Re: [postgis-users] setting up a read only user / group for AutoCAD, ArcGIS, QGIS, and MapServer.
On 4/14/2014 7:25 AM, Mark Volz wrote: Hello, I would like to set up a user account in PostGIS / PostGRES with the following: ·The user has read only access to all of the layers in a particular database. ·The user also have read only access to any layers added or updated through the shapefile uploader. ·The client software may be ArcGIS*, AutoCAD (Map), QGIS, MapServer, etc. *ArcGIS will use “query layers”, not SDE. If anyone has any cliff notes on how to properly set up read only permissions please let me know. Thank You Sincerely, Mark Volz, GISP You can think of users and groups pretty much the same. user and role are mostly interchangeable. Doesn't really matter who the owner of the db is, that can stay as-is. We'll create a new role: create user unwashed with password 'notpassword'; -- the difference between role and user is the can login right. For me I was gonna grant them all login rights anyway. You should be able to change the above to create role if you wanted to tighten it down. -- grant it select grant select on maintable to unwashed; -- if you use sequences, they need rights grant all on sequence maintable_id_seq to unwashed; -- func's need exec: grant execute on function update(userid integer) to unwashed; -- There might be other's I'm missing. -- Then create a new user in the unwashed group: create user bob with nocreaterole password 'notpassword' in role unwashed; Its simple to add/remove users now. When you create new stuff, remember to grant the unwashed select rights. :-) -Andy ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
Re: [postgis-users] curves geometries and topology
As long as they are simple circles, you should be able to convert back and forth between curves and lines. Splines, beziers, et al, are probably not going to work at all and would need to be approximated as lines. http://boundlessgeo.com/2012/01/getting-curvey/ On Mon, Apr 14, 2014 at 8:02 AM, Reijer Copier reijer.cop...@idgis.nlwrote: Dear list, According to the documentation, PostGIS Topology only supports edges made out of linestrings. However, we are currently working on a dataset that contains lots of curved geometries. It would be great if we could build topology based on those curved geometries without having to convert them to linestrings first. Is this possible? If not, what is the best way to deal with this situation? -- Kind regards, Reijer Copier IDgis bv ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users -- Eric Ladner ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
Re: [postgis-users] setting up a read only user / group for AutoCAD, ArcGIS, QGIS, and MapServer.
On Mon, Apr 14, 2014 at 8:01 AM, Andy Colson a...@squeakycode.net wrote: On 4/14/2014 7:25 AM, Mark Volz wrote: Hello, I would like to set up a user account in PostGIS / PostGRES with the following: ·The user has read only access to all of the layers in a particular database. ·The user also have read only access to any layers added or updated through the shapefile uploader. ·The client software may be ArcGIS*, AutoCAD (Map), QGIS, MapServer, etc. *ArcGIS will use “query layers”, not SDE. If anyone has any cliff notes on how to properly set up read only permissions please let me know. Thank You Sincerely, Mark Volz, GISP You can think of users and groups pretty much the same. user and role are mostly interchangeable. Doesn't really matter who the owner of the db is, that can stay as-is. We'll create a new role: create user unwashed with password 'notpassword'; -- the difference between role and user is the can login right. For me I was gonna grant them all login rights anyway. You should be able to change the above to create role if you wanted to tighten it down. -- grant it select grant select on maintable to unwashed; -- if you use sequences, they need rights grant all on sequence maintable_id_seq to unwashed; -- func's need exec: grant execute on function update(userid integer) to unwashed; -- There might be other's I'm missing. -- Then create a new user in the unwashed group: create user bob with nocreaterole password 'notpassword' in role unwashed; Its simple to add/remove users now. When you create new stuff, remember to grant the unwashed select rights. :-) There is also ALTER DEFAULT PRIVILEGES at the database level and at the schema level. It is handy when you are adding stuff so that you don't have to explicitly grant privileges every time. ALTER DEFAULT PRIVILEGES IN SCHEMA some_schema GRANT SELECT ON TABLES TO unwashed; -- Richard Greenwood richard.greenw...@gmail.com www.greenwoodmap.com ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
Re: [postgis-users] How to check if two linestring are near to each other
Hi
The test
select st_hausdorffdistance(st_geometryfromtext('LineString(0 0, 1 0)'),
st_geometryfromtext('LineString(0 5, 1 5)'))
gives a distance of 5, not 0 as one would expect if HD only measured shape
similarity, so I think it still can be used for your task. Something like
hibernate spatial should provide programmatic interfaces for common gis
functions, but I suspect you have to write native sql if you want to use
postgis-specific functions like hausdorffdistance.
Åsmund
On Mon, Apr 14, 2014 at 9:36 AM, Rémi Cura remi.c...@gmail.com wrote:
Hey,
I'm not so sure Hausdorff distance is what you want.
It measure how similar 2 shapes are, yet you could have two very similar
parts of a road network that are very far away.
In you case you are trying to express both lines that are close to each
other __and__ that are similar in shape.
Of course the obvious (but painfull) way to go would be to use postgis
topology with the tolerance set to your GPS error (+ width of the road).
This way close path would be merged automatically.
Cheers,
Rémi-C
2014-04-13 23:56 GMT+02:00 Raghavan Krishnasamylakshmanaperumal
rkris...@uic.edu:
Hi Åsmund,
Thanks for suggesting ST_HausdorffDistance, I tried this function
directly on the database using sql query and it looks like solving my
problem.
Are these functions ST_HausdorffDistance/ST_Distance available as java
APIs? I am trying to use org.postgis(postgis-jdbc-1.3.1.jar) library but
not sure how to access the above mentioned functions using java. Please
suggest me which package to look into to make use of these functions
programmatically?
Thanks in advance.
-Raghavan
On Sun, Apr 13, 2014 at 1:45 PM, Åsmund Tokheim asmun...@gmail.comwrote:
Hi
I think you should be able to use hausdorff distance
http://postgis.net/docs/ST_HausdorffDistance.html to recognize that the
green, red and blue lines in your image are all similar. This method will
fail to recognize shared portions of a path (e.g. if the blue line at some
point diverges from the red and green line), but I'm not sure if this is a
requirement for your task
Åsmund
On Sat, Apr 12, 2014 at 9:41 PM, Raghavan Krishnasamylakshmanaperumal
rkris...@uic.edu wrote:
Hi,
I have formed a graph using my GPS traces of running/biking activities
in which I have many edges representing the same path. For example every
time I run from node-A to node-B my GPS traces are noted close to each
other like the red,green,blue lines in the attached image. Actually those 3
lines are same(representing the same path), so I want to detect such
linestrings automatically and keep only one linestring and ignore others.
Is there any way in PostGIS which can help me to detect the
nearness/closeness of the linestrings?
--
Thanks and Regards,
Raghavan KL
___
postgis-users mailing list
postgis-users@lists.osgeo.org
http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
___
postgis-users mailing list
postgis-users@lists.osgeo.org
http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
--
Thanks and Regards,
Raghavan KL
___
postgis-users mailing list
postgis-users@lists.osgeo.org
http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
___
postgis-users mailing list
postgis-users@lists.osgeo.org
http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
___
postgis-users mailing list
postgis-users@lists.osgeo.org
http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
