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Draw point events as dots or raster ticks

Source: R/geom_event_point.R
geom_event_point.Rd

A ggplot2 layer that renders instantaneous events at each event's start time, with one row per label (or channel, ...) on the y axis. Two styles are available via style:

Usage

geom_event_point(
  mapping = NULL,
  data = NULL,
  ...,
  style = c("point", "raster"),
  size = 1.8,
  height = 0.7,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping

Aesthetic mapping. Merged on top of the defaults, so you only need to supply the aesthetics you want to override.

data

A data frame (typically an anievent). If NULL, inherits from the parent ggplot() call. Either way, rows with type != "point" are dropped from this layer.

style

Either "point" (default, a dot per event) or "raster" (a vertical tick per event).

size

Dot size, for style = "point". Default 1.8.

height

Tick height in y-axis units (1 = the spacing between adjacent rows), for style = "raster". Default 0.7.

na.rm, show.legend, inherit.aes, ...

Passed to ggplot2::layer().

Value

A ggplot2 layer.

Details

  • "point" (default) — a dot at each event time.

  • "raster" — a short vertical tick at each event time, the classic spike-raster look (more standard for e.g. neuron spike trains).

When the input has a type column (e.g. an aniframe::anievent()), rows with type != "point" are dropped — the point half of the state/point pair complementing geom_event_state().

The default mapping is only aes(x = start) — every other aesthetic is up to the caller. Common patterns:

  • aes(colour = label) — colour each mark by behaviour.

  • aes(y = label) (or y = channel, y = subject, ...) — spread marks across rows. With no y mapping all marks collapse onto a single line.

Opinionated wrappers (themes, colour scales, sensible defaults) are intended to live one layer up; this geom is deliberately bare.

This is a thin wrapper around ggplot2::GeomPoint ("point") or ggplot2::GeomSegment ("raster"), with a setup_data step that supplies a default y when none is mapped.