[postgis-users] PostGIS Raster Decimal?

Wed Mar 16 08:31:03 PDT 2011

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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