offset_beeswarm: An internal function to calculate new positions for...

In ggbeeswarm: Categorical Scatter (Violin Point) Plots

An internal function to calculate new positions for geom_beeswarm

Description

An internal function to calculate new positions for geom_beeswarm

Usage

offset_beeswarm(
  data,
  yLim.expand,
  xRange,
  yRange,
  method = "swarm",
  cex = 1,
  side = 0L,
  priority = "ascending",
  fast = TRUE,
  corral = "none",
  corral.width = 0.2
)

Arguments

data	A data.frame containing plotting data in columns x and y. Usually obtained from data processed by ggplot2.
yLim.expand	y data limits plus a small expansion using grDevices::extendrange
xRange	x axis scale range
yRange	y axis scale range
method	Method for arranging points (see Details below)
cex	Scaling for adjusting point spacing (see beeswarm::swarmx()). Values between 1 (default) and 3 tend to work best.
side	Direction to perform jittering: 0: both directions; 1: to the right or upwards; -1: to the left or downwards.
priority	Method used to perform point layout (see Details below)
fast	Use compiled version of swarm algorithm? This option is ignored for all methods expect "swarm" and "compactswarm".
corral	string. Method used to adjust points that would be placed to wide horizontally, default is "none". See details below.
corral.width	numeric. Width of the corral, default is 0.9.

Details

method: specifies the algorithm used to avoid overlapping points. The default "swarm" method places points in increasing order. If a point would overlap with an existing point, it is shifted sideways (along the group axis) by a minimal amount sufficient to avoid overlap.

While the "swarm" method places points in a predetermined order, the "compactswarm" method uses a greedy strategy to determine which point will be placed next. This often leads to a more tightly-packed layout. The strategy is very simple: on each iteration, a point that can be placed as close as possible to the non-data axis is chosen and placed. If there are two or more equally good points, priority is used to break ties.

The other 3 methods first discretise the values along the data axis, in order to create more efficient packing. The "square" method places points on a square grid, whereas "hex" uses a hexagonal grid. "centre"/"center" uses a square grid to produce a symmetric swarm. The number of break points for discretisation is determined by a combination of the available plotting area and the cex argument.

priority: controls the order in which points are placed, which generally has a noticeable effect on the plot appearance. "ascending" gives the 'traditional' beeswarm plot. "descending" is the opposite. "density" prioritizes points with higher local density. "random" places points in a random order. "none" places points in the order provided.

corral: By default, swarms from different groups are not prevented from overlapping, i.e. ⁠"corral = "none"⁠. Thus, datasets that are very large or unevenly distributed may produce ugly overlapping beeswarms. To control runaway points one can use the following methods. "gutter" collects runaway points along the boundary between groups. "wrap" implement periodic boundaries. "random" places runaway points randomly in the region. "omit" omits runaway points.

See Also

geom_beeswarm(), position_quasirandom(), beeswarm::swarmx()

Other position adjustments: position_beeswarm(), position_quasirandom()

ggbeeswarm documentation built on April 30, 2023, 1:09 a.m.