KSPEKSMSetHapTol#

Sets the tolerance for detecting a happy breakdown in EKSM.

Synopsis#

#include "petscksp.h" 
PetscErrorCode KSPEKSMSetHapTol(KSP ksp, PetscReal tol)

Logically Collective

Input Parameters#

  • ksp - the Krylov space solver context

  • tol - the tolerance for detecting a happy breakdown

Options Database Key#

  • -ksp_eksm_haptol tol - set tolerance for determining happy breakdown

Notes#

Happy breakdown is the rare case in KSPEKSM where a very near zero matrix entry is generated in the upper Hessenberg matrix indicating an ‘exact’ solution has been obtained.

The default tolerance value for detecting a happy breakdown with EKSM in PETSc is 1.0e-30.

See Also#

KSP: Linear System Solvers, KSPEKSM, KSPSetTolerances(), KSPGMRESSetHapTol()

Level#

intermediate

Location#

src/ksp/ksp/impls/eksm/eksm.c

Implementations#

KSPEKSMSetHapTol_EKSM() in src/ksp/ksp/impls/eksm/eksm.c


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