Large separations Δν_l,   n = ν_l,   n − ν_{l,   n − 1} for l = 0, 1, and 2 modes plotted as a function of the frequency (ν_l,   n + ν_{l,   n − 1})/2 for HD 52265 (symbols with error bars). A solid line shows the variations in Δν obtained with the envelope autocorrelation function. The grey area indicates 1-σ error bars. The inset shows the cosine filter with a full width at half maximum equal to 2 times the mean large separation used for computing the EACF.