code: def _slopes_directions(self, data, dX, dY, method='tarboton'):
          
          # %%
          if method == 'tarboton':
              return self._tarboton_slopes_directions(data, dX, dY)
          elif method == 'central':
              return self._central_slopes_directions(data, dX, dY)
docs: Wrapper to pick between various algorithms