:
-What is the status of PGRaster? Is any development now underway?
We have some resources to devote to this project over the next few years
and are very interested in forming collaborations to move this work
forward.
Pierre Racine
GIS/Programmer Analyst
University Laval
http://www.cef-cfr.ca
Thanks for your comments Regina,
if you look at Dane's posed problem in
previous postgis post, it is a common scenario where I have really
wanted RASTER in the database and where your proposed
ST_Intersection(RASTER, VECTOR), ST_Interects(RASTER,VECTOR) would have
worked nicely (e.g. steps from
Not sure where Paul is lurking these days, but I wanted to throw out
the name of an application that can already do half of what Pierre is
looking for: StarSpan.
http://starspan.casil.ucdavis.edu/doku/doku.php
This is the tool I use when ever I need to fuse raster with vector
data. Since it can
Nice to ear from you Paul. I still wear this PostGIS t-shirt you gave me
in Ottawa...
- You propose to do this because their is a great demand for it, but
the great demand is generally the stupid demand for images-in-database
just because. You must either somehow *stop* those people, or ensure
best regards
--imran
- Original Message
From: Paul Ramsey [EMAIL PROTECTED]
To: Pierre Racine [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED];
[EMAIL PROTECTED]; PostGIS Users Discussion
postgis-users@postgis.refractions.net
Sent: Monday, July 14, 2008 10:11:05 PM
décembre 2008 06:21
À : [EMAIL PROTECTED];
postgis-users@postgis.refractions.net
Cc : Pierre Racine
Objet : WKT Raster project: call for fundings
Hi all,
As some of you may know, I've been working the past two years
on the GNU Flash Player [1], something I've felt the need for
since I've been doing
Hi Tyler,
Sorry for the late answer.
In regards to slide 12, what would be the result of a
(raster1,raster2)-raster3 operation, if raster1 and raster2 had the
same SRID but had a different origins and pixel dimensions
such that the
cells locations were not coincident?
I haven't much study the
In progress...
Pierre
-Original Message-
From: postgis-devel-boun...@postgis.refractions.net
[mailto:postgis-devel-
boun...@postgis.refractions.net] On Behalf Of Paul Ramsey
Sent: 10 avril 2009 00:32
To: PostGIS Development Discussion; PostGIS Users Discussion
Subject: [postgis-devel]
Hi all,
The PostGIS Users Wiki has moved from:
http://postgis.refractions.net/support/wiki/
to:
http://trac.osgeo.org/postgis/wiki/UsersWikiMain
Please update your bookmarks... and Welcome!
This Trac Wiki system:
-has a better security system,
-keep history of changes,
-allows tables
Venkat,
GeoRaster is a Oracle specific terminology. PostGIS, however, supports the
raster type through the WKT Raster extension. WKT Raster is still in beta
development so you will have to download and compile it:
http://postgis.refractions.net/download/
Pierre
From:
There is no technical reason that should prevent WKT Raster of working with any
recent version of PostGIS. The doc should not then be changed. If it does not
compile it is another story.
If Kevin's trick does the job we can document it.
Pierre
-Original Message-
From:
Gilles,
Glad you could build WKT Raster and it's working fine.
In order to extract cells having value n and build a polygon from those
you would need ST_SelectByValue(raster, ‘expression’) which would return a
raster containing only the selected pixels (the others being filled with NODATA
Mukesh,
Sorry for the late answer. You can give a try to WKT Raster. You will have to
compile it though. Loading Geotiff should then be straightforward using
gdal2wktraster.py.
Pierre
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net]
/experimental.php
Hope that helps,
Regina
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Pierre
Racine
Sent: Monday, December 07, 2009 3:27 PM
To: PostGIS Users Discussion
Subject: Re: [postgis
Hi,
ST_Envelope(geometry) returns a kind of degenerated version (float4s instead of
float8s) of the extent of a geometry based on the cached BOX2D and
ST_Extent(geometry) is an aggregate.
Is there a non aggregate function which returns the exact extent (float8s) of a
geometry?
Try:
SELECT
...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Mark Cave-Ayland
Sent: 17 décembre 2009 05:22
To: PostGIS Users Discussion
Subject: Re: [postgis-users] Getting the exact extent of a geometry
Pierre Racine wrote:
Hi,
ST_Envelope(geometry) returns a kind of degenerated
How do I get the functions for postgis and how do I enable WKT Raster
extension?
Steve,
WKT Raster SQL functions must first be loaded in the database. You must execute
the rtpostgis.sql file located in the share/contrib folder. If you are using
pgAdmin III, just open the SQL file and execute
defined
DETAIL: Creating a shell type definition.
ERROR: could not access file $libdir/rtpostgis: No such file or directory
** Error **
ERROR: could not access file $libdir/rtpostgis: No such file or directory
SQL state: 58P01
Pierre Racine pierre.rac...@sbf.ulaval.ca
(geometry, geometry) does not exist
SQL state: 42883
Hint: No function matches the given name and argument types. You might need to
add explicit type casts.
Character: 8525
thanks
Steve
Pierre Racine pierre.rac...@sbf.ulaval.ca@postgis.refractions.net
Envoyé par : postgis-users-boun
Hi Steve,
Refer to http://trac.osgeo.org/postgis/wiki/WKTRaster/SpecificationWorking01
for the most complete documentation about gdal2wktraster.py The official doc is
still in development. Look in the PostgreSQL doc for a complete understanding
of the -m parameter.
You have probably produced
Hi PostGIS folks,
Now that you have a little bit of time after the release of PostGIS 1.5, I
would like to request your comments on the WKT Raster specifications drawn to
meet objective 0.1.6 - Being able to intersect vector and raster to produce
vector. In other word: what set of function do
Hi PostGIS folks,
Now that you have a little bit of time after the release of PostGIS 1.5, I
would like to request your comments on the WKT Raster specifications drawn to
meet objective 0.1.6 - Being able to intersect vector and raster to produce
vector. In other word: what set of function do
Rainer,
There is a difference between accessing a whole band of a multiband raster and
access a single pixel value.
The ST_Band(rast raster, band integer) function (not yet implemented) will
return a whole band (i.e. an object of type raster).
The ST_Value(rast raster, band integer, x
Ok: it should have been RFC instead of RFQ. I don't know what I was
thinking about...
Pierre
-Original Message-
From: postgis-devel-boun...@postgis.refractions.net [mailto:postgis-devel-
boun...@postgis.refractions.net] On Behalf Of Pierre Racine
Sent: 8 février 2010 13:52
To: postgis
-
From: postgis-devel-boun...@postgis.refractions.net
[mailto:postgis-devel-boun...@postgis.refractions.net] On Behalf Of Pierre
Racine
Sent: Wednesday, February 10, 2010 10:04 AM
To: PostGIS Development Discussion; (postgis-users@postgis.refractions.net)
Subject: Re: [postgis-devel] RFQ: WKT Raster
Marcello,
PostGIS handle only vector data. The raster part is under development and tools
to interpolate raster from points are planned even if there are not our first
priority.
Pierre
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net]
Ok forget about that... I was testing with 1.3. This is fixed in 1.5.
Pierre
-Original Message-
From: postgis-devel-boun...@postgis.refractions.net [mailto:postgis-devel-
boun...@postgis.refractions.net] On Behalf Of Pierre Racine
Sent: 9 avril 2010 15:00
To: PostGIS Users Discussion
Phil,
Glad you came with this question... No you're not the first and only one one to
ask this question. Actually WKT Raster is specifically designed to answer this
kind of need, but we are still working on it.
In a few weeks you will be able to do:
SELECT (gv).id, ST_X((gv).geom),
include ST_Reclass, ST_Clip,
ST_AsRaster, ST_Resample.
Let us know your need and your experience with WKT Raster.
Thanks,
Pierre Racine
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So now that you had it manually does it still complain that it can not find
libpq?
Some systems need us to explicit some installation paths (like Windows) in the
configure command.
Pierre
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
ST_Union is an aggregate function that you must use with a GROUP BY clause.
Here, you are not agregating anything.
Pierre
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Biddy
Sent: 15 juillet
What should happen when event A is at a distance n minus epsilon from B, B is
at a distance n-epsilon from C but A is at a distance 2*n-epsilon from C?
Should A and C be in the same cluster with B?
Pierre
-Original Message-
From: postgis-users-boun...@postgis.refractions.net
-utilities/
Thanks again for pointing me towards PAM/CLARA.
Cheers,
Will
On 15 July 2010 21:33, Pierre Racine pierre.rac...@sbf.ulaval.ca wrote:
I would suggest you ask your question to the r-sig-geo mailing list. You
will get a R solution. You
can then get your PostGIS table from R using the gdal
You're using PostgreSQL 8.3 right?
Replace
SELECT ST_Intersection((gv).geom, $1) intgeom
with
SELECT ST_Intersection((gv).geom, $1) AS intgeom...
I'll fix the source.
Pierre
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] On Behalf
Hi Sebastian,
I can convert ESRI Grid file to .sql without problem using gdal2wktraster.py
and the same parameters as you. I can do both integer and floating point
rasters.
Maybe this is a GDAL problem. Try to convert it using gdal_translate (to tiff
for example). This would be a better test
per CPU as for Oracle !
If you save extra money by not having buying an Oracle license and you are
interested in collaborating in the development of WKT Raster, let us know ;-)
Pierre
Sebastian
On Mon, Jul 19, 2010 at 5:00 PM, Pierre Racine pierre.rac...@sbf.ulaval.ca
wrote:
Hi Sebastian,
What
= numpy.empty([buf_ysize,buf_xsize], dtype = typecode)
MemoryError
On Mon, Jul 19, 2010 at 5:56 PM, Pierre Racine
pierre.rac...@sbf.ulaval.camailto:pierre.rac...@sbf.ulaval.ca wrote:
Hi Sebastian,
I can convert ESRI Grid file to .sql without problem using gdal2wktraster.py
and the same parameters
limits for vectorial data.
yuriesky
- Original Message -
From: Pierre Racine pierre.rac...@sbf.ulaval.ca
To: PostGIS Users Discussion postgis-users@postgis.refractions.net
Sent: Monday, July 19, 2010 10:25 AM
Subject: [!! SPAM] Re: [postgis-users] may have postgis store limits for a
big
I can split it in smaller georeferenced tiles... (how?)... but My
main question is: after that, how will the table look like ? how can I do the
same query (where id=1 or where name=UK etc...) ?
On Tue, Jul 20, 2010 at 2:31 PM, Pierre Racine
pierre.rac...@sbf.ulaval.camailto:pierre.rac
: Pierre Racine
Subject: Re: [postgis-users] WKTRaster : gdal2wktraster.py cannot read
AIG/Arc/Info Binary Grid
On 07/20/2010 05:47 PM, Pierre Racine wrote:
Since we have this bug with big rasters,
proven, any-size, ... ;-)
Who is proven? Well, running a dozen-TB seamless mosaic on PostgreSQL for many
Sabastian,
This is strange... They are all in the same folder? How many there are? As a
test, does it work if there is only 2?
Where did you get WKT Raster? Do you have the last version?
What if you do: gdal2wktraster.py --version
If you could reduce the big raster to a smaller one which
Hi George,
Unfortunalely st_setvalue is not yet implemented. You could have created an
empty raster (st_makeemptyraster) and set the pixels values with st_setvalue.
The only way to create a raster and set specific pixels value now is to
generate the HEX values representing the raster and to
Peter,
Are rasters in rasdaman georeferenced? How do I convert my vectorial PostGIS
points coordinates into rasdaman coordinates? Do I have to do all the math
myself?
Pierre
From: Peter Baumann [mailto:p.baum...@jacobs-university.de]
Sent: 21 juillet 2010 04:41
To: Pierre Racine
Subject: Re
ipX = X ordinate of upper-left pixel's upper-left corner in geographical units
ipY = Y ordinate of upper-left pixel's upper-left corner in geographical units
Pierre
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of George
Well it's still a bug that the process fail without the -k option, but we can
lower the priority. If we could have one of those rasters...
Pierre
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of
.
George
On Wed, Jul 21, 2010 at 12:42 PM, Pierre Racine
pierre.rac...@sbf.ulaval.camailto:pierre.rac...@sbf.ulaval.ca wrote:
Hi George,
Unfortunalely st_setvalue is not yet implemented. You could have created an
empty raster (st_makeemptyraster) and set the pixels values with st_setvalue
Hi,
It might be slow and arduous but the fact is that you can now edit raster in
the database with PostGIS WKT Raster. Eventually we will be able to edit block
by block but for now its pixel by pixel :-| Try:
ST_SetValue(rast raster, band integer, x integer, y integer, value float8)
if you
fair if you could rectify this statement.
Thanks,
Pierre
From: Peter Baumann [mailto:p.baum...@jacobs-university.de]
Sent: 21 juillet 2010 17:28
To: Pierre Racine
Cc: PostGIS Users Discussion
Subject: Re: [postgis-users] WKTRaster : gdal2wktraster.py cannot read
AIG/Arc/Info Binary Grid
Pierre
I would suggest to do everything with SQL views and pl/pgSQL functions. From
what I read, ORM seems to add an unnecessary, inefficient layer unless you want
to get involved in complex OO design and develop a portable solution
(http://en.wikipedia.org/wiki/Object-relational_mapping).
My two
Andreas,
This is one of the operation WKT Raster was made for. See the tutorial:
http://trac.osgeo.org/postgis/wiki/WKTRasterTutorial01
You will need to compile (if you are on Linux) or install (on Windows) the WKT
Raster PostGIS extension. You import your shapefiles, you import your raster,
Hi Tyler,
Is this the same geos you are using when compiling PostGIS? WKT Raster is
indirectly rependent on geos via PostGIS.
Pierre
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Tyler
Hi Stefan,
I'm aware of WKT and WKB in vector knowing OGC Simple Feature Spec.
I'm now wondering about the usage of the notion Well Known Text (WKT)
and Well Known Binary (WKB) for raster.
There is no WKT, WKB standards for raster and there is no standard (that I know
of) to store raster in a
As I said: no. They are not specified in public. I wish there would have
been a public spec to tell
me how to store raster but there is not.
I'd like to understand and support this better:
1. You write They are not specified in public.: But now they are at
least in the sense of PostGIS WKB,
Great. But I also specifically meant if the way of binary encoding is stable?
That's probably important for those application which read/write WKB
with their own means i.a. without PostGIS libraries.
I am pretty confident it will stay stable until we add new stuff to it.
Probably not before
I already saw the two first lines:
c:\wktraster_pg84\bin\gdal2wktraster.py:645: DeprecationWarning: integer argumen
t expected, got float
hexstr = binascii.hexlify(struct.pack(fmt_little, data)).upper()
But it didn't not prevent the script to create the sql file properly.
I guess this is
Hi Paolo,
You can use any srtm file from anywhere and generate the points using the
provided plsql function.
I wrote to the admin of the ftp site to see if it is permanently down... Will
see.
Pierre
-Original Message-
From: postgis-users-boun...@postgis.refractions.net
The site is back online...
ftp://srtm.csi.cgiar.org/SRTM_v41/SRTM_Data_GeoTIFF/
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Paolo Cavallini
Sent: 3 janvier 2011 10:27
To:
As far as export goes, I think you are right -- we already have that
in the GDAL PostGIS Raster driver, but that gave me a thought that the
planned PostGIS functions ST_AsJPEG, ST_AsTiff etc Maybe should just
piggy back on GDAL and be callled
ST_AsRasterOutputFormat(rast, 'sometype',
The GDAL toolkit will NOT be delivered in PostGIS 2.x package -- well at
least not to my knowledge. What I meant to say was that just the
libgdal.so, libgdal.dll PostGIS will have a dependency on, but
There is technically no requirement to package the accompanying tools --
e.g. gdal_translate,
@postgis.refractions.net
Subject: Re: [postgis-users] WKTRaster problems on Mac
I used QGIS to create the image. I tried Open Jump, but I can't get anything
to load at all using the commands below.
Might be my syntax, I've never used it before
I get the message x01 does not exist...
Ken
Pierre Racine-2
I suspect this is a problem with the QGIS plugin. I know the GDAL driver was
rewritten in december. Anybody knows the status of the QGIS plugin?
Pierre
I used QGIS to create the image. I tried Open Jump, but I can't get anything
to load at all using the commands below.
Might be my syntax, I've
Sunny,
There are two planned options for serving raster from PostGIS raster:
The first (1) is to just register the raster as out-of db raster. Only the
georeferences of each tile/raster is stored in the database along with the path
to the raster itself in the filesystem (you can add any other
tell the speed, and like mentionnend Simon it depends of many things.
But I did succeed to render (query and write to disk as an ascii file with prj
file) a 100x100 pixels 32b float, single band using gdal_translate in the
latest release version.
Etienne
On Mon, Jan 31, 2011 at 10:46 AM, Pierre
This tutorial will show you how to do exactly what you want with rasters:
http://trac.osgeo.org/postgis/wiki/WKTRasterTutorial01
Pierre
From: postgis-users-boun...@postgis.refractions.net
[postgis-users-boun...@postgis.refractions.net] On Behalf Of
I don't know if this would be fast but I would query those buffers which do not
intersects with a Union of the layer... Something like:
SELECT id, name, elevation, geom
FROM peaktable A, (SELECT ST_Union(ST_Buffer(geom, 5)) AS geom FROM peaktable) B
WHERE NOT ST_Intersects(ST_Buffer(A.geom, 5),
Hi,
What is the meaning of:
ERROR: lwcollection_construct: mixed dimension geometries: 0/2
SQL state: XX000
I get this when I do ST_Intersection() on two tables. Both tables contains only
one geometry. ST_Dimensions give 2 for both.
How can I fix it?
I tried ST_Buffer(geom, 0) without
Forgot to say:
ST_IsValid returns TRUE on both geometries...
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Pierre Racine
Sent: 16 février 2011 16:19
To: PostGIS Users Discussion
Subject
ST_MakeValid does the job but it is available only with 2.0...
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Pierre Racine
Sent: 16 février 2011 16:22
To: PostGIS Users Discussion
Subject: Re
You should just divide the area of your polygon by the area of one of your
pixel.
I want to investigate this example a little bit further. What is the size of
your raster in pixels? I understand that you did not tile it. Did you?
Pierre
From: postgis-users-boun...@postgis.refractions.net
By reducing the tile size from 100x100 to 50x50 I get much better performance.
But still vectorizing is faster than counting pixels...
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Pierre
Racine
Sent: 28 février 2011 10
Ok thanks. I got a bit confused regarding the vectorizing. Isnt that what i am
doing with this query?
I have now reduced the resolution to increase performance. Each cell is
now 0.02224x0.02224. (previous X 8)
Yes this is what you are doing. ST_Intersection will
I would use PostGIS raster:
first:
CREATE OR REPLACE FUNCTION ST_PixelAsPolygons(rast raster, band integer)
RETURNS SETOF geomval AS
$$
DECLARE
rast alias for $1;
w integer;
h integer;
x integer;
y integer;
result geomval;
BEGIN
Do you have the rtpostgis shared library in usr/local/pgsql-9.0/lib?
There should be libgdal as well.
Pierre
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of AJ7
Sent: 11 mars 2011 07:02
To:
-9.0/lib, but I
don't have any libgdal. where should I get this from? Is this why its not
working?
Pierre Racine-2 wrote:
Do you have the rtpostgis shared library in usr/local/pgsql-9.0/lib?
There should be libgdal as well.
Pierre
-Original Message-
From: postgis-users-boun
on my machine, so didn't bother
installing again. (all the installations from the link above worked fine).
Pierre Racine-2 wrote:
Is there any way I can see the list of file included in your kyngchaos
package?
libgdal is the base GDAL library. rtpostgis.so is dependent on it and
should be able
new ST_MapAlgebra function
(still to debug).
Pierre
-Original Message-
From: Pierre Racine
Sent: 14 mars 2011 10:55
To: Pierre Racine
Subject: FW: [postgis-users] PostGIS Raster Decimal?
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun
The version you got from kyngchaos is stating to be a bit old. Since this time
WKT Raster was integrated into PostGIS and gdal2wktraster.py was renamed
raster2pgsql.py.
Considering the version you have gdal2wktraster.py is the right script to
import raster in PostGIS.
You should not use -k
So would you advise me to get postgis from the trunk, and compile the
source, or its fine to work with the version from kyngchaos for now?
Depends if what you want to do is included or/and working fine in this version.
The last version is always better.
In terms of the image - well the image
, a bit problematic when working with climate data which very often
include decimal digits and often have weekly and monthly rasters for 100's of
years :)
Good luck.
Best,
Andreas
2011/3/14 Pierre Racine
pierre.rac...@sbf.ulaval.camailto:pierre.rac...@sbf.ulaval.ca
Andreas,
This is a well known
Be carefull here as PostGIS raster was not really intented to do this kind
of operation on so small images. It's like using a bazooka to kill a fly.
Many GIS packages will allow you to do this simple operation much easier
than PostGIS...
Why do you feel the need to use PostGIS for that?
Ah
See this tutorial:
http://trac.osgeo.org/postgis/wiki/WKTRasterTutorial01
search for Intersecting the caribou buffers with the elevation rasters
the query look like this:
CREATE TABLE resulttable AS
SELECT id,
(gv).geom AS the_geom,
(gv).val
FROM (SELECT id,
Discussion
Cc: Pierre Racine
Subject: Re: [postgis-users] PostGIS Raster Decimal?
Hi Pierre,
I will check it out tomorrow and give some feedback.
Cheers,
Andreas
2011/3/14 Pierre Racine
pierre.rac...@sbf.ulaval.camailto:pierre.rac...@sbf.ulaval.ca
I’m very aware of the problem. Will try to fix
Hi,
Is there a way now to produce a TIN (or Polyhedral surface I guess) from a
table of point geometry?
Thanks,
Pierre
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postgis-users mailing list
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, at 9:33 PM, Pierre Racine wrote:
Hi Pierre,
Is there a way now to produce a TIN (or Polyhedral surface I guess)
from a table of point geometry?
Nope, as the (initial) use case for TIN is not coverage, but rather
City Model
(so small precomputed volumes)
If we want such a thing we have
Hi,
I posted three PostGIS raster ideas for the Google Summer of Code program if
any student is interested in getting 5000$ for a summer job:
http://trac.osgeo.org/postgis/wiki/WKTRasterGSoC
Dealine is april 8th. Be quick!
Pierre Racine
___
postgis
= Where is the docu. for TIN in PostGIS?
I'm also looking for it...
There is no Point Cloud data type yet in PostGIS and Paul told me that
there are no plans to implement this yet as described here
http://opengeo.org/technology/postgis/coredevelopment/pointclouds/ .
= Still holds true?
Hi JP,
It all depends on the size of your raster coverage. If it is big, it should be
tiled (loaded using the raster2pgsal.py -k option and tiled as small as
possible 10x10 or 25x25) and in this case the ST_Intersects is useful. If it's
not tiled then the ST_Intersects is useless unless you
to filter out all the
empty geometries, so that is what I wanted. I will run a few tests to see if it
is working correctly.
Cheers,
JP
On Thu, Apr 28, 2011 at 3:32 PM, Pierre Racine
pierre.rac...@sbf.ulaval.camailto:pierre.rac...@sbf.ulaval.ca wrote:
Hi JP,
It all depends on the size of your raster
Hi,
I have one table with 21 000 000 polygons (most of the forest stands of Canada)
and another one with 25 very big polygons (I expect each of them intersects
with some 10 polygons from the first one). When I intersect the two tables
like this:
CREATE TABLE result AS
SELECT
I want to use daily weather variables that are in a grid for USA. I
would want store the daily variables ( a new grid each day) so I can
have a database that will allow the client to send a point lat/lon and
then return a calculation based on a few days worth of two or three
variables.
Do
Discussion
Subject: Re: [postgis-users] gridded data
Great info, thanks a lot.
If you think it best to store each weather variable in a separate table, then I
imagine that would be by date too, i.e. a table named max_temp_05_09_2011 or
something like that?
Thanks,
Steve
On 5/9/2011 11:55 AM, Pierre
Did you load/execute rtpostgis.sql in the database?
Also, I think this is not good practice to use your template database
(template_postgis20) to store data.
Pierre
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Virginia
1] Globally (i.e., not for an individual tile, but for the entire scene) I
want one histogram of raster values for pixels which are inside the fire
perimeter, and one histogram of raster values for pixels which are outside.
Stats functions like ST_Histogram() do not allow yet to compute stats
Hi all,
I'm preparing a presentation and I need some use cases for PostGIS Raster. I
would be grateful if people already using the raster side of PostGIS would
describe what they already do it. Bborie, Jorge, Regina, others? These uses
cases are vital for the project.
On my side we are using
Would it be possible that the driver needs a missing entry in the
raster_columns table?
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Jorge Arévalo
Sent: Monday, June 06, 2011 4:01 AM
To:
Pierre, is it possible to get a copy of your presentation after you've
delivered it?
It may be nice to use in attracting more participants in the academic
circles. I'm
currently thinking of some MRI, CT or X-Ray usage.
Thanks Bborie. You can already get the FOSS4G presentations I did in
And take 5 minute to answer to my thread How do you use PostGIS Raster?
Andreas... Thanks!
-Original Message-
From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-
boun...@postgis.refractions.net] On Behalf Of Jorge Arévalo
Sent: Tuesday, June 07, 2011 8:45 AM
It is true that PostGIS raster do not allow yet to reassemble raster
tiles into bigger rasters but you don't have to do that in order to
compute histogram on a tiled coverage. Just compute the histogram
for every tiles and aggregate the results using a GROUP BY query.
(Bborie: shouldn't we
For the second thing: Landsat scenes are ~7000x8000 pixels;
ST_DumpAsPolygons() gives
va huge set of geometries. The MODIS fire perimeters are also huge. The first
step is a
global (image-wide) analysis. It was very slow when I tried it. We need an
ST_Intersection
that returns a clipped
Two things:
1) For ST_Intersection to be fast the total area covered by nbr_polygons must
be relatively smaller than the modis area. If the intersecting surface is
similar to your modis area, ST_Intersection will try to vectorize all the
raster and this takes generally too much time and
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