Scatter plots of different physical parameters of the standard penumbral filament studied by Tiwari et al. (2013). The selected area also contains pixels belonging to the surroundings of the filament (spines). All plots are for the height log (τ) = 0. The four panels show scatter plots between: a) the field strength B and inclination γ; b) B and temperature T; c) the line-of-sight velocity v_LOS and T; and d) v_LOS and B. The vertical line in a) indicates γ = 90°; horizontal lines in panels c) and d) represent v_LOS = 0. Different parts of the filaments are identified in each plot.