Quasi-self-similar evolution of the shock-rarefaction wave system. To highlight how the system is tending towards self-similarity, the x-axis is normalised by the time t of the snapshot of the simulation, therefore shows the velocity at which the waves are propagating in normalised units. As the time is increased, the system tends towards a self-similar state. The reference time is taken at t₀ = 156 000τ and the distributions for t₀, t₀/ 2, t₀/ 4, t₀/ 8, and t₀/ 16 are plotted. The reference ideal MHD solution is indicated by the black dashed line.