Changes between Version 115 and Version 116 of WKTRaster/SpecificationWorking03
- Timestamp:
- Jun 13, 2011, 3:21:57 PM (13 years ago)
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WKTRaster/SpecificationWorking03
v115 v116 79 79 1) '''ST_MapAlgebraExpr() -''' A one raster version taking an '''expression''' of one pixel at a time. Already implemented... 80 80 81 2) '''ST_MapAlgebraFct() -''' A one raster version taking a '''user defined function''' (with optional parameters) of one pixel at a time. The function is a user defined PL/pgSQL function taking a float8 value and returning a value. Code was developped by David Zwarg, needs to be integrated in the source tree. This version is much faster than 1) but requires the user to write a PL/pgSQL function.81 2) '''ST_MapAlgebraFct() -''' A one raster version taking a '''user defined function''' (with optional parameters) of one pixel at a time. The function is a user defined PL/pgSQL function taking a float8 value and returning a value. [http://trac.osgeo.org/postgis/ticket/860 Code was developped by David Zwarg], needs to be integrated in the source tree. This version is much faster than 1) but requires the user to write a PL/pgSQL function. 82 82 83 83 3) '''ST_MapAlgebraFctNgb() -''' A one raster version taking a '''user defined function''' (with optional parameters) of the set of first, second, etc... '''neighbours''' of a pixel. The function is a user defined PL/pgSQL function taking a matrix containing the neighbour values and returning one value. Code do not exist yet but will be very much similar to 2). Out of bound pixels values are set to NULL. This version requires the user to write a PL/pgSQL function. Many predefined function should be delivered.
