[postgis-devel] [PostGIS] #588: [raster] Implement the one raster version of ST_MapAlgebra

[PostGIS]

#588: [raster] Implement the one raster version of ST_MapAlgebra
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  Reporter:  pracine         |       Owner:  jorgearevalo 
      Type:  task            |      Status:  closed       
  Priority:  medium          |   Milestone:  PostGIS 2.0.0
 Component:  postgis raster  |     Version:  trunk        
Resolution:  fixed           |    Keywords:               
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Comment(by robe):

 That's the weird thing - everything was going good and then suddenly I
 would get errors like SELECT CASE WHEN mod(200.00,2)  ... rast  (RAST does
 not exist) errors.

 Though I can't trip it up now with a case:  These work fine for example,
 but it wasn't the one I was testing yesterday (which is why I thought it
 was one of those heisenburgs).

 However I do keep on getting a notice that my initial value is truncated
 when I do things like this:

 ALTER TABLE dummy_rast ADD COLUMN map_rast raster;
 UPDATE dummy_rast
   SET map_rast = st_mapalgebra(rast, 'CASE WHEN mod(rast,2) = 1 THEN rast
 WHEN rast = 254 THEN 100 WHEN rast < 253 THEN mod(rast,4) ELSE rast END')
 WHERE rid = 2;

 Is that one of those weird windows bugs?

 Gives warning:


 {{{
 WARNING:  Initial pixel value for 8BUI band got truncated from -128.000000
 to 128
 }}}


 But result above looks right.


 I think the other case with the PixelType not working was user error on my
 part.  I had typed 2BB instead of 1BB or 2BUI.  I didn't get a warning
 message or error, but it didn't convert the pixeltype -- it left it as
 8BUI.  I think maybe we should throw an error if someone types in an
 invalid PixelType -- you know just for people like me :).  It wouldn't be
 pleasant if you thought that you had a 2BB pixel band and 1 million
 updates later, you realized it was really 8 BUI.

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/588#comment:7>
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