Hi Tasneem,
You will have to create a geometry first before you can use postgis
functions. Just 2 columns with coordinates are not enough (you're very
close though).
I would recommend to do some reading in the manual, especially here:
Hi Yamini,
I'm not sure I understand what you are trying to do.
Perhaps you can give the realworld example of your task or maybe an
image that explains?
If you need something of an 'outermost ring' around your area you might
consider using ST_ConcaveHull.
Hi Yamini,
Are you sure that multipolygons is what you want to work with? Since a
multipolygon can consist of multiple polygons (obviously) who share a
common centroid that can be way outside your actual polygons.
That said, I would make use of ST_Dumppoints to do that.
Something like:
Thanks for pointing that out David!
I got my example from an existing piece of code that needed measures
later on, so at that time it made sense to create the measure.
Nevertheless I'm hoping for some upgrade of the linear referencing
functions. Especially the option of offsetting along a line
,
Tom
On 27-7-2012 16:24, David William Bitner wrote:
What kind of upgrades are you after? ST_LocateAlong does allow for
offsetting along a line.
On Fri, Jul 27, 2012 at 3:16 AM, Tom van Tilburg
tom.van.tilb...@gmail.com mailto:tom.van.tilb...@gmail.com wrote:
Thanks for pointing that out
Hi Rob,
Points in a regular interval have always been a pain to create in
postgis. I hope someone will write a decent linear_reference code for
this some time soon.
Here's a way to do it:
1) make a line out of your points (ST_SetSrid(ST_MakeLine(pointa,
pointb), 27700))
2) add an M value
Perhaps the question would be better situated in the geoserver list but
I'll try my luck here first.
Did anyone recently succeeded in creating a coveragestore in geoserver
from pgraster data?
The only document around describing it I've seen is:
Hi Pedro,
You might try to create lines from the boat tracks (see examples in
manual for ST_MakeLine) and circles (st_buffer) from the proximity
areas around the buoy.
Now do a ST_Intersection(boatline, bouycircle). The result should be a
set of lines within the bouycircle. Every line stands
wrote:
On 07/20/2012 07:38 AM, Tom van Tilburg wrote:
Hi Pedro,
You might try to create lines from the boat tracks (see examples in
manual for ST_MakeLine) and circles (st_buffer) from the proximity
areas around the buoy.
Now do a ST_Intersection(boatline, bouycircle). The result should
stuck with an old server running PG 8.3 and can't use
WITH clause :D
Thanks Tom!
Pedro Doria Meunier
Telf. +351 291 933 006
GSM +351 915 818 823
Skype: pdoriam
On 07/20/2012 09:03 AM, Tom van Tilburg wrote:
Hmm, I would still think that, as long as you have a single line
per-boat, this would solve
Pedro, try this. No guarantee that it works on 8.3 though.
If you want this data live, make sure to use views instead of tables and
probably create a valid identifier for showing it from a mapserver.
I see one caveat by the way: if your boat passes the bouy but turns
outside your buffer and
...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Tom van Tilburg
Sent: Friday, July 06, 2012 9:37 AM
To: PostGIS Users Discussion
Subject: [postgis-users] Better way of removing pixelation with postgis raster
Hi list,
Im trying to create a landuse map for a customer
ok. I will try a bit of plpgsql'ing.
That reminds me to another question:
is there any place that people can drop their own scripts for a
wider audience?
I know there is some postgis wiki but it doesn't seem very active
or structured.
I would love to share my scripts and see some
...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] On
Behalf Of Tom van Tilburg
Sent: Tuesday, July 10, 2012 6:33 AM
To: postgis-users@postgis.refractions.net
Subject: Re: [postgis-users] possible bug: function
st_asgeojson(geometry) is not unique
On 10-7-2012 12:16
Worked great. Thanks!
On 11-7-2012 13:39, Paragon Corporation wrote:
In the postgis_upgrade_20_minor.sql file, there are a bunch of drop
commands at the end. Just run those and you should be fine.
Regina
http://www.postgis.us
___
postgis-users
In my opinion this should work:
SELECT ST_AsGeoJson(ST_MakePoint(1,2))
or: SELECT ST_AsGeoJson(ST_MakePoint(1,2)::geometry)
however, it produces:
--
ERROR: function st_asgeojson(geometry) is not unique
LINE 1: SELECT ST_AsGeoJson(ST_MakePoint(1,2))
^
HINT:
GEOS=3.3.5-CAPI-1.7.5 PROJ=Rel. 4.8.0, 6
March 2012 GDAL=GDAL 1.9.1, released 2012/05/15 LIBXML=2.7.8
TOPOLOGY RASTER
Does it work for you?
On 10-7-2012 11:38, Sandro Santilli wrote:
On Tue, Jul 10, 2012 at 11:35:20AM +0200, Tom van Tilburg wrote:
ERROR: function st_asgeojson(geometry
On 10-7-2012 12:16, Sandro Santilli wrote:
Also I see no double functions in public.functions nor are there
functions in any other place installed in the database.
select * from pg_proc where proname = 'st_asgeojson';
(I have 5 rows)
Seems I spoke too soon.. I just created a brand new empty
Hi list,
Im trying to create a landuse map for a customer that requires the
removal of pixelation (isolated islands of pixels, possible larger than
1 pixel).
To make things complicated, different pixelclasses have different
tresholds for removal.
For instance, class 1 is removed when the
st_minpossiblevalue(text) does not exist
SQL state: 42883
Hint: No function matches the given name and argument types. You might
need to add explicit type casts.
Context: PL/pgSQL function st_clip line 31 at assignment
2011/12/6 Tom van Tilburg tom.van.tilb...@gmail.com
mailto:tom.van.tilb
Divisions by zero shouldn't happen as far as I know, at most it should
give you null data as return.
Sounds like a bug.
Perhaps you can check:
http://trac.osgeo.org/postgis/browser/trunk/raster/scripts/plpgsql/st_summarystatsagg.sql
at line 69 it says: ($1).sum / ($1).count
my guess is that
Yes, well found.
I'm not familiar with plpgsql, but I'm sure it's easy to include some
conditional statement. Just check the postgres documentation.
You can also check if you can put the conditional into your SQL query
(something like 'WHERE count(rast) 0') so that you don't feed empty
Andreas,
I didn't have time to reproduce your problem yet. Did you have any
succes by yourself on this issue?
Could it have something to do with counting the non-data values as
value? This is what I experience with a similar function (ST_Clip) that
consequently gave me the value '0' instead
Pierre,
I just ran a test to see the difference between my old method and your
new method with ST_Clip and ST_SummaryStatsAgg and came up with the
following:
1. The old way took 38 secs. whereas the new one 46 (100 polygons,
usually covering part of 1 raster tile).
2. ST_Clip appears to
are you using?
On Fri, Nov 18, 2011 at 11:14 AM, Tom van Tilburg
tom.van.tilb...@gmail.com wrote:
Thanks guys!
It works now.
With this metadata issue fixed it is possible to use the 'one table as a
raster' mode on GDAL.
(and thus open it in QGIS)
Chrs,
Tom
Pierre,
This is great you're working on this. It is exactly what I think that
pgraster is going to make a great tool.
Last days I didn't really have time to check out things, hopefully this
week.
Cheers,
Tom
On 30-11-2011 19:19, Pierre Racine wrote:
Andreas, Tom,
I have put two new
Andreas,
We did approx. the same thing for non-quadrate polygons. Perhaps it
might be useful:
Step 1: Make a raster from every polygon, based on the grid
specifications of the elevation raster. Here is also the solution: the
raster cells will only be created for cells that have their
!
Andreas
2011/11/24 Tom van Tilburg tom.van.tilb...@gmail.com
mailto:tom.van.tilb...@gmail.com
Yes, I think so.
Current windows build is *r8221
*
Also, I think ST_Union(raster) (which I used in the
example) is not included
Joan,
I think your expression is wrong.
'kb1.rast+kb.rast'
should be:
'rast1+rast2'
Oddly enough, I would not expect this error message with that error, so
I'm curious wether it will make a change. Could it be there is any more
quotes in the query that we can't see?
Chrs,
Tom
On
...@postgis.refractions.net] On
Behalf Of Bborie Park
Sent: Thursday, November 17, 2011 1:52 PM
To: postgis-users@postgis.refractions.net
Subject: Re: [postgis-users] POSTGIS2.0: wrong nodatavalue
inST_BandMetaData()
On 11/17/2011 07:40 AM, Tom van Tilburg wrote:
Bborie, thnx for the quick response.
Is there a windows
Hi list,
Does anyone see the same happening as me with the ST_BandMetaData()?
See the following SQL:
UPDATE mytable
SET
rast = ST_SetBandNoDataValue(rast,1,0);
SELECT rid,
ST_Numbands(rast),
ST_BandNoDataValue(rast),
(foo.md).*
FROM (SELECT rid,
Hi list,
Does anyone see the same happening as me with the ST_BandMetaData()?
See the following SQL:
UPDATE mytable
SET
rast = ST_SetBandNoDataValue(rast,1,0);
SELECT rid,
ST_Numbands(rast),
ST_BandNoDataValue(rast),
(foo.md).*
FROM (SELECT rid,
Bborie, thnx for the quick response.
Is there a windows build available?
Thanks,
Tom
On 17-11-2011 15:51, Bborie Park wrote:
On Thu, Nov 17, 2011 at 4:14 AM, Tom van Tilburg
tom.van.tilb...@gmail.com wrote:
Result:
1;1;-99;32BSI;t;5.68386e-038;f;
2;1;-99;32BSI;t;5.68386e-038;f
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