[Repast-developer] Re: Repast-developer digest, Vol 1 #28 - 5 msgs

[<sky...@sa...>]

>Message: 4
>Date: Thu, 29 Nov 2001 11:13:14 -0600
>From: Thomas Howe <th...@sr...>
>To: rep...@li...
>Subject:  Re: [Repast-developer] 'Report'
>
>I guess that it is now my turn to add to the conversation.  For those of you
>who don't know, I am working on gis spaces.  Up to now, I've been using raster
>spaces whose nieghbors can be calculated just like grids.  Now that I'm getting
>to work on the vector spaces this approach is not appropriate.  From what I've
>read in this thread, I really like the idea of using radius to determine
>nieghborhoods.  This is how we have historically calculated this sort of thing
>in gis using the buffer.  the other approach I've seen is to maintain a
>congruency matrix that can be searched to find neighbors.  This might work for
>hexagonal spaces, but becomes problematic in gis spaces (even though that's
>where I've seen it) because of the non uniform nature of gis shapes.  I think
>that using the centroid and a buffer (either oval or circle) to calculate
>neighbors is a good way to approach the general space interface.  As Skye
>says,+the grid can use this functionality and add the moore, vn
>neighborhoods in the
>subclass.  Lord knows it will make my task easier if I don't have to deal with
>those concepts (I wouldn't even know where to begin).
>
>So, that's just what I'm thinking.
>
>-tom
>
>
>--__--__--
>
>Message: 5
>Date: Thu, 29 Nov 2001 11:16:01 -0600
>From: Thomas Howe <th...@sr...>
>To: rep...@li...
>Subject: [Repast-developer] (no subject)
>
>Ooops, one more thing.  In gis, we generally think of buffers a circular radii
>(is that the right word? :)).  As a matter of fact, all of the libraries I use
>and have seen (for gis) have a method called: buffer(double distance).  Just
>something to think about.  On the other hand, they also return a single object
>(a new geometry) instead of a collection, so I'm going to have to change that
>anyway.  But nonetheless.
>
>-Tom,
>who continues rambling
>
>P.S.  While I was frustrated with something else, I decided to try out the
>webstart stuff.  If anyone wants to see it in action, install webstart
>from the sun page, then go to http://stiltfire.src.uchicago.edu/test1.jnlp
>

I'm not at all familiar with the gis architecture, but one thing to
consider is how the space framework works with the network framework.  for
ex, if each spaces is keeping track of its adjacent neighbors, or you have
matrix for looking up neighbors, this is conceptualy identical to a
network, with all associated benifits and problems.  (i.e. if you are using
an adjacency matrix, mem requriments go up as the SQUARE of the number of
cells!)

also, I wonder if it is worth trying to do a bit of look ahead for how the
repast libraries are structred.  Will the the concepts under the 2d spaces
still make sense when extened to 3d?

webstart stuff sounds damn cool.  unfortunatly I've got a bit of a
bandwidth problem havn't looked at it.  be cool to bundle up the jinGirNew
demo and tell the authors..

xo,
 -skye