1: #include <petsc/private/tsimpl.h>

  3: const char *const TSConvergedReasons_Shifted[] = {
  4:   "ADJOINT_DIVERGED_LINEAR_SOLVE",
  5:   "FORWARD_DIVERGED_LINEAR_SOLVE",
  6:   "DIVERGED_STEP_REJECTED",
  7:   "DIVERGED_NONLINEAR_SOLVE",
  8:   "CONVERGED_ITERATING",
  9:   "CONVERGED_TIME",
 10:   "CONVERGED_ITS",
 11:   "CONVERGED_USER",
 12:   "CONVERGED_EVENT",
 13:   "CONVERGED_PSEUDO_FATOL",
 14:   "CONVERGED_PSEUDO_FATOL",
 15:   "TSConvergedReason","TS_",NULL};
 16: const char *const*TSConvergedReasons = TSConvergedReasons_Shifted + 4;

 18: /*@C
 19:   TSCreate - This function creates an empty timestepper. The problem type can then be set with TSSetProblemType() and the
 20:        type of solver can then be set with TSSetType().

 22:   Collective

 24:   Input Parameter:
 25: . comm - The communicator

 27:   Output Parameter:
 28: . ts   - The TS

 30:   Level: beginner

 32:   Developer Notes:
 33:     TS essentially always creates a SNES object even though explicit methods do not use it. This is
 34:                     unfortunate and should be fixed at some point. The flag snes->usessnes indicates if the
 35:                     particular method does use SNES and regulates if the information about the SNES is printed
 36:                     in TSView(). TSSetFromOptions() does call SNESSetFromOptions() which can lead to users being confused
 37:                     by help messages about meaningless SNES options.

 39: .seealso: TSSetType(), TSSetUp(), TSDestroy(), TSSetProblemType()
 40: @*/
 41: PetscErrorCode  TSCreate(MPI_Comm comm, TS *ts)
 42: {
 43:   TS             t;

 46:   *ts = NULL;
 47:   TSInitializePackage();

 49:   PetscHeaderCreate(t, TS_CLASSID, "TS", "Time stepping", "TS", comm, TSDestroy, TSView);

 51:   /* General TS description */
 52:   t->problem_type      = TS_NONLINEAR;
 53:   t->equation_type     = TS_EQ_UNSPECIFIED;

 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;

 63:   t->max_snes_failures = 1;
 64:   t->max_reject        = 10;
 65:   t->errorifstepfailed = PETSC_TRUE;

 67:   t->rhsjacobian.time  = PETSC_MIN_REAL;
 68:   t->rhsjacobian.scale = 1.0;
 69:   t->ijacobian.shift   = 1.0;

 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;

 79:   t->num_rhs_splits     = 0;

 81:   t->axpy_pattern       = UNKNOWN_NONZERO_PATTERN;
 82:   *ts = t;
 83:   return 0;
 84: }