xref: /petsc/src/ts/interface/tscreate.c (revision feff33ee0b5b037fa8f9f294dede656a2f85cc47)
1 #include <petsc/private/tsimpl.h>      /*I "petscts.h"  I*/
2 
3 const char *const TSConvergedReasons_Shifted[] = {
4   "DIVERGED_STEP_REJECTED",
5   "DIVERGED_NONLINEAR_SOLVE",
6   "CONVERGED_ITERATING",
7   "CONVERGED_TIME",
8   "CONVERGED_ITS",
9   "CONVERGED_USER",
10   "CONVERGED_EVENT",
11   "CONVERGED_PSEUDO_FATOL",
12   "CONVERGED_PSEUDO_FATOL",
13   "TSConvergedReason","TS_",0};
14 const char *const*TSConvergedReasons = TSConvergedReasons_Shifted + 2;
15 
16 /*@C
17   TSCreate - This function creates an empty timestepper. The problem type can then be set with TSSetProblemType() and the
18        type of solver can then be set with TSSetType().
19 
20   Collective on MPI_Comm
21 
22   Input Parameter:
23 . comm - The communicator
24 
25   Output Parameter:
26 . ts   - The TS
27 
28   Level: beginner
29 
30   Developer Notes:  TS essentially always creates a SNES object even though explicit methods do not use it. This is
31                     unfortunate and should be fixed at some point. The flag snes->usessnes indicates if the
32                     particular method does use SNES and regulates if the information about the SNES is printed
33                     in TSView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
34                     by help messages about meaningless SNES options.
35 
36 .keywords: TS, create
37 .seealso: TSSetType(), TSSetUp(), TSDestroy(), TSSetProblemType()
38 @*/
39 PetscErrorCode  TSCreate(MPI_Comm comm, TS *ts)
40 {
41   TS             t;
42   PetscErrorCode ierr;
43 
44   PetscFunctionBegin;
45   PetscValidPointer(ts,1);
46   *ts = NULL;
47   ierr = TSInitializePackage();CHKERRQ(ierr);
48 
49   ierr = PetscHeaderCreate(t, TS_CLASSID, "TS", "Time stepping", "TS", comm, TSDestroy, TSView);CHKERRQ(ierr);
50 
51   /* General TS description */
52   t->problem_type      = TS_NONLINEAR;
53   t->equation_type     = TS_EQ_UNSPECIFIED;
54 
55   t->ptime             = 0.0;
56   t->time_step         = 0.1;
57   t->max_time          = PETSC_MAX_REAL;
58   t->exact_final_time  = TS_EXACTFINALTIME_UNSPECIFIED;
59   t->steps             = 0;
60   t->max_steps         = PETSC_MAX_INT;
61   t->steprestart       = PETSC_TRUE;
62 
63   t->max_snes_failures = 1;
64   t->max_reject        = 10;
65   t->errorifstepfailed = PETSC_TRUE;
66 
67   t->rhsjacobian.time  = PETSC_MIN_REAL;
68   t->rhsjacobian.scale = 1.0;
69   t->ijacobian.shift   = 1.0;
70 
71   /* All methods that do adaptivity should specify
72    * its preferred adapt type in their constructor */
73   t->default_adapt_type = TSADAPTNONE;
74   t->atol               = 1e-4;
75   t->rtol               = 1e-4;
76   t->cfltime            = PETSC_MAX_REAL;
77   t->cfltime_local      = PETSC_MAX_REAL;
78 
79   *ts = t;
80   PetscFunctionReturn(0);
81 }
82