[kepler-dev] Kepler parameters

Edward A. Lee eal at eecs.berkeley.edu
Thu May 29 09:51:04 PDT 2008


Parameters appear in the MoML file only if they are overridden.
Actually, this is true not only of parameters, but actually of everything.
If you define a composite actor class, and then have several instances of
it, the contents of the instances do not appear in the MoML file unless
they are overridden.

There are two reasons for doing this:
 - It is more object-oriented (i.e., inheritance actually works)
 - MoML files are _much_ smaller than they would be.

There is a paper describe the (rather deep) mechanism behind this:


It would be easy to create a utility that describes (in MoML or any
other language) the full interface of an actor. In fact, the Documentation
utility does this...


At 08:13 AM 5/29/2008, Paul Allen wrote:
>Could somebody clarify something about actor parameters/properties for me?
>It appears to me that just by looking at a MOML file I can't figure out 
>the entire set of parameters/properties that can be set for an actor. 
>E.g., I look at the "Timed Plotter" actor in the 
>02-LotkaVolterraPredatorPrey.xml example workflow. The "Timed Plotter" 
>shows a "legend" parameter that can be set, but the MOML file doesn't 
>mention it. It's not until I dynamically ingest/parse the MOML file, or 
>manually look at the Java implementation of the actor that I get a clue 
>that the "legend" parameter is available. So, in general, I've got to 
>examine Java code or load/parse the actor/workflow in order to see the 
>entire list of settable parameters for an actor. Is that true?
>I assume that is true. That leads me to wonder what determines when an 
>actor parameter property is represented in a MOML file. Is it when a 
>parameter has a definite value? How are defaults handled? Will a 
>parameter with a non-null default value always appear in the MOML file? 
>The "legend" parameter of the ptolemy.actor.lib.gui.TimedPlotter actor 
>certainly shows that when there is no default and no value set, the 
>parameter isn't mentioned in the MOML file.
>Thanks for the info.
>- Paul
>Kepler-dev mailing list
>Kepler-dev at ecoinformatics.org

Edward A. Lee
Chair of EECS and Robert S. Pepper Distinguished Professor
231 Cory Hall, UC Berkeley, Berkeley, CA 94720-1770
phone: 510-642-0253, fax: 510-642-2845
eal at eecs.Berkeley.EDU, http://www.eecs.berkeley.edu/Faculty/Homepages/lee.html  

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