geom_point_trace {ggtrace}

Trace points

Description

This geom is similar to ggplot2::geom_point(), but also includes the ability to outline points of interest. geom_point_trace() accepts normal ggplot2 graphical parameters with some modifications. fill controls the color of each point, color controls the outline color, and stroke controls outline width, similar to how filled shapes are modified for other ggplot2 geoms. Additional parameters including size, linetype, and alpha are also accepted.

Usage

geom_point_trace(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  trace_position = "all",
  background_params = list(color = NA),
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping

Set of aesthetic mappings created by aes() or aes_(). If specified and inherit.aes = TRUE (the default), it is combined with the default mapping at the top level of the plot. You must supply mapping if there is no plot mapping.

data

The data to be displayed in this layer. There are three options:

If NULL, the default, the data is inherited from the plot data as specified in the call to ggplot().

A data.frame, or other object, will override the plot data. All objects will be fortified to produce a data frame. See fortify() for which variables will be created.

A function will be called with a single argument, the plot data. The return value must be a data.frame, and will be used as the layer data. A function can be created from a formula (e.g. ~ head(.x, 10)).

stat

The statistical transformation to use on the data for this layer, as a string.

position

Position adjustment, either as a string, or the result of a call to a position adjustment function.

...

Other arguments passed on to layer(). These are often aesthetics, used to set an aesthetic to a fixed value, like colour = "red" or size = 3. They may also be parameters to the paired geom/stat.

trace_position

Specifies which data points to outline, can be one of:

• "all" to outline every group plotted

• "bottom" to only outline the bottom layer of data points

• A predicate specifying which data points to outline. This must evaluate to TRUE or FALSE within the context of the input data. e.g. value > 100

background_params

Named list specifying aesthetic parameters to use for background data points when a predicate is passed to trace_position, e.g. list(color = "red")

na.rm

If FALSE, the default, missing values are removed with a warning. If TRUE, missing values are silently removed.

show.legend

logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes. It can also be a named logical vector to finely select the aesthetics to display.

inherit.aes

If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders().

Value

ggplot object

Aesthetics

geom_point_trace() understands the following aesthetics (required aesthetics are in bold):

• x

• y

• alpha

• colour

• fill

• group

• linetype

• shape

• size

• stroke

Learn more about setting these aesthetics in vignette("ggplot2-specs").

See Also

geom_point

Examples

# Modify outline color for each group
ggplot2::ggplot(
  clusters,
  ggplot2::aes(UMAP_1, UMAP_2, color = cluster)
) +
  geom_point_trace() +
  ggplot2::theme_minimal()

# Outline a subset of points
ggplot2::ggplot(
  clusters,
  ggplot2::aes(UMAP_1, UMAP_2, fill = cluster)
) +
  geom_point_trace(trace_position = signal < 0 | signal > 17) +
  ggplot2::theme_minimal()

# Modify appearance of background points
ggplot2::ggplot(
  clusters,
  ggplot2::aes(UMAP_1, UMAP_2, fill = cluster)
) +
  geom_point_trace(
    trace_position    = signal < 0 | signal > 17,
    background_params = list(color = NA, fill = "grey85")
  ) +
  ggplot2::theme_minimal()