Actual source code: tsimpl.h

  1: #pragma once

  3: #include <petscts.h>
  4: #include <petsc/private/petscimpl.h>

  6: /* SUBMANSEC = TS */

  8: /*
  9:     Timesteping context.
 10:       General DAE: F(t,U,U_t) = 0, required Jacobian is G'(U) where G(U) = F(t,U,U0+a*U)
 11:       General ODE: U_t = F(t,U) <-- the right-hand-side function
 12:       Linear  ODE: U_t = A(t) U <-- the right-hand-side matrix
 13:       Linear (no time) ODE: U_t = A U <-- the right-hand-side matrix
 14: */

 16: /*
 17:      Maximum number of monitors you can run with a single TS
 18: */
 19: #define MAXTSMONITORS 10

 21: PETSC_EXTERN PetscBool      TSRegisterAllCalled;
 22: PETSC_EXTERN PetscErrorCode TSRegisterAll(void);
 23: PETSC_EXTERN PetscErrorCode TSAdaptRegisterAll(void);

 25: PETSC_EXTERN PetscErrorCode TSRKRegisterAll(void);
 26: PETSC_EXTERN PetscErrorCode TSMPRKRegisterAll(void);
 27: PETSC_EXTERN PetscErrorCode TSARKIMEXRegisterAll(void);
 28: PETSC_EXTERN PetscErrorCode TSRosWRegisterAll(void);
 29: PETSC_EXTERN PetscErrorCode TSGLLERegisterAll(void);
 30: PETSC_EXTERN PetscErrorCode TSGLLEAdaptRegisterAll(void);
 31: PETSC_EXTERN PetscErrorCode TSIRKRegisterAll(void);

 33: typedef struct _TSOps *TSOps;

 35: struct _TSOps {
 36:   PetscErrorCode (*snesfunction)(SNES, Vec, Vec, TS);
 37:   PetscErrorCode (*snesjacobian)(SNES, Vec, Mat, Mat, TS);
 38:   PetscErrorCode (*setup)(TS);
 39:   PetscErrorCode (*step)(TS);
 40:   PetscErrorCode (*solve)(TS);
 41:   PetscErrorCode (*interpolate)(TS, PetscReal, Vec);
 42:   PetscErrorCode (*evaluatewlte)(TS, NormType, PetscInt *, PetscReal *);
 43:   PetscErrorCode (*evaluatestep)(TS, PetscInt, Vec, PetscBool *);
 44:   PetscErrorCode (*setfromoptions)(TS, PetscOptionItems);
 45:   PetscErrorCode (*destroy)(TS);
 46:   PetscErrorCode (*view)(TS, PetscViewer);
 47:   PetscErrorCode (*reset)(TS);
 48:   PetscErrorCode (*linearstability)(TS, PetscReal, PetscReal, PetscReal *, PetscReal *);
 49:   PetscErrorCode (*load)(TS, PetscViewer);
 50:   PetscErrorCode (*rollback)(TS);
 51:   PetscErrorCode (*getstages)(TS, PetscInt *, Vec *[]);
 52:   PetscErrorCode (*adjointstep)(TS);
 53:   PetscErrorCode (*adjointsetup)(TS);
 54:   PetscErrorCode (*adjointreset)(TS);
 55:   PetscErrorCode (*adjointintegral)(TS);
 56:   PetscErrorCode (*forwardsetup)(TS);
 57:   PetscErrorCode (*forwardreset)(TS);
 58:   PetscErrorCode (*forwardstep)(TS);
 59:   PetscErrorCode (*forwardintegral)(TS);
 60:   PetscErrorCode (*forwardgetstages)(TS, PetscInt *, Mat *[]);
 61:   PetscErrorCode (*getsolutioncomponents)(TS, PetscInt *, Vec *);
 62:   PetscErrorCode (*getauxsolution)(TS, Vec *);
 63:   PetscErrorCode (*gettimeerror)(TS, PetscInt, Vec *);
 64:   PetscErrorCode (*settimeerror)(TS, Vec);
 65:   PetscErrorCode (*startingmethod)(TS);
 66:   PetscErrorCode (*initcondition)(TS, Vec);
 67:   PetscErrorCode (*exacterror)(TS, Vec, Vec);
 68:   PetscErrorCode (*resizeregister)(TS, PetscBool);
 69: };

 71: /*
 72:    TSEvent - Abstract object to handle event monitoring
 73: */
 74: typedef struct _n_TSEvent *TSEvent;

 76: typedef struct _TSTrajectoryOps *TSTrajectoryOps;

 78: struct _TSTrajectoryOps {
 79:   PetscErrorCode (*view)(TSTrajectory, PetscViewer);
 80:   PetscErrorCode (*reset)(TSTrajectory);
 81:   PetscErrorCode (*destroy)(TSTrajectory);
 82:   PetscErrorCode (*set)(TSTrajectory, TS, PetscInt, PetscReal, Vec);
 83:   PetscErrorCode (*get)(TSTrajectory, TS, PetscInt, PetscReal *);
 84:   PetscErrorCode (*setfromoptions)(TSTrajectory, PetscOptionItems);
 85:   PetscErrorCode (*setup)(TSTrajectory, TS);
 86: };

 88: /* TSHistory is an helper object that allows inquiring
 89:    the TSTrajectory by time and not by the step number only */
 90: typedef struct _n_TSHistory *TSHistory;

 92: struct _p_TSTrajectory {
 93:   PETSCHEADER(struct _TSTrajectoryOps);
 94:   TSHistory tsh; /* associates times to unique step ids */
 95:   /* stores necessary data to reconstruct states and derivatives via Lagrangian interpolation */
 96:   struct {
 97:     PetscInt     order; /* interpolation order */
 98:     Vec         *W;     /* work vectors */
 99:     PetscScalar *L;     /* workspace for Lagrange basis */
100:     PetscReal   *T;     /* Lagrange times (stored) */
101:     Vec         *WW;    /* just an array of pointers */
102:     PetscBool   *TT;    /* workspace for Lagrange */
103:     PetscReal   *TW;    /* Lagrange times (workspace) */

105:     /* caching */
106:     PetscBool caching;
107:     struct {
108:       PetscObjectId    id;
109:       PetscObjectState state;
110:       PetscReal        time;
111:       PetscInt         step;
112:     } Ucached;
113:     struct {
114:       PetscObjectId    id;
115:       PetscObjectState state;
116:       PetscReal        time;
117:       PetscInt         step;
118:     } Udotcached;
119:   } lag;
120:   Vec         U, Udot;            /* used by TSTrajectory{Get|Restore}UpdatedHistoryVecs */
121:   PetscBool   usehistory;         /* whether to use TSHistory */
122:   PetscBool   solution_only;      /* whether we dump just the solution or also the stages */
123:   PetscBool   adjoint_solve_mode; /* whether we will use the Trajectory inside a TSAdjointSolve() or not */
124:   PetscViewer monitor;
125:   PetscBool   setupcalled;            /* true if setup has been called */
126:   PetscInt    recomps;                /* counter for recomputations in the adjoint run */
127:   PetscInt    diskreads, diskwrites;  /* counters for disk checkpoint reads and writes */
128:   char      **names;                  /* the name of each variable; each process has only the local names */
129:   PetscBool   keepfiles;              /* keep the files generated during the run after the run is complete */
130:   char       *dirname, *filetemplate; /* directory name and file name template for disk checkpoints */
131:   char       *dirfiletemplate;        /* complete directory and file name template for disk checkpoints */
132:   PetscErrorCode (*transform)(void *, Vec, Vec *);
133:   PetscErrorCode (*transformdestroy)(void *);
134:   void *transformctx;
135:   void *data;
136: };

138: typedef struct _TS_RHSSplitLink *TS_RHSSplitLink;
139: struct _TS_RHSSplitLink {
140:   TS              ts;
141:   char           *splitname;
142:   IS              is;
143:   TS_RHSSplitLink next;
144:   PetscLogEvent   event;
145: };

147: typedef struct _TS_EvaluationTimes *TSEvaluationTimes;
148: struct _TS_EvaluationTimes {
149:   PetscInt   num_time_points; /* number of time points */
150:   PetscReal *time_points;     /* array of the time span */
151:   PetscReal  reltol;          /* relative tolerance for span point detection */
152:   PetscReal  abstol;          /* absolute tolerance for span point detection */
153:   PetscReal  worktol;         /* the ultimate tolerance (variable), maintained within a single TS time step for consistency */
154:   PetscInt   time_point_idx;  /* index of the time_point to be reached next */
155:   PetscInt   sol_idx;         /* index into sol_vecs and sol_times */
156:   Vec       *sol_vecs;        /* array of the solutions at the specified time points */
157:   PetscReal *sol_times;       /* array of times that sol_vecs was taken at */
158: };

160: struct _p_TS {
161:   PETSCHEADER(struct _TSOps);
162:   TSProblemType  problem_type;
163:   TSEquationType equation_type;

165:   DM          dm;
166:   Vec         vec_sol;  /* solution vector in first and second order equations */
167:   Vec         vec_sol0; /* solution vector at the beginning of the step */
168:   Vec         vec_dot;  /* time derivative vector in second order equations */
169:   TSAdapt     adapt;
170:   TSAdaptType default_adapt_type;
171:   TSEvent     event;

173:   /* ---------------- Resize ---------------------*/
174:   PetscBool       resizerollback;
175:   PetscObjectList resizetransferobjs;

177:   /* ---------------- User (or PETSc) Provided stuff ---------------------*/
178:   PetscErrorCode (*monitor[MAXTSMONITORS])(TS, PetscInt, PetscReal, Vec, void *);
179:   PetscCtxDestroyFn *monitordestroy[MAXTSMONITORS];
180:   void              *monitorcontext[MAXTSMONITORS];
181:   PetscInt           numbermonitors;
182:   PetscErrorCode (*adjointmonitor[MAXTSMONITORS])(TS, PetscInt, PetscReal, Vec, PetscInt, Vec *, Vec *, void *);
183:   PetscCtxDestroyFn *adjointmonitordestroy[MAXTSMONITORS];
184:   void              *adjointmonitorcontext[MAXTSMONITORS];
185:   PetscInt           numberadjointmonitors;

187:   PetscErrorCode (*prestep)(TS);
188:   PetscErrorCode (*prestage)(TS, PetscReal);
189:   PetscErrorCode (*poststage)(TS, PetscReal, PetscInt, Vec *);
190:   PetscErrorCode (*postevaluate)(TS);
191:   PetscErrorCode (*poststep)(TS);
192:   PetscErrorCode (*functiondomainerror)(TS, PetscReal, Vec, PetscBool *);
193:   PetscErrorCode (*resizesetup)(TS, PetscInt, PetscReal, Vec, PetscBool *, void *);
194:   PetscErrorCode (*resizetransfer)(TS, PetscInt, Vec[], Vec[], void *);
195:   void *resizectx;

197:   /* ---------------------- Sensitivity Analysis support -----------------*/
198:   TSTrajectory trajectory; /* All solutions are kept here for the entire time integration process */
199:   Vec         *vecs_sensi; /* one vector for each cost function */
200:   Vec         *vecs_sensip;
201:   PetscInt     numcost; /* number of cost functions */
202:   Vec          vec_costintegral;
203:   PetscBool    adjointsetupcalled;
204:   PetscInt     adjoint_steps;
205:   PetscInt     adjoint_max_steps;
206:   PetscBool    adjoint_solve;     /* immediately call TSAdjointSolve() after TSSolve() is complete */
207:   PetscBool    costintegralfwd;   /* cost integral is evaluated in the forward run if true */
208:   Vec          vec_costintegrand; /* workspace for Adjoint computations */
209:   Mat          Jacp, Jacprhs;
210:   void        *ijacobianpctx, *rhsjacobianpctx;
211:   void        *costintegrandctx;
212:   Vec         *vecs_drdu;
213:   Vec         *vecs_drdp;
214:   Vec          vec_drdu_col, vec_drdp_col;

216:   /* first-order adjoint */
217:   PetscErrorCode (*rhsjacobianp)(TS, PetscReal, Vec, Mat, void *);
218:   PetscErrorCode (*ijacobianp)(TS, PetscReal, Vec, Vec, PetscReal, Mat, void *);
219:   PetscErrorCode (*costintegrand)(TS, PetscReal, Vec, Vec, void *);
220:   PetscErrorCode (*drdufunction)(TS, PetscReal, Vec, Vec *, void *);
221:   PetscErrorCode (*drdpfunction)(TS, PetscReal, Vec, Vec *, void *);

223:   /* second-order adjoint */
224:   Vec  *vecs_sensi2;
225:   Vec  *vecs_sensi2p;
226:   Vec   vec_dir; /* directional vector for optimization */
227:   Vec  *vecs_fuu, *vecs_guu;
228:   Vec  *vecs_fup, *vecs_gup;
229:   Vec  *vecs_fpu, *vecs_gpu;
230:   Vec  *vecs_fpp, *vecs_gpp;
231:   void *ihessianproductctx, *rhshessianproductctx;
232:   PetscErrorCode (*ihessianproduct_fuu)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);
233:   PetscErrorCode (*ihessianproduct_fup)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);
234:   PetscErrorCode (*ihessianproduct_fpu)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);
235:   PetscErrorCode (*ihessianproduct_fpp)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);
236:   PetscErrorCode (*rhshessianproduct_guu)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);
237:   PetscErrorCode (*rhshessianproduct_gup)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);
238:   PetscErrorCode (*rhshessianproduct_gpu)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);
239:   PetscErrorCode (*rhshessianproduct_gpp)(TS, PetscReal, Vec, Vec *, Vec, Vec *, void *);

241:   /* specific to forward sensitivity analysis */
242:   Mat       mat_sensip;           /* matrix storing forward sensitivities */
243:   Vec       vec_sensip_col;       /* space for a column of the sensip matrix */
244:   Vec      *vecs_integral_sensip; /* one vector for each integral */
245:   PetscInt  num_parameters;
246:   PetscInt  num_initialvalues;
247:   void     *vecsrhsjacobianpctx;
248:   PetscBool forwardsetupcalled;
249:   PetscBool forward_solve;
250:   PetscErrorCode (*vecsrhsjacobianp)(TS, PetscReal, Vec, Vec *, void *);

252:   /* ---------------------- IMEX support ---------------------------------*/
253:   /* These extra slots are only used when the user provides both Implicit and RHS */
254:   Mat Arhs; /* Right hand side matrix */
255:   Mat Brhs; /* Right hand side matrix used to construct the preconditioner */
256:   Vec Frhs; /* Right hand side function value */

258:   /* This is a general caching scheme to avoid recomputing the Jacobian at a place that has been previously been evaluated.
259:    * The present use case is that TSComputeRHSFunctionLinear() evaluates the Jacobian once and we don't want it to be immeditely re-evaluated.
260:    */
261:   struct {
262:     PetscReal        time;       /* The time at which the matrices were last evaluated */
263:     PetscObjectId    Xid;        /* Unique ID of solution vector at which the Jacobian was last evaluated */
264:     PetscObjectState Xstate;     /* State of the solution vector */
265:     MatStructure     mstructure; /* The structure returned */
266:     /* Flag to unshift Jacobian before calling the IJacobian or RHSJacobian functions.  This is useful
267:      * if the user would like to reuse (part of) the Jacobian from the last evaluation. */
268:     PetscBool reuse;
269:     PetscReal scale, shift;
270:   } rhsjacobian;

272:   struct {
273:     PetscReal shift; /* The derivative of the lhs wrt to Xdot */
274:   } ijacobian;

276:   MatStructure axpy_pattern; /* information about the nonzero pattern of the RHS Jacobian in reference to the implicit Jacobian */
277:   /* --------------------Nonlinear Iteration------------------------------*/
278:   SNES      snes;
279:   PetscBool usessnes; /* Flag set by each TSType to indicate if the type actually uses a SNES;
280:                            this works around the design flaw that a SNES is ALWAYS created with TS even when it is not needed.*/
281:   PetscInt  ksp_its;  /* total number of linear solver iterations */
282:   PetscInt  snes_its; /* total number of nonlinear solver iterations */
283:   PetscInt  num_snes_failures;
284:   PetscInt  max_snes_failures;

286:   /* --- Logging --- */
287:   PetscInt ifuncs, rhsfuncs, ijacs, rhsjacs;

289:   /* --- Data that is unique to each particular solver --- */
290:   PetscBool setupcalled; /* true if setup has been called */
291:   void     *data;        /* implementationspecific data */
292:   void     *ctx;         /* user context */

294:   PetscBool steprollback;        /* flag to indicate that the step was rolled back */
295:   PetscBool steprestart;         /* flag to indicate that the timestepper has to discard any history and restart */
296:   PetscBool stepresize;          /* flag to indicate that the discretization was resized */
297:   PetscInt  steps;               /* steps taken so far in all successive calls to TSSolve() */
298:   PetscReal ptime;               /* time at the start of the current step (stage time is internal if it exists) */
299:   PetscReal time_step;           /* current time increment */
300:   PetscReal time_step0;          /* proposed time increment at the beginning of the step */
301:   PetscReal ptime_prev;          /* time at the start of the previous step */
302:   PetscReal ptime_prev_rollback; /* time at the start of the 2nd previous step to recover from rollback */
303:   PetscReal solvetime;           /* time at the conclusion of TSSolve() */
304:   PetscBool stifflyaccurate;     /* flag to indicate that the method is stiffly accurate */

306:   TSConvergedReason      reason;
307:   PetscBool              errorifstepfailed;
308:   PetscInt               reject, max_reject;
309:   TSExactFinalTimeOption exact_final_time;

311:   PetscObjectParameterDeclare(PetscReal, rtol); /* Relative and absolute tolerance for local truncation error */
312:   PetscObjectParameterDeclare(PetscReal, atol);
313:   PetscObjectParameterDeclare(PetscReal, max_time); /* max time allowed */
314:   PetscObjectParameterDeclare(PetscInt, max_steps); /* maximum time-step number to execute until (possibly with nonzero starting value) */
315:   PetscObjectParameterDeclare(PetscInt, run_steps); /* maximum number of time steps for TSSolve to take on each call */
316:   Vec       vatol, vrtol;                           /* Relative and absolute tolerance in vector form */
317:   PetscReal cfltime, cfltime_local;
318:   PetscInt  start_step; /* step number at start of current run */

320:   PetscBool testjacobian;
321:   PetscBool testjacobiantranspose;
322:   /* ------------------- Default work-area management ------------------ */
323:   PetscInt nwork;
324:   Vec     *work;

326:   /* ---------------------- RHS splitting support ---------------------------------*/
327:   PetscInt        num_rhs_splits;
328:   TS_RHSSplitLink tsrhssplit;
329:   PetscBool       use_splitrhsfunction;
330:   SNES            snesrhssplit;

332:   /* ---------------------- Quadrature integration support ---------------------------------*/
333:   TS quadraturets;

335:   /* ---------------------- Time span support ---------------------------------*/
336:   TSEvaluationTimes eval_times;
337: };

339: struct _TSAdaptOps {
340:   PetscErrorCode (*choose)(TSAdapt, TS, PetscReal, PetscInt *, PetscReal *, PetscBool *, PetscReal *, PetscReal *, PetscReal *);
341:   PetscErrorCode (*destroy)(TSAdapt);
342:   PetscErrorCode (*reset)(TSAdapt);
343:   PetscErrorCode (*view)(TSAdapt, PetscViewer);
344:   PetscErrorCode (*setfromoptions)(TSAdapt, PetscOptionItems);
345:   PetscErrorCode (*load)(TSAdapt, PetscViewer);
346: };

348: struct _p_TSAdapt {
349:   PETSCHEADER(struct _TSAdaptOps);
350:   void *data;
351:   PetscErrorCode (*checkstage)(TSAdapt, TS, PetscReal, Vec, PetscBool *);
352:   struct {
353:     PetscInt    n;              /* number of candidate schemes, including the one currently in use */
354:     PetscBool   inuse_set;      /* the current scheme has been set */
355:     const char *name[16];       /* name of the scheme */
356:     PetscInt    order[16];      /* classical order of each scheme */
357:     PetscInt    stageorder[16]; /* stage order of each scheme */
358:     PetscReal   ccfl[16];       /* stability limit relative to explicit Euler */
359:     PetscReal   cost[16];       /* relative measure of the amount of work required for each scheme */
360:   } candidates;
361:   PetscBool   always_accept;
362:   PetscReal   safety;             /* safety factor relative to target error/stability goal */
363:   PetscReal   reject_safety;      /* extra safety factor if the last step was rejected */
364:   PetscReal   clip[2];            /* admissible time step decrease/increase factors */
365:   PetscReal   dt_min, dt_max;     /* admissible minimum and maximum time step */
366:   PetscReal   ignore_max;         /* minimum value of the solution to be considered by the adaptor */
367:   PetscBool   glee_use_local;     /* GLEE adaptor uses global or local error */
368:   PetscReal   scale_solve_failed; /* scale step by this factor if solver (linear or nonlinear) fails. */
369:   PetscReal   matchstepfac[2];    /* factors to control the behaviour of matchstep */
370:   NormType    wnormtype;
371:   PetscViewer monitor;
372:   PetscInt    timestepjustdecreased_delay; /* number of timesteps after a decrease in the timestep before the timestep can be increased */
373:   PetscInt    timestepjustdecreased;
374:   PetscReal   dt_eval_times_cached; /* time step before hitting a TS evaluation time point */
375: };

377: typedef struct _p_DMTS  *DMTS;
378: typedef struct _DMTSOps *DMTSOps;
379: struct _DMTSOps {
380:   TSRHSFunctionFn *rhsfunction;
381:   TSRHSJacobianFn *rhsjacobian;

383:   TSIFunctionFn *ifunction;
384:   PetscErrorCode (*ifunctionview)(void *, PetscViewer);
385:   PetscErrorCode (*ifunctionload)(void **, PetscViewer);

387:   TSIJacobianFn *ijacobian;
388:   PetscErrorCode (*ijacobianview)(void *, PetscViewer);
389:   PetscErrorCode (*ijacobianload)(void **, PetscViewer);

391:   TSI2FunctionFn *i2function;
392:   TSI2JacobianFn *i2jacobian;

394:   TSTransientVariableFn *transientvar;

396:   TSSolutionFn *solution;
397:   TSForcingFn  *forcing;

399:   PetscErrorCode (*destroy)(DMTS);
400:   PetscErrorCode (*duplicate)(DMTS, DMTS);
401: };

403: /*S
404:    DMTS - Object held by a `DM` that contains all the callback functions and their contexts needed by a `TS`

406:    Level: developer

408:    Notes:
409:    Users provide callback functions and their contexts to `TS` using, for example, `TSSetIFunction()`. These values are stored
410:    in a `DMTS` that is contained in the `DM` associated with the `TS`. If no `DM` was provided by
411:    the user with `TSSetDM()` it is automatically created by `TSGetDM()` with `DMShellCreate()`.

413:    Users very rarely need to worked directly with the `DMTS` object, rather they work with the `TS` and the `DM` they created

415:    Multiple `DM` can share a single `DMTS`, often each `DM` is associated with
416:    a grid refinement level. `DMGetDMTS()` returns the `DMTS` associated with a `DM`. `DMGetDMTSWrite()` returns a unique
417:    `DMTS` that is only associated with the current `DM`, making a copy of the shared `DMTS` if needed (copy-on-write).

419:    See `DMKSP` for details on why there is a needed for `DMTS` instead of simply storing the user callbacks directly in the `DM` or the `TS`

421:    Developer Note:
422:    The original `dm` inside the `DMTS` is NOT reference counted  (to prevent a reference count loop between a `DM` and a `DMSNES`).
423:    The `DM` on which this context was first created is cached here to implement one-way
424:    copy-on-write. When `DMGetDMTSWrite()` sees a request using a different `DM`, it makes a copy of the `DMTS`.

426: .seealso: [](ch_ts), `TSCreate()`, `DM`, `DMGetDMTSWrite()`, `DMGetDMTS()`, `TSSetIFunction()`, `DMTSSetRHSFunctionContextDestroy()`,
427:           `DMTSSetRHSJacobian()`, `DMTSGetRHSJacobian()`, `DMTSSetRHSJacobianContextDestroy()`, `DMTSSetIFunction()`, `DMTSGetIFunction()`,
428:           `DMTSSetIFunctionContextDestroy()`, `DMTSSetIJacobian()`, `DMTSGetIJacobian()`, `DMTSSetIJacobianContextDestroy()`,
429:           `DMTSSetI2Function()`, `DMTSGetI2Function()`, `DMTSSetI2FunctionContextDestroy()`, `DMTSSetI2Jacobian()`,
430:           `DMTSGetI2Jacobian()`, `DMTSSetI2JacobianContextDestroy()`, `DMKSP`, `DMSNES`
431: S*/
432: struct _p_DMTS {
433:   PETSCHEADER(struct _DMTSOps);
434:   PetscContainer rhsfunctionctxcontainer;
435:   PetscContainer rhsjacobianctxcontainer;

437:   PetscContainer ifunctionctxcontainer;
438:   PetscContainer ijacobianctxcontainer;

440:   PetscContainer i2functionctxcontainer;
441:   PetscContainer i2jacobianctxcontainer;

443:   void *transientvarctx;

445:   void *solutionctx;
446:   void *forcingctx;

448:   void *data;

450:   /* See the developer note for DMTS above */
451:   DM originaldm;
452: };

454: PETSC_INTERN PetscErrorCode DMTSUnsetRHSFunctionContext_Internal(DM);
455: PETSC_INTERN PetscErrorCode DMTSUnsetRHSJacobianContext_Internal(DM);
456: PETSC_INTERN PetscErrorCode DMTSUnsetIFunctionContext_Internal(DM);
457: PETSC_INTERN PetscErrorCode DMTSUnsetIJacobianContext_Internal(DM);
458: PETSC_INTERN PetscErrorCode DMTSUnsetI2FunctionContext_Internal(DM);
459: PETSC_INTERN PetscErrorCode DMTSUnsetI2JacobianContext_Internal(DM);

461: PETSC_EXTERN PetscErrorCode DMGetDMTS(DM, DMTS *);
462: PETSC_EXTERN PetscErrorCode DMGetDMTSWrite(DM, DMTS *);
463: PETSC_EXTERN PetscErrorCode DMCopyDMTS(DM, DM);
464: PETSC_EXTERN PetscErrorCode DMTSView(DMTS, PetscViewer);
465: PETSC_EXTERN PetscErrorCode DMTSLoad(DMTS, PetscViewer);
466: PETSC_EXTERN PetscErrorCode DMTSCopy(DMTS, DMTS);

468: struct _n_TSEvent {
469:   PetscReal *fvalue_prev;                                                                   /* value of indicator function at the left end-point of the event interval */
470:   PetscReal *fvalue;                                                                        /* value of indicator function at the current point */
471:   PetscReal *fvalue_right;                                                                  /* value of indicator function at the right end-point of the event interval */
472:   PetscInt  *fsign_prev;                                                                    /* sign of indicator function at the left end-point of the event interval */
473:   PetscInt  *fsign;                                                                         /* sign of indicator function at the current point */
474:   PetscInt  *fsign_right;                                                                   /* sign of indicator function at the right end-point of the event interval */
475:   PetscReal  ptime_prev;                                                                    /* time at the previous point (left end-point of the event interval) */
476:   PetscReal  ptime_right;                                                                   /* time at the right end-point of the event interval */
477:   PetscReal  ptime_cache;                                                                   /* the point visited by the TS before the event interval was detected; cached - to reuse if necessary */
478:   PetscReal  timestep_cache;                                                                /* time step considered by the TS before the event interval was detected; cached - to reuse if necessary */
479:   PetscInt  *side;                                                                          /* upon bracket subdivision, indicates which sub-bracket is taken further, -1 -> left one, +1 -> right one, +2 -> neither, 0 -> zero-crossing located */
480:   PetscInt  *side_prev;                                                                     /* counts the repeating previous side's (with values: -n <=> '-1'*n; +n <=> '+1'*n); used in the Anderson-Bjorck iteration */
481:   PetscReal  timestep_postevent;                                                            /* first time step after the event; can be PETSC_DECIDE */
482:   PetscReal  timestep_2nd_postevent;                                                        /* second time step after the event; can be PETSC_DECIDE */
483:   PetscReal  timestep_min;                                                                  /* minimum time step */
484:   PetscBool *justrefined_AB;                                                                /* this flag shows if the given indicator function i = [0..nevents) participated in Anderson-Bjorck process in the last iteration of TSEventHandler() */
485:   PetscReal *gamma_AB;                                                                      /* cumulative scaling factor for the Anderson-Bjorck iteration */
486:   PetscErrorCode (*indicator)(TS, PetscReal, Vec, PetscReal *, void *);                     /* this callback defines the user function(s) whose sign changes indicate events */
487:   PetscErrorCode (*postevent)(TS, PetscInt, PetscInt[], PetscReal, Vec, PetscBool, void *); /* user post-event callback */
488:   void       *ctx;                                                                          /* user context for indicator and postevent callbacks */
489:   PetscInt   *direction;                                                                    /* zero crossing direction to trigger the event: +1 -> going positive, -1 -> going negative, 0 -> any */
490:   PetscBool  *terminate;                                                                    /* 1 -> terminate time stepping on event location, 0 -> continue */
491:   PetscInt    nevents;                                                                      /* number of events (indicator functions) to handle on the current MPI process */
492:   PetscInt    nevents_zero;                                                                 /* number of events triggered */
493:   PetscInt   *events_zero;                                                                  /* list of the events triggered */
494:   PetscReal  *vtol;                                                                         /* array of tolerances for the indicator function zero check */
495:   PetscInt    iterctr;                                                                      /* iteration counter: used both for reporting and as a status indicator */
496:   PetscBool   processing;                                                                   /* this flag shows if the event-resolving iterations are in progress, or the post-event dt handling is in progress */
497:   PetscBool   revisit_right;                                                                /* [sync] "revisit the bracket's right end", if true, then fvalue(s) are not calculated, but are taken from fvalue_right(s) */
498:   PetscViewer monitor;
499:   /* Struct to record the events */
500:   struct {
501:     PetscInt   ctr;      /* Recorder counter */
502:     PetscReal *time;     /* Event times */
503:     PetscInt  *stepnum;  /* Step numbers */
504:     PetscInt  *nevents;  /* Number of events occurring at the event times */
505:     PetscInt **eventidx; /* Local indices of the events in the event list */
506:   } recorder;
507:   PetscInt recsize; /* Size of recorder stack */
508:   PetscInt refct;   /* Reference count */
509: };

511: PETSC_EXTERN PetscErrorCode TSEventInitialize(TSEvent, TS, PetscReal, Vec);
512: PETSC_EXTERN PetscErrorCode TSEventDestroy(TSEvent *);
513: PETSC_EXTERN PetscErrorCode TSEventHandler(TS);
514: PETSC_EXTERN PetscErrorCode TSAdjointEventHandler(TS);

516: PETSC_EXTERN PetscLogEvent TS_AdjointStep;
517: PETSC_EXTERN PetscLogEvent TS_Step;
518: PETSC_EXTERN PetscLogEvent TS_PseudoComputeTimeStep;
519: PETSC_EXTERN PetscLogEvent TS_FunctionEval;
520: PETSC_EXTERN PetscLogEvent TS_JacobianEval;
521: PETSC_EXTERN PetscLogEvent TS_ForwardStep;

523: typedef enum {
524:   TS_STEP_INCOMPLETE, /* vec_sol, ptime, etc point to beginning of step */
525:   TS_STEP_PENDING,    /* vec_sol advanced, but step has not been accepted yet */
526:   TS_STEP_COMPLETE    /* step accepted and ptime, steps, etc have been advanced */
527: } TSStepStatus;

529: struct _n_TSMonitorLGCtx {
530:   PetscDrawLG lg;
531:   PetscBool   semilogy;
532:   PetscInt    howoften; /* when > 0 uses step % howoften, when negative only final solution plotted */
533:   PetscInt    ksp_its, snes_its;
534:   char      **names;
535:   char      **displaynames;
536:   PetscInt    ndisplayvariables;
537:   PetscInt   *displayvariables;
538:   PetscReal  *displayvalues;
539:   PetscErrorCode (*transform)(void *, Vec, Vec *);
540:   PetscCtxDestroyFn *transformdestroy;
541:   void              *transformctx;
542: };

544: struct _n_TSMonitorSPCtx {
545:   PetscDrawSP sp;
546:   PetscInt    howoften;     /* when > 0 uses step % howoften, when negative only final solution plotted */
547:   PetscInt    retain;       /* Retain n points plotted to show trajectories, or -1 for all points */
548:   PetscBool   phase;        /* Plot in phase space rather than coordinate space */
549:   PetscBool   multispecies; /* Change scatter point color based on species */
550:   PetscInt    ksp_its, snes_its;
551: };

553: struct _n_TSMonitorHGCtx {
554:   PetscDrawHG *hg;
555:   PetscInt     howoften; /* when > 0 uses step % howoften, when negative only final solution plotted */
556:   PetscInt     Ns;       /* The number of species to histogram */
557:   PetscBool    velocity; /* Plot in velocity space rather than coordinate space */
558: };

560: struct _n_TSMonitorEnvelopeCtx {
561:   Vec max, min;
562: };

564: /*
565:     Checks if the user provide a TSSetIFunction() but an explicit method is called; generate an error in that case
566: */
567: static inline PetscErrorCode TSCheckImplicitTerm(TS ts)
568: {
569:   TSIFunctionFn *ifunction;
570:   DM             dm;

572:   PetscFunctionBegin;
573:   PetscCall(TSGetDM(ts, &dm));
574:   PetscCall(DMTSGetIFunction(dm, &ifunction, NULL));
575:   PetscCheck(!ifunction, PetscObjectComm((PetscObject)ts), PETSC_ERR_ARG_INCOMP, "You are attempting to use an explicit ODE integrator but provided an implicit function definition with TSSetIFunction()");
576:   PetscFunctionReturn(PETSC_SUCCESS);
577: }

579: PETSC_INTERN PetscErrorCode TSGetRHSMats_Private(TS, Mat *, Mat *);
580: /* this is declared here as TSHistory is not public */
581: PETSC_EXTERN PetscErrorCode TSAdaptHistorySetTSHistory(TSAdapt, TSHistory, PetscBool);

583: PETSC_INTERN PetscErrorCode TSTrajectoryReconstruct_Private(TSTrajectory, TS, PetscReal, Vec, Vec);
584: PETSC_INTERN PetscErrorCode TSTrajectorySetUp_Basic(TSTrajectory, TS);

586: PETSC_EXTERN PetscLogEvent TSTrajectory_Set;
587: PETSC_EXTERN PetscLogEvent TSTrajectory_Get;
588: PETSC_EXTERN PetscLogEvent TSTrajectory_GetVecs;
589: PETSC_EXTERN PetscLogEvent TSTrajectory_SetUp;
590: PETSC_EXTERN PetscLogEvent TSTrajectory_DiskWrite;
591: PETSC_EXTERN PetscLogEvent TSTrajectory_DiskRead;

593: struct _n_TSMonitorDrawCtx {
594:   PetscViewer viewer;
595:   Vec         initialsolution;
596:   PetscBool   showinitial;
597:   PetscInt    howoften; /* when > 0 uses step % howoften, when negative only final solution plotted */
598:   PetscBool   showtimestepandtime;
599: };

601: struct _n_TSMonitorVTKCtx {
602:   char    *filenametemplate;
603:   PetscInt interval; /* when > 0 uses step % interval, when negative only final solution plotted */
604: };

606: struct _n_TSMonitorSolutionCtx {
607:   PetscBool skip_initial; // Skip the viewer the first time TSMonitorSolution is run (within a single call to `TSSolve()`)
608: };