Radial density distribution of the spaxels in the oxygen abundance-galactocentric distance space for the same galaxy as in Fig. 3 (right panels). The radial distances are deprojected and normalised to the disc effective radius. The diamonds represent the mean oxygen abundance values, with the error bars representing the corresponding standard deviations, for bins of 0.25 r_e and the red solid line the error-weighted linear fit derived for values within the range between 0.5 and 2.0 r_e (yellow diamonds). The parameters of the fit are shown in the upper right corner of the panels, including the zero point (a), the slope (b) and the correlation coefficient (r). The violet dots correspond to the oxygen abundances derived for the individual H ii  regions, and the dashed black line is the linear regression for these points.