TABLE 3.

Summary of the definition of the positional features. All the listed ML features can also be computed for the AP axis. For units, cm stands for centimeter, ° for degree (angle), and − for unitless

Feature	Full name	Formula	Units
MEAN ML	Mean ML coordinate	$\frac{1}{\mathrm{N}}{\mathrm{\Sigma }}_n{\mathit{\text{ML}}}_n$	cm
MEAN DIST. ML	Mean distance ML	$\frac{1}{\mathrm{N}}{\sum }_n\left|X_n\right|$	cm
MEAN DIST.	Mean distance	$\frac{1}{\mathrm{N}}{\sum }_n\left|R_n\right|$	cm
MAX ML	Maximal distance ML	max n |Xn |	cm
MAX RADIUS	Maximal distance	max n |Rn |	cm
RMS ML	Root mean square ML	$\sqrt{\frac{1}{\mathrm{N}}{\sum }_n{X}_n^2}$	cm
RMS RADIUS	Root mean square radius	$\sqrt{\frac{1}{\mathrm{N}}{\sum }_n{R}_n^2}$	cm
RANGE ML	Amplitude ML	maxn,m |Xn − Xm |	cm
RANGE ML‐AP	Amplitude ML‐AP	${\text{max}}_{1\le n\le m\le \mathrm{N}}\sqrt{{\left(X_n‐X_m\right)}^2+{\left(Y_n‐Y_m\right)}^2}$	cm
RANGE RATIO	Ratio of amplitudes	$\frac{\text{Range}\text{ML}}{\text{Range}\text{AP}}$	—
PLANAR DEV.	Planar deviation	$\sqrt{\text{RMS}{\text{ML}}^2+\text{RMS}{\text{AP}}^2}$	cm
COEF. SWAY DIR.	Coefficient of sway direction	$\frac{\text{COV}}{\text{RMS}\text{ML}\times \text{RMS}\text{AP}}$	—
95% CONF. AREA	95% confidence ellipse area	See Def.	cm²
PRINCIPAL SWAY DIR.	Principal sway direction	$\text{arccos}\left(\frac{\left|v_2\right|}{\sqrt{v_1^2+v_2^2}}\right)\times \frac{180}{\pi }$	°