petsc-3.9.4 2018-09-11
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KSP_DIVERGED_INDEFINITE_PC

 It appears the preconditioner is indefinite (has both positive and negative eigenvalues) and this Krylov method (KSPCG) requires it to be positive definite

Notes: This can happen with the PCICC preconditioner, use -pc_factor_shift_positive_definite to force the PCICC preconditioner to generate a positive definite preconditioner

See Also

KSPSolve(), KSPGetConvergedReason(), KSPConvergedReason, KSPSetTolerances()

Level

beginner

Location

src/ksp/ksp/guess/../../../../include/petscksp.h

Examples

src/ksp/pc/examples/tutorials/ex1.c.html
src/ksp/pc/examples/tutorials/ex2.c.html

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