traipse (version 0.3.0)

track_angle: Track angle

Description

Calculate internal track angle on longitude, latitude input vectors. The unit of angle is degrees.

Usage

track_angle(x, y)

Value

a numeric vector of the relative internal angle between sequential locations in degrees, see Details

Arguments

x

longitude

y

latitude

Details

By convention the first and last values are set to NA missing value, because the angle applies to the location between each previous and next location.

To use this on multiple track ids, use a grouped data frame with tidyverse code like data %>% group_by(id) %>% mutate(angle = track_angle(lon, lat)).

The maximum possible value is 180 and the minimum is 0.

Examples

track_angle(trips0$x, trips0$y)[1:10]

## maximum value
track_angle(c(0, 0, 0), c(0, 1, 2))
## minimum value
track_angle(c(0, 0, 0), c(0, 1, 0))