hod"><B><FONT SIZE="+1">Method</FONT></B></A>
<PRE>
  The matrix Q is represented as a product of symplectic reflectors
  and Givens rotations

  Q = diag( H(1),H(1) ) G(1) diag( F(1),F(1) )
      diag( H(2),H(2) ) G(2) diag( F(2),F(2) )
                        ....
      diag( H(k),H(k) ) G(k) diag( F(k),F(k) ),

  where k = min(m,n).

  Each H(i) has the form

        H(i) = I - tau * w * w'

  where tau is a real scalar, and w is a real vector with
  w(1:i-1) = 0 and w(i) = 1; w(i+1:m) is stored on exit 