petsc-master 2014-10-20
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KSPGetConvergedReason

Gets the reason the KSP iteration was stopped.

Synopsis

#include "petscksp.h" 
PetscErrorCode  KSPGetConvergedReason(KSP ksp,KSPConvergedReason *reason)
Not Collective

Input Parameter

ksp -the KSP context

Output Parameter

reason -negative value indicates diverged, positive value converged, see KSPConvergedReason

Possible values for reason

See also manual page for each reason.

guess: beginner

Notes: Can only be called after the call the KSPSolve() is complete.

Keywords

KSP, nonlinear, set, convergence, test

See Also

KSPSetConvergenceTest(), KSPConvergedDefault(), KSPSetTolerances(), KSPConvergedReason

Level:intermediate
Location:
src/ksp/ksp/interface/iterativ.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages

Examples

src/ksp/pc/examples/tutorials/ex1.c.html
src/ksp/pc/examples/tutorials/ex2.c.html
src/ksp/ksp/examples/tutorials/ex10.c.html
KSP_CONVERGED_RTOL (residual 2- norm decreased by a factor of rtol, from 2-norm of right hand side)
KSP_CONVERGED_ATOL (residual 2- norm less than abstol)
KSP_CONVERGED_ITS (used by the preonly preconditioner that always uses ONE iteration, or when the KSPConvergedSkip() convergence- test routine is set.
KSP_CONVERGED_CG_NEG_CURVE- . KSP_CONVERGED_CG_CONSTRAINED
KSP_CONVERGED_STEP_LENGTH- . KSP_DIVERGED_ITS (required more than its to reach convergence)
KSP_DIVERGED_DTOL (residual norm increased by a factor of divtol)- . KSP_DIVERGED_NANORINF (residual norm became Not-a-number or Inf likely due to 0/0)
KSP_DIVERGED_BREAKDOWN (generic breakdown in method)- - KSP_DIVERGED_BREAKDOWN_BICG (Initial residual is orthogonal to preconditioned initial residual. Try a different preconditioner, or a different initial Level.)