petsc-3.14.5 2021-03-03
Report Typos and Errors

# PCGALERKIN

Build (part of) a preconditioner by P S R (where P is often R^T)

      Use PCGalerkinSetRestriction(pc,R) and/or PCGalerkinSetInterpolation(pc,P) followed by

      PCGalerkinGetKSP(pc,&ksp); KSPSetOperators(ksp,A,....)

Developer Note: If KSPSetOperators() has not been called on the inner KSP then PCGALERKIN could use MatRARt() or MatPtAP() to compute the operators automatically. Should there be a prefix for the inner KSP. There is no KSPSetFromOptions_Galerkin() that calls KSPSetFromOptions() on the inner KSP

### See Also

PCCreate(), PCSetType(), PCType (for list of available types), PC,
PCSHELL, PCKSP, PCGalerkinSetRestriction(), PCGalerkinSetInterpolation(), PCGalerkinGetKSP()

### Level

intermediate

### Location

src/ksp/pc/impls/galerkin/galerkin.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages