PCVPBJACOBI#
Variable size point block Jacobi preconditioner
Notes#
See PCJACOBI for point Jacobi preconditioning, PCPBJACOBI for fixed point block size, and PCBJACOBI for large size blocks
This works for MATAIJ matrices
Uses dense LU factorization with partial pivoting to invert the blocks; if a zero pivot is detected a PETSc error is generated.
One must call MatSetVariableBlockSizes() to use this preconditioner
Developer Notes#
This should support the PCSetErrorIfFailure() flag set to PETSC_TRUE to allow
the factorization to continue even after a zero pivot is found resulting in a Nan and hence
terminating KSP with a KSP_DIVERGED_NANORINF allowing
a nonlinear solver/ODE integrator to recover without stopping the program as currently happens.
Perhaps should provide an option that allows generation of a valid preconditioner
even if a block is singular as the PCJACOBI does.
See Also#
MatSetVariableBlockSizes(), PCCreate(), PCSetType(), PCType, PC, PCJACOBI, PCPBJACOBI, PCBJACOBI
Level#
beginner
Location#
src/ksp/pc/impls/vpbjacobi/vpbjacobi.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages