Comparison between atmospheric parameters derived from spectral indices and high-resolution analyses for the calibration sample. The first column shows the direct comparison between the two sets of parameters, with T_eff, [Fe/H], and log g  on the top, middle, and bottom rows, respectively. The differences between the results from the indices and high-resolution as a function of the latter are presented in the remaining panels. The differences for T_eff, [Fe/H], and log g  are shown in the top, middle, and bottom rows, respectively. The dependency with the high-resolution effective temperatures, metallicities, and surface gravities are given in columns 2, 3, and 4, respectively. In all panels, the solid black line represents perfect agreement. The dashed blue and red lines mark, respectively, the offsets of ±100 and ±200 K for T_eff, ±0.10 and ±0.20 dex for [Fe/H], and ±0.20 and ±0.40 dex for log g. There is a good agreement between the two sets of atmospheric parameters and no significant offsets and trends in the residuals.