Local stellar velocity distribution perturbed to linear order at the solar galactocentric radius and azimuth at three different heights (left: z = 0 kpc, middle: z = 0.3 kpc, right: z = 1 kpc), when perturbed by a bar (perturbing potential of Sect. 2.4) with pattern speed Ω_b = 1.89Ω₀. Top row: epicyclic approximation. Bottom row: Stäckel fudge. The scale of the colour bar is different in the upper and lower panels for z = 1 kpc.