def density_2d(self, r, kwargs_profile):
        """
        computes the projected density along the line-of-sight
        :param r: radius (arcsec)
        :param kwargs_profile: keyword argument list with lens model parameters
        :return: 2d projected density at projected radius r
        """
        kwargs = copy.deepcopy(kwargs_profile)
        try:
            del kwargs['center_x']
            del kwargs['center_y']
        except:
            pass
        # integral of self._profile.density(np.sqrt(x^2+r^2))* dx, 0, infty
        out = integrate.quad(lambda x: 2*self._profile.density(np.sqrt(x**2+r**2), **kwargs), 0, 100)
        return out[0]