def create_particles(): x = np.linspace(0, 10, 10) m = np.ones_like(x) y = np.zeros_like(x) z = np.zeros_like(x) h = np.ones_like(x) * 0.2 fluid = ParticleArray(name='fluid', x=x, y=y, z=z, m=m, h=h) fluid.add_constant('total_mass', 0.0) return [fluid]