How to have annotated text style to inherit from theme_set() options

ggplot2, r

Solution

If ggplot2 is loaded then this should give you the properties currently in force (if they are different than the defaults):

theme(text = element_text())$text[ c("family", "size") ]

?annotate tells us that ... "Unlike typical a geom function, the properties of the geoms are not mapped from variables of a data frame, but are instead in as vectors.". I'm assuming this to mean that `annotate` does not look in `theme()` for its font information, although that is not specifically covered by that sentence. There is also a later comment that makes me think this might be by design: " ... but all other aesthetics are set. This means that layers created with this function will never affect the legend."

And the comment in ?annotate: "These are not scaled, so you can do (e.g.) colour = "red" to get a red point." I think the defaults for axis have a particular ratio on sizes but have not manage to find the specifics in the help files. This seems to give similar size for the annotation as for the axis titles:

ggplot(data1.df, aes(x = Axis1, y = Axis2, shape = Plant, color = Type)) + 
       geom_point(size = 5) +  
       annotate("text", x=0.4, y=0.0, label="Label", 
                 family= theme_get()$text[["family"]], 
                 size= theme_get()$text[["size"]]/2.5, 
                 fontface="italic") + 
       theme(legend.position="none")

If you are interested in pursuing the "why" use 2.5 question you can look at ?rel and the example that uses `theme(axis.title.x = element_text(size = rel(2.5)))`.

Problem

How to uniformly define text style (size and family) for both plot text elements and additional annotations? The following MWE ``` library(ggplot2) data1.df <- data.frame(Plant = c("Plant1", "Plant1", "Plant1", "Plant2", "Plant2", "Plant2"), Type = c(1, 2, 3, 1, 2, 3), Axis1 = c(0.2, -0.4, 0.8, -0.2, -0.7, 0.1), Axis2 = c(0.5, 0.3, -0.1, -0.3, -0.1, -0.8)) theme_set(theme_bw() + theme(text=element_text(family="Palatino", size=10))) ggplot(data1.df, aes(x = Axis1, y = Axis2, shape = Plant, color = Type)) + geom_point(size = 5) + annotate("text", x=0.4, y=0.0, label="Label", fontface="italic") + theme(legend.position="none") ``` produces with "Label" not consistent with the theme `element_text()` definitions.

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