Get spatially discretized heading and speed over time
get_heading_and_speed_spatial.RdGets spatially discretized heading for a given individual trajectory
This is defined as the unit vector pointing from the individual's current location at time t to
its location after it mas moved a distance of at least R.
Usage
get_heading_and_speed_spatial(
x_i,
y_i,
R,
t_idxs = 1:length(x_i),
forward = T,
seconds_per_time_step = 1
)Arguments
- x_i
vector of x coordinates for the trajectory
- y_i
vector of y coordinates for the trajectory
- R
radius used to compute the headings
- forward
whether to go forward in time from current position (if T), or backward (if F) when computing headings
- seconds_per_time_step
number of seconds corresponding to each time step
- t_idxs:
time indexes at which to compute the headings (defaults to entire trajectory)
Value
Returns a list containing $heads: a time series of the heading of
the individual (a vector of the same length as x_i and y_i), in radians, computed based on
spatial discretization around the time point,$speeds: a time series of the speed of the individual at each time point, and
$dts: time differences between the current point and the first point outside of the radius R (either forward or backward in time)
vector of spatially discretized headings, computed at all times or at times t_idxs if specified (other times are then filled in with NAs)