     transmission matrix D.
          On exit, the leading P-by-M part of this array contains
          the intermediary direct input/output transmission matrix
          D1 (see METHOD).
          The array D is not referenced if JOBD = 'Z'.

  LDD     INTEGER
          The leading dimension of array D.
          LDD &gt;= MAX(1,P) if JOBD = 'D'.
          LDD &gt;= 1 if JOBD = 'Z'.

  F       (input) DOUBLE PRECISION array, dimension (LDF,P)
          If FBTYPE = 'O', the leading M-by-P part of this array