bank_ftxv

        FTxV   Generic Fitter Vertex bank.  One for each fitted vertex
        ==============================================================
 
    Contact:  D. L. Wark, Oxford.
 
    Revision History:-
    ================
 
    2.07  N. West     First version.  Derived from part of the FT bank.
    3.02  C. Jillings Add correlations.
 

 
Description
-----------
 
    One bank generated for each fitted event vertex by the relevant fitter.
Each type of fitter produces its own type of FTxV bank, for example, the quad
fitter produces an FTQV bank.  The first part of the vertex bank for all
fitters is the same, and it is this common part that is described here.  If a
fitter produces further words an entry will appear in this list:-
 
FTQV The quad fitter
FTTV The time fitter
 
 
Reference Links
---------------
 
    None.
 
 
Structural Links
----------------
 
 -1  -KFTXV_FTXT  FTxT   Link to first track (if fit produces track information)
 
 
Status Bits
-----------
 
Note: Any status bit parameters are defined to work with bit functions such as
      IAND and BTEST.
 
 
Data Words
----------
 
    Data types: B(bit), I, F, D(double), H(hollerith 4 char)
 
  +1  F KFTXV_X      Fitted X.
  +2  F KFTXV_Y      Fitted Y.
  +3  F KFTXV_Z      Fitted Z.
  +4  F KFTXV_T      Fitted time.
 
Only the above words are common to all fitters. However, most fitters will
provide error estimates on these fitted quantities.  Unless correlations are
being taken into account, it is recommended that fitters follow this format:-
 
  +5  F KFTXV_DX     Error on fitted X.
  +6  F KFTXV_DY     Error on fitted Y.
  +7  F KFTXV_DZ     Error on fitted Z.
  +8  F KFTXV_DT     Error on fitted T.
 
If correlations are also supplied it is recommended that fitters follow this
format:-

  +9  F KFTXV_C11      
 +10  F KFTXV_C12      
 +11  F KFTXV_C13      
 +12  F KFTXV_C14      
 +13  F KFTXV_C22      
 +14  F KFTXV_C23      
 +15  F KFTXV_C24      
 +16  F KFTXV_C33      
 +17  F KFTXV_C34      
 +18  F KFTXV_C44      
 
Notes
-----
 
1)  All fitters produce an FTx and at least one FTxV.  If the fitter can fit
    multiple vertices, then FTxV will be a chain.  If track information is
    produced at any vertex, it will be recorded in an FTxT supported from the
    FTxV.