Getting the Best Titles

After a change of context, MTT must ensure that all its titles are valid. A titles bank must satisfy two requirements before it can be considered as valid:-

• The date of the context must be within the bank's date validity range. The start date of the validity range is inclusive, the end date is exclusive. So, for there to be no gap, the start date of the next version of a bank should be the same as the end date of the previous one.

• The data type must match. Matching is possible at 3 levelss:-
  1. The bank's data type equals the context's data type.

  2. The context data type is a Monte Carlo data type and the bank's data type is the real data equivalent. For example, for MC SNO data (type 22) Real SNO data (type 12) is a match.

  3. The bank's data type is 0 - the universal data type.

  The ordering above reflects the quality of the match; the higher the position, the better the quality.

It may well happen that two or more banks satisfy the above criteria. In this case each bank is assigned a priority, and the highest priority bank is taken. Priorities are assigned to ensure that:-

• Banks that have come from titles files always take priority over those from the database. This allows user to modify existing or develop new titles banks simply by placing them in a titles file. Only once they have been fully checked need they be added to the database.

• Banks from the same source (titles file or database) are ordered according to the quality of the data type matching. So, for a given bank, a data type of 0 can be provided as a default that can then be overridden by one that exactly matches the type of detector and finally by one that matches detector type and event source (MC or Real).

If two banks have the same priority, the one with the later validity starting date is takes priority and if they have the same starting date, the one that was read in first is taken.