On Fri, Sep 10, 2010 at 2:00 PM, Ian Hinder ian.hinder@aei.mpg.de wrote:
On 10 Sep 2010, at 20:49, Roland Haas wrote:
Hello all,
When the Multipole thorn was first written at Penn State for debugging, we were using it with WeylScal4 and to avoid incompatibilities with early parameter files, when the "variables" parameter was added we decided that if it was left blank, it would default to the WeylScal4 Psi4 variable. This is not a good logical default, as the thorn provides generic mode decomposition. I would like to remove this, and the patch is attached. OK to commit?
Would it be possible to make the default for the parameter "variables" to be "WeylScal4::Psi4r{sw=-2 cmplx='WeylScal4::Psi4i' name='psi4'}"? I would expect that for most (vacuum) runs done with the code in the Einstein Toolkit one would decompose Psi4 so this default would make sense. Also it would keep the thorn backwards compatible :-)
Sorry - I only saw this message after committing the patch. What you are asking for, as far as I can tell, is the behaviour that was implemented. It has been printing the following warning for 3 years:
WARNING: No Multipole::variables string has been specified. For compatibility, the current default is to use "WeylScal4::Psi4r{sw=-2 cmplx='WeylScal4::Psi4i' name='psi4'}" but in future, this default will change to "". Please update your parameter files to include this new parameter.
so I think you have had enough time to update parameter files :)
I don't think Roland suggested to have this "silent default" where the thorn checks for an empty parameter value. I think Roland suggested to set this as the default value for the parameter, using the standard Cactus mechanism for this.
Roland, this is a good idea.
-erik