M subtype values obtained by using the code HAMMER versus the values obtained in this work. Upper panel: differences with the values given in the literature. Random values between ±0.2 have been added to the HAMMER values to facilitate the comparison. The symbol ⟨⟩ in the legend represents the median difference. The black continuous line represents the 1:1 relation, whilst the dashed lines correspond to ±1 spectral subtype.