Transverse fundamental kink mode in a coronal slab with a density contrast ρ_i/ρ_e = 3. Shown are the dependences on [k_y, k_z] of (a) the angle between the group velocity v_gr and the z-direction, and (b) the angle between the group velocity v_gr and the phase velocity v_ph. The angles are in degrees and measured counterclockwise from v_gr to ${\widehat{\mathit{e}}}_z$ or v_ph. Superimposed are the filled contours of Λ_i, the ratio of the magnetic pressure gradient force to the magnetic tension force. All contours are equally spaced. The angle information allows the fundamental to be classified into two regimes as labeled in panel c (see text for details).