PCASMType#

Determines the type of additive Schwarz method, PCASM, to use

Synopsis#

typedef enum {
  PC_ASM_NONE,
  PC_ASM_RESTRICT,
  PC_ASM_INTERPOLATE,
  PC_ASM_BASIC,
  PC_ASM_WEIGHTED
} PCASMType;

Values#

PC_ASM_NONE - Residuals from ghost points are not used, computed ghost values are discarded. Not very good.
PC_ASM_RESTRICT - Residuals from ghost points are used but computed values in ghost region are discarded [CS99]. Default.
PC_ASM_INTERPOLATE - Residuals from ghost points are not used, computed values in ghost region are added back in.
PC_ASM_BASIC - Symmetric version where residuals from the ghost points are used and computed values in ghost regions are added together. Classical standard additive Schwarz as introduced in [DW87].
PC_ASM_WEIGHTED - Full restriction and interpolation, with local corrections scaled by user-provided diagonal weights from PCASMWeightedSetScaling().

References#

[CS99]

X.-C. Cai and M. Sarkis. A restricted additive Schwarz preconditioner for general sparse linear systems. SIAM J. Scientific Computing, 21:792–797, 1999.

[DW87]

Maksymilian Dryja and Olof Widlund. An additive variant of the Schwarz alternating method for the case of many subregions. Ultracomputer Research Laboratory, Univ., Courant Inst. of Mathematical …, 1987.

Level#

beginner

Location#

include/petscpctypes.h

Examples#

src/ksp/ksp/tutorials/ex8.c
src/ksp/pc/tests/ex13.c
src/ksp/pc/tests/ex13f.F90

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