The distance modulus, mod0 [mag] is either computed from the distance catalogue or using the Tully-Fisher or Faber-Jackson relations. When measurements are available in the distance catalogue , mod0 is computed as the weighted average of those measurements. ... The Tully-Fisher relation uses the corrected total magnitude btc and the maximum velocity of rotation vmaxg . ... Another parameter, modz (redshift distance modulus), estimates the luminosity-distance using the redshift. ...