nsformations, as follows:
          = 'N':  Do not form Q;
          = 'I':  Q is initialized to the unit matrix and the
                  orthogonal transformation matrix Q is returned;
          = 'U':  The given matrix Q is updated by the orthogonal
                  row transformations used in the reduction.

  JOBZ    CHARACTER*1
          Indicates whether the user wishes to accumulate in a
          matrix Z the orthogonal column transformations, as
          follows:
          = 'N':  Do not form Z;