On 22 June 2012 21:22, Joshua Lieberman <j...@oklieb.net> wrote: > Dan, > > The coincident first and last positions in a polygon coordinate list are in > GeoRSS because they are specified that way in both OGC and ISO standards and > therefore implemented that way in most every piece of geospatial software. It > is hard to track down all of the reasons for this, but technically the > polygon boundary is defined by linear interpolation between adjacent > coordinate tuples, so it helps with consistency. The order of the coordinate > positions usually has topological significance as well. Pretty much every > polygon coordinate string in the world is constructed this way (including the > example in (http://dev.iptc.org/rNews-10-The-Geo-Coordinates-Class , mangled > a bit), so it's an interoperability issue as far as reusing geodata. > > There are OWL / RDF representations defined for GeoRSS > (http://www.w3.org/2005/Incubator/geo/XGR-geo-20071023/W3C_XGR_Geo_files/geo_2007.owl) > and WKT or well-known-text (http://schemas.opengis.net/geosparql/) which > might also be useful for defining geo-schemas.
Thanks! Very helpful :) Are there any 'classic' samples / test cases / examples for which we might usefully provide a schema.org version alongside GeoRSS / KML / etc versions of the same structure? > Cheers, > > Josh > > On Jun 22, 2012, at 10:57 AM, Dan Brickley wrote: > >> Hi folks >> >> Can I ask for some help with http://schema.org/GeoShape ? >> >> I'm working on http://schema.org/, and it's come to my attention that >> we have some half-baked geo stuff in there which I'd like to get >> fixed. See #geo logs below. Basically there are a bunch of structures >> derived from fairly similar stuff from IPTC's rNews 1.0, which itself >> seems based on GeoRSS. I'd like to fix up our docs to have plausible >> examples, as well link appropriately to GeoRSS and other related >> specs. >> >> There are more details in >> http://lists.w3.org/Archives/Public/public-vocabs/2012Jun/0116.html >> >> Thanks for any advice, >> >> Dan >> >> 14:36 danbri: ahem, >> http://stackoverflow.com/questions/10297279/what-are-the-appropriate-formats-for-the-properties-of-http-schema-org-geoshap/10466686 >> 14:36 danbri: seems like we've some geo- cleanup to do in >> http://schema.org/GeoShape ... advice welcomed >> 14:36 danbri: details >> http://lists.w3.org/Archives/Public/public-vocabs/2012Jun/0116.html >> 14:46 danbri: apparently schema.org geo is based on rNews is based on geoRss >> 14:47 danbri: and I'm told ... >> 14:47 danbri: 'In the GeoRSS spec, you'll see that the first and last >> actually are the same, 45.256 -110.45, <georss:polygon> 45.256 >> -110.45 46.46 -109.48 43.84 -109.86 45.256 -110.45 ' >> 14:47 danbri: in the rNews examples we don't have the repetition; I >> took it to be implicit and redundant. Thoughts? >> 14:49 danbri looks at http://www.georss.org/simple#Polygon >> 14:50 danbri: "A polygon contains a space separated list of >> latitude-longitude pairs, with each pair separated by whitespace. >> There must be at least four pairs, with the last being identical to >> the first (so a polygon has a minimum of three actual points)." >> 14:50 danbri: is the final one acting like a check? >> >> _______________________________________________ >> Geowanking mailing list >> Geowanking@geowanking.org >> http://geowanking.org/mailman/listinfo/geowanking_geowanking.org > _______________________________________________ Geowanking mailing list Geowanking@geowanking.org http://geowanking.org/mailman/listinfo/geowanking_geowanking.org
