Snap angles to fixed-width circular bin centres

Bins angles (in radians) into fixed-width sectors and returns each angle snapped to its bin's centre. Snapping coincident-binned angles to a common value is the standard precursor to a stacked dot plot: feed the result to stack_headings (with the default tol = NULL) to build clean radial columns.

Usage

bin_angles(angles, width, phase = 0)

Arguments

angles

Numeric vector of angles in radians. NA is preserved.

width

Bin width in radians; must be a single positive number. For a 5-degree bin use pi / 36.

phase

Radian location of a bin centre. The default 0 places bin centres at 0, width, 2 * width, ..., so the reference direction sits on a column rather than on a bin boundary. Set phase = width / 2 to reproduce the edge-aligned bins of circular::plot.circular (centres at width / 2, 3 * width / 2, ...). Any phase is allowed – e.g. with width = pi / 2, phase = pi / 4 the bin boundaries fall on the axes, binning by quadrant.

Value

A numeric vector the same length as angles, each value snapped to its bin centre and wrapped to [0, 2 * pi).

See also

stack_headings, add_stacked_headings

Examples

# 5-degree bins centred on the reference direction
bin_angles(c(0.01, 0.10, 0.11), width = pi / 36)
#> [1] 0.00000000 0.08726646 0.08726646
# circular-package style (edge-aligned) bins
bin_angles(c(0.01, 0.10, 0.11), width = pi / 36, phase = pi / 72)
#> [1] 0.04363323 0.13089969 0.13089969