I just updated my oldish Local Density Analysis script to Python (v.lda.py) and created a new companion script (v.nn.py) for measuring the Nearest Neighbor coefficient for a vector points file, or the Nearest Neighbor between two files as a measure of correspondence (or lack thereof) between the two maps.
The LDA script will calculate the local density coefficient for a group of points, as an index of clustering, and between two different vector maps as a measure of the amount of similarity between points on two different maps. Both scripts are available in the GASS_ADDONS site. Michael ____________________ C. Michael Barton Director, Center for Social Dynamics & Complexity Professor of Anthropology, School of Human Evolution & Social Change Arizona State University voice: 480-965-6262 (SHESC), 480-727-9746 (CSDC) fax: 480-965-7671 (SHESC), 480-727-0709 (CSDC) www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu On Jul 1, 2011, at 9:00 AM, <[email protected]> <[email protected]> wrote: > Send grass-user mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.osgeo.org/mailman/listinfo/grass-user > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of grass-user digest..." > > > Today's Topics: > > 1. Re: v.generalize issues (Markus Metz) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 30 Jun 2011 17:04:52 +0200 > From: Markus Metz <[email protected]> > Subject: Re: [GRASS-user] v.generalize issues > To: Christian Guirreri <[email protected]> > Cc: [email protected] > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1 > > On Thu, Jun 30, 2011 at 4:47 PM, Christian Guirreri > <[email protected]> wrote: >> I'm on GRASS 6.4.1. QGIS 1.7.0 >> > In this version, v.generalize is still broken. You would need a recent > version of GRASS 6.4.2. For Windows, you can get a recent version > here: > > http://wingrass.fsv.cvut.cz/grass64/ > > Markus M > > >> On Thu, Jun 30, 2011 at 10:18 AM, Markus Metz >> <[email protected]> wrote: >>> >>> On Thu, Jun 30, 2011 at 4:01 PM, Christian Guirreri >>> <[email protected]> wrote: >>>> I'm a brand new user to GIS?- my goal right now is to heavily simplify >>>> Tiger >>>> 2010 county and distrct data, without producing gaps between boundaries. >>>> I've been testing this with v.generalize in grass via QuantumGIS - I've >>>> had >>>> tons of issues with the Grass toolbox crashing, but have narrowed down >>>> to >>>> using the Hermite algorithm. While it works, I'm having some bizarre >>>> issues >>>> with it. Apologies for the cross-post with the PostGIS mailing list. >>>> >>>> In the attached gif of California counties, from left to right, I have >>>> used >>>> the following tolerance values with the Hermite algorithm: >>>> ?- original >>>> ?- 1.0 >>>> ?- 0.08 >>>> ?- 0.01 >>>> ?- 0.00001 >>>> >>>> Why do counties disappear entirely as I decrease the tolerance? >>>> >>> This problem has been fixed in GRASS 6.4 only 2 weeks ago (June 13). >>> Please update your GRASS version if possible. >>> >>> Markus M >>> >>> >>>> In the Grass Tools I choose the v.generalize function. I choose Boundary >>>> as >>>> the feature type (though I've tried checking others, as well as all of >>>> them >>>> and it doesn't seem to change anything). Everything else is default, >>>> except >>>> for tolerance as notated above. >>>> >>>> When I tested this originally on only Arkansas and Mississippi, I got >>>> really >>>> nice results. I then tried it on the entire US and had the missing >>>> counties >>>> problem. So I tried only California, and still have the same issue. >>>> >>>> I've tried other algorithms, but this has so far given me the detail I >>>> want >>>> - of course sans counties! Any thoughts? >>>> >>>> Thanks, >>>> ?- Chris >>>> _______________________________________________ >>>> grass-user mailing list >>>> [email protected] >>>> http://lists.osgeo.org/mailman/listinfo/grass-user >>>> >>>> >> >> > > > ------------------------------ > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > > > End of grass-user Digest, Vol 63, Issue 3 > ***************************************** _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
