          The leading dimension of the array B.  LDB &gt;= N.

  D       (input) DOUBLE PRECISION array, dimension (LDD, N)
          The leading N/2-by-N part of this array must contain the
          first block row of the second matrix of a J B' J' B - b D.
          The matrix D has to be Hamiltonian. The strict lower
          triangle of the (1,2) block is not referenced.

  LDD     INTEGER
          The leading dimension of the array D.  LDD &gt;= N/2.

  MACPAR  (input)  DOUBLE PRECISION array, dimen