The difference in the rectified spectrum obtained for the Sun using the quadratic Bézier scheme and KORG's default scheme. The purple and brown lines show the result obtained using modified Bézier interpolation and cubic spline interpolation of α _λ , respectively. (This is separate from the interpolation of the source function, which uses Bézier curves in both cases.) The difference between all three methods is small compared to the difference in spectra obtained from different codes, but nevertheless larger than is ideal.