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# KSP_CONVERGED_ATOL
norm(r) <= atol 

See `KSPNormType` and `KSPSetNormType()` for possible norms that may be used. By default
for left preconditioning it is the 2-norm of the preconditioned residual, and the
2-norm of the residual for right preconditioning

See also `KSP_CONVERGED_RTOL` which may apply before this tolerance.


## See Also
 [](ch_ksp), `KSPNormType`, `KSP_CONVERGED_RTOL`, `KSP_DIVERGED_DTOL`, `KSPSolve()`, `KSPGetConvergedReason()`, `KSPConvergedReason`, `KSPSetTolerances()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/include/petscksp.h.html#KSP_CONVERGED_ATOL">include/petscksp.h</A>


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