Changes between Version 21 and Version 22 of WKTRaster/SpecificationWorking02


Ignore:
Timestamp:
09/03/10 14:03:50 (14 years ago)
Author:
pracine
Comment:

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  • WKTRaster/SpecificationWorking02

    v21 v22  
    1616 
    1717----
    18 == '''Objective B02x - Implement better support for NULL, Empty, HasNoBand(rast), HasNoBand(rast, band) and BandIsNoData rasters in all functions.''' ==
     18== '''Objective B02x - Implement better support for NULL, Empty, !HasNoBand(rast), !HasNoBand(rast, band) and !BandIsNoData rasters in all functions.''' ==
    1919
    2020 Each function shoul better handle NULL rasters, empty rasterm rasters with no band and bands only filled with nodata values.
    … …  
    2222 * Generally, when NULL rasters are provided, return NULL. If the function involves a second non NULL raster and something can be done with it, do it.
    2323 * Generally, when empty rasters are provided (ST_IsEmpty, width=0 or height=0), return an empty raster. If the function involves a second non empty raster and something can be done with it, do it.
    24  * Generally, when a HasNoBand(rast) or a HasNoBand(rast, band) raster is provided return a raster with no band but with the right extent. If the function involves a second raster having a band or the band, treat the first missing band like a BandIsNoData.
    25  * A BandIsNoData raster is a normal raster but many functions can be optimized with this type of raster.
    26  * All functions having missing the requested information (about its extent when it is a NULL or an empty raster or about its band when it is a HasNoBand(rast) or a HasNoBand(rast, band) raster) should return NULL or a documented value.
     24 * Generally, when a !HasNoBand(rast) or a !HasNoBand(rast, band) raster is provided return a raster with no band but with the right extent. If the function involves a second raster having a band or the band, treat the first missing band like a !BandIsNoData.
     25 * A !BandIsNoData raster is a normal raster but many functions can be optimized with this type of raster.
     26 * All functions having missing the requested information (about its extent when it is a NULL or an empty raster or about its band when it is a !HasNoBand(rast) or a !HasNoBand(rast, band) raster) should return NULL or a documented value.
    2727 * Try as less as possible to return EXCEPTION (or ERROR).
    2828