Add -pc_fieldsplit_block_size 2 See example petsc/src/snes/examples/tutorials/ex19.c: ./ex19 -snes_monitor_short -ksp_monitor_short -pc_type fieldsplit -pc_fieldsplit_block_size 2 -pc_fieldsplit_0_fields 0,1 -pc_fieldsplit_1_fields 0,1 -pc_fieldsplit_type multiplicative -snes_view -fieldsplit_pc_type lu -da_refine 1 -ksp_type fgmres
(see runex19_8 in petsc/src/snes/examples/tutorials/makefile) Hong On Fri, Dec 27, 2013 at 9:25 PM, subramanya sadasiva <[email protected]>wrote: > Hi, > I have a nonlinear system with 6 variables grouped in two sets of 3. I am > trying to get a fieldsplit preconditioner working . I have the following > options set up > > -pc_type fieldsplit > -pc_fieldsplit_type multiplicative > -fieldsplit_0_fields 0,2,4 > -fieldsplit_1_fields 1,3,5 > -fieldsplit_0_ksp cg > -fieldsplit_1_ksp cg > -fieldsplit_0_pc hypre > -fieldsplit_1_pc hypre > > However, I get the following error. My installation of libmesh has block > matrices disabled, which I've seen to cause problems with fieldsplit. Any > ideas what might cause this error? > Thanks, > Subramanya > > > > [0]PETSC ERROR: --------------------- Error Message > ------------------------------------ > [0]PETSC ERROR: Petsc has generated inconsistent data! > [0]PETSC ERROR: Unhandled case, must have at least two fields, not 1! > [0]PETSC ERROR: > ------------------------------------------------------------------------ > [0]PETSC ERROR: Petsc Release Version 3.4.3, unknown > [0]PETSC ERROR: See docs/changes/index.html for recent updates. > [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting. > [0]PETSC ERROR: See docs/index.html for manual pages. > >
