[postgis-users] PostGIS Raster Decimal?

Tue Mar 29 04:18:31 PDT 2011

2011/3/29 Andreas Forø Tollefsen <andreasft at gmail.com>:
> Any news about the raster decimal type ticket #650?
> Best,
> Andreas
>

Hello,

I'm currently working on ticket #837. Ticket #650 is temporarily
frozen (http://postgis.refractions.net/pipermail/postgis-devel/2011-March/012243.html).
We want to focus in a few functionalities for official PostGIS 2.0
release.

Anyway, I don't know if Frank worked on that topic during the last code sprint.

Best regards,

-- 
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

> 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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>>> >
>>> >
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>>
>
>