sds_id	IN:	Data set identifier returned by SDcreate or SDselect
	max	OUT:	Maximum value of the range
	min	OUT:	Minimum value of the range

	Purpose	Retrieves the maximum and minimum values of the range.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	SDgetrange retrieves the maximum value of the range into the parameter max and the minimum value into the parameter min. The maximum and minimum values must be previously set via a call to SDsetrange.
		It is assumed that the data type for the maximum and minimum range values are the same as that of the data.

	FORTRAN	integer function sfgrange(sds_id, max, min)
		integer sds_id
		<valid numeric data type> max, min