On Thu, Mar 15, 2012 at 12:47 AM, Yang <[email protected]> wrote: > actually I just looked at the ogrinfo -al output of the shape file, > it seems that because when I generated the file, I called > > > SimpleFeatureTypeBuilder builder = new SimpleFeatureTypeBuilder(); > builder.setCRS(DefaultGeographicCRS.WGS84); // <- Coordinate > reference system > > the shape file is marked as in the WGS84 coordinate system: > > ogrinfo -al /tmp/ttt.shp > INFO: Open of `/tmp/ttt.shp' > using driver `ESRI Shapefile' successful. > > Layer name: ttt > Geometry: Point > Feature Count: 2 > Extent: (0.000000, 0.000000) - (100.000000, 0.000000) > Layer SRS WKT: > GEOGCS["WGS84(DD)", > DATUM["WGS84", > SPHEROID["WGS84",6378137.0,298.257223563]], > PRIMEM["Greenwich",0.0], > UNIT["degree",0.017453292519943295], > AXIS["Geodetic longitude",EAST], > AXIS["Geodetic latitude",NORTH]] > gml_id: String (254.0) > OGRFeature(ttt):0 > gml_id (String) = 12345 > POINT (0 0) > > OGRFeature(ttt):1 > gml_id (String) = 2222 > POINT (100 0) > > > > > > so the WGS84 is marking is simply ignored when dwithin() is run, and it > simply assumes a flat coordinate system?
Yes, all distance based filters work in a flat coordinate system, changing that so that they work fine over the ellipsoid is no small task. Cheers Andrea -- ------------------------------------------------------- Ing. Andrea Aime GeoSolutions S.A.S. Tech lead Via Poggio alle Viti 1187 55054 Massarosa (LU) Italy phone: +39 0584 962313 fax: +39 0584 962313 mob: +39 339 8844549 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.youtube.com/user/GeoSolutionsIT http://www.linkedin.com/in/andreaaime http://twitter.com/geowolf ------------------------------------------------------- ------------------------------------------------------------------------------ This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure _______________________________________________ GeoTools-GT2-Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
