Skip to contents

Mean Resultant Vector Length

Source: R/circular_stats.R
circ_r.Rd

Computes the mean resultant vector length for circular data, a measure of concentration (0 = uniform, 1 = perfectly aligned). Port of MATLAB circ_r from the Circular Statistics Toolbox (Berens, 2009).

Usage

circ_r(alpha, w = NULL, d = 0, dim = 1)

Arguments

alpha

numeric vector or matrix of angles in radians.

w

optional weights (same dimensions as alpha). If NULL, uniform weights.

d

optional spacing of bin centers for binned data (radians). If provided, applies correction factor for bias in estimation of r.

dim

integer; dimension along which to compute (default 1).

Value

Mean resultant length (scalar for vector input, vector/array otherwise).

References

Berens P (2009). CircStat: A MATLAB Toolbox for Circular Statistics. Journal of Statistical Software, 31(10), 1-21.

Zar JH (2010). Biostatistical Analysis. 5th ed. Prentice Hall. (Equation 26.16)

See also

circ_mean, circ_vtest

Examples

# Highly concentrated data
angles <- c(0, 0.1, -0.1, 0.05)
circ_r(angles)  # Should be close to 1
#> [1] 0.9972679

# Uniformly distributed data
angles_uniform <- seq(0, 2*pi, length.out = 100)
circ_r(angles_uniform)  # Should be close to 0
#> [1] 0.01