This function returns the record numbers within a subsetted time period for a particular level. 
            Examples
            In this example, we get the number of records and record numbers within the subsetted area of interest defined in EOS_PT_DEFTIMEPERIOD for the 0th level:
            status = EOS_PT_PERIODRECS(pointID, periodID, 0, nrec, recs)
            Syntax
            Result = EOS_PT_PERIODRECS(pointID, periodID, level, nrec, recs)
            Return Value
            Returns SUCCEED (0) if successful and FAIL (–1) otherwise.
            Arguments
            pointID 
            Point id (long).
            periodID 
            Period id (long) returned by EOS_PT_DEFTIMEPERIOD.
            level
            Point level (0-based long).
            nrec
            A named variable that will contain the number of records (long) within time period in level.
            recs
            A named variable that will contain the record numbers (long) of subsetted records in level.
            Keywords
            None
             
            Version History