On Wed, Jul 16, 2014 at 4:40 PM, Sun, Hui <[email protected]> wrote: > Thank you Matt. I've corrected it to > > ./ex70 -nx 32 -ny 48 -fieldsplit_1_pc_type jacobi > > > However the output is still: > > > residual u = 2.6315e-05 > > residual p = 0.000229872 > > residual [u,p] = 0.000231373 > > discretization error u = 0.00633503 > > discretization error p = 0.121534 > > discretization error [u,p] = 0.121699 > > WARNING! There are options you set that were not used! > > WARNING! could be spelling mistake, etc! > > Option left: name:-fieldsplit_1_pc_type value: jacobi > > > If I type > > > ./ex70 -help | grep fieldsplit_1_ > > > the output is that nothing coming out. >
That seems to show that you are not using PCFIELDSPLIT at all. Are you? You can check using -ksp_view Matt > > ------------------------------ > *From:* Matthew Knepley [[email protected]] > *Sent:* Wednesday, July 16, 2014 2:32 PM > > *To:* Sun, Hui > *Cc:* [email protected] > *Subject:* Re: [petsc-users] why a certain option cannot be used > > On Wed, Jul 16, 2014 at 4:25 PM, Matthew Knepley <[email protected]> > wrote: > >> On Wed, Jul 16, 2014 at 4:22 PM, Sun, Hui <[email protected]> wrote: >> >>> Thank you Matt for answering, however even with that I don't think it >>> works. For example, the command >>> >>> ./ex70 -nx 32 -ny 48 -fieldsplit_1_type jacobi >>> >> >> You have mistyped. Look carefully at my last message: >> >> -fieldsplit_1_pc_type jacobi >> > > I also want to note that you can see all the available options with > -help. It does produce > a lot of output, but you can segregate it by prefix ("fieldsplit_1_"). You > can also see the > prefix of each solver component using -ksp_view. > > Matt > > >> Matt >> >> >>> gives me the following output >>> >>> >>> residual u = 2.6315e-05 >>> >>> residual p = 0.000229872 >>> >>> residual [u,p] = 0.000231373 >>> >>> discretization error u = 0.00633503 >>> >>> discretization error p = 0.121534 >>> >>> discretization error [u,p] = 0.121699 >>> >>> WARNING! There are options you set that were not used! >>> >>> WARNING! could be spelling mistake, etc! >>> >>> Option left: name:-fieldsplit_1_type value: jacobi >>> >>> >>> Furthermore, if I look into the possible options with keyword >>> fieldsplit involved by the command: >>> >>> >>> ./ex70 -help | grep -A5 fieldsplit >>> >>> >>> I get this output: >>> >>> >>> eisenstat ilu icc cholesky asm gasm ksp composite redundant nn mat >>> fieldsplit galerkin exotic hmpi asa cp lsc redistribute svd gamg tfs >>> (PCSetType) >>> >>> -pc_use_amat: <FALSE> use Amat (instead of Pmat) to define >>> preconditioner in nested inner solves (PCSetUseAmat) >>> >>> Krylov Method (KSP) options >>> ------------------------------------------------- >>> >>> -ksp_type <gmres>: Krylov method (one of) cg groppcg pipecg cgne nash >>> stcg gltr richardson >>> >>> chebyshev gmres tcqmr bcgs ibcgs fbcgs fbcgsr bcgsl cgs tfqmr cr >>> pipecr lsqr preonly qcg bicg fgmres minres symmlq lgmres lcd gcr pgmres >>> specest dgmres (KSPSetType) >>> >>> -ksp_max_it <10000>: Maximum number of iterations (KSPSetTolerances) >>> >>> >>> So I don't see any option that's similar to -fieldsplit_1_type. >>> >>> >>> Hui >>> >>> >>> >>> ------------------------------ >>> *From:* Matthew Knepley [[email protected]] >>> *Sent:* Wednesday, July 16, 2014 2:16 PM >>> *To:* Sun, Hui >>> *Cc:* [email protected] >>> *Subject:* Re: [petsc-users] why a certain option cannot be used >>> >>> On Wed, Jul 16, 2014 at 4:09 PM, Sun, Hui <[email protected]> wrote: >>> >>>> I want to solve Stokes equation using user defined schur complement >>>> preconditioner. So I'm reading and testing snes/examples/tutorial/ex55.c, >>>> and ex70.c. In these examples, there are comments about the usage, for >>>> example: >>>> >>>> mpiexec -n 2 ./stokes -nx 32 -ny 48 -fieldsplit_1_user_pc. >>>> >>>> However the option -fieldsplit_1_user_pc is not recognized by the >>>> executable. The output of the above command is: >>>> >>> >>> This ("user_pc") is just a mnemonic. What it means is that you can use >>> any PC in this slot. What he should have written is >>> >>> -fieldsplit_1_pc_type <user pc> >>> >>> Thanks, >>> >>> Matt >>> >>> >>>> residual u = 2.6315e-05 >>>> >>>> residual p = 0.000229872 >>>> >>>> residual [u,p] = 0.000231373 >>>> >>>> discretization error u = 0.00633503 >>>> >>>> discretization error p = 0.121534 >>>> >>>> discretization error [u,p] = 0.121699 >>>> >>>> WARNING! There are options you set that were not used! >>>> >>>> WARNING! could be spelling mistake, etc! >>>> >>>> Option left: name:-fieldsplit_1_user_pc (no value) >>>> >>>> >>>> I'm wondering what's going on. Is that because I need some specific >>>> options during my configuring of the package? By the way, the version of >>>> PETSc I'm using is 3.4.4. >>>> >>>> >>>> Best, >>>> >>>> Hui >>>> >>> >>> >>> >>> -- >>> What most experimenters take for granted before they begin their >>> experiments is infinitely more interesting than any results to which their >>> experiments lead. >>> -- Norbert Wiener >>> >> >> >> >> -- >> What most experimenters take for granted before they begin their >> experiments is infinitely more interesting than any results to which their >> experiments lead. >> -- Norbert Wiener >> > > > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
