Re: [Swarm-Support] torus

[Paul Johnson]

Lord Jim wrote:
> Hello,
> 
> I have a simple question some of you could probably answer: why in most of 
> the examples programmer have chosen to use a toroidal space as environment? 
> Which is the advantage?
> 

I think it is just a matter of custom and experience.

I've usually tried to write my models so they work both ways, so the
world is actually square or it "wraps around," and then compare results.
 In some models, the "hard edges" at the end of the world have a serious
effect on model dynamics--plagues are contained, for example.  In some
models, there is no discernible effect.

At the Swarmfest about 6 years ago, there were some natural scientists
having an argument about the meaning of the edges and whether or not the
edges represent anything meaningful.  The earth does have continents
with edges, so maybe we need models with hard edges, but not necessarily
rectangular worlds.  If you don't make your model wrap on the edges, or
make it into a geodesic or some other thing without edge effects, then
you will always worry that the artificially imposed edges are having an
effect.

PJ

-- 
Paul E. Johnson                       email: address@hidden
Dept. of Political Science            http://pj.freefaculty.org
1541 Lilac Lane, Rm 504
University of Kansas                  Office: (785) 864-9086
Lawrence, Kansas 66044-3177           FAX: (785) 864-5700