petsc-3.6.2 2015-10-02
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# KSPCGS

This code implements the CGS (Conjugate Gradient Squared) method.

### Options Database Keys

see KSPSolve() -

References: Sonneveld, 1989.

Notes: Does not require a symmetric matrix. Does not apply transpose of the matrix. Supports left and right preconditioning, but not symmetric.

Developer Notes: Has this weird support for doing the convergence test with the natural norm, I assume this works only with no preconditioning and symmetric positive definite operator.

### See Also

KSPCreate(), KSPSetType(), KSPType (for list of available types), KSP, KSPBCGS, KSPSetPCSide()

Level:beginner
Location:src/ksp/ksp/impls/cgs/cgs.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages