No worries, I think system dynamics modeling questions are much more
interesting than "Why doesn't Ptolemy II run properly under Windows
3.1?" questions. :-)
I think that there is a great opportunity to move in to other markets
here.
I'll see if I can find some time to look at some of these other
packages.
_Crhistopher
--------
Christopher,
Thanks for the reply. I promise there will be no more system dynamics
modeling questions unless I can find a bankroll for you (still looking for
me tho).
FYI
Ventana has a free stripped down version called Vensim PLE:
http://www.vensim.com/
I also use STELLA from iseesystems.com
Powersim
A well done introduction to SD:
http://www.systemdynamics.org/DL-IntroSysDyn/
Lou
----- Original Message -----
From: "Christopher Brooks" <[EMAIL PROTECTED]>
To: "Louis Macovsky, Dynamic BioSystems" <[EMAIL PROTECTED]>
Cc: <ptolemy-hackers@bennett.EECS.Berkeley.EDU>
Sent: Thursday, May 04, 2006 9:45 AM
Subject: Re: Berkeley Madonna and System Dynamics
> Hi Lou,
>
> Wikipedia defines System Dynamics as:
>
> System dynamics is one approach to modeling the dynamics of complex
> systems such as population, ecological and economic systems, which
> usually interact strongly with each other. Systems Dynamics was
> founded in the early 1960s by Jay W. Forrester of the MIT Sloan School
> of Management with the establishment of the MIT System Dynamics
> Group. At that time, he began applying what he had learned about
> systems during his work in electrical engineering to everyday kinds of
> systems. What makes using System Dynamics different from other
> approaches to studying complex systems is the use of feedback
> loops. Stocks and flows are the basic building blocks of a System
> Dynamics model. They help describe how a system is connected by
> feedback loops which create the nonlinearity found so frequently in
> modern day problems. Computer software is used to simulate a system
> dynamics model of the situation being studied. Running "what if"
> simulations to test certain policies on such a model can greatly aid
> in understanding how the system changes over time.
>
> (http://en.wikipedia.org/wiki/System_Dynamics)
>
> I'm not sure what SD software looks like and how it differs from
> Ptolemy. The wiki page has some links to some software, a quick
> glance did not bring up a screen shot. Is there a particular package
> I should look at?
>
> There are several ways to encourage development in an area:
> 1) Provide financial support the Ptolemy project via the California
> Micro grant system. This requires finding a student, or covering
> Edward's time or my time. Details are at
> http://ptolemy/sponsoring_main.htm
>
> 2) Do the work yourself, follow the Ptolemy style guide and
> contribute the software. See
> http://ptolemy/ptolemyII/ptIIfaq.htm#Contributions
>
> 3) This sounds like it might work well in Kepler, where the
> CT domain gets reskinned as an SD model. Kepler is doing lots
> of usability work and has nifty icons. Kepler is targeted
> more towards scientists whereas Ptolemy is targeted towards
> researchers interested in models of computation. It sounds like
> your stakeholders would prefer Kepler over Ptolemy.
>
> _Christopher
>
> --------
>
> Hi,
>
> I use System Dynamics (SD) models to engage stakeholders (those of
> little background or interest in the necessary math but are the
> policy-makers, hold the purse strings, and hold the biases as the
> system experts). I believe SD is probably the most intuitive
> modeling platform to build CT models but there are many
> constraints that Kepler/Ptolemy could rectify. I am asking my
> question under the notion that stakeholders will have trouble
> "seeing" their system with the Ptolemy mapping/icon modeling
> layer. Models are probably useless in the practical world if
> stakeholders cannot "buy into" the model. To many stakeholders,
> modeling is intellectual voodoo and there is a lack of trust
> (e.g. you can prove anything to the layperson with the wrong
> statistics model) that must be overcome and SD is a tool that
> enables this.
>
> What would it take to encourage Ptolemy developers to build a
> SD-like layer of system modeling (using icons of stock and flows
> and also keep the converters and look-up tables or graphs)
> interfaced with the more mathematically versatile modeling of
> ptolemy. For example the SD stock is the integration thus a link
> to an integrator actor (?). A package of SD-specific actors?
>
>
> Thanks,
> Lou
>
> ----- Original Message -----
> From: "Haiyang Zheng" <[EMAIL PROTECTED]>
> To: "Christopher Brooks" <[EMAIL PROTECTED]>; "Louis Macovsky,
Dynamic
> BioSystems" <[EMAIL PROTECTED]>
> Cc: <[EMAIL PROTECTED]>;
<ptolemy-hackers@bennett.eecs.berkeley.edu>
> Sent: Monday, May 01, 2006 8:56 AM
> Subject: Re: Berkeley Madonna and System Dynamics
>
>
> > Hi, Lou,
> >
> > Sorry for the late reply. I was out of town. As for your
> > question, there is no connection between BM and ptolemy.
> >
> > -Haiyang
> >
> >
> > ----- Original Message -----
> > From: "Christopher Brooks" <[EMAIL PROTECTED]>
> > To: "Louis Macovsky, Dynamic BioSystems"
> > <[EMAIL PROTECTED]>
> > Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> > Sent: Friday, April 28, 2006 11:04 AM
> > Subject: Re: Berkeley Madonna and System Dynamics
> >
> >
> > > Hi Lou,
> > >
> > > There is no Berkeley Madonna interface that I know of.
> > >
> > > I've cc'd Haiyang Zheng here, he is our local CT expert,
> > > he might know.
> > >
> > > Haiyang, if you respond, can you cc
> > > [EMAIL PROTECTED]
> > >
> > >
> > > _Christopher
> > >
> > > --------
> > >
> > > Thanks for the reply to the GIS querry.
> > >
> > > Another one:
> > > I use system dynamics platforms of CT modeling. Its
> > > mapping or systems
> > > concept drawing layer is great for educating and
> > > involving stakeholders in
> > > the modeling process.
> > >
> > > In that Oster's Berkeley Madonna (BM) was born at UCB,
> > > I would like to know
> > > if anyone has linked system dynamics platforms such as
> > > BM or any of the
> > > other system dynamics packages to Ptolemy or Kepler.
> > >
> > > Thanks again,
> > > Lou
> > >
> > >
> > >
> > >
> >
> -------------------------------------------------------------------
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-----
> -
> -
> > > -
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> > > --------
> > >
> >
> >
>
> --------
>
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