I have used system dynamics programs like STELLA for physiological, pharmacological, and ecotoxicological models/simulations. The pharmacological models in particular are quite robust. Applications with stock and flow diagrams simplify communication with those unfamiliar with the mathematics.
http://www.systemdynamics.org/conferences/2007/proceed/papers/HELAL482.pdf is a recent conference paper that I would like to pass on to you. If you have the time, I would like your reaction to the concept of CT and Discrete hybrid modeling and if this paper's methodology is relavant to your methods or approach to programming for Kepler. Again I am not a programmer. Thanks for the discussion, Louis ----- Original Message ----- From: "Matthew Jones" <[email protected]> To: "Edward A. Lee" <eal at eecs.berkeley.edu> Cc: "Timothy McPhillips" <tmcphillips at mac.com>; "PtolemyMailingList" <ptolemy-hackers at bennett.EECS.Berkeley.EDU>; "[User List] KEPLER-USER" <kepler-users at ecoinformatics.org> Sent: Thursday, January 31, 2008 10:59 PM Subject: Re: [kepler-users] System Dynamics Actor? >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 >>> >>> ---------------------------------------------------------------------------- >>> Posted to the ptolemy-hackers mailing list. Please send administrative >>> mail for this list to: ptolemy-hackers-request at ptolemy.eecs.berkeley.edu >>> >> >> ------------ >> 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 >> _______________________________________________ >> Kepler-users mailing list >> Kepler-users at ecoinformatics.org >> http://mercury.nceas.ucsb.edu/ecoinformatics/mailman/listinfo/kepler-users > > -- > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 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 > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > ---------------------------------------------------------------------------- > Posted to the ptolemy-hackers mailing list. Please send administrative > mail for this list to: ptolemy-hackers-request at ptolemy.eecs.berkeley.edu >
