Sexual cycles (CYCLES) are defined by Mdate, Ddate, and Tdate sexual cycle transition events. CYCLES should be created and destroyed in correspondence with Mdate, Tdates, and Ddates. But Babase contains other information related to sexual cycles, most obviously sexskin swelling This section describes how this information is related to specific sexual cycles.[221]
The determination of when a new sexual cycle starts is, because by definition a cycle is a periodicity with no start and no end, arbitrary[222], as then is the determination of which cycle to associate various data with. The method used by Babase was chosen for its simplicity and its ability to be consistently applied to all sorts of cycle related data. It may lead to what may be non-intuitive results. As with all things Babase, users must take care to familiarize themselves with the intricacies[223] of the system, and the data.
Babase uses the date of the measurement, of whatever data, sexskin swelling, PCS color, etc., to determine which sexual cycle the measurement should be associated with. Dates are assigned to cycles by virtue of falling in the interval each cycle spans, each cycle starting with an Mdate and continuing through the day before the next Mdate; although cycles can be “cut off” by cessation, or initiation, of observation. The following method implements these policies and can be used as a guide when there are questions as to the specifics:[224]
Relate the measurement to the cycle of the Mdate, Tdate, or Ddate that falls on the date of the measurement or is the latest Mdate, Tdate, or Ddate preceding the measurement, so long as there is no gap in observation between the measurement date and Mdate, Tdate, or Ddate. If there is no such Mdate, Tdate, or Ddate due to gaps in observation or simple lack of data then relate the measurement to the cycle of the earliest Tdate or Ddate that follows the measurement but is not separated from the measurement by a gap in observation or an intervening Mdate. If there is no such Tdate or Ddate then the measurement may not be recorded in Babase.
Because there are conditions under which sexual cycle related data may not be recorded in Babase, and, as a rule, Babase does not automatically delete data, Babase will not permit some orderings of data maintenance operations. For example, Babase will not allow a gap in observation to be inserted after a female's last Ddate but before her last sexual swelling date because this would require removal of the sexual swelling information. An alternate ordering of the operations resulting in identical database content is required. In the above example either the sexual swelling data must be deleted or subsequent Mdates, Tdates, or Ddates must be entered before the gap in observation may be entered.
[221] For information on how Mdates, Tdates, and Ddates are aggregated into sexual cycles see both the CYCLES and the CYCPOINTS documentation.
[222] The decision to define a cycle as starting with an Mdate and ending in a Ddate is traditional, and yet not entirely sensible as the first cycle at menarche will assuredly not have a Mdate. In addition should an individual cease cycling due to pathology or old age the last cycle will not have a Tdate or Ddate. A definition of cycle that more closely parallels the life of an egg, starting with Tdate and ending with Mdates, would seem to make the most sense.
[223] Babase doesn't have quirks, it has intricacies. This will be on the midterm.