I figured it out a bit ago.. finally.. because I'm a dweeb.. I assumed buffer was a memory function :) It greatly confused me. I just started up with PostGIS a few weeks ago and am just now seeing the term buffer in all the programs I've been using for GIS visualization.
Thanks for the description :) Shane On 9/18/07, Nico Mandery <[EMAIL PROTECTED]> wrote: > > Hi Shane, > > sorry for the delay, i had no access to the Internet for while. > > here is a short definition of the term buffer from > http://www.fws.gov/data/IMADS/glossary.htm : > > buffer - A zone of a specified distance around coverage features. Both > constant- and variable-width buffers can be generated for a set of > coverage features based on each feature's attribute values. The > resulting buffer zones form polygons-areas that are either inside or > outside the specified buffer distance from each feature. Buffers are > useful for proximity analysis (e.g., find all stream segments within > 300 feet of a proposed logging area). > > In this context you could create a buffer with a distance X and a > buffer with a distance Y around the point, and then look for point > wicht are in the in the area of (bufferX-bufferY). > > nico > > >Could you reply with a URL to what buffers are and how they would be > >used in this context? I'm >totally unfamiliar. > > > > > > On 9/9/07, Nico Mandery < nicomandery <at> googlemail.com> wrote: > >> Hi Rainer, > >> > >> You could could use a buffer instead of bounding boxes. > >> Just an idea > >> > >> Nico > >> > >> Am Sonntag 09 September 2007 schrieb postgis <at> jochem.name: > >> > Hi, > >> > > >> > what I want to do is finding certain features in some distance around > a > >> > certain point. Those features should be located in some corridor > between X > >> > and Y km around this point. Currently I've solved this problem by > >> > computing two bounding boxes of X and Y km around the point and > taking the > >> > difference of those. So far so good. > >> > > >> > But I don't want to have some quadratic box but a real circle - is > there > >> > any way to achieve this? > >> > > >> > Best regards, > >> > Rainer > >> > _______________________________________________ > >> > postgis-users mailing list > >> > postgis-users <at> postgis.refractions.net > >> > http://postgis.refractions.net/mailman/listinfo/postgis-users > >> _______________________________________________ > >> postgis-users mailing list > >> postgis-users <at> postgis.refractions.net > >> http://pos > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users >
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