code: def get_data_range(self, arr=None, preference='cell'):
          
          if arr is None:
              # use active scalar array
              _, arr = self.active_scalar_info
          if isinstance(arr, str):
              arr = get_scalar(self, arr, preference=preference)
          # If array has no tuples return a NaN range
          if arr is None or arr.size == 0:
              return (np.nan, np.nan)
          # Use the array range
          return np.nanmin(arr), np.nanmax(arr)
docs: Get the non-NaN min and max of a named scalar array
  
          Parameters
          ----------
          arr : str, np.ndarray, optional
              The name of the array to get the range. If None, the active scalar
              is used
  
          preference : str, optional
              When scalars is specified, this is the perfered scalar type to
              search for in the dataset.  Must be either ``'point'`` or ``'cell'``