:orphan:
# TSPseudoSetVerifyTimeStep
Sets a user-defined routine to verify the quality of the last timestep.
## Synopsis
```
#include "petscts.h"
PetscErrorCode TSPseudoSetVerifyTimeStep(TS ts, PetscErrorCode (*dt)(TS, Vec, void *, PetscReal *, PetscBool *), void *ctx)
```
Logically Collective
## Input Parameters
- ***ts -*** timestep context
- ***dt -*** user-defined function to verify timestep
- ***ctx -*** [optional] user-defined context for private data for the timestep verification routine (may be `NULL`)
## Calling sequence of `func`
```none
PetscErrorCode func(TS ts, Vec update, void *ctx, PetscReal *newdt, PetscBool *flag);
```
- ***ts -*** the time-step context
- ***update -*** latest solution vector
- ***ctx -*** [optional] timestep context
- ***newdt -*** the timestep to use for the next step
- ***flag -*** flag indicating whether the last time step was acceptable
## Note
The routine set here will be called by `TSPseudoVerifyTimeStep()`
during the timestepping process.
## See Also
[](ch_ts), `TSPSEUDO`, `TSPseudoVerifyTimeStepDefault()`, `TSPseudoVerifyTimeStep()`
## Level
advanced
## Location
src/ts/impls/pseudo/posindep.c
## Implementations
TSPseudoSetVerifyTimeStep_Pseudo in src/ts/impls/pseudo/posindep.c
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