[postgis-users] using operator

Hi List, how do I check if two 3d-point sets overlap? I see the operator should be able to compare the bounding boxes, but how do I do it? I can not get the or ST_Intersects function to work. Here is what I am trying to do: SELECT ST_Collect(pkt) FROM pktbsp ST_Collect(pkt) FROM

Re: [postgis-users] using operator

Hi, It looks like you're having a little bit of trouble with the SQL. That is understandable though, your problem is a little tricky, because it requires you to nest a query. You should first note that it is not possible to have two FROM statements in a single query. Start by breaking down

Re: [postgis-users] using operator

Thank you Aman for your detailed answer. I understand why it did not work in the first place now. And yes, I need to learn SQL properly. Regards, Jan Zitat von Aman Verma aman.ve...@mcgill.ca: Hi, It looks like you're having a little bit of trouble with the SQL. That is understandable

Re: [postgis-users] USGS NED Dataset

Thanks! that is exactly what I needed to know. I'm in the painful process of downloading the NED data from there seamless download application - I can not tell you how frustrating these stupid apps are. Just give me a simple ftp site and wget would be so much easier for the users. -Steve On

Re: [postgis-users] USGS NED Dataset

* Stephen Woodbridge (wood...@swoodbridge.com) wrote: Thanks! that is exactly what I needed to know. I'm in the painful process of downloading the NED data from there seamless download application - I can not tell you how frustrating these stupid apps are. Just give me a simple ftp site

Re: [postgis-users] Problem cleaning invalid geometries

Hi, I am just wondering if there is a way to minimize the extent on which the cleangeometry() function will act, or rewrite it so that it only checks out the parts of the multipolygon near the problem area, rather than having to wait for it to check the validity of all the pieces of the

Re: [postgis-users] USGS NED Dataset

Stephen Frost wrote: * Stephen Woodbridge (wood...@swoodbridge.com) wrote: Thanks! that is exactly what I needed to know. I'm in the painful process of downloading the NED data from there seamless download application - I can not tell you how frustrating these stupid apps are. Just give

Re: [postgis-users] Problem cleaning invalid geometries

You could use ST_Dump() to split your multipolygon up and then run validity check/fix on the individual components...? P On Fri, Aug 20, 2010 at 9:44 AM, L Bogert-OBrien dlaw...@ncf.ca wrote: Hi, I am just wondering if there is a way to minimize the extent on which the cleangeometry()

Re: [postgis-users] USGS NED Dataset

There used to be a service called geotorrent. It'd be nice if someone started that back up. How much data are you trying to download? You can still find some of the DEMs as a file download without having to deal with the seamless site. On Fri, Aug 20, 2010 at 10:50 AM, Ron M

Re: [postgis-users] USGS NED Dataset

FYI there is a copy of the USGS NED on a fat pipe @ http://collections.sdsc.edu/dac2/telascience/telascience_data/elevation/usgs_ned/ On Aug 20, 2010, at 1:58 PM, Mike Swope wrote: There used to be a service called geotorrent. It'd be nice if someone started that back up. How much data

Re: [postgis-users] USGS NED Dataset

Norman, Awesome! this is much easier to deal with. There is no metadata with it, but it looks like it might be the 1 arc sec, 30m/pixel, data in a 16bit tiff. How do I interpret the pixel values? as meters from the ellipsoid? Thanks, -Steve On 8/20/2010 2:18 PM, Norman Vine wrote: FYI

[postgis-users] Vector Grid / Fishnet - ST_MakeEnvelope

Hi all. I am currently developing a global vector grid from a set of centroid points. My data includes a csv file defining the x and y coordinate of each point. These points are imported into a table. I then add a point geometry field and apply the ST_MakePoint function to create the point

Re: [postgis-users] Vector Grid / Fishnet - ST_MakeEnvelope

Andreas, ST_SetSRID requires an SRID as the second argument. e.g. ST_SetSRID(geom, 4326) I'm assuming that is what you are missing. Leo http://www.postgis.us _ From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-boun...@postgis.refractions.net] On Behalf

[postgis-users] USGS NED Dataset

5. Re: USGS NED Dataset (Stephen Woodbridge) -- I haven't done it myself, but a friend got a lot of data by mailing external hard drives. He might have gone through this email: bulkdatai...@usgs.gov listed here: http://ned.usgs.gov/Ned/faq.asp#DATA Bests, Eli

[postgis-users] tweaking a query to use less memory

Hello, I am running postGIS on a Ubuntu linux laptop with 4Gb of memory. I need to calculate a value for each of 320,000 polygons based on neighboring polygons (within 1/10 of a mile). I stopped the query below after 2.5 hours because it used 3.8Gb of memory and the swap was at 1Gb and rising.

[postgis-users] WKT Raster - geos version error while running rtpostgis.sql

I am trying to run WKT Raster's rtpostgis.sql against a database, but am encountering in the following error: psql:/usr/share/postgresql/8.4/contrib/rtpostgis.sql:32: ERROR: could not load library /usr/lib/postgresql/8.4/lib/rtpostgis.so: libgeos-3.2.0.so: cannot open shared object file: No

Re: [postgis-users] tweaking a query to use less memory

David, Don't use ST_Intersects and buffer. That is really slow. Try replacing that with ST_DWithin. If that's still too slow you may want to consider simplifying some of your larger geometries. ST_DWithin(p1.wkb_geometry, p2.wkb_geometry,528)

[postgis-users] topology in postgis

Hi there, I am studying the topology support in postgis. It seems it requires loading the topological data into table using insert command. I wonder if I have already got a layer, say a polygon layer with cleaned topology. Can postgis build the topology based on the polygon layer directly.