DHDADXi:

------------------------------------------------------------------------
   Interface to DHDADX. 
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   Form:
   H = DHDADXi( x, u )
------------------------------------------------------------------------

   ------
   Inputs
   ------
   x             State vector [ra, dec, bias]
   u             Auxiliary vector [us;ue]

   -------
   Outputs
   -------
   da            Dihedral angle

------------------------------------------------------------------------

Children:

SAAD: SAAttDet/DHDADX