Oxygen abundance (i.e. 12+log(O/H)) estimations based in the calibration by Marino et al. (2013) as a function of galactocentric distance. Gradients have been derived using the median values estimated for different galactocentric distance intervals. Within each galactocentric distance interval, the median values of the data are represented by blue (red) squares. The blue dots represent metallicity measurements obtained from all the spaxels while the red dots indicate those spaxels where the emission lines are originated in star-forming regions. The blue and red bands indicate the results of our Bayesian linear best fits to the data with the same colour coding as for the individual measurements. The dark and light shaded bands correspond to the confidence intervals at 1-σ and 2-σ levels, respectively. The black dot at the bottom left of the plot represents the median error of all (blue) points.