TrajSinuosity2 {trajr}

Sinuosity of a trajectory

Description

Calculates the sinuosity of a trajectory as defined by Benhamou (2004), equation 8. This is a corrected version of the sinuosity index defined in Bovet & Benhamou (1988), which is suitable for a wider range of turning angle distributions, and does not require a constant step length.

Usage

TrajSinuosity2(trj, compass.direction = NULL)

Arguments

trj

A Trajectory object.

compass.direction

if not NULL, turning angles are calculated for a directed walk, assuming the specified compass direction (in radians). Otherwise, a random walk is assumed.

Details

This function implements the formula

S = 2[p(((1 + c)/(1 - c)) + b^2)]^{-0.5}

where p is the mean step length, c is the mean cosine of turning angles, and b is the coefficient of variation of the step length.

References

Benhamou, S. (2004). How to reliably estimate the tortuosity of an animal's path. Journal of Theoretical Biology, 229(2), 209-220. doi:10.1016/j.jtbi.2004.03.016

See Also

TrajSinuosity for the uncorrected sinuosity index.