Thanks, Steven, the combination of st_dwithin and st_distance seems to do it.
M. Stephen Woodbridge skrev: > On 7/27/2013 9:10 AM, Morten Sickel wrote: >> I would like to repeat an analysis that has been done in arcgis (10.1) >> in >> postgis (1.5) (I am running on debian, I could have upgraded, but as my >> project soon is finished, I would like to, if possible finish it in 1.5) >> >> The ananlysis in arc is done using the near table function: >> >> http://resources.arcgis.com/en/help/main/10.1/index.html#//00080000001n000000 >> >> does this exist in postgis 1.5 (or newer)? > > This sounds like it just creates a list of features within a a search > radius of a given feature. > > select a.fid as in_fid, > b.fid, > st_distance(a.the_geom, b.the_geom) as distance > from in_feature_table a, > features_table b > where st_dwithn(a.the_geom, b.the_geom, search_radius) > order by a.fid, st_distance(a.the_geom, b.the_geom) asc; > > If you want to select the in_feature by its fid then > > select a.fid as in_fid, > b.fid, > st_distance(a.the_geom, b.the_geom) as distance > from features_table a, > features_table b > where a.fid in (list_of_in_feature_ids) and a.fid != b.fid and > st_dwithn(a.the_geom, b.the_geom, search_radius) > order by a.fid, st_distance(a.the_geom, b.the_geom) asc; > > -Steve > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
