Re: [postgis-users] Instructions on Installing Postgis on Solaris
I wish I could, but I really don't know how to use wiki other than reading it :) Could you add it for me please? Cheers, Li -Original Message- From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Mark Cave-Ayland Sent: Friday, 25 June 2010 2:40 AM To: PostGIS Users Discussion Subject: Re: [postgis-users] Instructions on Installing Postgis on Solaris Chen, Li [Contractor] wrote: > So I am sending the following instructions to share experience with > others who also want to install postgis on solaris. The main steps are > the same as listed in the postgis manual, but I added some details where > I think appropriate. Thank you! Would you like to create a Solaris page on the PostGIS wiki containing this information? ATB, Mark. -- Mark Cave-Ayland - Senior Technical Architect PostgreSQL - PostGIS Sirius Corporation plc - control through freedom http://www.siriusit.co.uk t: +44 870 608 0063 Sirius Labs: http://www.siriusit.co.uk/labs ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Polygon to line
Hi Ricardo,
Having been through the mailing list's archives myself over the last few weeks,
i came up with the following recipe:
First you dump all multipolygons into polygons:
SELECT
(ST_Dump(the_geom)).geom AS the_geom
INTO polygon_table
FROM multipolygon_table
and create an index on that one
CREATE INDEX geo_idx_polygon_temp ON polygon_table_temp USING GIST (the_geom);
VACUUM ANALYZE polygon_table_temp;
then you create a new table that contains the borders using ST_Intersection:
CREATE TABLE borders AS
SELECT
ST_Intersection(t1.the_geom,t2.the_geom) AS the_geom
FROM
polygon_table_temp AS t1,
polygon_table_temp AS t2
WHERE
t1.the_geom && t2.the_geom;
These borders are duplicated, as the intersection is computed twice (A
intersects B and B intersects A). Also contains records of geometry other than
multilinestring
DELETE FROM borders WHERE GeometryType(the_geom) <> 'MULTILINESTRING'::text;
SELECT Populate_Geometry_Columns('borders'::regclass);
ALTER TABLE borders ADD COLUMN gid SERIAL;
ALTER TABLE borders ADD PRIMARY KEY (gid);
CREATE INDEX geo_idx_borders ON borders USING GIST (the_geom);
VACUUM ANALYZE borders;
so remove duplicates:
DELETE FROM borders WHERE
borders.gid <
(SELECT MAX(b.gid )
FROM borders b
WHERE b.the_geom && borders.the_geom
AND ST_Equals(borders.the_geom, b.the_geom));
REINDEX TABLE borders;
VACUUM ANALYZE borders;
That should do it. Thanks to previous postings to this mailing list!
regards,
Edward
Date: Thu, 24 Jun 2010 16:53:54 -0300
From: vilella.rica...@gmail.com
To: postgis-users@postgis.refractions.net
Subject: [postgis-users] Polygon to line
Hi all, is the first time I use the list. I have a polygon that represent a
country, if i want extract only the sides that touch with other polygon. How i
have to do? The result should be a MultiLineString or a LineString representing
the limits of the country but without the coast line if it has one. I tried
with ST_Touches but i can't get it work.
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[postgis-users] Polygon to line
Hi all, is the first time I use the list. I have a polygon that represent a country, if i want extract only the sides that touch with other polygon. How i have to do? The result should be a MultiLineString or a LineString representing the limits of the country but without the coast line if it has one. I tried with ST_Touches but i can't get it work. ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Instructions on Installing Postgis on Solaris
Chen, Li [Contractor] wrote: So I am sending the following instructions to share experience with others who also want to install postgis on solaris. The main steps are the same as listed in the postgis manual, but I added some details where I think appropriate. Thank you! Would you like to create a Solaris page on the PostGIS wiki containing this information? ATB, Mark. -- Mark Cave-Ayland - Senior Technical Architect PostgreSQL - PostGIS Sirius Corporation plc - control through freedom http://www.siriusit.co.uk t: +44 870 608 0063 Sirius Labs: http://www.siriusit.co.uk/labs ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
[postgis-users] Which naming convention to use
When talking about Postgis and PostgreSQL which is the correct: Postgis/PostgreSQL or PostgreSQL/Postgis. -- Sent from my mobile device Sindile Bidla Tel: 0823408538 Fax: 0865246419 ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Round up coordinates?
Hallo The problem is that even if you round your coordinates with ST_SnapToGrid, the edges between the vertexes will cross "not rounded land". So the intersection will most likely fail without the buffer if the intersection is expected somewhere between the rounded vertex points. Another way of doing it is using ST_DWithin instead. I don't know which one is most effective. Hope That Helps Nicklas 2010-06-23 João Paulo Hespanha wrote: I have a number of cadastral boundaries (in predio_polylines) and >property beacons (in propertybeacon) in a PostGIS database. The >coordinates have a non-default srid of 9102160 and are stored with >double precision. >When I run the following topological query (boundaries crossing a >certain beacon) without the buffer, I get no results. The data has an >internal resolution of 0.01 meter (from original source) and quality no >better than 0.1 meter. How can I round up the coordinates such that the >query can run without the buffer? > >BTW, is it possible to build a small graphical form to run the querying, >changing the b.gid parameter? (in uDIG? :-) > > >Topo query: >select > l.gid, > l.nfolhapred, > b.gid, > b.tipo >from > predio_polylines as l, > propertybeacon as b >where > b.gid = 1000 AND > (ST_Intersects(ST_Buffer(ST_EndPoint(l.the_geom), 0.01), >ST_Buffer(b.the_geom, 0.01)) OR > ST_Intersects(ST_Buffer(ST_StartPoint(l.the_geom), 0.01), >ST_Buffer(b.the_geom, 0.01))); > > >___ >postgis-users mailing list >postgis-users@postgis.refractions.net >http://postgis.refractions.net/mailman/listinfo/postgis-users > >___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
