PCSPAISetEpsilon#

Set the tolerance for the PCSPAI preconditioner

Synopsis#

#include "petscpc.h" 
PetscErrorCode PCSPAISetEpsilon(PC pc, PetscReal epsilon1)

Input Parameters#

  • pc - the preconditioner

  • epsilon1 - the tolerance (default .4)

Note#

espilon1 must be between 0 and 1. It controls the quality of the approximation of M to the inverse of A. Higher values of epsilon1 lead to more work, more fill, and usually better preconditioners. In many cases the best choice of epsilon1 is the one that divides the total solution time equally between the preconditioner and the solver.

See Also#

KSP: Linear System Solvers, PCSPAI, PCSetType()

Level#

intermediate

Location#

src/ksp/pc/impls/spai/ispai.c

Implementations#

PCSPAISetEpsilon_SPAI() in src/ksp/pc/impls/spai/ispai.c


Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages