Brhs);CHKERRQ(ierr);
3583   ierr = MatMult(Arhs,U,F);CHKERRQ(ierr);
3584   PetscFunctionReturn(0);
3585 }
3586 
3587 #undef __FUNCT__
3588 #define __FUNCT__ "TSComputeRHSJacobianConstant"
3589 /*@C
3590    TSComputeRHSJacobianConstant - Reuses a Jacobian that is time-independent.
3591 
3592    Collective on TS
3593 
3594    Input Arguments:
3595 +  ts - time stepping context
3596 .  t - time at which to evaluate
3597 .  U - state at which to evaluate
3598 -  ctx - context
3599 
3600    Output Arguments:
3601 +  A - pointer to operator
3602 .  B - pointer to preconditioning matrix
3603 -  flg - matrix structure flag
3604 
3605    Level: intermediate
3606 
3607    Notes:
3608    This function is intended to be passed to TSSetRHSJacobian() to evaluate the Jacobian for linear time-independent problems.
3609 
3610 .seealso: TSSetRHSFunction(), TSSetRHSJacobian(), TSComputeRHSFunctionLinear()
3611 @*/
3612 PetscErrorCode TSComputeRHSJacobianConstant(TS ts,PetscReal t,Vec U,Mat A,Mat B,void *ctx)
3613 {
3614   PetscFunctionBegin;
3615   PetscFunctionReturn(0);
3616 }
3617 
3618 #undef __FUNCT__
3619 #define __FUNCT__ "TSComputeIFunctionLinear"
3620 /*@C
3621    TSComputeIFunctionLinear - Evaluate the left hand side via the user-provided Jacobian, for linear problems only
3622 
3623    Collective on TS
3624 
3625    Input Arguments:
3626 +  ts - time stepping context
3627 .  t - time at which to evaluate
3628 .  U - state at which to evaluate
3629 .  Udot - time derivative of state vector
3630 -  ctx - context
3631 
3632    Output Arguments:
3633 .  F - left hand side
3634 
3635    Level: intermediate
3636 
3637    Notes:
3638    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
3639    user is required to write their own TSComputeIFunction.
3640    This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems.
3641    The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().
3642 
3643 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant()
3644 @*/
3645 PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
3646 {
3647   PetscErrorCode ierr;
3648   Mat            A,B;
3649 
3650   PetscFunctionBegin;
3651   ierr = TSGetIJacobian(ts,&A,&B,NULL,NULL);CHKERRQ(ierr);
3652   ierr = TSComputeIJacobian(ts,t,U,Udot,1.0,A,B,PETSC_TRUE);CHKERRQ(ierr);
3653   ierr = MatMult(A,Udot,F);CHKERRQ(ierr);
3654   PetscFunctionReturn(0);
3655 }
3656 
3657 #undef __FUNCT__
3658 #define __FUNCT__ "TSComputeIJacobianConstant"
3659 /*@C
3660    TSComputeIJacobianConstant - Reuses a time-independent for a semi-implicit DAE or ODE
3661 
3662    Collective on TS
3663 
3664    Input Arguments:
3665 +  ts - time stepping context
3666 .  t - time at which to evaluate
3667 .  U - state at which to evaluate
3668 .  Udot - time derivative of state vector
3669 .  shift - shift to apply
3670 -  ctx - context
3671 
3672    Output Arguments:
3673 +  A - pointer to operator
3674 .  B - pointer to preconditioning matrix
3675 -  flg - matrix structure flag
3676 
3677    Level: advanced
3678 
3679    Notes:
3680    This function is intended to be passed to TSSetIJacobian() to evaluate the Jacobian for linear time-independent problems.
3681 
3682    It is only appropriate for problems of the form
3683 
3684 $     M Udot = F(U,t)
3685 
3686   where M is constant and F is non-stiff.  The user must pass M to TSSetIJacobian().  The current implementation only
3687   works with IMEX time integration methods such as TSROSW and TSARKIMEX, since there is no support for de-constructing
3688   an implicit operator of the form
3689 
3690 $    shift*M + J
3691 
3692   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
3693   a copy of M or reassemble it when requested.
3694 
3695 .seealso: TSSetIFunction(), TSSetIJacobian(), TSComputeIFunctionLinear()
3696 @*/
3697 PetscErrorCode TSComputeIJacobianConstant(TS ts,PetscReal t,Vec U,Vec Udot,PetscReal shift,Mat A,Mat B,void *ctx)
3698 {
3699   PetscErrorCode ierr;
3700 
3701   PetscFunctionBegin;
3702   ierr = MatScale(A, shift / ts->ijacobian.shift);CHKERRQ(ierr);
3703   ts->ijacobian.shift = shift;
3704   PetscFunctionReturn(0);
3705 }
3706 
3707 #undef __FUNCT__
3708 #define __FUNCT__ "TSGetEquationType"
3709 /*@
3710    TSGetEquationType - Gets the type of the equation that TS is solving.
3711 
3712    Not Collective
3713 
3714    Input Parameter:
3715 .  ts - the TS context
3716 
3717    Output Parameter:
3718 .  equation_type - see TSEquationType
3719 
3720    Level: beginner
3721 
3722 .keywords: TS, equation type
3723 
3724 .seealso: TSSetEquationType(), TSEquationType
3725 @*/
3726 PetscErrorCode  TSGetEquationType(TS ts,TSEquationType *equation_type)
3727 {
3728   PetscFunctionBegin;
3729   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3730   PetscValidPointer(equation_type,2);
3731   *equation_type = ts->equation_type;
3732   PetscFunctionReturn(0);
3733 }
3734 
3735 #undef __FUNCT__
3736 #define __FUNCT__ "TSSetEquationType"
3737 /*@
3738    TSSetEquationType - Sets the type of the equation that TS is solving.
3739 
3740    Not Collective
3741 
3742    Input Parameter:
3743 +  ts - the TS context
3744 .  equation_type - see TSEquationType
3745 
3746    Level: advanced
3747 
3748 .keywords: TS, equation type
3749 
3750 .seealso: TSGetEquationType(), TSEquationType
3751 @*/
3752 PetscErrorCode  TSSetEquationType(TS ts,TSEquationType equation_type)
3753 {
3754   PetscFunctionBegin;
3755   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3756   ts->equation_type = equation_type;
3757   PetscFunctionReturn(0);
3758 }
3759 
3760 #undef __FUNCT__
3761 #define __FUNCT__ "TSGetConvergedReason"
3762 /*@
3763    TSGetConvergedReason - Gets the reason the TS iteration was stopped.
3764 
3765    Not Collective
3766 
3767    Input Parameter:
3768 .  ts - the TS context
3769 
3770    Output Parameter:
3771 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3772             manual pages for the individual convergence tests for complete lists
3773 
3774    Level: beginner
3775 
3776    Notes:
3777    Can only be called after the call to TSSolve() is complete.
3778 
3779 .keywords: TS, nonlinear, set, convergence, test
3780 
3781 .seealso: TSSetConvergenceTest(), TSConvergedReason
3782 @*/
3783 PetscErrorCode  TSGetConvergedReason(TS ts,TSConvergedReason *reason)
3784 {
3785   PetscFunctionBegin;
3786   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3787   PetscValidPointer(reason,2);
3788   *reason = ts->reason;
3789   PetscFunctionReturn(0);
3790 }
3791 
3792 #undef __FUNCT__
3793 #define __FUNCT__ "TSSetConvergedReason"
3794 /*@
3795    TSSetConvergedReason - Sets the reason for handling the convergence of TSSolve.
3796 
3797    Not Collective
3798 
3799    Input Parameter:
3800 +  ts - the TS context
3801 .  reason - negative value indicates diverged, positive value converged, see TSConvergedReason or the
3802             manual pages for the individual convergence tests for complete lists
3803 
3804    Level: advanced
3805 
3806    Notes:
3807    Can only be called during TSSolve() is active.
3808 
3809 .keywords: TS, nonlinear, set, convergence, test
3810 
3811 .seealso: TSConvergedReason
3812 @*/
3813 PetscErrorCode  TSSetConvergedReason(TS ts,TSConvergedReason reason)
3814 {
3815   PetscFunctionBegin;
3816   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3817   ts->reason = reason;
3818   PetscFunctionReturn(0);
3819 }
3820 
3821 #undef __FUNCT__
3822 #define __FUNCT__ "TSGetSolveTime"
3823 /*@
3824    TSGetSolveTime - Gets the time after a call to TSSolve()
3825 
3826    Not Collective
3827 
3828    Input Parameter:
3829 .  ts - the TS context
3830 
3831    Output Parameter:
3832 .  ftime - the final time. This time should correspond to the final time set with TSSetDuration()
3833 
3834    Level: beginner
3835 
3836    Notes:
3837    Can only be called after the call to TSSolve() is complete.
3838 
3839 .keywords: TS, nonlinear, set, convergence, test
3840 
3841 .seealso: TSSetConvergenceTest(), TSConvergedReason
3842 @*/
3843 PetscErrorCode  TSGetSolveTime(TS ts,PetscReal *ftime)
3844 {
3845   PetscFunctionBegin;
3846   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3847   PetscValidPointer(ftime,2);
3848   *ftime = ts->solvetime;
3849   PetscFunctionReturn(0);
3850 }
3851 
3852 #undef __FUNCT__
3853 #define __FUNCT__ "TSGetSNESIterations"
3854 /*@
3855    TSGetSNESIterations - Gets the total number of nonlinear iterations
3856    used by the time integrator.
3857 
3858    Not Collective
3859 
3860    Input Parameter:
3861 .  ts - TS context
3862 
3863    Output Parameter:
3864 .  nits - number of nonlinear iterations
3865 
3866    Notes:
3867    This counter is reset to zero for each successive call to TSSolve().
3868 
3869    Level: intermediate
3870 
3871 .keywords: TS, get, number, nonlinear, iterations
3872 
3873 .seealso:  TSGetKSPIterations()
3874 @*/
3875 PetscErrorCode TSGetSNESIterations(TS ts,PetscInt *nits)
3876 {
3877   PetscFunctionBegin;
3878   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3879   PetscValidIntPointer(nits,2);
3880   *nits = ts->snes_its;
3881   PetscFunctionReturn(0);
3882 }
3883 
3884 #undef __FUNCT__
3885 #define __FUNCT__ "TSGetKSPIterations"
3886 /*@
3887    TSGetKSPIterations - Gets the total number of linear iterations
3888    used by the time integrator.
3889 
3890    Not Collective
3891 
3892    Input Parameter:
3893 .  ts - TS context
3894 
3895    Output Parameter:
3896 .  lits - number of linear iterations
3897 
3898    Notes:
3899    This counter is reset to zero for each successive call to TSSolve().
3900 
3901    Level: intermediate
3902 
3903 .keywords: TS, get, number, linear, iterations
3904 
3905 .seealso:  TSGetSNESIterations(), SNESGetKSPIterations()
3906 @*/
3907 PetscErrorCode TSGetKSPIterations(TS ts,PetscInt *lits)
3908 {
3909   PetscFunctionBegin;
3910   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3911   PetscValidIntPointer(lits,2);
3912   *lits = ts->ksp_its;
3913   PetscFunctionReturn(0);
3914 }
3915 
3916 #undef __FUNCT__
3917 #define __FUNCT__ "TSGetStepRejections"
3918 /*@
3919    TSGetStepRejections - Gets the total number of rejected steps.
3920 
3921    Not Collective
3922 
3923    Input Parameter:
3924 .  ts - TS context
3925 
3926    Output Parameter:
3927 .  rejects - number of steps rejected
3928 
3929    Notes:
3930    This counter is reset to zero for each successive call to TSSolve().
3931 
3932    Level: intermediate
3933 
3934 .keywords: TS, get, number
3935 
3936 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetSNESFailures(), TSSetMaxSNESFailures(), TSSetErrorIfStepFails()
3937 @*/
3938 PetscErrorCode TSGetStepRejections(TS ts,PetscInt *rejects)
3939 {
3940   PetscFunctionBegin;
3941   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3942   PetscValidIntPointer(rejects,2);
3943   *rejects = ts->reject;
3944   PetscFunctionReturn(0);
3945 }
3946 
3947 #undef __FUNCT__
3948 #define __FUNCT__ "TSGetSNESFailures"
3949 /*@
3950    TSGetSNESFailures - Gets the total number of failed SNES solves
3951 
3952    Not Collective
3953 
3954    Input Parameter:
3955 .  ts - TS context
3956 
3957    Output Parameter:
3958 .  fails - number of failed nonlinear solves
3959 
3960    Notes:
3961    This counter is reset to zero for each successive call to TSSolve().
3962 
3963    Level: intermediate
3964 
3965 .keywords: TS, get, number
3966 
3967 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSSetMaxSNESFailures()
3968 @*/
3969 PetscErrorCode TSGetSNESFailures(TS ts,PetscInt *fails)
3970 {
3971   PetscFunctionBegin;
3972   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
3973   PetscValidIntPointer(fails,2);
3974   *fails = ts->num_snes_failures;
3975   PetscFunctionReturn(0);
3976 }
3977 
3978 #undef __FUNCT__
3979 #define __FUNCT__ "TSSetMaxStepRejections"
3980 /*@
3981    TSSetMaxStepRejections - Sets the maximum number of step rejections before a step fails
3982 
3983    Not Collective
3984 
3985    Input Parameter:
3986 +  ts - TS context
3987 -  rejects - maximum number of rejected steps, pass -1 for unlimited
3988 
3989    Notes:
3990    The counter is reset to zero for each step
3991 
3992    Options Database Key:
3993  .  -ts_max_reject - Maximum number of step rejections before a step fails
3994 
3995    Level: intermediate
3996 
3997 .keywords: TS, set, maximum, number
3998 
3999 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxSNESFailures(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4000 @*/
4001 PetscErrorCode TSSetMaxStepRejections(TS ts,PetscInt rejects)
4002 {
4003   PetscFunctionBegin;
4004   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4005   ts->max_reject = rejects;
4006   PetscFunctionReturn(0);
4007 }
4008 
4009 #undef __FUNCT__
4010 #define __FUNCT__ "TSSetMaxSNESFailures"
4011 /*@
4012    TSSetMaxSNESFailures - Sets the maximum number of failed SNES solves
4013 
4014    Not Collective
4015 
4016    Input Parameter:
4017 +  ts - TS context
4018 -  fails - maximum number of failed nonlinear solves, pass -1 for unlimited
4019 
4020    Notes:
4021    The counter is reset to zero for each successive call to TSSolve().
4022 
4023    Options Database Key:
4024  .  -ts_max_snes_failures - Maximum number of nonlinear solve failures
4025 
4026    Level: intermediate
4027 
4028 .keywords: TS, set, maximum, number
4029 
4030 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), SNESGetConvergedReason(), TSGetConvergedReason()
4031 @*/
4032 PetscErrorCode TSSetMaxSNESFailures(TS ts,PetscInt fails)
4033 {
4034   PetscFunctionBegin;
4035   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4036   ts->max_snes_failures = fails;
4037   PetscFunctionReturn(0);
4038 }
4039 
4040 #undef __FUNCT__
4041 #define __FUNCT__ "TSSetErrorIfStepFails"
4042 /*@
4043    TSSetErrorIfStepFails - Error if no step succeeds
4044 
4045    Not Collective
4046 
4047    Input Parameter:
4048 +  ts - TS context
4049 -  err - PETSC_TRUE to error if no step succeeds, PETSC_FALSE to return without failure
4050 
4051    Options Database Key:
4052  .  -ts_error_if_step_fails - Error if no step succeeds
4053 
4054    Level: intermediate
4055 
4056 .keywords: TS, set, error
4057 
4058 .seealso:  TSGetSNESIterations(), TSGetKSPIterations(), TSSetMaxStepRejections(), TSGetStepRejections(), TSGetSNESFailures(), TSSetErrorIfStepFails(), TSGetConvergedReason()
4059 @*/
4060 PetscErrorCode TSSetErrorIfStepFails(TS ts,PetscBool err)
4061 {
4062   PetscFunctionBegin;
4063   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4064   ts->errorifstepfailed = err;
4065   PetscFunctionReturn(0);
4066 }
4067 
4068 #undef __FUNCT__
4069 #define __FUNCT__ "TSMonitorSolutionBinary"
4070 /*@C
4071    TSMonitorSolutionBinary - Monitors progress of the TS solvers by VecView() for the solution at each timestep. Normally the viewer is a binary file
4072 
4073    Collective on TS
4074 
4075    Input Parameters:
4076 +  ts - the TS context
4077 .  step - current time-step
4078 .  ptime - current time
4079 .  u - current state
4080 -  viewer - binary viewer
4081 
4082    Level: intermediate
4083 
4084 .keywords: TS,  vector, monitor, view
4085 
4086 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4087 @*/
4088 PetscErrorCode  TSMonitorSolutionBinary(TS ts,PetscInt step,PetscReal ptime,Vec u,void *viewer)
4089 {
4090   PetscErrorCode ierr;
4091   PetscViewer    v = (PetscViewer)viewer;
4092 
4093   PetscFunctionBegin;
4094   ierr = VecView(u,v);CHKERRQ(ierr);
4095   PetscFunctionReturn(0);
4096 }
4097 
4098 #undef __FUNCT__
4099 #define __FUNCT__ "TSMonitorSolutionVTK"
4100 /*@C
4101    TSMonitorSolutionVTK - Monitors progress of the TS solvers by VecView() for the solution at each timestep.
4102 
4103    Collective on TS
4104 
4105    Input Parameters:
4106 +  ts - the TS context
4107 .  step - current time-step
4108 .  ptime - current time
4109 .  u - current state
4110 -  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4111 
4112    Level: intermediate
4113 
4114    Notes:
4115    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.
4116    These are named according to the file name template.
4117 
4118    This function is normally passed as an argument to TSMonitorSet() along with TSMonitorSolutionVTKDestroy().
4119 
4120 .keywords: TS,  vector, monitor, view
4121 
4122 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4123 @*/
4124 PetscErrorCode TSMonitorSolutionVTK(TS ts,PetscInt step,PetscReal ptime,Vec u,void *filenametemplate)
4125 {
4126   PetscErrorCode ierr;
4127   char           filename[PETSC_MAX_PATH_LEN];
4128   PetscViewer    viewer;
4129 
4130   PetscFunctionBegin;
4131   ierr = PetscSNPrintf(filename,sizeof(filename),(const char*)filenametemplate,step);CHKERRQ(ierr);
4132   ierr = PetscViewerVTKOpen(PetscObjectComm((PetscObject)ts),filename,FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
4133   ierr = VecView(u,viewer);CHKERRQ(ierr);
4134   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
4135   PetscFunctionReturn(0);
4136 }
4137 
4138 #undef __FUNCT__
4139 #define __FUNCT__ "TSMonitorSolutionVTKDestroy"
4140 /*@C
4141    TSMonitorSolutionVTKDestroy - Destroy context for monitoring
4142 
4143    Collective on TS
4144 
4145    Input Parameters:
4146 .  filenametemplate - string containing a format specifier for the integer time step (e.g. %03D)
4147 
4148    Level: intermediate
4149 
4150    Note:
4151    This function is normally passed to TSMonitorSet() along with TSMonitorSolutionVTK().
4152 
4153 .keywords: TS,  vector, monitor, view
4154 
4155 .seealso: TSMonitorSet(), TSMonitorSolutionVTK()
4156 @*/
4157 PetscErrorCode TSMonitorSolutionVTKDestroy(void *filenametemplate)
4158 {
4159   PetscErrorCode ierr;
4160 
4161   PetscFunctionBegin;
4162   ierr = PetscFree(*(char**)filenametemplate);CHKERRQ(ierr);
4163   PetscFunctionReturn(0);
4164 }
4165 
4166 #undef __FUNCT__
4167 #define __FUNCT__ "TSGetAdapt"
4168 /*@
4169    TSGetAdapt - Get the adaptive controller context for the current method
4170 
4171    Collective on TS if controller has not been created yet
4172 
4173    Input Arguments:
4174 .  ts - time stepping context
4175 
4176    Output Arguments:
4177 .  adapt - adaptive controller
4178 
4179    Level: intermediate
4180 
4181 .seealso: TSAdapt, TSAdaptSetType(), TSAdaptChoose()
4182 @*/
4183 PetscErrorCode TSGetAdapt(TS ts,TSAdapt *adapt)
4184 {
4185   PetscErrorCode ierr;
4186 
4187   PetscFunctionBegin;
4188   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4189   PetscValidPointer(adapt,2);
4190   if (!ts->adapt) {
4191     ierr = TSAdaptCreate(PetscObjectComm((PetscObject)ts),&ts->adapt);CHKERRQ(ierr);
4192     ierr = PetscLogObjectParent((PetscObject)ts,(PetscObject)ts->adapt);CHKERRQ(ierr);
4193     ierr = PetscObjectIncrementTabLevel((PetscObject)ts->adapt,(PetscObject)ts,1);CHKERRQ(ierr);
4194   }
4195   *adapt = ts->adapt;
4196   PetscFunctionReturn(0);
4197 }
4198 
4199 #undef __FUNCT__
4200 #define __FUNCT__ "TSSetTolerances"
4201 /*@
4202    TSSetTolerances - Set tolerances for local truncation error when using adaptive controller
4203 
4204    Logically Collective
4205 
4206    Input Arguments:
4207 +  ts - time integration context
4208 .  atol - scalar absolute tolerances, PETSC_DECIDE to leave current value
4209 .  vatol - vector of absolute tolerances or NULL, used in preference to atol if present
4210 .  rtol - scalar relative tolerances, PETSC_DECIDE to leave current value
4211 -  vrtol - vector of relative tolerances or NULL, used in preference to atol if present
4212 
4213    Level: beginner
4214 
4215 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSGetTolerances()
4216 @*/
4217 PetscErrorCode TSSetTolerances(TS ts,PetscReal atol,Vec vatol,PetscReal rtol,Vec vrtol)
4218 {
4219   PetscErrorCode ierr;
4220 
4221   PetscFunctionBegin;
4222   if (atol != PETSC_DECIDE && atol != PETSC_DEFAULT) ts->atol = atol;
4223   if (vatol) {
4224     ierr = PetscObjectReference((PetscObject)vatol);CHKERRQ(ierr);
4225     ierr = VecDestroy(&ts->vatol);CHKERRQ(ierr);
4226 
4227     ts->vatol = vatol;
4228   }
4229   if (rtol != PETSC_DECIDE && rtol != PETSC_DEFAULT) ts->rtol = rtol;
4230   if (vrtol) {
4231     ierr = PetscObjectReference((PetscObject)vrtol);CHKERRQ(ierr);
4232     ierr = VecDestroy(&ts->vrtol);CHKERRQ(ierr);
4233 
4234     ts->vrtol = vrtol;
4235   }
4236   PetscFunctionReturn(0);
4237 }
4238 
4239 #undef __FUNCT__
4240 #define __FUNCT__ "TSGetTolerances"
4241 /*@
4242    TSGetTolerances - Get tolerances for local truncation error when using adaptive controller
4243 
4244    Logically Collective
4245 
4246    Input Arguments:
4247 .  ts - time integration context
4248 
4249    Output Arguments:
4250 +  atol - scalar absolute tolerances, NULL to ignore
4251 .  vatol - vector of absolute tolerances, NULL to ignore
4252 .  rtol - scalar relative tolerances, NULL to ignore
4253 -  vrtol - vector of relative tolerances, NULL to ignore
4254 
4255    Level: beginner
4256 
4257 .seealso: TS, TSAdapt, TSVecNormWRMS(), TSSetTolerances()
4258 @*/
4259 PetscErrorCode TSGetTolerances(TS ts,PetscReal *atol,Vec *vatol,PetscReal *rtol,Vec *vrtol)
4260 {
4261   PetscFunctionBegin;
4262   if (atol)  *atol  = ts->atol;
4263   if (vatol) *vatol = ts->vatol;
4264   if (rtol)  *rtol  = ts->rtol;
4265   if (vrtol) *vrtol = ts->vrtol;
4266   PetscFunctionReturn(0);
4267 }
4268 
4269 #undef __FUNCT__
4270 #define __FUNCT__ "TSErrorNormWRMS"
4271 /*@
4272    TSErrorNormWRMS - compute a weighted norm of the difference between a vector and the current state
4273 
4274    Collective on TS
4275 
4276    Input Arguments:
4277 +  ts - time stepping context
4278 -  Y - state vector to be compared to ts->vec_sol
4279 
4280    Output Arguments:
4281 .  norm - weighted norm, a value of 1.0 is considered small
4282 
4283    Level: developer
4284 
4285 .seealso: TSSetTolerances()
4286 @*/
4287 PetscErrorCode TSErrorNormWRMS(TS ts,Vec Y,PetscReal *norm)
4288 {
4289   PetscErrorCode    ierr;
4290   PetscInt          i,n,N;
4291   const PetscScalar *u,*y;
4292   Vec               U;
4293   PetscReal         sum,gsum;
4294 
4295   PetscFunctionBegin;
4296   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4297   PetscValidHeaderSpecific(Y,VEC_CLASSID,2);
4298   PetscValidPointer(norm,3);
4299   U = ts->vec_sol;
4300   PetscCheckSameTypeAndComm(U,1,Y,2);
4301   if (U == Y) SETERRQ(PetscObjectComm((PetscObject)U),PETSC_ERR_ARG_IDN,"Y cannot be the TS solution vector");
4302 
4303   ierr = VecGetSize(U,&N);CHKERRQ(ierr);
4304   ierr = VecGetLocalSize(U,&n);CHKERRQ(ierr);
4305   ierr = VecGetArrayRead(U,&u);CHKERRQ(ierr);
4306   ierr = VecGetArrayRead(Y,&y);CHKERRQ(ierr);
4307   sum  = 0.;
4308   if (ts->vatol && ts->vrtol) {
4309     const PetscScalar *atol,*rtol;
4310     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4311     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4312     for (i=0; i<n; i++) {
4313       PetscReal tol = PetscRealPart(atol[i]) + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4314       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4315     }
4316     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4317     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4318   } else if (ts->vatol) {       /* vector atol, scalar rtol */
4319     const PetscScalar *atol;
4320     ierr = VecGetArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4321     for (i=0; i<n; i++) {
4322       PetscReal tol = PetscRealPart(atol[i]) + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4323       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4324     }
4325     ierr = VecRestoreArrayRead(ts->vatol,&atol);CHKERRQ(ierr);
4326   } else if (ts->vrtol) {       /* scalar atol, vector rtol */
4327     const PetscScalar *rtol;
4328     ierr = VecGetArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4329     for (i=0; i<n; i++) {
4330       PetscReal tol = ts->atol + PetscRealPart(rtol[i]) * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4331       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4332     }
4333     ierr = VecRestoreArrayRead(ts->vrtol,&rtol);CHKERRQ(ierr);
4334   } else {                      /* scalar atol, scalar rtol */
4335     for (i=0; i<n; i++) {
4336       PetscReal tol = ts->atol + ts->rtol * PetscMax(PetscAbsScalar(u[i]),PetscAbsScalar(y[i]));
4337       sum += PetscSqr(PetscAbsScalar(y[i] - u[i]) / tol);
4338     }
4339   }
4340   ierr = VecRestoreArrayRead(U,&u);CHKERRQ(ierr);
4341   ierr = VecRestoreArrayRead(Y,&y);CHKERRQ(ierr);
4342 
4343   ierr  = MPI_Allreduce(&sum,&gsum,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4344   *norm = PetscSqrtReal(gsum / N);
4345   if (PetscIsInfOrNanScalar(*norm)) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
4346   PetscFunctionReturn(0);
4347 }
4348 
4349 #undef __FUNCT__
4350 #define __FUNCT__ "TSSetCFLTimeLocal"
4351 /*@
4352    TSSetCFLTimeLocal - Set the local CFL constraint relative to forward Euler
4353 
4354    Logically Collective on TS
4355 
4356    Input Arguments:
4357 +  ts - time stepping context
4358 -  cfltime - maximum stable time step if using forward Euler (value can be different on each process)
4359 
4360    Note:
4361    After calling this function, the global CFL time can be obtained by calling TSGetCFLTime()
4362 
4363    Level: intermediate
4364 
4365 .seealso: TSGetCFLTime(), TSADAPTCFL
4366 @*/
4367 PetscErrorCode TSSetCFLTimeLocal(TS ts,PetscReal cfltime)
4368 {
4369   PetscFunctionBegin;
4370   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4371   ts->cfltime_local = cfltime;
4372   ts->cfltime       = -1.;
4373   PetscFunctionReturn(0);
4374 }
4375 
4376 #undef __FUNCT__
4377 #define __FUNCT__ "TSGetCFLTime"
4378 /*@
4379    TSGetCFLTime - Get the maximum stable time step according to CFL criteria applied to forward Euler
4380 
4381    Collective on TS
4382 
4383    Input Arguments:
4384 .  ts - time stepping context
4385 
4386    Output Arguments:
4387 .  cfltime - maximum stable time step for forward Euler
4388 
4389    Level: advanced
4390 
4391 .seealso: TSSetCFLTimeLocal()
4392 @*/
4393 PetscErrorCode TSGetCFLTime(TS ts,PetscReal *cfltime)
4394 {
4395   PetscErrorCode ierr;
4396 
4397   PetscFunctionBegin;
4398   if (ts->cfltime < 0) {
4399     ierr = MPI_Allreduce(&ts->cfltime_local,&ts->cfltime,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr);
4400   }
4401   *cfltime = ts->cfltime;
4402   PetscFunctionReturn(0);
4403 }
4404 
4405 #undef __FUNCT__
4406 #define __FUNCT__ "TSVISetVariableBounds"
4407 /*@
4408    TSVISetVariableBounds - Sets the lower and upper bounds for the solution vector. xl <= x <= xu
4409 
4410    Input Parameters:
4411 .  ts   - the TS context.
4412 .  xl   - lower bound.
4413 .  xu   - upper bound.
4414 
4415    Notes:
4416    If this routine is not called then the lower and upper bounds are set to
4417    PETSC_NINFINITY and PETSC_INFINITY respectively during SNESSetUp().
4418 
4419    Level: advanced
4420 
4421 @*/
4422 PetscErrorCode TSVISetVariableBounds(TS ts, Vec xl, Vec xu)
4423 {
4424   PetscErrorCode ierr;
4425   SNES           snes;
4426 
4427   PetscFunctionBegin;
4428   ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
4429   ierr = SNESVISetVariableBounds(snes,xl,xu);CHKERRQ(ierr);
4430   PetscFunctionReturn(0);
4431 }
4432 
4433 #if defined(PETSC_HAVE_MATLAB_ENGINE)
4434 #include <mex.h>
4435 
4436 typedef struct {char *funcname; mxArray *ctx;} TSMatlabContext;
4437 
4438 #undef __FUNCT__
4439 #define __FUNCT__ "TSComputeFunction_Matlab"
4440 /*
4441    TSComputeFunction_Matlab - Calls the function that has been set with
4442                          TSSetFunctionMatlab().
4443 
4444    Collective on TS
4445 
4446    Input Parameters:
4447 +  snes - the TS context
4448 -  u - input vector
4449 
4450    Output Parameter:
4451 .  y - function vector, as set by TSSetFunction()
4452 
4453    Notes:
4454    TSComputeFunction() is typically used within nonlinear solvers
4455    implementations, so most users would not generally call this routine
4456    themselves.
4457 
4458    Level: developer
4459 
4460 .keywords: TS, nonlinear, compute, function
4461 
4462 .seealso: TSSetFunction(), TSGetFunction()
4463 */
4464 PetscErrorCode  TSComputeFunction_Matlab(TS snes,PetscReal time,Vec u,Vec udot,Vec y, void *ctx)
4465 {
4466   PetscErrorCode  ierr;
4467   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4468   int             nlhs  = 1,nrhs = 7;
4469   mxArray         *plhs[1],*prhs[7];
4470   long long int   lx = 0,lxdot = 0,ly = 0,ls = 0;
4471 
4472   PetscFunctionBegin;
4473   PetscValidHeaderSpecific(snes,TS_CLASSID,1);
4474   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4475   PetscValidHeaderSpecific(udot,VEC_CLASSID,4);
4476   PetscValidHeaderSpecific(y,VEC_CLASSID,5);
4477   PetscCheckSameComm(snes,1,u,3);
4478   PetscCheckSameComm(snes,1,y,5);
4479 
4480   ierr = PetscMemcpy(&ls,&snes,sizeof(snes));CHKERRQ(ierr);
4481   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4482   ierr = PetscMemcpy(&lxdot,&udot,sizeof(udot));CHKERRQ(ierr);
4483   ierr = PetscMemcpy(&ly,&y,sizeof(u));CHKERRQ(ierr);
4484 
4485   prhs[0] =  mxCreateDoubleScalar((double)ls);
4486   prhs[1] =  mxCreateDoubleScalar(time);
4487   prhs[2] =  mxCreateDoubleScalar((double)lx);
4488   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4489   prhs[4] =  mxCreateDoubleScalar((double)ly);
4490   prhs[5] =  mxCreateString(sctx->funcname);
4491   prhs[6] =  sctx->ctx;
4492   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeFunctionInternal");CHKERRQ(ierr);
4493   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4494   mxDestroyArray(prhs[0]);
4495   mxDestroyArray(prhs[1]);
4496   mxDestroyArray(prhs[2]);
4497   mxDestroyArray(prhs[3]);
4498   mxDestroyArray(prhs[4]);
4499   mxDestroyArray(prhs[5]);
4500   mxDestroyArray(plhs[0]);
4501   PetscFunctionReturn(0);
4502 }
4503 
4504 
4505 #undef __FUNCT__
4506 #define __FUNCT__ "TSSetFunctionMatlab"
4507 /*
4508    TSSetFunctionMatlab - Sets the function evaluation routine and function
4509    vector for use by the TS routines in solving ODEs
4510    equations from MATLAB. Here the function is a string containing the name of a MATLAB function
4511 
4512    Logically Collective on TS
4513 
4514    Input Parameters:
4515 +  ts - the TS context
4516 -  func - function evaluation routine
4517 
4518    Calling sequence of func:
4519 $    func (TS ts,PetscReal time,Vec u,Vec udot,Vec f,void *ctx);
4520 
4521    Level: beginner
4522 
4523 .keywords: TS, nonlinear, set, function
4524 
4525 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4526 */
4527 PetscErrorCode  TSSetFunctionMatlab(TS ts,const char *func,mxArray *ctx)
4528 {
4529   PetscErrorCode  ierr;
4530   TSMatlabContext *sctx;
4531 
4532   PetscFunctionBegin;
4533   /* currently sctx is memory bleed */
4534   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4535   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4536   /*
4537      This should work, but it doesn't
4538   sctx->ctx = ctx;
4539   mexMakeArrayPersistent(sctx->ctx);
4540   */
4541   sctx->ctx = mxDuplicateArray(ctx);
4542 
4543   ierr = TSSetIFunction(ts,NULL,TSComputeFunction_Matlab,sctx);CHKERRQ(ierr);
4544   PetscFunctionReturn(0);
4545 }
4546 
4547 #undef __FUNCT__
4548 #define __FUNCT__ "TSComputeJacobian_Matlab"
4549 /*
4550    TSComputeJacobian_Matlab - Calls the function that has been set with
4551                          TSSetJacobianMatlab().
4552 
4553    Collective on TS
4554 
4555    Input Parameters:
4556 +  ts - the TS context
4557 .  u - input vector
4558 .  A, B - the matrices
4559 -  ctx - user context
4560 
4561    Output Parameter:
4562 .  flag - structure of the matrix
4563 
4564    Level: developer
4565 
4566 .keywords: TS, nonlinear, compute, function
4567 
4568 .seealso: TSSetFunction(), TSGetFunction()
4569 @*/
4570 PetscErrorCode  TSComputeJacobian_Matlab(TS ts,PetscReal time,Vec u,Vec udot,PetscReal shift,Mat *A,Mat *B,MatStructure *flag, void *ctx)
4571 {
4572   PetscErrorCode  ierr;
4573   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4574   int             nlhs  = 2,nrhs = 9;
4575   mxArray         *plhs[2],*prhs[9];
4576   long long int   lx = 0,lxdot = 0,lA = 0,ls = 0, lB = 0;
4577 
4578   PetscFunctionBegin;
4579   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4580   PetscValidHeaderSpecific(u,VEC_CLASSID,3);
4581 
4582   /* call Matlab function in ctx with arguments u and y */
4583 
4584   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4585   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4586   ierr = PetscMemcpy(&lxdot,&udot,sizeof(u));CHKERRQ(ierr);
4587   ierr = PetscMemcpy(&lA,A,sizeof(u));CHKERRQ(ierr);
4588   ierr = PetscMemcpy(&lB,B,sizeof(u));CHKERRQ(ierr);
4589 
4590   prhs[0] =  mxCreateDoubleScalar((double)ls);
4591   prhs[1] =  mxCreateDoubleScalar((double)time);
4592   prhs[2] =  mxCreateDoubleScalar((double)lx);
4593   prhs[3] =  mxCreateDoubleScalar((double)lxdot);
4594   prhs[4] =  mxCreateDoubleScalar((double)shift);
4595   prhs[5] =  mxCreateDoubleScalar((double)lA);
4596   prhs[6] =  mxCreateDoubleScalar((double)lB);
4597   prhs[7] =  mxCreateString(sctx->funcname);
4598   prhs[8] =  sctx->ctx;
4599   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSComputeJacobianInternal");CHKERRQ(ierr);
4600   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4601   *flag   =  (MatStructure) mxGetScalar(plhs[1]);CHKERRQ(ierr);
4602   mxDestroyArray(prhs[0]);
4603   mxDestroyArray(prhs[1]);
4604   mxDestroyArray(prhs[2]);
4605   mxDestroyArray(prhs[3]);
4606   mxDestroyArray(prhs[4]);
4607   mxDestroyArray(prhs[5]);
4608   mxDestroyArray(prhs[6]);
4609   mxDestroyArray(prhs[7]);
4610   mxDestroyArray(plhs[0]);
4611   mxDestroyArray(plhs[1]);
4612   PetscFunctionReturn(0);
4613 }
4614 
4615 
4616 #undef __FUNCT__
4617 #define __FUNCT__ "TSSetJacobianMatlab"
4618 /*
4619    TSSetJacobianMatlab - Sets the Jacobian function evaluation routine and two empty Jacobian matrices
4620    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
4621 
4622    Logically Collective on TS
4623 
4624    Input Parameters:
4625 +  ts - the TS context
4626 .  A,B - Jacobian matrices
4627 .  func - function evaluation routine
4628 -  ctx - user context
4629 
4630    Calling sequence of func:
4631 $    flag = func (TS ts,PetscReal time,Vec u,Vec udot,Mat A,Mat B,void *ctx);
4632 
4633 
4634    Level: developer
4635 
4636 .keywords: TS, nonlinear, set, function
4637 
4638 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4639 */
4640 PetscErrorCode  TSSetJacobianMatlab(TS ts,Mat A,Mat B,const char *func,mxArray *ctx)
4641 {
4642   PetscErrorCode  ierr;
4643   TSMatlabContext *sctx;
4644 
4645   PetscFunctionBegin;
4646   /* currently sctx is memory bleed */
4647   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4648   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4649   /*
4650      This should work, but it doesn't
4651   sctx->ctx = ctx;
4652   mexMakeArrayPersistent(sctx->ctx);
4653   */
4654   sctx->ctx = mxDuplicateArray(ctx);
4655 
4656   ierr = TSSetIJacobian(ts,A,B,TSComputeJacobian_Matlab,sctx);CHKERRQ(ierr);
4657   PetscFunctionReturn(0);
4658 }
4659 
4660 #undef __FUNCT__
4661 #define __FUNCT__ "TSMonitor_Matlab"
4662 /*
4663    TSMonitor_Matlab - Calls the function that has been set with TSMonitorSetMatlab().
4664 
4665    Collective on TS
4666 
4667 .seealso: TSSetFunction(), TSGetFunction()
4668 @*/
4669 PetscErrorCode  TSMonitor_Matlab(TS ts,PetscInt it, PetscReal time,Vec u, void *ctx)
4670 {
4671   PetscErrorCode  ierr;
4672   TSMatlabContext *sctx = (TSMatlabContext*)ctx;
4673   int             nlhs  = 1,nrhs = 6;
4674   mxArray         *plhs[1],*prhs[6];
4675   long long int   lx = 0,ls = 0;
4676 
4677   PetscFunctionBegin;
4678   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4679   PetscValidHeaderSpecific(u,VEC_CLASSID,4);
4680 
4681   ierr = PetscMemcpy(&ls,&ts,sizeof(ts));CHKERRQ(ierr);
4682   ierr = PetscMemcpy(&lx,&u,sizeof(u));CHKERRQ(ierr);
4683 
4684   prhs[0] =  mxCreateDoubleScalar((double)ls);
4685   prhs[1] =  mxCreateDoubleScalar((double)it);
4686   prhs[2] =  mxCreateDoubleScalar((double)time);
4687   prhs[3] =  mxCreateDoubleScalar((double)lx);
4688   prhs[4] =  mxCreateString(sctx->funcname);
4689   prhs[5] =  sctx->ctx;
4690   ierr    =  mexCallMATLAB(nlhs,plhs,nrhs,prhs,"PetscTSMonitorInternal");CHKERRQ(ierr);
4691   ierr    =  mxGetScalar(plhs[0]);CHKERRQ(ierr);
4692   mxDestroyArray(prhs[0]);
4693   mxDestroyArray(prhs[1]);
4694   mxDestroyArray(prhs[2]);
4695   mxDestroyArray(prhs[3]);
4696   mxDestroyArray(prhs[4]);
4697   mxDestroyArray(plhs[0]);
4698   PetscFunctionReturn(0);
4699 }
4700 
4701 
4702 #undef __FUNCT__
4703 #define __FUNCT__ "TSMonitorSetMatlab"
4704 /*
4705    TSMonitorSetMatlab - Sets the monitor function from Matlab
4706 
4707    Level: developer
4708 
4709 .keywords: TS, nonlinear, set, function
4710 
4711 .seealso: TSGetFunction(), TSComputeFunction(), TSSetJacobian(), TSSetFunction()
4712 */
4713 PetscErrorCode  TSMonitorSetMatlab(TS ts,const char *func,mxArray *ctx)
4714 {
4715   PetscErrorCode  ierr;
4716   TSMatlabContext *sctx;
4717 
4718   PetscFunctionBegin;
4719   /* currently sctx is memory bleed */
4720   ierr = PetscMalloc(sizeof(TSMatlabContext),&sctx);CHKERRQ(ierr);
4721   ierr = PetscStrallocpy(func,&sctx->funcname);CHKERRQ(ierr);
4722   /*
4723      This should work, but it doesn't
4724   sctx->ctx = ctx;
4725   mexMakeArrayPersistent(sctx->ctx);
4726   */
4727   sctx->ctx = mxDuplicateArray(ctx);
4728 
4729   ierr = TSMonitorSet(ts,TSMonitor_Matlab,sctx,NULL);CHKERRQ(ierr);
4730   PetscFunctionReturn(0);
4731 }
4732 #endif
4733 
4734 
4735 
4736 #undef __FUNCT__
4737 #define __FUNCT__ "TSMonitorLGSolution"
4738 /*@C
4739    TSMonitorLGSolution - Monitors progress of the TS solvers by plotting each component of the solution vector
4740        in a time based line graph
4741 
4742    Collective on TS
4743 
4744    Input Parameters:
4745 +  ts - the TS context
4746 .  step - current time-step
4747 .  ptime - current time
4748 -  lg - a line graph object
4749 
4750    Level: intermediate
4751 
4752     Notes: each process in a parallel run displays its component solutions in a separate window
4753 
4754 .keywords: TS,  vector, monitor, view
4755 
4756 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView()
4757 @*/
4758 PetscErrorCode  TSMonitorLGSolution(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4759 {
4760   PetscErrorCode    ierr;
4761   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4762   const PetscScalar *yy;
4763   PetscInt          dim;
4764 
4765   PetscFunctionBegin;
4766   if (!step) {
4767     PetscDrawAxis axis;
4768     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4769     ierr = PetscDrawAxisSetLabels(axis,"Solution as function of time","Time","Solution");CHKERRQ(ierr);
4770     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4771     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4772     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4773   }
4774   ierr = VecGetArrayRead(u,&yy);CHKERRQ(ierr);
4775 #if defined(PETSC_USE_COMPLEX)
4776   {
4777     PetscReal *yreal;
4778     PetscInt  i,n;
4779     ierr = VecGetLocalSize(u,&n);CHKERRQ(ierr);
4780     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4781     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4782     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4783     ierr = PetscFree(yreal);CHKERRQ(ierr);
4784   }
4785 #else
4786   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4787 #endif
4788   ierr = VecRestoreArrayRead(u,&yy);CHKERRQ(ierr);
4789   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4790     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4791   }
4792   PetscFunctionReturn(0);
4793 }
4794 
4795 #undef __FUNCT__
4796 #define __FUNCT__ "TSMonitorLGError"
4797 /*@C
4798    TSMonitorLGError - Monitors progress of the TS solvers by plotting each component of the solution vector
4799        in a time based line graph
4800 
4801    Collective on TS
4802 
4803    Input Parameters:
4804 +  ts - the TS context
4805 .  step - current time-step
4806 .  ptime - current time
4807 -  lg - a line graph object
4808 
4809    Level: intermediate
4810 
4811    Notes:
4812    Only for sequential solves.
4813 
4814    The user must provide the solution using TSSetSolutionFunction() to use this monitor.
4815 
4816    Options Database Keys:
4817 .  -ts_monitor_lg_error - create a graphical monitor of error history
4818 
4819 .keywords: TS,  vector, monitor, view
4820 
4821 .seealso: TSMonitorSet(), TSMonitorDefault(), VecView(), TSSetSolutionFunction()
4822 @*/
4823 PetscErrorCode  TSMonitorLGError(TS ts,PetscInt step,PetscReal ptime,Vec u,void *dummy)
4824 {
4825   PetscErrorCode    ierr;
4826   TSMonitorLGCtx    ctx = (TSMonitorLGCtx)dummy;
4827   const PetscScalar *yy;
4828   Vec               y;
4829   PetscInt          dim;
4830 
4831   PetscFunctionBegin;
4832   if (!step) {
4833     PetscDrawAxis axis;
4834     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4835     ierr = PetscDrawAxisSetLabels(axis,"Error in solution as function of time","Time","Solution");CHKERRQ(ierr);
4836     ierr = VecGetLocalSize(u,&dim);CHKERRQ(ierr);
4837     ierr = PetscDrawLGSetDimension(ctx->lg,dim);CHKERRQ(ierr);
4838     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4839   }
4840   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
4841   ierr = TSComputeSolutionFunction(ts,ptime,y);CHKERRQ(ierr);
4842   ierr = VecAXPY(y,-1.0,u);CHKERRQ(ierr);
4843   ierr = VecGetArrayRead(y,&yy);CHKERRQ(ierr);
4844 #if defined(PETSC_USE_COMPLEX)
4845   {
4846     PetscReal *yreal;
4847     PetscInt  i,n;
4848     ierr = VecGetLocalSize(y,&n);CHKERRQ(ierr);
4849     ierr = PetscMalloc1(n,&yreal);CHKERRQ(ierr);
4850     for (i=0; i<n; i++) yreal[i] = PetscRealPart(yy[i]);
4851     ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yreal);CHKERRQ(ierr);
4852     ierr = PetscFree(yreal);CHKERRQ(ierr);
4853   }
4854 #else
4855   ierr = PetscDrawLGAddCommonPoint(ctx->lg,ptime,yy);CHKERRQ(ierr);
4856 #endif
4857   ierr = VecRestoreArrayRead(y,&yy);CHKERRQ(ierr);
4858   ierr = VecDestroy(&y);CHKERRQ(ierr);
4859   if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) {
4860     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4861   }
4862   PetscFunctionReturn(0);
4863 }
4864 
4865 #undef __FUNCT__
4866 #define __FUNCT__ "TSMonitorLGSNESIterations"
4867 PetscErrorCode TSMonitorLGSNESIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4868 {
4869   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4870   PetscReal      x   = ptime,y;
4871   PetscErrorCode ierr;
4872   PetscInt       its;
4873 
4874   PetscFunctionBegin;
4875   if (!n) {
4876     PetscDrawAxis axis;
4877 
4878     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4879     ierr = PetscDrawAxisSetLabels(axis,"Nonlinear iterations as function of time","Time","SNES Iterations");CHKERRQ(ierr);
4880     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4881 
4882     ctx->snes_its = 0;
4883   }
4884   ierr = TSGetSNESIterations(ts,&its);CHKERRQ(ierr);
4885   y    = its - ctx->snes_its;
4886   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4887   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4888     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4889   }
4890   ctx->snes_its = its;
4891   PetscFunctionReturn(0);
4892 }
4893 
4894 #undef __FUNCT__
4895 #define __FUNCT__ "TSMonitorLGKSPIterations"
4896 PetscErrorCode TSMonitorLGKSPIterations(TS ts,PetscInt n,PetscReal ptime,Vec v,void *monctx)
4897 {
4898   TSMonitorLGCtx ctx = (TSMonitorLGCtx) monctx;
4899   PetscReal      x   = ptime,y;
4900   PetscErrorCode ierr;
4901   PetscInt       its;
4902 
4903   PetscFunctionBegin;
4904   if (!n) {
4905     PetscDrawAxis axis;
4906 
4907     ierr = PetscDrawLGGetAxis(ctx->lg,&axis);CHKERRQ(ierr);
4908     ierr = PetscDrawAxisSetLabels(axis,"Linear iterations as function of time","Time","KSP Iterations");CHKERRQ(ierr);
4909     ierr = PetscDrawLGReset(ctx->lg);CHKERRQ(ierr);
4910 
4911     ctx->ksp_its = 0;
4912   }
4913   ierr = TSGetKSPIterations(ts,&its);CHKERRQ(ierr);
4914   y    = its - ctx->ksp_its;
4915   ierr = PetscDrawLGAddPoint(ctx->lg,&x,&y);CHKERRQ(ierr);
4916   if (((ctx->howoften > 0) && (!(n % ctx->howoften)) && (n > -1)) || ((ctx->howoften == -1) && (n == -1))) {
4917     ierr = PetscDrawLGDraw(ctx->lg);CHKERRQ(ierr);
4918   }
4919   ctx->ksp_its = its;
4920   PetscFunctionReturn(0);
4921 }
4922 
4923 #undef __FUNCT__
4924 #define __FUNCT__ "TSComputeLinearStability"
4925 /*@
4926    TSComputeLinearStability - computes the linear stability function at a point
4927 
4928    Collective on TS and Vec
4929 
4930    Input Parameters:
4931 +  ts - the TS context
4932 -  xr,xi - real and imaginary part of input arguments
4933 
4934    Output Parameters:
4935 .  yr,yi - real and imaginary part of function value
4936 
4937    Level: developer
4938 
4939 .keywords: TS, compute
4940 
4941 .seealso: TSSetRHSFunction(), TSComputeIFunction()
4942 @*/
4943 PetscErrorCode TSComputeLinearStability(TS ts,PetscReal xr,PetscReal xi,PetscReal *yr,PetscReal *yi)
4944 {
4945   PetscErrorCode ierr;
4946 
4947   PetscFunctionBegin;
4948   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
4949   if (!ts->ops->linearstability) SETERRQ(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"Linearized stability function not provided for this method");
4950   ierr = (*ts->ops->linearstability)(ts,xr,xi,yr,yi);CHKERRQ(ierr);
4951   PetscFunctionReturn(0);
4952 }
4953 
4954 #undef __FUNCT__
4955 #define __FUNCT__ "TSRollBack"
4956 /*@
4957    TSRollBack - Rolls back one time step
4958 
4959    Collective on TS
4960 
4961    Input Parameter:
4962 .  ts - the TS context obtained from TSCreate()
4963 
4964    Level: advanced
4965 
4966 .keywords: TS, timestep, rollback
4967 
4968 .seealso: TSCreate(), TSSetUp(), TSDestroy(), TSSolve(), TSSetPreStep(), TSSetPreStage(), TSInterpolate()
4969 @*/
4970 PetscErrorCode  TSRollBack(TS ts)
4971 {
4972   PetscErrorCode ierr;
4973 
4974   PetscFunctionBegin;
4975   PetscValidHeaderSpecific(ts, TS_CLASSID,1);
4976 
4977   if (!ts->ops->rollback) SETERRQ1(PetscObjectComm((PetscObject)ts),PETSC_ERR_SUP,"TSRollBack not implemented for type '%s'",((PetscObject)ts)->type_name);
4978   ierr = (*ts->ops->rollback)(ts);CHKERRQ(ierr);
4979   ts->time_step = ts->ptime - ts->ptime_prev;
4980   ts->ptime = ts->ptime_prev;
4981   PetscFunctionReturn(0);
4982 }
4983 
4984