@pytest.fixture
def disc_particles_all(solid_disk):
    'Solid disc with velocities.'
    (mass_s, pos_s, vel_s) = solid_disk(N_part=100)
    (mass_g, pos_g, vel_g) = solid_disk(N_part=100)
    return (mass_s, pos_s, vel_s, mass_g, pos_g, vel_g)
Solid disc with velocities.
@pytest.fixture
def disc_particles_all(solid_disk):
    
    (mass_s, pos_s, vel_s) = solid_disk(N_part=100)
    (mass_g, pos_g, vel_g) = solid_disk(N_part=100)
    return (mass_s, pos_s, vel_s, mass_g, pos_g, vel_g)