petsc-3.13.6 2020-09-29
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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/tutorials/ex1.c.html
src/ksp/pc/tutorials/ex2.c.html

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