TSSetEventHandler#

Sets a function used for detecting events

Synopsis#

#include "petscts.h" 
PetscErrorCode TSSetEventHandler(TS ts, PetscInt nevents, PetscInt direction[], PetscBool terminate[], PetscErrorCode (*eventhandler)(TS ts, PetscReal t, Vec U, PetscScalar fvalue[], void *ctx), PetscErrorCode (*postevent)(TS ts, PetscInt nevents_zero, PetscInt events_zero[], PetscReal t, Vec U, PetscBool forwardsolve, void *ctx), void *ctx)

Logically Collective

Input Parameters#

  • ts - the TS context obtained from TSCreate()

  • nevents - number of local events

  • direction - direction of zero crossing to be detected. -1 => Zero crossing in negative direction, 0.1 => Zero crossing in positive direction, 0 => both ways (one for each event)

  • terminate - flag to indicate whether time stepping should be terminated after event is detected (one for each event)

  • eventhandler - a change in sign of this function (see direction) is used to determine an even has occurred

  • postevent - [optional] post-event function, this function can change properties of the solution, ODE etc at the time of the event

  • ctx - [optional] user-defined context for private data for the event detector and post event routine (use NULL if no context is desired)

Calling sequence of eventhandler#

  • ts - the TS context

  • t - current time

  • U - current iterate

  • fvalue - function value of events at time t

  • ctx - [optional] context passed with eventhandler

Calling sequence of postevent#

  • ts - the TS context

  • nevents_zero - number of local events whose event function has been marked as crossing 0

  • events_zero - indices of local events which have been marked as crossing 0

  • t - current time

  • U - current solution

  • forwardsolve - Flag to indicate whether TS is doing a forward solve (1) or adjoint solve (0)

  • ctx - the context passed with eventhandler

Note#

The eventhandler is actually the event detector function and the postevent function actually handles the desired changes that should take place at the time of the event

See Also#

TS: Scalable ODE and DAE Solvers, TSEvent, TSCreate(), TSSetTimeStep(), TSSetConvergedReason()

Level#

intermediate

Location#

src/ts/event/tsevent.c

Examples#

src/ts/tutorials/ex44.c
src/ts/tutorials/ex40.c
src/ts/tutorials/ex41.c

Index of all TS routines
Table of Contents for all manual pages
Index of all manual pages