code: def _scalar_to_vector(self, m):
          
          if not isinstance(m.y0, numbers.Number):
              return m
          else:
              m = copy.deepcopy(m)
              t0 = 0.0
              if isinstance(m.y0, numbers.Integral):
                  numtype = np.float64
              else:
                  numtype = type(m.y0)
              y0_orig = m.y0
              m.y0 = np.array([m.y0], dtype=numtype)
              def make_vector_fn(fn):
                  def newfn(y, t):
                      return np.array([fn(y[0], t)], dtype=numtype)
                  newfn.__name__ = fn.__name__
                  return newfn
              def make_matrix_fn(fn):
                  def newfn(y, t):
                      return np.array([[fn(y[0], t)]], dtype=numtype)
                  newfn.__name__ = fn.__name__
                  return newfn
              def make_coupling_fn(fn):
                  def newfn(source_y, target_y, weight):
                      return np.array([fn(source_y[0], target_y[0], weight)])
                  newfn.__name__ = fn.__name__
                  return newfn
              if isinstance(m.f(y0_orig, t0), numbers.Number):
                  m.f = make_vector_fn(m.f)
              if hasattr(m, 'G') and isinstance(m.G(y0_orig,t0), numbers.Number):
                  m.G = make_matrix_fn(m.G)
              if (hasattr(m, 'coupling') and
                      isinstance(m.coupling(y0_orig, y0_orig, 0.5),
                                 numbers.Number)):
                  m.coupling = make_coupling_fn(m.coupling)
              return m
docs: Allow submodels with scalar equations. Convert to 1D vector systems.
          Args:
            m (Model)