 strictly
          negative real part.
          = 'N':  do not compute the deflating subspace;
          = 'C':  compute the deflating subspace and store it in the
                  leading subarray of Q.

  ORTH    CHARACTER*1
          If COMPQ = 'C', specifies the technique for computing an
          orthogonal basis of the deflating subspace, as follows:
          = 'P':  QR factorization with column pivoting;
          = 'S':  singular value decomposition.
          If COMPQ = 'N', the ORTH value is 