Phil,

I now see where 'accumulated variance' is used in the context of Principal
Components Analysis where it represents how much of the variance is explained by
a set of component vectors. Is this how you're using the term?

Given this usage, I would guess that if you described the agents' states with
position and velocity vectors, a given number of principal components would have
increasing accumulated variance as the swarm becomes more organized. 

Or, perhaps you are talking about describing the motion of the swarm as a single
entity? In that case, I would say it depends on the parameters of the model.
Some settings yield swarms that break symmetry in linear momentum and move at a
constant rate in a given direction. Other settings in a model yield more
stationary swarms that buzz around much like gnats around a light. These swarms
may exhibit random-walk dynamics. 

FWIW, We have a swarm model/visualization at
http://www.redfish.com/projects/SwarmEffects/ where you can vary agent behaviors
to get different macro swarms. Focus on changing the "Average Position", "Avoid"
and "Average Direction" sliders. These sliders weight how much a given behavior
contributes to a summed vector that is an agent's next move.

-Steve



> -----Original Message-----
> From: Stephen Guerin [mailto:[EMAIL PROTECTED] 
> Sent: Wednesday, September 06, 2006 11:55 PM
> To: [EMAIL PROTECTED]; 'The Friday Morning Applied Complexity 
> Coffee Group'
> Subject: Re: [FRIAM] Do you know? Do 'swarms' follow random walks?
> 
> Hi Phil,
> 
> > Has anyone checked to see if any alife 'swarms' display 
> accumulative 
> > variance?
> 
> I haven't come across the term 'accumulative variance' 
> before. Do you have a web pointer?
> 
> As a swarm organizes, the agents' directions and velocities 
> become more correlated with each other. ie agents become more 
> constrained as they lose degrees of freedom. Would you 
> interpret this to be decreasing variance? 
> 
> -Steve
> 
> 
> 
> > -----Original Message-----
> > From: Phil Henshaw [mailto:[EMAIL PROTECTED]
> > Sent: Wednesday, September 06, 2006 8:24 PM
> > To: 'The Friday Morning Applied Complexity Coffee Group'
> > Subject: [FRIAM] Do you know? Do 'swarms' follow random walks?
> > 
> > Has anyone checked to see if any alife 'swarms' display 
> accumulative 
> > variance?
> > 
> > If you were to design one to do that, would it have a structure 
> > comparable to populations of organisms living in ecologies?
> > 
> > -In case anyone's curious I have a high quality direct measure of 
> > accumulative variance.
> > 
> > 
> > Phil Henshaw                       ¸¸¸¸.·´ ¯ `·.¸¸¸¸
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > 680 Ft. Washington Ave 
> > NY NY 10040                       
> > tel: 212-795-4844                 
> > e-mail: [EMAIL PROTECTED]          
> > explorations: www.synapse9.com    
> > 
> > 
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED]
> > > [mailto:[EMAIL PROTECTED] On Behalf Of Phil Henshaw
> > > Sent: Tuesday, September 05, 2006 8:30 PM
> > > To: 'The Friday Morning Applied Complexity Coffee Group'
> > > Subject: [FRIAM] nature walks!
> > > 
> > > 
> > > 
> > > I am dually impressed at Amazon's ability to know what
> > undergarments
> > > it's random visitors might be advised to
> > > try....:) (just marvelous!) but still I have some questions about 
> > > reality 101.
> > > 
> > > If molecules in thermal motion follow random walks, do
> > fluids composed
> > > of molecules in thermal motion do so as well?   I've run into the
> > > strangest confusion among Darwinian theorists, both from
> > journals of
> > > paleontology and evolutionary biology.  I have a quite good paper 
> > > that's unpublishable because I stick my neck out to say 
> populations 
> > > have no non-extraordinary mechanisms for changing by random walks.
> > > 
> > > a) am I wrong and there are some?   a.1)clue me in..
> > > b) do you know a journal for people literate in evolution
> > theory that
> > > might be willing to consider the issue based on physical 
> mechanisms?
> > > 
> > > 
> > > Phil Henshaw                       ¸¸¸¸.·´ ¯ `·.¸¸¸¸
> > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > 680 Ft. Washington Ave 
> > > NY NY 10040                       
> > > tel: 212-795-4844                 
> > > e-mail: [EMAIL PROTECTED]          
> > > explorations: www.synapse9.com    
> > > 
> > > 
> > > 
> > > 
> > > ============================================================
> > > FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at 
> > > cafe at St. John's College lectures, archives, 
> unsubscribe, maps at 
> > > http://www.friam.org
> > > 
> > > 
> > 
> > 
> > 
> > ============================================================
> > FRIAM Applied Complexity Group listserv Meets Fridays 
> 9a-11:30 at cafe 
> > at St. John's College lectures, archives, unsubscribe, maps at 
> > http://www.friam.org
> > 
> > 
> 
> 
> ============================================================
> FRIAM Applied Complexity Group listserv
> Meets Fridays 9a-11:30 at cafe at St. John's College 
> lectures, archives, unsubscribe, maps at http://www.friam.org
> 
> 


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