position_beeswarm: Separate coincident points with the beeswarm package

View source: R/position-beeswarm.R

position_beeswarmR Documentation

Separate coincident points with the beeswarm package

Description

Offset points to avoid overplotting using the swarmx function from the beeswarm package.

Usage

position_beeswarm(
  method = "swarm",
  spacing = 1,
  side = 0L,
  priority = "ascending",
  fast = TRUE,
  dodge.width = NULL,
  corral = "none",
  corral.width = 0.2
)

Arguments

method

string. Method for arranging points, default is "swarm". See details below.

spacing

numeric. Relative spacing between points, default is 1. You should adjust this if you change the size of the points. Generally the spacing should be 2/3 of the point size i.e. if size = 3, then spacing = 2, but this is ultimately up to personal preference.

side

integer. Direction to perform jittering: use 0L for both directions; 1L for right/upwards; -1L for left/downwards.

priority

string. Method used to perform point layout when method is "swarm", "swarm2", or "compactswarm", default is "ascending"; ignored otherwise. See details below.

fast

Use compiled version of algorithm? This option is ignored for all methods except "swarm", "swarm2", and "compactswarm".

dodge.width

numeric. Amount to dodge points from different aesthetic groups, default is NULL for no dodging.

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 0.2.

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. The "swarm2" method is very similar to "swarm" but more closely follows the method used in the beeswarm package.

While the "swarm" and "swarm2" 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 spacing 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

position_quasirandom()

Examples

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csdaw/ggbeeswarm2 documentation built on Sept. 10, 2022, 9:23 a.m.