[postgis-devel] Expected behavior of rt_raster_has_no_band function

Bborie Park dustymugs at gmail.com
Thu Oct 20 20:31:51 PDT 2011


Hey all,

I'm wondering as to the proper behavior of the rt_raster_has_no_band
function (and ST_).  I'm getting the following from calls to
ST_HasNoBand...

1. SELECT ST_HasNoBand(
	ST_AddBand(
		ST_AddBand(
			ST_AddBand(
				ST_MakeEmptyRaster(2, 2, 10, 10, 2, 2, 0, 0)
				, 1, '64BF', 1234.5678, NULL
			)
			, '64BF', 987.654321, NULL
		)
		, '64BF', 9876.
	)
, 1)

returns FALSE

2. SELECT ST_HasNoBand(
	ST_AddBand(
		ST_AddBand(
			ST_AddBand(
				ST_MakeEmptyRaster(2, 2, 10, 10, 2, 2, 0, 0)
				, 1, '64BF', 1234.5678, NULL
			)
			, '64BF', 987.654321, NULL
		)
		, '64BF', 9876.
	)
, 4)

returns TRUE

3. SELECT ST_HasNoBand(
	ST_AddBand(
		ST_AddBand(
			ST_AddBand(
				ST_MakeEmptyRaster(2, 2, 10, 10, 2, 2, 0, 0)
				, 1, '64BF', 1234.5678, NULL
			)
			, '64BF', 987.654321, NULL
		)
		, '64BF', 9876.
	)
, 0)

returns FALSE

4. SELECT ST_HasNoBand(
	ST_AddBand(
		ST_AddBand(
			ST_AddBand(
				ST_MakeEmptyRaster(2, 2, 10, 10, 2, 2, 0, 0)
				, 1, '64BF', 1234.5678, NULL
			)
			, '64BF', 987.654321, NULL
		)
		, '64BF', 9876.
	)
, -1)

returns FALSE

Are the answers for #3 and #4 above correct?  I expected those to be
TRUE as the band index of a raster are 1-based in PostgreSQL.

-bborie



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