Fig. 6.

Parameter search for optimal performance of helix tracing. (A–C) Minimum helix length cutoff (y-axis) and α-threshold (x-axis) are being evaluated with respect to (A) recall R, (B) precision P and (C) F1 score. (D) Choosing a too low minimum helix length cutoff leads to a very high recall R with low precision P corresponding to promiscuous tracing including contamination and noise. (E) Choosing a too low α-threshold results in very high precision P at the expense of poor recall R. Using this parameter combination, a large fraction of available helix traces is not detected. (F) Optimal parameter pair yields best performance of the algorithm according to F1-score representing a tradeoff between high precision P and high recall R.