Changes between Version 207 and Version 208 of WKTRaster/SpecificationWorking03

Timestamp:

Jul 24, 2012, 1:42:57 PM (12 years ago)

Author:

pracine

Comment:

—

WKTRaster/SpecificationWorking03

@@ -18 +18 @@
 == ''Note that accomplished objectives have been moved at the bottom of the page.'' ==
 
-----
-== '''Objective 2.0.04 - Implement better support for NULL, Empty, !HasNoBand(rast), !HasNoBand(rast, band) and !BandIsNoData rasters in all functions.''' ==
-
- Each function should better handle NULL rasters, empty rasterm rasters with no band and bands only filled with nodata values.
-
-  1) 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.
-
-  2) 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.
-
-  2) 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.
-
-  4) A !BandIsNoData raster is a normal raster but many functions can be optimized with this type of raster.
-
-  5) 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.
-
-  6) Try as less as possible to return EXCEPTION (or ERROR).
-
- See discussion in http://trac.osgeo.org/postgis/ticket/594
-
-'''ST_IsEmpty(rast) -> boolean'''
-
- Returns TRUE if the raster width or the raster height is 0.
-
-'''ST_HasNoBand'''
-
- '''Variants'''
-
-  1) ST_HasNoBand(rast, band) -> boolean
-
-  2) ST_HasNoBand(rast) -> boolean
-
- Returns TRUE if the the raster does not have this band.
-
- Variant 2 returns TRUE if the the raster does not have any band.
-
-'''ST_BandIsNoData''' 
-
- '''Variants'''
-
-  1) ST_BandIsNoData(rast, band) -> boolean
-
-  2) ST_BandIsNoData(rast) -> boolean
-
- Returns TRUE if the specified raster band is only filled with no data value.
-
- Variant 2 default to band 1.
-
- '''Implementation details'''
-
- This require a new flag to be set in the core at import and at edition. See discussion in http://trac.osgeo.org/postgis/ticket/593
 
 ----
@@ -510 +460 @@
 
 ----
+== '''Objective FV.22 - Implement better support for NULL, Empty, !HasNoBand(rast), !HasNoBand(rast, band) and !BandIsNoData rasters in all functions.''' ==
+
+ Each function should better handle NULL rasters, empty rasterm rasters with no band and bands only filled with nodata values.
+
+  1) 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.
+
+  2) 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.
+
+  2) 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.
+
+  4) A !BandIsNoData raster is a normal raster but many functions can be optimized with this type of raster.
+
+  5) 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.
+
+  6) Try as less as possible to return EXCEPTION (or ERROR).
+
+ See discussion in http://trac.osgeo.org/postgis/ticket/594
+
+'''ST_IsEmpty(rast) -> boolean'''
+
+ Returns TRUE if the raster width or the raster height is 0.
+
+'''ST_HasNoBand'''
+
+ '''Variants'''
+
+  1) ST_HasNoBand(rast, band) -> boolean
+
+  2) ST_HasNoBand(rast) -> boolean
+
+ Returns TRUE if the the raster does not have this band.
+
+ Variant 2 returns TRUE if the the raster does not have any band.
+
+'''ST_BandIsNoData''' 
+
+ '''Variants'''
+
+  1) ST_BandIsNoData(rast, band) -> boolean
+
+  2) ST_BandIsNoData(rast) -> boolean
+
+ Returns TRUE if the specified raster band is only filled with no data value.
+
+ Variant 2 default to band 1.
+
+ '''Implementation details'''
+
+ This require a new flag to be set in the core at import and at edition. See discussion in http://trac.osgeo.org/postgis/ticket/593
+
+----
 == '''Other functions''' ==
  
@@ -521 +522 @@
 
 == Accomplished objectives ==
-