[postgis-devel] [PostGIS] #866: [raster] Change the ST_MapAlgebra nodatavalueexpr text parameter for nodatavaluerepl

PostGIS trac at osgeo.org
Sat Oct 1 06:36:12 PDT 2011

#866: [raster] Change the ST_MapAlgebra nodatavalueexpr text parameter for
 Reporter:  pracine         |       Owner:  dzwarg       
     Type:  defect          |      Status:  assigned     
 Priority:  blocker         |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  

Comment(by pracine):

 Replying to [comment:4 dzwarg]:
 > Is this ticket intended to only change the ''name'' of the parameter
 from "nodatavalueexpr" to "nodatavaluerepl"?
 > Or does this ticket also imply that the evaluation of the
 "nodatavaluerepl" string will no longer occur, and that any text passed in
 as this parameter gets converted to the raster cell data type and stored
 as "newinitialvalue" in RASTER_mapAlgebra?

 This is not just a parameter name change. The expression passed should
 evaluate to a numeric value the same type of the resulting pixel type. I
 guess the best bet for the type of this parameter is double precision even
 if the requested resulting raster pixel type is int. Yes this value should
 be used to initialize the raster in order to avoid (skipping) computing
 values for nodata values.

 I would change the script/plpgsql/st_mapalgebra.sql first.

 Sorry for the late answer.

Ticket URL: <https://trac.osgeo.org/postgis/ticket/866#comment:5>
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