# TSGetIFunction
Returns the vector where the implicit residual is stored and the function/context to compute it. 
## Synopsis
```
#include "petscts.h"  
PetscErrorCode TSGetIFunction(TS ts, Vec *r, TSIFunction *func, void **ctx)
```
Not Collective


## Input Parameter

- ***ts -*** the `TS` context



## Output Parameters

- ***r -*** vector to hold residual (or NULL)
- ***func -*** the function to compute residual (or NULL)
- ***ctx -*** the function context (or NULL)





## See Also
 [](chapter_ts), `TS`, `TSSetIFunction()`, `SNESGetFunction()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/interface/ts.c.html#TSGetIFunction">src/ts/interface/ts.c</A>


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[Index of all TS routines](index.md)  
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