Add stacked heading dots as a ggplot2 layer

Places one point per observation at its heading angle, stacking coincident angles radially to avoid overplotting. If stack_r is already a column in data (from a prior call to stack_headings), it is used as-is; otherwise stacking is computed internally.

Usage

add_stacked_headings(
  data,
  col = NULL,
  step = 0.025,
  start_sep = 0,
  tol = NULL,
  direction = "inward",
  base_r = 1,
  shade = FALSE,
  shape = FALSE,
  group = NULL,
  colour = "black",
  colour_col = NULL,
  size = 2,
  alpha = 1,
  ...
)

Arguments

data: A data frame with an angle column in radians, typically a headings_frame.
col: Name of the angle column. Defaults to the heading_col attribute when data is a headings_frame.
step, start_sep, tol, direction, base_r: Passed to stack_headings when stack_r is absent. See that function for details. step sets the gap between dots and start_sep offsets the first dot off the reference circle.
shade: If TRUE, map stack_n to the alpha aesthetic (scaled 0.2–1 across the observed range). Overrides the fixed alpha argument.
shape: Passed to stack_headings to request per-observation shape encoding. Shape is also applied when shape_code is already a column in data. Mapped to ggplot2 shape integers: 1 = hollow, 16 = filled, 21 = filled with ring.
group: Optional column name; stack within each group independently (e.g. one stacking per facet). Default NULL.
colour: Fixed point colour (ignored when colour_col is set).
colour_col: Optional column name to map to the colour aesthetic.
size: Point size passed to geom_point().
alpha: Fixed alpha. Ignored when shade = TRUE.
...: Additional arguments passed to ggplot2::geom_point().

Value

A geom_point() layer.

Usage

Arguments

Value

See also