Modify components of a theme

Themes are a powerful way to customize the non-data components of your plots: i.e. titles, labels, fonts, background, gridlines, and legends. Themes can be used to give plots a consistent customized look. Modify a single plot's theme using theme(); see theme_update() if you want modify the active theme, to affect all subsequent plots. Theme elements are documented together according to inheritance, read more about theme inheritance below.

theme(
  line,
  rect,
  text,
  title,
  aspect.ratio,
  axis.title,
  axis.title.x,
  axis.title.x.top,
  axis.title.x.bottom,
  axis.title.y,
  axis.title.y.left,
  axis.title.y.right,
  axis.text,
  axis.text.x,
  axis.text.x.top,
  axis.text.x.bottom,
  axis.text.y,
  axis.text.y.left,
  axis.text.y.right,
  axis.ticks,
  axis.ticks.x,
  axis.ticks.x.top,
  axis.ticks.x.bottom,
  axis.ticks.y,
  axis.ticks.y.left,
  axis.ticks.y.right,
  axis.ticks.length,
  axis.ticks.length.x,
  axis.ticks.length.x.top,
  axis.ticks.length.x.bottom,
  axis.ticks.length.y,
  axis.ticks.length.y.left,
  axis.ticks.length.y.right,
  axis.line,
  axis.line.x,
  axis.line.x.top,
  axis.line.x.bottom,
  axis.line.y,
  axis.line.y.left,
  axis.line.y.right,
  legend.background,
  legend.margin,
  legend.spacing,
  legend.spacing.x,
  legend.spacing.y,
  legend.key,
  legend.key.size,
  legend.key.height,
  legend.key.width,
  legend.text,
  legend.text.align,
  legend.title,
  legend.title.align,
  legend.position,
  legend.direction,
  legend.justification,
  legend.box,
  legend.box.just,
  legend.box.margin,
  legend.box.background,
  legend.box.spacing,
  panel.background,
  panel.border,
  panel.spacing,
  panel.spacing.x,
  panel.spacing.y,
  panel.grid,
  panel.grid.major,
  panel.grid.minor,
  panel.grid.major.x,
  panel.grid.major.y,
  panel.grid.minor.x,
  panel.grid.minor.y,
  panel.ontop,
  plot.background,
  plot.title,
  plot.title.position,
  plot.subtitle,
  plot.caption,
  plot.caption.position,
  plot.tag,
  plot.tag.position,
  plot.margin,
  strip.background,
  strip.background.x,
  strip.background.y,
  strip.placement,
  strip.text,
  strip.text.x,
  strip.text.y,
  strip.switch.pad.grid,
  strip.switch.pad.wrap,
  ...,
  complete = FALSE,
  validate = TRUE
)

Arguments

line	all line elements (`element_line()`)
rect	all rectangular elements (`element_rect()`)
text	all text elements (`element_text()`)
title	all title elements: plot, axes, legends (`element_text()`; inherits from `text`)
aspect.ratio	aspect ratio of the panel
axis.title, axis.title.x, axis.title.y, axis.title.x.top, axis.title.x.bottom, axis.title.y.left, axis.title.y.right	labels of axes (`element_text()`). Specify all axes' labels (`axis.title`), labels by plane (using `axis.title.x` or `axis.title.y`), or individually for each axis (using `axis.title.x.bottom`, `axis.title.x.top`, `axis.title.y.left`, `axis.title.y.right`). `axis.title..` inherits from `axis.title.*` which inherits from `axis.title`, which in turn inherits from `text`
axis.text, axis.text.x, axis.text.y, axis.text.x.top, axis.text.x.bottom, axis.text.y.left, axis.text.y.right	tick labels along axes (`element_text()`). Specify all axis tick labels (`axis.text`), tick labels by plane (using `axis.text.x` or `axis.text.y`), or individually for each axis (using `axis.text.x.bottom`, `axis.text.x.top`, `axis.text.y.left`, `axis.text.y.right`). `axis.text..` inherits from `axis.text.*` which inherits from `axis.text`, which in turn inherits from `text`
axis.ticks, axis.ticks.x, axis.ticks.x.top, axis.ticks.x.bottom, axis.ticks.y, axis.ticks.y.left, axis.ticks.y.right	tick marks along axes (`element_line()`). Specify all tick marks (`axis.ticks`), ticks by plane (using `axis.ticks.x` or `axis.ticks.y`), or individually for each axis (using `axis.ticks.x.bottom`, `axis.ticks.x.top`, `axis.ticks.y.left`, `axis.ticks.y.right`). `axis.ticks..` inherits from `axis.ticks.*` which inherits from `axis.ticks`, which in turn inherits from `line`
axis.ticks.length, axis.ticks.length.x, axis.ticks.length.x.top, axis.ticks.length.x.bottom, axis.ticks.length.y, axis.ticks.length.y.left, axis.ticks.length.y.right	length of tick marks (`unit`)
axis.line, axis.line.x, axis.line.x.top, axis.line.x.bottom, axis.line.y, axis.line.y.left, axis.line.y.right	lines along axes (`element_line()`). Specify lines along all axes (`axis.line`), lines for each plane (using `axis.line.x` or `axis.line.y`), or individually for each axis (using `axis.line.x.bottom`, `axis.line.x.top`, `axis.line.y.left`, `axis.line.y.right`). `axis.line..` inherits from `axis.line.*` which inherits from `axis.line`, which in turn inherits from `line`
legend.background	background of legend (`element_rect()`; inherits from `rect`)
legend.margin	the margin around each legend (`margin()`)
legend.spacing, legend.spacing.x, legend.spacing.y	the spacing between legends (`unit`). `legend.spacing.x` & `legend.spacing.y` inherit from `legend.spacing` or can be specified separately
legend.key	background underneath legend keys (`element_rect()`; inherits from `rect`)
legend.key.size, legend.key.height, legend.key.width	size of legend keys (`unit`); key background height & width inherit from `legend.key.size` or can be specified separately
legend.text	legend item labels (`element_text()`; inherits from `text`)
legend.text.align	alignment of legend labels (number from 0 (left) to 1 (right))
legend.title	title of legend (`element_text()`; inherits from `title`)
legend.title.align	alignment of legend title (number from 0 (left) to 1 (right))
legend.position	the position of legends ("none", "left", "right", "bottom", "top", or two-element numeric vector)
legend.direction	layout of items in legends ("horizontal" or "vertical")
legend.justification	anchor point for positioning legend inside plot ("center" or two-element numeric vector) or the justification according to the plot area when positioned outside the plot
legend.box	arrangement of multiple legends ("horizontal" or "vertical")
legend.box.just	justification of each legend within the overall bounding box, when there are multiple legends ("top", "bottom", "left", or "right")
legend.box.margin	margins around the full legend area, as specified using `margin()`
legend.box.background	background of legend area (`element_rect()`; inherits from `rect`)
legend.box.spacing	The spacing between the plotting area and the legend box (`unit`)
panel.background	background of plotting area, drawn underneath plot (`element_rect()`; inherits from `rect`)
panel.border	border around plotting area, drawn on top of plot so that it covers tick marks and grid lines. This should be used with `fill = NA` (`element_rect()`; inherits from `rect`)
panel.spacing, panel.spacing.x, panel.spacing.y	spacing between facet panels (`unit`). `panel.spacing.x` & `panel.spacing.y` inherit from `panel.spacing` or can be specified separately.
panel.grid, panel.grid.major, panel.grid.minor, panel.grid.major.x, panel.grid.major.y, panel.grid.minor.x, panel.grid.minor.y	grid lines (`element_line()`). Specify major grid lines, or minor grid lines separately (using `panel.grid.major` or `panel.grid.minor`) or individually for each axis (using `panel.grid.major.x`, `panel.grid.minor.x`, `panel.grid.major.y`, `panel.grid.minor.y`). Y axis grid lines are horizontal and x axis grid lines are vertical. `panel.grid..` inherits from `panel.grid.*` which inherits from `panel.grid`, which in turn inherits from `line`
panel.ontop	option to place the panel (background, gridlines) over the data layers (`logical`). Usually used with a transparent or blank `panel.background`.
plot.background	background of the entire plot (`element_rect()`; inherits from `rect`)
plot.title	plot title (text appearance) (`element_text()`; inherits from `title`) left-aligned by default
plot.title.position, plot.caption.position	Alignment of the plot title/subtitle and caption. The setting for `plot.title.position` applies to both the title and the subtitle. A value of "panel" (the default) means that titles and/or caption are aligned to the plot panels. A value of "plot" means that titles and/or caption are aligned to the entire plot (minus any space for margins and plot tag).
plot.subtitle	plot subtitle (text appearance) (`element_text()`; inherits from `title`) left-aligned by default
plot.caption	caption below the plot (text appearance) (`element_text()`; inherits from `title`) right-aligned by default
plot.tag	upper-left label to identify a plot (text appearance) (`element_text()`; inherits from `title`) left-aligned by default
plot.tag.position	The position of the tag as a string ("topleft", "top", "topright", "left", "right", "bottomleft", "bottom", "bottomright) or a coordinate. If a string, extra space will be added to accommodate the tag.
plot.margin	margin around entire plot (`unit` with the sizes of the top, right, bottom, and left margins)
strip.background, strip.background.x, strip.background.y	background of facet labels (`element_rect()`; inherits from `rect`). Horizontal facet background (`strip.background.x`) & vertical facet background (`strip.background.y`) inherit from `strip.background` or can be specified separately
strip.placement	placement of strip with respect to axes, either "inside" or "outside". Only important when axes and strips are on the same side of the plot.
strip.text, strip.text.x, strip.text.y	facet labels (`element_text()`; inherits from `text`). Horizontal facet labels (`strip.text.x`) & vertical facet labels (`strip.text.y`) inherit from `strip.text` or can be specified separately
strip.switch.pad.grid	space between strips and axes when strips are switched (`unit`)
strip.switch.pad.wrap	space between strips and axes when strips are switched (`unit`)
...	additional element specifications not part of base ggplot2. In general, these should also be defined in the `element tree` argument.
complete	set this to `TRUE` if this is a complete theme, such as the one returned by `theme_grey()`. Complete themes behave differently when added to a ggplot object. Also, when setting `complete = TRUE` all elements will be set to inherit from blank elements.
validate	`TRUE` to run `validate_element()`, `FALSE` to bypass checks.

Theme inheritance

Theme elements inherit properties from other theme elements hierarchically. For example, axis.title.x.bottom inherits from axis.title.x which inherits from axis.title, which in turn inherits from text. All text elements inherit directly or indirectly from text; all lines inherit from line, and all rectangular objects inherit from rect. This means that you can modify the appearance of multiple elements by setting a single high-level component.

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

Examples

p1 <- ggplot(mtcars, aes(wt, mpg)) +
  geom_point() +
  labs(title = "Fuel economy declines as weight increases")
p1

# Plot ---------------------------------------------------------------------
p1 + theme(plot.title = element_text(size = rel(2)))
p1 + theme(plot.background = element_rect(fill = "green"))

# Panels --------------------------------------------------------------------

p1 + theme(panel.background = element_rect(fill = "white", colour = "grey50"))
p1 + theme(panel.border = element_rect(linetype = "dashed", fill = NA))
p1 + theme(panel.grid.major = element_line(colour = "black"))
p1 + theme(
  panel.grid.major.y = element_blank(),
  panel.grid.minor.y = element_blank()
)

# Put gridlines on top of data
p1 + theme(
  panel.background = element_rect(fill = NA),
  panel.grid.major = element_line(colour = "grey50"),
  panel.ontop = TRUE
)

# Axes ----------------------------------------------------------------------
# Change styles of axes texts and lines
p1 + theme(axis.line = element_line(size = 3, colour = "grey80"))
p1 + theme(axis.text = element_text(colour = "blue"))
p1 + theme(axis.ticks = element_line(size = 2))

# Change the appearance of the y-axis title
p1 + theme(axis.title.y = element_text(size = rel(1.5), angle = 90))

# Make ticks point outwards on y-axis and inwards on x-axis
p1 + theme(
  axis.ticks.length.y = unit(.25, "cm"),
  axis.ticks.length.x = unit(-.25, "cm"),
  axis.text.x = element_text(margin = margin(t = .3, unit = "cm"))
)

# \donttest{
# Legend --------------------------------------------------------------------
p2 <- ggplot(mtcars, aes(wt, mpg)) +
  geom_point(aes(colour = factor(cyl), shape = factor(vs))) +
  labs(
    x = "Weight (1000 lbs)",
    y = "Fuel economy (mpg)",
    colour = "Cylinders",
    shape = "Transmission"
   )
p2

# Position
p2 + theme(legend.position = "none")
p2 + theme(legend.justification = "top")
p2 + theme(legend.position = "bottom")

# Or place legends inside the plot using relative coordinates between 0 and 1
# legend.justification sets the corner that the position refers to
p2 + theme(
  legend.position = c(.95, .95),
  legend.justification = c("right", "top"),
  legend.box.just = "right",
  legend.margin = margin(6, 6, 6, 6)
)

# The legend.box properties work similarly for the space around
# all the legends
p2 + theme(
  legend.box.background = element_rect(),
  legend.box.margin = margin(6, 6, 6, 6)
)

# You can also control the display of the keys
# and the justification related to the plot area can be set
p2 + theme(legend.key = element_rect(fill = "white", colour = "black"))
p2 + theme(legend.text = element_text(size = 8, colour = "red"))
p2 + theme(legend.title = element_text(face = "bold"))

# Strips --------------------------------------------------------------------

p3 <- ggplot(mtcars, aes(wt, mpg)) +
  geom_point() +
  facet_wrap(~ cyl)
p3

p3 + theme(strip.background = element_rect(colour = "black", fill = "white"))
p3 + theme(strip.text.x = element_text(colour = "white", face = "bold"))
p3 + theme(panel.spacing = unit(1, "lines"))
# }

Arguments

Theme inheritance

See also

Examples