theme_get
Get, set, and modify the active theme
The current/active theme (see theme()
) is automatically applied to every
plot you draw. Use theme_get
to get the current theme, and theme_set
to
completely override it. theme_update
and theme_replace
are shorthands for
changing individual elements.
Usage
theme_get()theme_set(new)
theme_update(...)
theme_replace(...)
e1 %+replace% e2
Arguments
- new
new theme (a list of theme elements)
- ...
named list of theme settings
- e1, e2
Theme and element to combine
Value
theme_set
, theme_update
, and theme_replace
invisibly return the previous theme so you can easily save it, then
later restore it.
Adding on to a theme
+
and %+replace%
can be used to modify elements in themes.
+
updates the elements of e1 that differ from elements specified (not
NULL) in e2. Thus this operator can be used to incrementally add or modify
attributes of a ggplot theme.
In contrast, %+replace%
replaces the entire element; any element of a
theme not specified in e2 will not be present in the resulting theme (i.e.
NULL). Thus this operator can be used to overwrite an entire theme.
theme_update
uses the +
operator, so that any unspecified values in the
theme element will default to the values they are set in the theme.
theme_replace
uses %+replace%
to completely replace the element, so any
unspecified values will overwrite the current value in the theme with
NULL
.
In summary, the main differences between theme_set()
, theme_update()
,
and theme_replace()
are:
theme_set()
completely overrides the current theme.theme_update()
modifies a particular element of the current theme using the+
operator.theme_replace()
modifies a particular element of the current theme using the%+replace%
operator.
See Also
Examples
# NOT RUN {
p <- ggplot(mtcars, aes(mpg, wt)) +
geom_point()
p
# Use theme_set() to completely override the current theme.
# theme_update() and theme_replace() are similar except they
# apply directly to the current/active theme.
# theme_update() modifies a particular element of the current theme.
# Here we have the old theme so we can later restore it.
# Note that the theme is applied when the plot is drawn, not
# when it is created.
old <- theme_set(theme_bw())
p
theme_set(old)
theme_update(panel.grid.minor = element_line(colour = "red"))
p
theme_set(old)
theme_replace(panel.grid.minor = element_line(colour = "red"))
p
theme_set(old)
p
# Modifying theme objects -----------------------------------------
# You can use + and %+replace% to modify a theme object.
# They differ in how they deal with missing arguments in
# the theme elements.
add_el <- theme_grey() +
theme(text = element_text(family = "Times"))
add_el$text
rep_el <- theme_grey() %+replace%
theme(text = element_text(family = "Times"))
rep_el$text
# }