def convergence_from_grid(self, grid):
if self.has_mass_profile:<EOL><INDENT>return sum(map(lambda p: p.convergence_from_grid(grid), self.mass_profiles))<EOL><DEDENT>else:<EOL><INDENT>return np.zeros((grid.shape[<NUM_LIT:0>],))<EOL><DEDENT>
Compute the summed convergence of the galaxy's mass profiles using a grid of Cartesian (y,x) \
        coordinates.

        If the galaxy has no mass profiles, a grid of zeros is returned.

        See *profiles.mass_profiles* module for details of how this is performed.

        Parameters
        ----------
        grid : ndarray
            The (y, x) coordinates in the original reference frame of the grid.