Wedge diagrams (α − cz) of galaxies and loose groups in the Perseus‐Pisces redshift survey (only the region with low Galactic extinction −1﹩^{\mathrm{h}\,}_{.}﹩5 ≤ α ≤ +3﹩^{\mathrm{h}\,}_{.}﹩0, 0° ≤ δ ≤ +40°; all samples are cut within cz_cut = 11,000 km s⁻¹). Groups are identified with the adaptive friends‐of‐friends algorithm of Huchra & Geller (1982) (see text and Table 1). (a) Galaxy sample PPS1. (b) Galaxy sample PPS2. (c) Group sample TB96₁. (d) Group sample TB96₂.