[postgis-users] PostGIS Raster Decimal?

Andreas Forø Tollefsen andreasft at gmail.com
Tue Mar 29 03:57:40 PDT 2011


Any news about the raster decimal type ticket #650?

Best,
Andreas

2011/3/22 Andreas Forø Tollefsen <andreasft at gmail.com>

> Just double checked that my raster pixel values are indeed stored as
> decimal values.
> select ST_Value(rast,560,100) FROM gpw95;
> returns:
> 11678.7138671875
>
>
> 2011/3/16 Jorge Arévalo <jorge.arevalo at deimos-space.com>
>
>> On Wed, Mar 16, 2011 at 2:53 PM, Pierre Racine
>> <Pierre.Racine at sbf.ulaval.ca> wrote:
>> > Yes, this is ticket 837
>> >
>> > http://trac.osgeo.org/postgis/ticket/837
>> >
>> > Jorge, are those numerous warning normal?
>>
>> The warnings are normal if debug option is enabled. But what strikes
>> me is printf shows real and truncated value as same value. I think
>> this is caused because both values are compared in this way:
>>
>> if (doubleValue1 != doubleValue2) printf(....)
>>
>> instead of
>>
>> if (fabs(doubleValue1 - doubleValue2) > FLT_EPSILON) printf(....)
>>
>> So, this warning message is probably generated in setBits function.
>> Anyway, I don't think that's the reason of the memory error.
>>
>> --
>> Jorge Arévalo
>> Internet & Mobilty Division, DEIMOS
>> jorge.arevalo at deimos-space.com
>> http://es.linkedin.com/in/jorgearevalo80
>> http://mobility.grupodeimos.com/
>> http://gis4free.wordpress.com
>> http://geohash.org/ezjqgrgzz0g
>>
>>
>> > ________________________________________
>> > From: postgis-users-bounces at postgis.refractions.net [
>> postgis-users-bounces at postgis.refractions.net] On Behalf Of Andreas Forø
>> Tollefsen [andreasft at gmail.com]
>> > Sent: Wednesday, March 16, 2011 9:24 AM
>> > To: PostGIS Users Discussion
>> > Subject: Re: [postgis-users] PostGIS Raster Decimal?
>> >
>> > Is the above memory issue known for the ST_MapAlgebra function?
>> > Did you experience this Regina?
>> >
>> > I will try with some other rasters.
>> > The WARNING lines are just a sample. I think it went through a couple of
>> thousands before it ran out of memory.
>> > Is it not strange that the truncated values are the same as the original
>> values?
>> >
>> > Andreas
>> >
>> > 2011/3/15 Andreas Forø Tollefsen <andreasft at gmail.com<mailto:
>> andreasft at gmail.com>>
>> > Hi Pierre,
>> > I got memory issues as well.
>> > I tried with this query:
>> > SELECT ST_MapAlgebra(rast, 'rast*10') INTO algtest FROM gpw90;
>> >
>> >
>> > WARNING:  Pixel value for 32BF band got truncated from 47519.1 to
>> 47519.1
>> > WARNING:  Pixel value for 32BF band got truncated from 185494 to 185494
>> > WARNING:  Pixel value for 32BF band got truncated from 28485.1 to
>> 28485.1
>> > WARNING:  Pixel value for 32BF band got truncated from 10927.1 to
>> 10927.1
>> >
>> >
>> > ERROR:  out of memory
>> > DETAIL:  Failed on request of size 19.
>> >
>> > ********** Error **********
>> >
>> > ERROR: out of memory
>> > SQL state: 53200
>> > Detail: Failed on request of size 19.
>> >
>> > 2011/3/14 Paragon Corporation <lr at pcorp.us<mailto:lr at pcorp.us>>
>> > Pierre,
>> >
>> > Actually the single raster version is documented.  Though I did run into
>> memory issues -- so still think we need some work on that.
>> >
>> > http://www.postgis.org/documentation/manual-svn/RT_ST_MapAlgebra.html
>> >
>> > Regina
>> > http://www.postgis.us
>> >
>> >
>> >
>> > ________________________________
>> > From: postgis-users-bounces at postgis.refractions.net<mailto:
>> postgis-users-bounces at postgis.refractions.net> [mailto:
>> postgis-users-bounces at postgis.refractions.net<mailto:
>> postgis-users-bounces at postgis.refractions.net>] On Behalf Of Andreas Forø
>> Tollefsen
>> > Sent: Monday, March 14, 2011 2:03 PM
>> > To: PostGIS Users 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.Racine at sbf.ulaval.ca<mailto:
>> Pierre.Racine at sbf.ulaval.ca>>
>> > I’m very aware of the problem. Will try to fix it the best we can.
>> >
>> > Why not testing ST_MapAlgebra and give us your feedback? It is still to
>> document but the specifications are in this page:
>> >
>> > http://trac.osgeo.org/postgis/wiki/WKTRaster/SpecificationWorking02
>> >
>> > Pierre
>> >
>> > From: postgis-users-bounces at postgis.refractions.net<mailto:
>> postgis-users-bounces at postgis.refractions.net> [mailto:
>> postgis-users-bounces at postgis.refractions.net<mailto:
>> postgis-users-bounces at postgis.refractions.net>] On Behalf Of Andreas Forø
>> Tollefsen
>> > Sent: 14 mars 2011 11:24
>> > To: PostGIS Users Discussion
>> > Subject: Re: [postgis-users] PostGIS Raster Decimal?
>> >
>> > Hi Pierre.
>> >
>> > Yes. I think that would be an appropriate temporary fix.
>> > Still, 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.Racine at sbf.ulaval.ca<mailto:
>> Pierre.Racine at sbf.ulaval.ca>>
>> > Andreas,
>> >
>> > This is a well known problem. See ticket
>> http://trac.osgeo.org/postgis/ticket/650
>> >
>> > I will discuss this problem with Frank this week at the code sprint in
>> Montreal.
>> >
>> > For now you can use some GIS with map algebra capability to multiply
>> your raster by 10 before importing or test our brand 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-bounces at postgis.refractions.net<mailto:
>> postgis-users-bounces at postgis.refractions.net> [mailto:postgis-users-
>> <mailto:postgis-users->
>> >>bounces at postgis.refractions.net<mailto:bounces at postgis.refractions.net>]
>> On Behalf Of Andreas Forø Tollefsen
>> >>Sent: 14 mars 2011 10:53
>> >>To: PostGIS Users Discussion
>> >>Subject: [postgis-users] PostGIS Raster Decimal?
>> >>
>> >>Hi. Again.
>> >>
>> >>I have been working on some raster data in PostGIS lately.
>> >>However, i have some issues with the raster values become integer after
>> importing the sql to postgis.
>> >>For instance this procedure:
>> >>
>> >>C:\prio_grid\source\gpw>c:\python26\python
>> c:\prio_grid\script\raster2pgsql.py -
>> >>r c:\prio_grid\source\gpw\lrc30p90\glp90ag30\w001001.adf -t gpw90 -s
>> 4326 -o gpw
>> >>90.sql -I -M
>> >>
>> >>Then to database:
>> >>C:\prio_grid\source\gpw>psql -h 192.168.1.55 -d priogrid -f gpw90.sql
>> >>
>> >>Querying this data:
>> >>SELECT gpw90.gid, ((gpw90.gpw90val).val) AS gpw90
>> >>INTO popgrid
>> >>FROM (SELECT priogrid_land.gid, ST_Intersection(gpw90.rast,
>> priogrid_land.centroid) AS gpw90val FROM
>> >>gpw90, priogrid_land WHERE ST_Intersects(priogrid_land.centroid,
>> gpw90.rast)) AS gpw90
>> >>WHERE gpw90.gid = 139303
>> >>GROUP BY gid,((gpw90.gpw90val))
>> >>;
>> >>
>> >>Gives:
>> >>gid; gpw90
>> >>139303;39849
>> >>
>> >>The value in the original raster is:
>> >>39849.2
>> >>
>> >>Question is then. How can i ensure that raster remain decimal and not
>> integer after this import and
>> >>query process?
>> >>
>> >>Thanks.
>> >>Andreas
>> > _______________________________________________
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>> >
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