Diagnostic diagrams for the galaxies (SDSS spectral class = GALAXY) from the PSS-CSO (blue) and the ECS (green) samples with S/N ≥ 3 for used lines. Top: [N II] based BPT diagram for z < 0.35 with the upper limit for SF galaxies from Kewley et al. (2006; dashed), the lower limit for AGNs from Kauffmann et al. (2003a; dotted), and the separation between AGNs and LINERs from Schawinski et al. (2007; dashed). Middle: KEx diagram with demarcation lines from Zhang & Hao (2018). Bottom: WHAN diagram with demarcation lines from Cid Fernandes et al. (2011).