PCAIRSetRDrop

Sets the relative drop tolerance applied to R by PCAIR on each level after it is built

Synopsis

PETSC_EXTERN PetscErrorCode PCAIRSetRDrop(PC pc, PetscReal input_real)

Logically Collective

Input Parameters

• pc - the PCAIR preconditioner context

• input_real - the relative (inf norm) drop tolerance applied to R

Options Database Key

• -pc_air_r_drop input_real - drop tolerance for R; defaults to 0.01

Note

After R is built on each level, entries smaller than this relative (infinity-norm) tolerance are dropped, sparsifying R to reduce memory and cycle cost; a larger tolerance drops more and gives cheaper but less accurate grid-transfer operators. Set to 0 to disable dropping.

See Also

KSP: Linear System Solvers, PCAIR, PCAIRGetRDrop(), PCAIRSetADrop()

Level

advanced

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