Top row: bar morphologies for the gS0, gSa, and gSb models at t = 2 Gyr. For each galaxy we show a set of three panels: the disc surface density face-on view is presented in the square panel, with the bar side-on and head-on views in the attached right and bottom panels, respectively. Bottom row: m = 2 Fourier amplitudes, A₂/A₀, as a function of radius from t = 0 to t = 3 Gyr as indicated by the color bar in the rightmost panel. The formation and evolution of a bar can be seen clearly in all inner discs. Deviations from zero in the outer disc indicate the strength of two-armed spirals.