[Trilinos-Users] ML

[Jonathan Hu]

Hi Thomas,

    Actually, it means neither.   The (unused) parameter "default 
values" with value "SA" indicates that ML is using the SA default 
values.  That parameter is just a text label and is created at the same 
time the SA defaults are set.  Does this make sense?

Regards,
Jonathan

Thomas George wrote:
> Hi Jonathan,
>
> Thanks for the reply. Does this mean that even though I wanted it to use 
>   the SA parameters, ML has just decided on its own that there were 
> better parameters and ignored my suggestions or is it that my 
> suggestions didn't get transmitted properly? Please let me know. Thanks.
>
> -Thomas
>
>
> Jonathan Hu wrote:
>   
>> Thomas,
>>
>>    This is not an error or bug, simply a warning that certain parameters 
>> were set but not used.  This check is done when the method 
>> MLPrec->PrintUnused(0) is invoked after you've created the ML 
>> preconditioner.
>>
>> Regards,
>> Jonathan
>>
>>
>>     
>>> Today's Topics:
>>>
>>>    1. ML (Thomas George)
>>>
>>>
>>> ----------------------------------------------------------------------
>>>
>>> Message: 1
>>> Date: Mon, 12 Jan 2009 10:16:33 -0600
>>> From: "Thomas George" <tgeorge at cs.tamu.edu>
>>> Subject: [Trilinos-Users] ML
>>> To: Trilinos <Trilinos-Users at software.sandia.gov>
>>> Message-ID: <496B6CE1.6080206 at cs.tamu.edu>
>>> Content-Type: text/plain; charset=iso-8859-1; format=flowed
>>>
>>> Hi,
>>>
>>> I am trying to use ML along with Belos with the default SA or DD 
>>> parameters as described in the user guide. However, I do get the 
>>> following message.  Depending on the default setting I use I get 
>>> different warnings for SA, DD etc. I didn't have a statement to use 
>>> smoother "ifpack list" in my code at all. Is this a bug in my code? I am 
>>> using version 8.03.
>>>
>>> ------------------------------------------------------------------------------
>>> Unused parameters:
>>> WARNING: Parameter "default values" SA   [unused] is unused
>>> WARNING: Parameter "smoother: ifpack list"    [unused] is unused
>>> ------------------------------------------------------------------------------
>>>
>>>
>>>
>>>
>>> The snippet of code that tries to set the default is shown below and the 
>>> call to the preconditioner creation is also shown.
>>>
>>>   Teuchos::ParameterList List;
>>>
>>>     if(PrecType == "SA") {
>>>       cout<< " Setting default SA parameters " << endl ;
>>>       ML_Epetra::SetDefaults("SA",List) ;
>>>       List.set("smoother: type","symmetric Gauss-Seidel");
>>>      } else if(PrecType =="DD") {
>>>       cout<< " Setting default DD parameters " << endl ;
>>>       ML_Epetra::SetDefaults("DD",List) ;
>>>     } else if(PrecType =="DD-ML") {
>>>       cout<< " Setting default DD-ML parameters " << endl ;
>>>       ML_Epetra::SetDefaults("DD-ML",List) ;
>>>     } else {
>>>       cout << "Unknown default parameter setting " << PrecType << endl ;
>>>       MPI_Finalize() ;
>>>       exit (-1) ;
>>>     }
>>>     // overwrite some parameters. Please refer to the user's guide
>>>     // for more information
>>>     // some of the parameters do not differ from their default value,
>>>     // and they are here reported for the sake of clarity
>>>    
>>>     // output level, 0 being silent and 10 verbose
>>>     List.set("output", verbose) ;
>>>     List.set("max levels", maxLevels) ;
>>>     List.set("smoother: sweeps", smoothSweeps) ;
>>>     List.set("coarse: max size", maxCoarseSize) ;
>>>
>>>
>>>     cmembytes1(&mem1);
>>>     start = MPI_Wtime() ;
>>>     RCP<ML_Epetra::MultiLevelPreconditioner> Prec = Teuchos::rcp(new 
>>> ML_Epetra::
>>> MultiLevelPreconditioner(*A, List)) ;
>>>     assert(Prec != Teuchos::null) ;
>>>     // verify unused parameters on process 0 put -1 to print on all
>>>     // processes
>>>     Prec->PrintUnused(0);
>>>    
>>>