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Annotate axis ticks

Source: R/axis-panel-reference.R
axis_ticks.Rd

Draws axis ticks at specified break positions along a floating axis line. Requires coord_cartesian(clip = "off").

Usage

axis_ticks(
  xintercept = NULL,
  yintercept = NULL,
  breaks,
  length = ggplot2::rel(1),
  colour = NULL,
  linewidth = NULL,
  linetype = NULL,
  arrow = NULL,
  layout = NULL
)

Arguments

xintercept

One or more x positions for vertical axis lines, in data coordinates or wrapped in I() for normalised panel coordinates (npc). May be a vector; each value produces a separate axis.

yintercept

One or more y positions for horizontal axis lines, in data coordinates or wrapped in I() for normalised panel coordinates (npc). May be a vector; each value produces a separate axis.

breaks

A numeric vector of break positions in data coordinates, or wrapped in I() for npc. Pass a list the same length as the total number of axes to use different breaks per axis.

length

Total tick length. Supports rel(). Negative values flip the tick direction. Defaults to rel(1). May be a vector recycled across all breaks in order.

colour

Inherits from axis.ticks in the set theme. May be a vector recycled across all breaks in order.

linewidth

Inherits from axis.ticks in the set theme. Supports rel(). May be a vector recycled across all breaks in order.

linetype

Inherits from axis.ticks in the set theme. May be a vector recycled across all breaks in order.

arrow

A grid::arrow() specification, or a list recycled across all breaks. The arrowhead points toward the axis line. Must use list() not c() when supplying multiple values. E.g. grid::arrow(angle = 15, length = unit(1.5, "mm"), type = "closed").

layout

Controls which panels the annotation appears in. NULL (default) repeats in all panels. An integer targets a specific panel. "fixed" repeats in all panels ignoring faceting variables. See ggplot2::layer() for full details.

Value

A list of ggplot2 annotation layers.

Details

Ticks always point in the positive direction by default (right for xintercept, up for yintercept). Use a negative length to flip them (e.g. length = -rel(1)).