Theme elements — margin • ggplot2

In conjunction with the theme system, the element_ functions specify the display of how non-data components of the plot are drawn.

element_blank(): draws nothing, and assigns no space.
element_rect(): borders and backgrounds.
element_line(): lines.
element_text(): text.

rel() is used to specify sizes relative to the parent, margin() is used to specify the margins of elements.

margin(t = 0, r = 0, b = 0, l = 0, unit = "pt")

element_blank()

element_rect(
  fill = NULL,
  colour = NULL,
  size = NULL,
  linetype = NULL,
  color = NULL,
  inherit.blank = FALSE
)

element_line(
  colour = NULL,
  size = NULL,
  linetype = NULL,
  lineend = NULL,
  color = NULL,
  arrow = NULL,
  inherit.blank = FALSE
)

element_text(
  family = NULL,
  face = NULL,
  colour = NULL,
  size = NULL,
  hjust = NULL,
  vjust = NULL,
  angle = NULL,
  lineheight = NULL,
  color = NULL,
  margin = NULL,
  debug = NULL,
  inherit.blank = FALSE
)

rel(x)

Arguments

t, r, b, l: Dimensions of each margin. (To remember order, think trouble).
unit: Default units of dimensions. Defaults to "pt" so it can be most easily scaled with the text.
fill: Fill colour.
colour, color: Line/border colour. Color is an alias for colour.
size: Line/border size in mm; text size in pts.
linetype: Line type. An integer (0:8), a name (blank, solid, dashed, dotted, dotdash, longdash, twodash), or a string with an even number (up to eight) of hexadecimal digits which give the lengths in consecutive positions in the string.
inherit.blank: Should this element inherit the existence of an element_blank among its parents? If TRUE the existence of a blank element among its parents will cause this element to be blank as well. If FALSE any blank parent element will be ignored when calculating final element state.
lineend: Line end Line end style (round, butt, square)
arrow: Arrow specification, as created by grid::arrow()
family: Font family
face: Font face ("plain", "italic", "bold", "bold.italic")
hjust: Horizontal justification (in \([0, 1]\))
vjust: Vertical justification (in \([0, 1]\))
angle: Angle (in \([0, 360]\))
lineheight: Line height
margin: Margins around the text. See margin() for more details. When creating a theme, the margins should be placed on the side of the text facing towards the center of the plot.
debug: If TRUE, aids visual debugging by drawing a solid rectangle behind the complete text area, and a point where each label is anchored.
x: A single number specifying size relative to parent element.

Value

An S3 object of class element, rel, or margin.

Examples

plot <- ggplot(mpg, aes(displ, hwy)) + geom_point()

plot + theme(
  panel.background = element_blank(),
  axis.text = element_blank()
)


plot + theme(
  axis.text = element_text(colour = "red", size = rel(1.5))
)


plot + theme(
  axis.line = element_line(arrow = arrow())
)


plot + theme(
  panel.background = element_rect(fill = "white"),
  plot.margin = margin(2, 2, 2, 2, "cm"),
  plot.background = element_rect(
    fill = "grey90",
    colour = "black",
    size = 1
  )
)