Fits of MILES spectra with the MILES interpolator for three representative stars. For each star, the top panel represents the flux distribution, normalized to an average of one, and the bottom ones the residuals between the observation and the best-fitted interpolated spectrum (observation − model). The fit was performed with ULySS. The continuous green lines are the  ± 1σ errors, assuming a constant error spectrum and χ² = 1. The clear blue lines are the multiplicative polynomials.