:orphan:
# SNESSolve
Solves a nonlinear system F(x) = b. Call `SNESSolve()` after calling `SNESCreate()` and optional routines of the form `SNESSetXXX()`. 
## Synopsis
```
#include "petscsnes.h"  
PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
```
Collective


## Input Parameters

- ***snes -*** the `SNES` context
- ***b -*** the constant part of the equation F(x) = b, or `NULL` to use zero.
- ***x -*** the solution vector.





## Note
The user should initialize the vector,x, with the initial guess
for the nonlinear solve prior to calling `SNESSolve()`.  In particular,
to employ an initial guess of zero, the user should explicitly set
this vector to zero by calling `VecSet()`.


## See Also
 [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
`SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
`SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/interface/snes.c.html#SNESSolve">src/snes/interface/snes.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex1.c.html">src/snes/tutorials/ex1.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex12.c.html">src/snes/tutorials/ex12.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex13.c.html">src/snes/tutorials/ex13.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex14.c.html">src/snes/tutorials/ex14.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex15.c.html">src/snes/tutorials/ex15.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex16.c.html">src/snes/tutorials/ex16.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex17.c.html">src/snes/tutorials/ex17.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex18.c.html">src/snes/tutorials/ex18.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex19.c.html">src/snes/tutorials/ex19.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex1f.F90.html">src/snes/tutorials/ex1f.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex2.c.html">src/snes/tutorials/ex2.c</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/composite/snescomposite.c.html#SNESSolve_Composite">SNESSolve_Composite in src/snes/impls/composite/snescomposite.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/fas/fas.c.html#SNESSolve_FAS">SNESSolve_FAS in src/snes/impls/fas/fas.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/gs/snesgs.c.html#SNESSolve_NGS">SNESSolve_NGS in src/snes/impls/gs/snesgs.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ksponly/ksponly.c.html#SNESSolve_KSPONLY">SNESSolve_KSPONLY in src/snes/impls/ksponly/ksponly.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ls/ls.c.html#SNESSolve_NEWTONLS">SNESSolve_NEWTONLS in src/snes/impls/ls/ls.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ms/ms.c.html#SNESSolve_MS">SNESSolve_MS in src/snes/impls/ms/ms.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/multiblock/multiblock.c.html#SNESSolve_Multiblock">SNESSolve_Multiblock in src/snes/impls/multiblock/multiblock.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/nasm/nasm.c.html#SNESSolve_NASM">SNESSolve_NASM in src/snes/impls/nasm/nasm.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ncg/snesncg.c.html#SNESSolve_NCG">SNESSolve_NCG in src/snes/impls/ncg/snesncg.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ngmres/anderson.c.html#SNESSolve_Anderson">SNESSolve_Anderson in src/snes/impls/ngmres/anderson.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ngmres/snesngmres.c.html#SNESSolve_NGMRES">SNESSolve_NGMRES in src/snes/impls/ngmres/snesngmres.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/ntrdc/ntrdc.c.html#SNESSolve_NEWTONTRDC">SNESSolve_NEWTONTRDC in src/snes/impls/ntrdc/ntrdc.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/patch/snespatch.c.html#SNESSolve_Patch">SNESSolve_Patch in src/snes/impls/patch/snespatch.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/qn/qn.c.html#SNESSolve_QN">SNESSolve_QN in src/snes/impls/qn/qn.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/richardson/snesrichardson.c.html#SNESSolve_NRichardson">SNESSolve_NRichardson in src/snes/impls/richardson/snesrichardson.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/shell/snesshell.c.html#SNESSolve_Shell">SNESSolve_Shell in src/snes/impls/shell/snesshell.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/tr/tr.c.html#SNESSolve_NEWTONTR">SNESSolve_NEWTONTR in src/snes/impls/tr/tr.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/vi/rs/virs.c.html#SNESSolve_VINEWTONRSLS">SNESSolve_VINEWTONRSLS in src/snes/impls/vi/rs/virs.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/impls/vi/ss/viss.c.html#SNESSolve_VINEWTONSSLS">SNESSolve_VINEWTONSSLS in src/snes/impls/vi/ss/viss.c</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/snes/interface/snes.c)


[Index of all SNES routines](index.md)  
[Table of Contents for all manual pages](/manualpages/index.md)  
[Index of all manual pages](/manualpages/singleindex.md)