    diagonal form. The local transformation matrix is itself a
          product of non-unitary equivalence transformations having
          elements with magnitude less than or equal to PMAX.
          If JOBX = 'N', this array is not referenced.

  LDX     INTEGER
          The leading dimension of the array X.
          LDX &gt;= 1,        if JOBX = 'N';
          LDX &gt;= MAX(1,N), if JOBX = 'U'.

  Y       (input/output) COMPLEX*16 array, dimension (LDY,*)
          On entry, if JOBY = 'U', the leadin