Desperately seeking DYNAMO

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Bill Harris
Senior Member
Posts: 75
Joined: Fri Mar 29, 2002 3:39 am

Desperately seeking DYNAMO

Post by Bill Harris »

Malczynski, Leonard A"" <lamalcz@sandia.gov> writes:

> I am trying to convert two circa 1975 DYNAMO models into another system
> dynamics software tool.

Len,

If I dig deeply into my memory, I recall writing programs around what
were essentially DYNAMO statements to create running simulation models
without having DYNAMO itself. I wasn't parsing and compiling the DYNAMO
code (although I was tempted to see if I could do something useful with
lex and yacc or their GNU counterparts)--just incorporating it into the
program I wrote. I can't recall right now if I used C, Pascal, or even
C64 Logo (I told you it was a while back).

At any rate, DYNAMO isn't a complex language; this was fairly easy to
do, and I suspect it might be easier and quicker to get right than
converting a DYNAMO model into a GUI-based environment, for the
structural differences would be smaller. Basic SD models aren't hard to
program; The Systems Thinker just published an article I wrote on SD
modeling using SimPack, gnuplot, and Dia (all free).

Bill
From: Bill Harris <bill_harris@facilitatedsystems.com>

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John Voyer
Junior Member
Posts: 4
Joined: Fri Mar 29, 2002 3:39 am

Desperately seeking DYNAMO

Post by John Voyer »

I guess this situation has been satisfactorily resolved, but I wanted to
mention one other thing. I have successfully translated several DYNAMO
models into Vensim ones by using the information in Richardson and
Pugh's book ""Introduction to System Dynamics Modeling with Dynamo."" The
stocks and flows and most of the auxiliaries are essentially identical.
The only problem I had was that some of the built-in functions, and to a
lesser extent the table functions, were different and had to be finessed
in Vensim. It was actually quite fun to do that kind of translation.



John J. Voyer, Ph.D.
Professor of Business Administration
School of Business
University of Southern Maine
96 Falmouth St.
Box 9300
Portland, ME 04104-9300

voyer@usm.maine.edu
phone: 207-780-4597
fax: 207-780-4662
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