array, dimension (LDA,N)
          The leading N-by-N upper Hessenberg part of this array
          must contain a real Schur form matrix S. The elements
          below the upper Hessenberg part of the array A are not
          referenced. The 2-by-2 blocks must only correspond to
          complex conjugate pairs of eigenvalues (not to real
          eigenvalues).

  LDA     INTEGER
          The leading dimension of array A.  LDA &gt;= MAX(1,N).

  B       (input/output) DOUBLE PRECISION array, dimension