On 7/6/06, Matt Funk <mafunk at nmsu.edu> wrote: > > Hi, > > In the html web manual for PETSc: > > KSPCG is described as the preconditioned conjugate gradient iterative > method > with: The PCG method requires both the matrix and preconditioner to be > symmetric positive (semi) definite. > > For KSPCG do you need to specify a preconditioner type ie: Jacobi or is > there > a default the KSPCG uses.
The default on 1 proc is ILU, and many is Block Jacobi. Reason for question is that for the system I am solving I need to specify > -pc_type none for KSPCG to run. If I do not turn the PC off then the > solver > does not run. Other KSP types like BiCG and GMRES work fine when I > specify a > PC. I have no idea what "deos not run" means. CG should work with any preconditioner that applies an SPD matrix. Matt -- "Failure has a thousand explanations. Success doesn't need one" -- Sir Alec Guiness -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20060706/e5115ba0/attachment.htm>
