[GRASS-user] Re: proximity mapping / site clustering

[Dylan Beaudette]

One more example for fun...

#see previous email in thread by D.E.B.

# add in cost derived from slope map, and distance to some initial point 
b_start:
echo "596204.6875|4917668.75" | v.in.ascii  out=b_start
r.cost in=slope out=b_cost start_points=b_start stop_points=bugsites -k

#add this to bugsites att tables
echo "ALTER TABLE bugsites add column s_cost double" | db.execute
v.what.rast vect=bugsites rast=b_cost column=s_cost

#export busgites
v.out.ascii.db in=bugsites out=bugsites.xy columns='s_cost'

# similar R commands, but standardize the data frame prior to partitionin 
around medoid approach:

y.pam <- pam(y, 5, stand=TRUE)

#yields slightly different results. note red 'dot' is the location of some 
arbitrary starting point ' b_start'
http://169.237.35.250/~dylan/temp/spatial_clustering_idea2-cost.png


Seriously, I really wish that GRASS, R, PostGIS, etc. weren't so damn 
flexible - then I would stick to my work instead of trying out things like 
this!

Cheers,

Dylan


On Friday 21 July 2006 14:33, M S wrote:
> followup/correction.
>
> The "hubbing" does not have to occur along the optimal route (steiner
> tree).  this is "line of sight" orientated (cell towers as example).
>
> On 7/21/06, M S <mseibel at gmail.com> wrote:
> >  So far the network engineer/planner (who happens to be my Dad) I have
> > been working with on using GRASS for WAN Network engineering and design
> > has been working out awesome.  After a successful steiner tree, i have
> > come to another problem to solve with GRASS.
> >
> > i have all these sites on the minimal connection network.  what i need to
> > do now on a simplistic level, is cluster the sites or aggregate them.
> > Clustering them by proximity is the first step, even though traffic
> > generation is another factor that will have to be added.
> >
> > I have looked at v.net.iso and v.net.alloc, but none seem to produce the
> > results sought after.  is there a function or combination of functions
> > that might cluster sites on the network based upon their proximity to
> > each other?
> >
> >
> > i used v.net.iso with roughly a mile iso band.  i was able to highlight
> > on the optimal network all sites within a mile of each other but those
> > were not the desired results.
> >
> > Any ideas?
> >
> > thanks in advance

-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341