Testing the numerical scheme for aliasing, a feature of finite difference methods, which spuriously increases the energy of a wave that swings from leading to trailing. At the resolutions and mesh-Reynolds numbers we use, this effect is successfully suppressed. The wave has a wavenumber k_x,0 =  − 16π/L_x, which means 4, 8, 16, and 32 points per wavelength at resolutions 32, 64, 128, and 256, respectively. The wiggling is due to excitation of compressible modes not present in the analytical solution.