The magnitude distributions of the SDSS observations and the TRILEGAL simulations generated with parameter sets 1 to 4 (top to bottom). The x- and y-axes are similar to the bottom panel of Fig. 1. The error bars (blue) are from SDSS DR7 data with the colour limit of 0.2 ≤ (g − r) < 1.2. The black solid line represents the model star count predictions of TRILEGAL. The dotted (red), dashed (cyan), and dot-dashed (green) lines stand for the thin disc, thick disc, and halo of the TRILEGAL model, respectively. (A colour version is available on-line.)