Get the turning angle between points.

Gets the relative heading between two positions using the law of cosines. The turning angle is returned in degrees. Users should apply this function to one individual at a time, ideally by splittng a dataframe with multiple individuals into a list of dataframes.

atl_turning_angle(data, x = "x", y = "y", time = "time")

Arguments

data	A dataframe or similar which must have the columns specified by x, y, and time.
x	The x coordinate.
y	The y coordinate.
time	The timestamp in seconds since the UNIX epoch.

Value

A vector of turning angles in degrees. Negative degrees indicate 'left' turns. There are two fewer angles than the number of rows in the dataframe.

Author

Pratik R. Gupte

Examples

if (FALSE) {
data$angle <- atl_turning_angle(data,
  x = "x", y = "y", time = "time"
)
}