Set theme elements
Use this function to modify theme settings.
theme(..., complete = FALSE, validate = TRUE)
... |
a list of element name, element pairings that modify the existing theme. |
complete |
set this to TRUE if this is a complete theme, such as
the one returned |
validate |
TRUE to run validate_element, FALSE to bypass checks. |
Theme elements can inherit properties from other theme elements.
For example, axis.title.x 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.
For more examples of modifying properties using inheritance,
%+replace%.
To see a graphical representation of the inheritance tree, see the last example below.
The individual theme elements are:
| 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 | label of axes
(element_text; inherits from text) |
| axis.title.x | x axis label
(element_text; inherits from axis.title) |
| axis.title.y | y axis label
(element_text; inherits from axis.title) |
| axis.text | tick labels along axes
(element_text; inherits from text) |
| axis.text.x | x axis tick labels
(element_text; inherits from axis.text) |
| axis.text.y | y axis tick labels
(element_text; inherits from axis.text) |
| axis.ticks | tick marks along axes
(element_line; inherits from line) |
| axis.ticks.x | x axis tick marks
(element_line; inherits from axis.ticks) |
| axis.ticks.y | y axis tick marks
(element_line; inherits from axis.ticks) |
| axis.ticks.length | length of tick marks
(unit) |
| axis.line | lines along axes
(element_line; inherits from line) |
| axis.line.x | line along x axis
(element_line; inherits from axis.line) |
| axis.line.y | line along y axis
(element_line; inherits from axis.line) |
| legend.background | background of legend
(element_rect; inherits from rect) |
| legend.margin | extra space added around legend
(unit) |
| legend.key | background underneath legend keys
(element_rect; inherits from rect) |
| legend.key.size | size of legend keys
(unit; inherits from legend.key.size) |
| legend.key.height | key background height
(unit; inherits from legend.key.size) |
| legend.key.width | key background width
(unit; inherits from legend.key.size) |
| 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) |
| 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") |
| 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.margin | margin around facet panels
(unit) |
| panel.margin.x | horizontal margin around facet panels
(unit; inherits from panel.margin) |
| panel.margin.y | vertical margin around facet panels
(unit; inherits from panel.margin) |
| panel.grid | grid lines
(element_line; inherits from line) |
| panel.grid.major | major grid lines
(element_line; inherits from panel.grid) |
| panel.grid.minor | minor grid lines
(element_line; inherits from panel.grid) |
| panel.grid.major.x | vertical major grid lines
(element_line; inherits from panel.grid.major) |
| panel.grid.major.y | horizontal major grid lines
(element_line; inherits from panel.grid.major) |
| panel.grid.minor.x | vertical minor grid lines
(element_line; inherits from panel.grid.minor) |
| panel.grid.minor.y | horizontal minor grid lines
(element_line; inherits from panel.grid.minor) |
| panel.ontop | option to place the panel (background, gridlines)
over the data layers. Usually used with a transparent
or blank panel.background. (logical) |
| 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.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.margin | margin around entire plot
(unit with the sizes of the top, right, bottom, and
left margins) |
| strip.background | background of facet labels
(element_rect; inherits from rect) |
| strip.text | facet labels
(element_text; inherits from text) |
| strip.text.x | facet labels along horizontal direction
(element_text; inherits from strip.text) |
| strip.text.y | facet labels along vertical direction
(element_text; inherits from strip.text) |
| 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) |
p <- ggplot(mtcars, aes(mpg, wt)) +
geom_point()
p
p + theme(panel.background = element_rect(colour = "pink"))
p + theme_bw()
# Scatter plot of gas mileage by vehicle weight
p <- ggplot(mtcars, aes(wt, mpg)) +
geom_point()
# Calculate slope and intercept of line of best fit
coef(lm(mpg ~ wt, data = mtcars))
p + geom_abline(intercept = 37, slope = -5)
# Calculate correlation coefficient
with(mtcars, cor(wt, mpg, use = "everything", method = "pearson"))
#annotate the plot
p + geom_abline(intercept = 37, slope = -5) +
geom_text(data = data.frame(), aes(4.5, 30, label = "Pearson-R = -.87"))
# Change the axis labels
# Original plot
p
p + labs(x = "Vehicle Weight", y = "Miles per Gallon")
# Or
p + labs(x = "Vehicle Weight", y = "Miles per Gallon")
# Change title appearance
p <- p + labs(title = "Vehicle Weight-Gas Mileage Relationship")
# Set title to twice the base font size
p + theme(plot.title = element_text(size = rel(2)))
p + theme(plot.title = element_text(size = rel(2), colour = "blue"))
# Add a subtitle and adjust bottom margin
p + labs(title = "Vehicle Weight-Gas Mileage Relationship",
subtitle = "You need to wrap long subtitleson manually") +
theme(plot.subtitle = element_text(margin = margin(b = 20)))
# Changing plot look with themes
DF <- data.frame(x = rnorm(400))
m <- ggplot(DF, aes(x = x)) +
geom_histogram()
# Default is theme_grey()
m
# Compare with
m + theme_bw()
# Manipulate Axis Attributes
m + theme(axis.line = element_line(size = 3, colour = "red", linetype = "dotted"))
m + theme(axis.text = element_text(colour = "blue"))
m + theme(axis.text.y = element_blank())
m + theme(axis.ticks = element_line(size = 2))
m + theme(axis.title.y = element_text(size = rel(1.5), angle = 90))
m + theme(axis.title.x = element_blank())
m + theme(axis.ticks.length = unit(.85, "cm"))
# Legend Attributes
z <- ggplot(mtcars, aes(wt, mpg)) +
geom_point(aes(colour = factor(cyl)))
z
z + theme(legend.position = "none")
z + theme(legend.position = "bottom")
# Or use relative coordinates between 0 and 1
z + theme(legend.position = c(.5, .5))
# Add a border to the whole legend
z + theme(legend.background = element_rect(colour = "black"))
# Legend margin controls extra space around outside of legend:
z + theme(legend.background = element_rect(),
legend.margin = unit(1, "cm"))
z + theme(legend.background = element_rect(),
legend.margin = unit(0, "cm"))
# Or to just the keys
z + theme(legend.key = element_rect(colour = "black"))
z + theme(legend.key = element_rect(fill = "yellow"))
z + theme(legend.key.size = unit(2.5, "cm"))
z + theme(legend.text = element_text(size = 20, colour = "red", angle = 45))
z + theme(legend.title = element_text(face = "italic"))
# To change the title of the legend use the name argument
# in one of the scale options
z + scale_colour_brewer(name = "My Legend")
z + scale_colour_grey(name = "Number of \nCylinders")
# Panel and Plot Attributes
z + theme(panel.background = element_rect(fill = "black"))
z + theme(panel.border = element_rect(linetype = "dashed", colour = "black"))
z + theme(panel.grid.major = element_line(colour = "blue"))
z + theme(panel.grid.minor = element_line(colour = "red", linetype = "dotted"))
z + theme(panel.grid.major = element_line(size = 2))
z + theme(panel.grid.major.y = element_blank(),
panel.grid.minor.y = element_blank())
z + theme(plot.background = element_rect())
z + theme(plot.background = element_rect(fill = "green"))
# Faceting Attributes
set.seed(4940)
dsmall <- diamonds[sample(nrow(diamonds), 1000), ]
k <- ggplot(dsmall, aes(carat, ..density..)) +
geom_histogram(binwidth = 0.2) +
facet_grid(. ~ cut)
k + theme(strip.background = element_rect(colour = "purple", fill = "pink",
size = 3, linetype = "dashed"))
k + theme(strip.text.x = element_text(colour = "red", angle = 45, size = 10,
hjust = 0.5, vjust = 0.5))
k + theme(panel.margin = unit(5, "lines"))
k + theme(panel.margin.y = unit(0, "lines"))
# Put gridlines on top
meanprice <- tapply(diamonds$price, diamonds$cut, mean)
cut <- factor(levels(diamonds$cut), levels = levels(diamonds$cut))
df <- data.frame(meanprice, cut)
g <- ggplot(df, aes(cut, meanprice)) + geom_bar(stat = "identity")
g + geom_bar(stat = "identity") +
theme(panel.background = element_blank(),
panel.grid.major.x = element_blank(),
panel.grid.minor.x = element_blank(),
panel.grid.minor.y = element_blank(),
panel.ontop = TRUE)
# Modify a theme and save it
mytheme <- theme_grey() + theme(plot.title = element_text(colour = "red"))
p + mythemePlease choose more modern alternatives, such as Google Chrome or Mozilla Firefox.