DAP4: Coordinate Systems Element
John has noted that in CDM, he introduced a notion of Coordinate System which is a set of maps defined independently of any variable. In xml, this would be something like this.
<CoordinateSystem name="..."> <map variable="var1"/> ... <map variable="varn"/> </CoordinateSystem>
The argument for it is that sets of maps are often going to be used in identical form in a number of variables. Further, it allows one to add attributes to the coordinate system element to provide extra information.
Do we add this element to the DDX?
There seems no immediate hurry on this. It can be added rather transparently later on when a demonstrated need exists.