code: def deflections_from_grid(self, grid):
          
          eta = self.grid_to_grid_radii(grid=grid)
          deflection = np.multiply(2. * self.einstein_radius_rescaled, np.divide(
              np.add(np.power(np.add(self.core_radius ** 2, np.square(eta)), (3. - self.slope) / 2.),
                     -self.core_radius ** (3 - self.slope)), np.multiply((3. - self.slope), eta)))
          return self.grid_to_grid_cartesian(grid=grid, radius=deflection)
docs: Calculate the deflection angles at a given set of arc-second gridded coordinates.
  
          Parameters
          ----------
          grid : grids.RegularGrid
              The grid of (y,x) arc-second coordinates the deflection angles are computed on.