sds_id	IN:	Data set identifier returned by SDcreate or SDselect
	label	IN:	Label (predefined attribute)
	unit	IN:	Unit (predefined attribute)
	format	IN:	Format (predefined attribute)
	coordsys	IN:	Coordinate system (predefined attribute)

	Purpose	Sets the predefined attributes for a data set.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	SDsetdatastrs sets the predefined attributes of the data set, identified by sds_id, to the values specified in the parameters label, unit, format and coordsys. The predefined attributes are label, unit, format, and coordinate system. If the user does not want a string returned, the corresponding parameter can be set to NULL in C and an empty string in Fortran.
		For more information about predefined attributes, refer to Section 3.10 of the HDF User's Guide.

	FORTRAN	integer function sfsdtstr(sds_id, label, unit, format, coordsys)
		integer sds_id
		character*(*) label, unit, format, coordsys