Re: Some questions Re: [Swarm-Modelling] EcoLab implementation of Stupid Model

[Russell Standish]

On Sun, Oct 08, 2006 at 05:55:57AM -0700, krishnan raman wrote:
> Prof. Russell Standish
>    
>   I am very interested to know about Ecolab.
>   A few questions.
>    
>   1) Can you please give a few examples of problems where you have found it 
> useful to use Ecolab.    Do you have descriptive papers on these that you 
> could send me copies of ?

I've been meaning to set up a web page with links to research
papers. In the meantime, you can take a look at 

http://parallel.hpc.unsw.edu.au/rks/ecolab/node2.html

which is a bit out of date.

> 
>   2)  While running EcoLab, do I compile it as a project ?
>   Does this result in a .exe ?  ( Which, e.g., I could think of calling, with 
> parameters, from another program).

You compile your model to an executable (eg .exe on Windows), which
takes a TCL script as its first argument. Subsequent arguments are
available to the script as $argv(0), $argv(1) and so on.

>     Does it require that I have some version of C++ on my PC ?
>    

Yes. For windows, the recommended approach is to obtain Cygwin (by
downloading from http://www.cygwin.com, or purchasing a DVD if your
bandwidth costs too much), which is a unix emulation layer. Cygwin
comes with a C++ compiler (g++). There are
instructions for how to set up EcoLab in Cygwin in the doucmentation,
as I support that configuration.

It would presumably be possible to use EcoLab under Visual Studio
(say), as I have striven to keep EcoLab's code as standard conforming
as possible. However, it would be a brave (or perhaps extremely
confident) programmer who would take on this task. I am not personally
planning to support EcoLab on VS, but if someone else wants to do it,
I'm happy to accept patches.

>    
>   4)   I am trying to download EcoLab ( for a MS Windows environment), but 
> have not yet been able to do so.  I am trying the Superb-East mirror ( 
> McLean, Virginia, USA).
>   Any recommendations ?
>    

I do not provide compiled code, as EcoLab is meant to be used with
user models which need to be compiled. However, I did once provide a
Windows executable for a specific model - see
http://parallel.hpc.unsw.edu.au/rks/KeenEtAlMultiFirmSimulation/ .

Whether the executable still works on current Windows releases, I have no idea.

My suggestions: read the installation instructions on the online
documentation, especially the Cygwin section.

Download and install Cygwin. If you have lots of disk space, just
install everything, otherwise at least  bash, binutils, cygwin, diff, 
fileutils, findutils,  gcc, grep, gzip, make, tar, textutils, w32api, 
X-windows, zlib

Download and install tcltkblt-cygwin.tar.gz from sourceforge. The
TCL/Tk package supplied with Cygwin does not work with EcoLab

The download ecolab.4.D20.tar.gz, unpack and type "make" in the top
level directory. This will build the library, as well as several
example models that live in the models directory.

Any questions or difficulties, email address@hidden, or
lodge a bug report on the SF site. The package was tested against the
current Cygwin at time of release, but that was nearly a year ago.

>   Thanks.
>    
>   K. Raman
>   ====================================
>   Dr. K. Raman
>   43 Alderwood Drive
>   West Hartford (Connecticut)  06117
>   USA
>   email: address@hidden
>    
>    
>    
>    
>   
> ======================================================
> Russell Standish <address@hidden> wrote:
>   Just a heads up that I have uploaded an EcoLab version of Railsback et
> al.'s Stupid Model to the EcoLab website
> (http://ecolab.sourceforge.net). This is a useful exercise in
> providing a pedagogical model for learning how to use EcoLab, it provides
> insights to me as a developer into what needs to be improved in EcoLab
> and also provides a rather limited benchmark comparison between
> different ABM platforms.
> 
> In the spirit of Railsback's paper, I didn't attempt to fix EcoLab's
> shortcomings, but rather programmed to the existing publically
> available version of the package (4.D20).
> 
> I don't seem to have edit priveleges on Swarm.org any more, otherwise
> I'd create some links to the code.
> 
> I will be writing a more detailed report later, but I can summarise a
> few of my findings.
> 
> 1) EcoLab is about as easy to implement the StupidModel as reported by
> Railsback et al for Repast and Mason. The first step took a little
> longer, as there were no existing example models for using
> Graphcode to implement spaces. Help for spaces is an area for
> improvement.
> 
> 2) Performance was about twice as fast as the Repast Java
> implementation when run in batch mode. However, a small amount of
> optimisation was needed to get this - first cut implementations
> could be a lot slower. In GUI mode, EcoLab was substantially
> slower, predominently due to the use of BLT widgets for
> plotting. In summary, with modern Java virtual machines, the
> performance penalty for using Java is not a significant factor.
> 
> 3) I did a parallel version of the model, but did not get performance
> improvements (I still haven't investigated this)
> 
> 4) For agent based modeling, some form of smart pointer structure is
> essential (Java's object reference model has this feature built
> into the language). EcoLab has an undocumented "ref" class, which
> wasn't up to the job, so I reimplemented this for StupidProject.
> 
> 5) Using vectors of smart references seemed to be a natural way of
> implementing scheduling - one can readily sort or randomise the
> ordering of method calls using C++ standard library
> functionality. StupidModel uses periodic scheduling, but aperiodic
> scheduling should also be handled by means using sets of references
> (I'll have a go at implementing some other classic models such as
> the mousetrap).
> 
> Cheers
> 
> -- 
> 
> *PS: A number of people ask me about the attachment to my email, which
> is of type "application/pgp-signature". Don't worry, it is not a
> virus. It is an electronic signature, that may be used to verify this
> email came from me if you have PGP or GPG installed. Otherwise, you
> may safely ignore this attachment.
> 
> ----------------------------------------------------------------------------
> A/Prof Russell Standish Phone 0425 253119 (mobile)
> Mathematics 
> UNSW SYDNEY 2052 address@hidden 
> Australia http://parallel.hpc.unsw.edu.au/rks
> International prefix +612, Interstate prefix 02
> ----------------------------------------------------------------------------
> _______________________________________________
> Modelling mailing list
> address@hidden
> http://www.swarm.org/mailman/listinfo/modelling
> 

> _______________________________________________
> Modelling mailing list
> address@hidden
> http://www.swarm.org/mailman/listinfo/modelling


-- 
*PS: A number of people ask me about the attachment to my email, which
is of type "application/pgp-signature". Don't worry, it is not a
virus. It is an electronic signature, that may be used to verify this
email came from me if you have PGP or GPG installed. Otherwise, you
may safely ignore this attachment.

----------------------------------------------------------------------------
A/Prof Russell Standish                  Phone 0425 253119 (mobile)
Mathematics                              
UNSW SYDNEY 2052                         address@hidden             
Australia                                http://parallel.hpc.unsw.edu.au/rks
            International prefix  +612, Interstate prefix 02
----------------------------------------------------------------------------

pgpq6RfAByyOT.pgp
Description: PGP signature