Appendix 2—figure 3. Elongation rate curves for different orders of the wave front fit of Main Text Figure 3A: Linear (A), quadratic (B), and cubic (C).

(D) χ² of the fit of the wave front of Main Text Figure 3A for different fitting orders, together with the mean error on the elongation rate curves. The negligible improvement of the goodness-of-fit after the first order justifies the use of a linear fit for further analysis.