ifies whether or not the orthogonal transformations
          should be accumulated in the array Q, as follows:
          = 'N': do not modify Q;
          = 'U': modify (update) the array Q by the orthogonal
                 transformations that are applied to the matrices in
                 the array A to reduce them to periodic Schur form;
          = 'I': like COMPQ = 'U', except that each matrix in the
                 array Q will be first initialized to the identity
                 matrix;
        