Comparison of the (O/H)_R oxygen abundances with abundances estimated through other calibrations for our sample of MaNGA galaxies. The circles in each panel show the central (intersect) oxygen abundances. The plus symbols indicate abundances (intersect values) at the optical radius R₂₅. The solidline shows the oxygen abundances for the sample of H II regions in the nearby galaxies. The long-dashed line shows the oxygen abundances for those H II regions obtained with the lines R₂, N₂, and S₂ increased bya factor of 1.3 to simulate the DIG contribution to the spectra. The short-dashed line indicates unity.