code: def _vector_or_scalar(x, type='row'):
      
      if isinstance(x, (list, tuple)):
          x = np.array(x)
      if isinstance(x, np.ndarray):
          assert x.ndim == 1
          if type == 'column':
              x = x[:, None]
      return x
docs: Convert an object to either a scalar or a row or column vector.