[Trilinos-Users] ML options unused

Salinger, Andrew agsalin at sandia.gov
Wed Jul 1 10:50:03 MDT 2009

Hi Nico,

I think what is happening is that the ParameterList is being
printed out at the beginning of the run, where the ML parameters
have not yet been accessed. I expect that if you print out the
parameter list again at the end, they will no longer be "unused".
There is not a centralized parser that reads all the options at
the beginning.

I'm glad you're making progress with Trilinos. If you have
some good success, forward us a Figure so we can see what
you have been able to do.


-----Original Message-----
From: trilinos-users-bounces at software.sandia.gov [mailto:trilinos-users-bounces at software.sandia.gov] On Behalf Of Nico Schlömer
Sent: Wednesday, July 01, 2009 6:09 AM
To: trilinos-users at software.sandia.gov
Subject: [Trilinos-Users] ML options unused


now here's once more strange behavior in the latest Trilinos:

We're using the ML preconditioner here within NOX (but I guess it shouldn't make a bit difference where it's used), and tell ML to do something like

============== *snip* ==============
 lsParams.set("Preconditioner", "ML");
  Teuchos::ParameterList& MLParams = lsParams.sublist("ML");
  MLParams.set("ML output"                    , 10 );
  MLParams.set("smoother: sweeps"             , 0 );
  MLParams.set("coarse: max size"             , 70000);
  MLParams.set("coarse: type"             , "Amesos-KLU");
============== *snip* ==============

>From what the output of a run suggests

============== *snip* ==============
         coarse: max size = 70000   [unused]
         aggregation: smoothing sweeps = 0   [unused]
         coarse: max size = 70000   [unused]
         coarse: type = Amesos-KLU   [unused]
         smoother: sweeps = 0   [unused]
============== *snap* ==============

you'd think that you misspelled the option keys or something like that, at least that the options aren't used. When looking at ML's output (generated by setting "ML output" to 10), what you can see is

============== *snip* ==============
** Leaving column map of Main linear system matrix unchanged [...] Max coarse size = 70000 [...] Amesos (level 0) : Building KLU [...] ============== *snap* ==============

Now, what, are they used or not?


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