Hi All,
Slightly off topic from geoserver, but still related, and this mailing list has a really good grpup…
If I have point data, and wish to serve polygons representing the distribution of those point data, is there an algorithm (or function in Geotools?) I can use that groups the points into polygons allowing for a maximum distance between any 2 points?
Thanks for any pointers of where to find such a thing.
Tim
Hi Tim,
I cannot nothing of anything off the top of my head that would do this.
JTS has a number of algorithms that come with the library, but i am not
sure if something like this is one of them.
I suggest you post to the JTS list:
http://lists.jump-project.org/mailman/listinfo/jts-devel
Martin Davis will let you know if there is anything in JTS that will do
this, and if not, how much work it will be to implement.
-Justin
Tim Robertson wrote:
Hi All,
Slightly off topic from geoserver, but still related, and this mailing
list has a really good grpup...If I have point data, and wish to serve polygons representing the
distribution of those point data, is there an algorithm (or function in
Geotools?) I can use that groups the points into polygons allowing for a
maximum distance between any 2 points?Thanks for any pointers of where to find such a thing.
Tim
!DSPAM:4007,47665770160231628642973!
------------------------------------------------------------------------
-------------------------------------------------------------------------
SF.Net email is sponsored by:
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services
for just about anything Open Source.
http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace!DSPAM:4007,47665770160231628642973!
------------------------------------------------------------------------
_______________________________________________
Geoserver-users mailing list
Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users!DSPAM:4007,47665770160231628642973!
--
Justin Deoliveira
The Open Planning Project
http://topp.openplans.org
I am not sure exaclty how you want to represent this, but another
possibility would be to use PostGIS to produce a spatial view of your
data, which could then be represented in Geoserver. I am not exactly
sure how you would produce a polygon from two points, but there are a
plethora of spatial functions in PostGIS that should serve your
purpose. I regularly do the opposite, to represent polygons as points,
using their centroids, which is can be dynamically calculated by
PostGIS.
If you can provide more detail about the data (or actual data), I
could try and help you formulate such a view, if you are interested in
going down that route.
Best regards,
Jason
On Dec 17, 2007 12:02 PM, Tim Robertson <trobertson@anonymised.com> wrote:
Hi All,
Slightly off topic from geoserver, but still related, and this mailing list
has a really good grpup...If I have point data, and wish to serve polygons representing the
distribution of those point data, is there an algorithm (or function in
Geotools?) I can use that groups the points into polygons allowing for a
maximum distance between any 2 points?Thanks for any pointers of where to find such a thing.
Tim
-------------------------------------------------------------------------
SF.Net email is sponsored by:
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services
for just about anything Open Source.
http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace
_______________________________________________
Geoserver-users mailing list
Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users
Thanks Jason and Justin,
Basically we have 120million point data for various species (e.g.
http://data.gbif.org/species), and we are doing grid based approaches for
mapping at present. We would like to start producing polygon data for the
species distributions, but obviously if a species exists in Northern USA
and also Eastern Europe, we have clusters of points on 2 continents, so
would need 2 polygons. Thus I was looking for an algorithm to include
maximum distance between any 2 points. The other problem/challenge, is
that we dont use a geospatial DB as it just does not work with that volume
to have point data as the indexes are too big - plus we aim to grow to
1Billion in the near future.
I'll keep hunting and post back if I find an algorithm.
Many thanks
Tim
I am not sure exaclty how you want to represent this, but another
possibility would be to use PostGIS to produce a spatial view of your
data, which could then be represented in Geoserver. I am not exactly
sure how you would produce a polygon from two points, but there are a
plethora of spatial functions in PostGIS that should serve your
purpose. I regularly do the opposite, to represent polygons as points,
using their centroids, which is can be dynamically calculated by
PostGIS.If you can provide more detail about the data (or actual data), I
could try and help you formulate such a view, if you are interested in
going down that route.Best regards,
JasonOn Dec 17, 2007 12:02 PM, Tim Robertson <trobertson@anonymised.com> wrote:
Hi All,
Slightly off topic from geoserver, but still related, and this mailing
list
has a really good grpup...If I have point data, and wish to serve polygons representing the
distribution of those point data, is there an algorithm (or function in
Geotools?) I can use that groups the points into polygons allowing for a
maximum distance between any 2 points?Thanks for any pointers of where to find such a thing.
Tim
-------------------------------------------------------------------------
SF.Net email is sponsored by:
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services
for just about anything Open Source.
http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace
_______________________________________________
Geoserver-users mailing list
Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users