[postgis-users] No intersection between two rasters notice

[Bborie Park]

1. rast::geometry = ST_ConvexHull(rast).

2. I'd assume so... I'm just used to using boolean TRUE or FALSE.

-bborie

On 01/16/2013 12:58 PM, Francois Hugues wrote:
> One more time thank you for the answer Bborie !
> 
> Two more details :
> 1. I didn't know it was possible to use rast::geometry. Is it similar as st_convexhull, st_envelope ?
> 2. You wrote st_touches != TRUE. Is it the same as ='f'. One is faster than the other ?
> 
> Hugues.
> 
>  
> 
> -----Message d'origine-----
> De : postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-bounces at lists.osgeo.org] De la part de Bborie Park
> Envoyé : mardi 15 janvier 2013 18:26
> À : postgis-users at lists.osgeo.org
> Objet : Re: [postgis-users] No intersection between two rasters notice
> 
> Yes, part of the issue is due to adjacent tiles.  If you're using PostGIS 2.0, add something like...
> 
> AND ST_Touches(rast1::geometry, rast2::geometry) != TRUE
> 
> If you're running PostGIS from svn...
> 
> AND ST_Touches(rast1, rast2) != TRUE
> 
> -bborie
> 
> On 01/15/2013 08:45 AM, Francois Hugues wrote:
>> Hi everyone,
>>
>> I'm facing a new difficulty with rasters. This time with 
>> st_MapAlgebraExpr (the whole query is below). I have this notice when 
>> I try to cross two rasters with exactly similar tiles.
>> NOTICE:  The two rasters provided have no intersection.  Returning no 
>> band raster
>>
>> To avoid to cross tiles with others where there were effectively no 
>> intersection I tried the where clause "where st_intersects(rast1, 
>> rast2)" but the problem is not really solved. Is it because of 
>> adjacent tiles ?
>>
>> Is there a more effective (and faster) way to use mapalgebra and to 
>> avoid this creation of empty tiles which prevent to use st_convexhull 
>> (and every function which use convexhull) ?
>>
>> Hugues.
>>
>> select alti.rid, st_mapalgebraexpr(alti.rast, slopes.rast, 
>> '[rast1]*[rast2]', '32BF', 'NULL', 'NULL', 'NULL') rast from 
>> rasters.alti_cons_ign_alpes alti, rasters.slopes_alpes slopes where 
>> st_intersects(alti.rast, slopes.rast)
>>
>> _______________________________________________
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>>
> 
> --
> Bborie Park
> Programmer
> Center for Vectorborne Diseases
> UC Davis
> 530-752-8380
> bkpark at ucdavis.edu
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-- 
Bborie Park
Programmer
Center for Vectorborne Diseases
UC Davis
530-752-8380
bkpark at ucdavis.edu