Per-group tests of circular uniformity — test

Tests whether each group's headings are uniformly distributed (i.e. no preferred direction), using any of four classical tests. The Rayleigh test ("rayleigh", default) returns an exact numeric p-value; the other three ("kuiper", "rao", "watson") use look-up tables and the p_value column contains the tabled significance level rather than a continuous p-value.

Usage

test_uniformity(
  hd,
  group_col = NULL,
  angle_col = "heading",
  test = c("rayleigh", "kuiper", "rao", "watson"),
  p_adjust = "none"
)

Arguments

hd: Data frame with a heading column in radians.
group_col: Column to group by. NULL tests the whole data frame as one group.
angle_col: Heading column name. Default "heading".
test: One of "rayleigh" (default), "kuiper", "rao", or "watson".
p_adjust: Multiple-comparison correction method passed to p.adjust. Default "none". Applies only when group_col is supplied; a p_value_adj column is added to the result. Recommended: "BH" (Benjamini-Hochberg) when testing many conditions. Only meaningful for the Rayleigh test (exact p-values).

Value

Tidy data frame with columns group_col (if supplied), statistic, p_value, n, test, and p_value_adj (when p_adjust != "none").