Barry, There are two sets of output for both virs and viss. Slow convergence aside I can't see why line search fails after we hit lower bound at some nodes? I tried quadratic and cubic line search both and got the same result.
Best, Ata On Jan 26, 2012, at 9:07 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > Don't even touch VISS, focus on RS. What solver did you use in the run you > sent the output for? > > * If SS please rerun (with -snes_monitor) with RS and send the output > again. > > * If RS then it is very puzzling that you get that slow convergence since > the number of active constraints does not change so it should converge just > like plain old Newton. > > Barry > > > > On Jan 25, 2012, at 8:55 AM, Ataollah Mesgarnejad wrote: > >> Barry, >> >> Here is my output from my program with petsc-dev (txt files attached). Even >> with petsc-dev (revision 21929), SNES (I tried VISS and VIRS) takes a long >> time to converge (>50 iterations) from a small problem (99 HEX20 elements, >> 681 DOFs for SNES). The exodusII output files are uploaded in the link; I >> attached pictures of last time step for Psi field which we solve with SNESVI >> and u field which the displacement in the x-direction and is my loading. As >> it was the case with petsc-3.2 line search diverges as soon as we hit the >> lower bound in a neighborhood of nodes. I ran with KSPPREONLY and PCLU to >> exclude possibility of LS failure because of the KSP tol. >> >> Best, >> Ata >> >> link to exodusII files: http://cl.ly/0g431o443v240x1h2h1B >> >> <output-viss.txt><axial-tension-virs-u.png><axial-tension-virs-psi.png><axial-tension-viss-psi.png><axial-tension-viss-u.png><output-virs.txt> >
