This subclass describes the data that is applied to structures such as Raster. The data type of the included values is described by the attribute contentStructure, if desired, textual names can also be applied to the data types. The attribute contentValues contains all the data to be applied to the structure as a single stream of bytes. The assignment of the stream of bytes to the structure is provided by the ContentStructure attribute indexingScheme. Note that information regarding the actual assignment to real world positions to the values is not addressed here. In the following example consisder the application of a two layered raster structure. A A B C1.0 1.0 1.0 1.0 A A B B1.0 1.0 1.0 3.1 A A A C1.0 1.0 2.8 2.8 C C C A1.0 1.0 1.0 2.8 One layer contains character values and the other contains real values. The grid class description defines these layers as being of 4x4 dimension with the origin at the upper left and with ordering specified as rowOrder. The contentStructure attribute contains the attribute structure, which for this example is given as follows: structure: List { ElementStructure( instancePrimitive:String TelementsPerValue:1 ) ElementStructure( instancePrimitive:Real32 elementsPerValue:1 ) } An example of the application of each choice of index scheme to the content values is given below. The definition of structure, as given above, remains the same regardless of which index scheme is used. StructuredData( contentStructure: ContentStructure( IndexScheme:sequentialArray structure: as specified above ) contentValues: A A B C A A B B A A A C C C C A 1.0 1.0 1.0 1.0 1.0 1.0 1.0 3.1 1.0 1.0 2.8 2.8 1.0 1.0 1.0 2.8 ) StructuredData( contentStructure: ContentStructure( IndexScheme:interleavedArray structure: as specified on previous page ) contentValues: A 1.0 A 1.0 B 1.0 C 1.0 A 1.0 A 1.0 B 1.0 B 3.1 A 1.0 A 1.0 A 2.8 C 2.8 C 1.0 C 1.0 C 1.0 A 2.8 ) StructuredData( contentStructure: ContentStructure( IndexScheme:runLengthEncoded
structure:as specified on previous page
)
contentValues:
2A 1B 1C 2A 2B 3A 4C 1A 71.0 13.1 21.0 22.8 31.0 12.8
)
StructuredData(
contentStructure:
ContentStructure(
IndexScheme:nTree
structure: as specified on previous page
)
contentValues:
1A 21B 22C 23B 24B 31A 32A 33C 34C 41A 42C 43C
44A 11.0 211.0 221.0 231.0 243.1 31.0 412.8 422.8
431.0 442.8
)
All four examples of structured data are possible. It would be up to the user to decide which scheme was most appropriate.