Difference of angular values

Computes lagged differences between successive angles (in radians) and converts each raw subtraction into the shortest signed angular distance using calculate_angular_difference(). The output mimics base::diff(), returning NAs for the first lag positions so it works nicely inside dplyr::mutate().

Usage

diff_angle(x, lag = 1L)

Arguments

x

Numeric vector of angles (radians).

lag

Positive integer indicating the lag (default = 1L). Must be an integer ≥ 1.

Value

Numeric vector of the same length as x. The first lag entries are NA; subsequent entries contain the angular differences.

Examples

# Simple example
angles <- c(0, pi/2, pi, 3*pi/2)
diff_angle(angles)
#> [1]       NA 1.570796 1.570796 1.570796

# Using a lag of 2
diff_angle(angles, lag = 2L)
#> [1]       NA       NA 3.141593 3.141593