def new_system(star_mass=1 | units.MSun, star_radius=1 | units.RSun, disk_minimum_radius=0.05 | units.AU, disk_maximum_radius=10 | units.AU, disk_mass=20 | MEarth, accurancy=0.0001, planet_density=3 | units.g / units.cm**3, rng=None, kepler=None): central_particle = Particle() central_particle.mass = star_mass central_particle.position = (0, 0, 0) | units.AU central_particle.velocity = (0, 0, 0) | units.kms central_particle.radius = star_radius central_particle.name = "star" central_particle.type = "star" central_particle.id = 0 if rng is None: rng = numpy.random converter = nbody_system.nbody_to_si(1 | units.MSun, 1 | units.AU) if kepler is None: kepler = Kepler(converter) kepler.initialize_code() m, r, f = new_planet_distribution(disk_minimum_radius, disk_maximum_radius, disk_mass, accurancy) planets = make_planets(central_particle, m, r, density=planet_density, phi=0, theta=None, kepler=kepler, rng=rng) planets.name = "planet" planets.type = "planet" for i in range(len(planets)): planets[i].id = i central_particle.planets = planets kepler.stop() p = Particles() p.add_particle(central_particle) return p