Results for the HIMF from the combined stacking case as a function of the chosen sample size (N) and assuming the polynomial model for the M_HI − M_⋆ relation. We show the main results from this paper: N = 6598 (blue squares), N = 10² (gray circles), N = 10³ (purple downward triangles), N = 10⁴ (green stars), and N = 10⁵ (orange diamonds). We also display the HIMF from ALFALFA at z ∼ 0 as a dashed black line for comparison. A tiny horizontal shift was applied to the data points to avoid overlaps and to ease visualization.