Compute a circular interval arc from heading angles
Source:R/circular_plotting.R
compute_circ_interval.RdReturns a data frame of arc bounds centred on the circular mean direction. Two built-in statistics are available: a bootstrap confidence interval for the mean direction (`"bootstrap_ci"`, via [circular::mle.vonmises.bootstrap.ci()]) and +/-1 circular SD (`"sd"`, via [circular::sd.circular()]). The `lower` and `upper` columns of the output can be replaced with Bayesian credible interval bounds from any model before passing to [add_circ_interval()].
Usage
compute_circ_interval(
headings_df,
heading_col = "heading",
facets = NULL,
group_col = NULL,
stat = c("bootstrap_ci", "sd"),
boot_reps = 1000L,
boot_alpha = 0.05,
axial = FALSE
)Arguments
- headings_df
Data frame containing heading angles.
- heading_col
Name of the heading column (radians). Default `"heading"`.
- facets
Character vector of column names used for faceting (placement). One row is returned per occupied combination of `facets` and `group_col`. Each column is preserved in the output so `facet_grid()`/`facet_wrap()` can place the layer correctly. Default `NULL`.
- group_col
Single column name used for colour grouping. When set, one row is returned per group and the column is preserved in the output for colour mapping in [add_circ_interval()]. Default `NULL`.
- stat
Statistic: `"bootstrap_ci"` (default) or `"sd"`.
- boot_reps
Integer. Bootstrap replicates for `stat = "bootstrap_ci"`. Default `1000L`. Ignored when `stat = "sd"`.
- boot_alpha
Significance level for the bootstrap CI. Default `0.05` produces a 95% interval.
- axial
Logical. Treat the angles as axial (bidirectional, mod-pi) data: the interval is computed via the angle-doubling method and `mean_dir` is reported as an axis in `[0, pi)`, with the endpoints scaled accordingly. Default `FALSE` (ordinary directional data).