= R Ggplot2 =

The '''`ggplot2`''' package is a graphing library.

<<TableOfContents>>

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== Installation ==

`ggplot2` is commonly used through [[R/Tidyverse|Tidyverse]].

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== Usage ==

`ggplot()` returns a `ggplot` object. Components are inserted with the addition (`+`) operator.

{{{
library(tidyverse)
ggplot(data = DATA, mapping = aes(MAPPINGS)) +  GEOM_FUNC()
}}}

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== Theming ==

'''Themes''' are used to customize the appearance of a graph. They are applied to a `ggplot` object with the addition (`+`) operator.

{{{
library(tidyverse)
ggplot(data = DATA, mapping = aes(MAPPINGS)) +  GEOM_FUNC() + THEME_OBJ
}}}



=== Theme Objects ===

A set of default themes are provided by the `ggplot2` package. theya re accessible from these functions:

 * `theme_grey()`
 * `theme_gray()`
 * `theme_bw()`
 * `theme_linedraw()`
 * `theme_light()`
 * `theme_dark()`
 * `theme_minimal()`
 * `theme_classic()`
 * `theme_void()`
 * `theme_test()`

Otherwise, construct a theme object using `theme()`.

{{{
library(tidyverse)
mytheme <- theme(OPTIONS)
ggplot(data = DATA, mapping = aes(MAPPINGS)) +  GEOM_FUNC() + mytheme
}}}

A common strategy is to use one of the above default themes as a starting point and then to apply customizations.

{{{
library(tidyverse)
ggplot(data = DATA, mapping = aes(MAPPINGS)) +  GEOM_FUNC() + theme_minimal() + theme(OPTIONS)
}}}



=== Options ===

To set the font for a graph's text:

{{{
theme(text = element_text(family = "DejaVu"))
}}}

To enlarge the title:

{{{
theme(plot.title = element_text(size = 20))
}}}

Note that targetting `title` instead of `plot.title` would affect the size of ''all'' title-like objects (e.g. axes labels, legend title, and so on).

To rotate the x-axis labels 90 degrees:

{{{
theme(axis.text.x = element_text(angle = 90, hjust = 0.5, vjust = 0.5))
}}}

To color the y-axis labels:

{{{
theme(axis.text.y = element_text(colour = "grey20"))
}}}

To italicize the group titles in a faceted plot:

{{{
theme(strip.text = element_text(face = "italic"))
}}}

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== See also ==

[[https://ggplot2.tidyverse.org/reference/theme.html|ggplot2 theme reference]]

[[https://ggplot2.tidyverse.org/reference/ggtheme.html|ggplot2 default themes reference]]



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