Re: [Libmesh-devel] Tolerance Defaults

2008-09-18 Thread Roy Stogner
Jed Brown wrote: >> On Wed, 17 Sep 2008, Derek Gaston wrote: >>> Another problem is with setting command-line options... I'm calling >>> KSPSetTolerances and SNESSetTolerances now... using the values >>> specified in the equation systems parameters. It appears that those >>> values override any co

Re: [Libmesh-devel] Tolerance Defaults

2008-09-18 Thread Jed Brown
On Thu 2008-09-18 07:57, Derek Gaston wrote: > From a research perspective you are absolutely right. What you probably > aren't considering is that some people (e.g. me) are trying to build > commercial / production codes on top of libMesh / PetsC and from that > standpoint you want to have

Re: [Libmesh-devel] Tolerance Defaults

2008-09-18 Thread Derek Gaston
On Sep 17, 2008, at 3:39 PM, Roy Stogner wrote: > Yeah, oxymorons don't quite pass my "non-confusing" criterion. ;-) > > "nonlinear solver initial linear tolerance", > "nonlinear solver linear maximum iterations"? > > Still confusing, and I'm open to better ideas, but at least this way > the cont

Re: [Libmesh-devel] Tolerance Defaults

2008-09-18 Thread Derek Gaston
On Sep 18, 2008, at 2:33 AM, Jed Brown wrote: >> Exactly. > > Motivation to use Eisenstat-Walker? Indeed - I used this option yesterday and it worked well for several of our problems. > If you set these *before* you call SNESSetFromOptions() then the > command > line options will be used if

Re: [Libmesh-devel] Tolerance Defaults

2008-09-18 Thread Jed Brown
On Wed 2008-09-17 16:10, Roy Stogner wrote: > > On Wed, 17 Sep 2008, Derek Gaston wrote: > > > This causes some trouble during non-linear solves as you end up > > _way_ over solving the initial non-linear steps > > Exactly. Motivation to use Eisenstat-Walker? > > Another problem is with settin

Re: [Libmesh-devel] Tolerance Defaults

2008-09-17 Thread Roy Stogner
On Wed, 17 Sep 2008, Derek Gaston wrote: > On Sep 17, 2008, at 3:10 PM, Roy Stogner wrote: >> I'm not sure how to rename things to reflect that in a non-confusing >> way, though. > "nonlinear linear solver tolerance" > "nonlinear linear solver maximum iterations" > etc... Yeah, oxymorons don'

Re: [Libmesh-devel] Tolerance Defaults

2008-09-17 Thread Derek Gaston
On Sep 17, 2008, at 3:10 PM, Roy Stogner wrote: >> (which in our case actually leads to non-convergence in some cases). > > Really? Then they're doing it wrong. Well... it doesn't lead to divergence... it's just that we have some highly non-linear problems that if you oversolve the first couple

Re: [Libmesh-devel] Tolerance Defaults

2008-09-17 Thread Roy Stogner
On Wed, 17 Sep 2008, Derek Gaston wrote: > It looks like for the linear solver tolerances there are defaults > specified in equation_systems.C. Similarly I have defined defaults > for all the non-linear tolerances. The trouble is that TOLERANCE * > TOLERANCE for "linear solve tolerance" is quit