code: def limits(self):
          
          if not hasattr(self, '_limits'):
              xmax = max(abs(self.data.array[0]))
              xmin = min(self.data.array[0])
  
              x_error = self.data.error[0]
              if isinstance(x_error, numpy.ndarray):
                  if x_error.ndim == 0: xmax = xmax + x_error
  
              if xmin < 0:
                  self._limits = (-xmax, xmax)
              else:
                  self._limits = (0, xmax)
  
          return self._limits
docs: Limits to use for the independent variable whenever
          creating a linespace, plot, etc.
  
          Defaults to `(-x, x)` where `x` is the largest absolute value
          of the data corresponding to the independent variable.
          If no such values are negative, defaults to `(0, x)` instead.