Relations between the bar radius R_bar and the SDSS r-band absolute magnitude M_r, bar strength S_bar, and corotation radius R_cr for the selected sample of 77 galaxies. The Spearman rank correlation r, two-sided significance p, and number of σ from the null hypothesis are given in each panel for the selected sample of 77 galaxies. The points are colour-coded according to the value of ℛ. Results obtained using different bands with respect to the SDSS r-band are represented with a square symbol. The results for the Milky Way are shown both for the short bar case (black open diamond) and long bar case (black open square).