V-test for Non-uniformity with Specified Mean Direction

Computes the V-test for circular data, testing whether the population is non-uniformly distributed with a specified mean direction. Port of MATLAB circ_vtest from the Circular Statistics Toolbox (Berens, 2009).

Usage

circ_vtest(alpha, dir, w = NULL, d = 0)

Arguments

alpha

numeric vector of angles in radians.

dir

suspected mean direction in radians.

w

optional weights for binned data (same length as alpha).

d

optional bin spacing for binned data (radians) for bias correction.

Value

list with:

pval

p-value of the V-test (one-tailed)

v

V statistic

Details

The V-test is more powerful than the Rayleigh test when there is reason to believe in a specific mean direction.

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.

See also

circ_mean, circ_r

Examples

# Test if data clusters around 0
angles <- rnorm(50, mean = 0, sd = 0.5)
result <- circ_vtest(angles, dir = 0)
result$pval
#> [1] 0