[kepler-users] System Dynamics Actor?

Matthew Jones jones at nceas.ucsb.edu
Thu Jan 31 22:59:46 PST 2008


I think ecologists would use that sort of thing a lot.  They like stella 
for its simplicity as a model prototyping tool, even when they end up 
implementing the models for their final runs in a different system. 
I've even seen Stella used as a front end in the Spatial Modeling 
Environment (SME) for building stock-flow models that are then run 
through a code-generator to produce executables that are run on high-end 
parallel supercomputers (see [1]).  We don't have the resources right 
now to tackle this project, but I think it would indeed be valuable.

Matt

[1] http://www.uvm.edu/giee/SME3/

Edward A. Lee wrote:
> It does sound like it would be an interesting project to build
> some Stocks and Flows actors, a-la Stella... The underlying ODE
> solver of the CT or Continuous domains would be leveraged...
> 
> Anyone interested in doing that?
> 
> Edward
> 
> At 02:06 PM 1/31/2008, Timothy McPhillips wrote:
>> Hi Louis,
>>
>> As Edward mentioned, the continuous time domain can be used to model  
>> dynamic systems of the sort I think you are talking about.  However,  
>> these models aren't quite as easy to build or understand as STELLA  
>> models, say.  A few years ago I spent a few days trying to emulate  
>> STELLA's capabilities (i.e, modeling dynamic systems in terms of  
>> stocks and flows) in Kepler, but the results weren't as clean as  
>> STELLA models for a number of reasons, most especially because the  
>> stocks and flows were not distinct actors.  I, too, would like to see  
>> such support in Kepler, along with capabilities for easily running  
>> these models multiple times in a parameter sweep or search,  
>> summarizing the results of multiple runs of the model, etc.
>>
>> Cheers,
>>
>> Tim
>>
>> On Jan 31, 2008, at 11:50 AM, Louis Macovsky wrote:
>>
>>> Hi,
>>>
>>> Is there any work being done to add a system dynamics Actor?
>>>
>>> I have raised this question about 1.5 yrs ago but I am still hoping  
>>> to hear
>>> that it is someone's project using for example BerkeleyMadonna
>>> http://www.berkeleymadonna.com/ and maybe the more suitable  
>>> JMadonna which
>>> is in development.  I point out JMadonna because I "assume" that its
>>> development would be accessible to Ptolemy and Keppler developers.
>>>
>>> There is an open source SD application that is a relatively new  
>>> addition to
>>> NetLogo.  Could it be a candidate around which an Actor could be  
>>> developed?
>>>
>>> In addition to BerkeleyMadonna, I use STELLA http:// www.iseesystems.com/ and
>>> Vensim http://www.vensim.com/ .  I have not used Simile
>>> http://simulistics.com/ but for a commercial SD package it may be a
>>> candidate to work around.  There are other SD programs but I have  
>>> not used
>>> them.
>>>
>>> I am not a programmer, so I do not have the answers and perhaps I  
>>> am not
>>> even posing the right question(s).
>>>
>>> Thanks,
>>> Louis
>>>
>>>
>>> _______________________________________________
>>> Kepler-users mailing list
>>> Kepler-users at ecoinformatics.org
>>> http://mercury.nceas.ucsb.edu/ecoinformatics/mailman/listinfo/ kepler-users
>>
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>>
> 
> ------------ 
> 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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-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Matthew B. Jones
Director of Informatics Research and Development
National Center for Ecological Analysis and Synthesis (NCEAS)
UC Santa Barbara
jones at nceas.ucsb.edu                       Ph: 1-907-523-1960
http://www.nceas.ucsb.edu/ecoinfo
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



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