Re: [Swarm-Support] Heatbug code question

[Doug Donalson]

It actually makes a bit of sense that the cell does the work.  A bug moves 
around the space at random.  It would be quite inefficiant to have to update 
the bug with new neighbor cells at each time instance.  It is much easier to 
just initialize each cell with its neighbors and then share the results with 
visiting bugs.  The real question that should be asked, and it may be your 
actual question, is whether a "bug" can have immediate knowledge of the 
characteristics of all the surrounding cells simply by asking its present 
cell or whether it should actually have to physically (virtually?) visit the 
cells to know what their "environment" is like.  That has to be decided 
depending on what you are actually simulating.  I would assume that a drop 
of water would generally follow the steapest path and so it would not need 
to visit all surrounding cells.  It would just "ask" its present cell for 
the neighbow cell with the lowest elevation adn move htere.  In contrast, I 
am working on a simulation of an endangered bird right now and my present 
grid/cell size is 500X500 meters (the resolution of my hydrology map). 
Because this is a large spatial scale compared to how the birds view their 
environment, the sparrows must actually move into a neighbor cell before 
they can determine its characteristics.  However, they do get the "address" 
of the new cell from their present cell.

For what it's worth,

Doug Donalson

----- Original Message ----- 
From: "Crile Doscher" <address@hidden>
To: <address@hidden>
Sent: Sunday, November 14, 2004 7:52 PM
Subject: [Swarm-Support] Heatbug code question


> Hi there,
>   This question relates to the logic of the Heatbug code, specifically why 
> a method is
> implemented where it is.  If that sounds like you, read on!
>   I'm putting together a simulation of braided rivers where water objects 
> (originally
> called drops until I realised that that name was special...) flow over a 
> river bed and find
> their way by moving in the direction of the steepest slope.  I've been 
> paying attention to
> how Heatbug implements bug movement and wonder why it is that the actual 
> method
> that looks at the eight cell neighbourhood around a particular cell 
> (findExtremeType) is
> implemented in HeatSpace.m rather than in Heatbug.m. The Heatbug then 
> determines
> which cell it will move to, but HeatSpace does the work of figuring out 
> which cell would
> be the best to move to.  This is part of the process of getting my head 
> around Objective
> C.  Any thoughts?  Thanks -
> Crile
>
> Dr Crile Doscher
> Natural Resources Engineering
> Lincoln University
> New Zealand
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