TrajEmax

Emax, the maximum expected displacement, is a single-valued measure of
straightness defined by (Cheung, Zhang, Stricker, &amp; Srinivasan, 2007). Emax-a
is a dimensionless, scale-independent measure of the maximum possible
expected displacement. Emax-b is <code>Emax-a * mean step length</code>, and gives
the maximum possible expected displacement in spatial units. Values closer to
0 are more sinuous, while larger values (approaching infinity) are
straighter.

A toolbox to assist with statistical analysis of animal trajectories.
It provides simple access to algorithms for calculating and assessing a variety of
characteristics such as speed and acceleration, as well as multiple measures of
straightness or tortuosity. Some support is provided for 3-dimensional trajectories.
McLean & Skowron Volponi (2018) <doi:10.1111/eth.12739>.

Jim McLean

trajr

Animal Trajectory Analysis

TrajEmax function

<dl><dt>trj</dt>
<dd>Trajectory to be analysed.</dd>
<dt>eMaxB</dt>
<dd>If TRUE, calculates and returns Emax-b, otherwise returns
Emax-a.</dd>
<dt>compass.direction</dt>
<dd>if not <code>NULL</code>, turning angles are calculated
for a directed walk, assuming the specified compass direction (in radians).
Otherwise, a random walk is assumed.</dd></dl>

Arguments

Trajectory straightness index, E-max — TrajEmax

<dl>

<dt>trj</dt>
<dd>Trajectory to be analysed.</dd>


<dt>eMaxB</dt>
<dd>If TRUE, calculates and returns Emax-b, otherwise returns
Emax-a.</dd>


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

</dl>

TrajEmax: Trajectory straightness index, E-max

Description

Usage

Value

Arguments

References