在ggplot2标题表达式中使用italic()和一个变量 [英] Using italic() with a variable in ggplot2 title expression
问题描述
使用 ggplot2
制作地图并尝试使用 expression()$ c $的组合来斜体显示图形标题的一部分c>和
italic()
使用一个字符串,我的地图按需要出来: c $ c $> plottitle < - 表达式(paste('示例地图','italic'''))
犯罪< - data.frame(state = tolower(rownames(USArrests) ),USArrests)
states_map< - map_data(state)
map< - ggplot(crime,aes(map_id = state))+
geom_map(aes(fill = Murder) ,
map = states_map)+
expand_limits(x = states_map $ long,
y = states_map $ lat)+
labs(title = plottitle)
map
但是,当我尝试做同样的事情,但使用一个对象而不是字符串时,该对象不计算为所需的字符串:
word< - 'italics'
plottitle2< - 表达式(粘贴('示例地图',它(aic(fill =谋杀),
map = states_map) )+
expand_limits(x = states_map $ long,
y = states_map $ lat)+
labs(title = plottitle2)
map
在应用<$ c $之前,如何获取向量 word
来评估c> italic()?
bquote或substitute应该有效,
a ='text'
plot(1,1,main = bquote(italic(。(a))))
plot(1,1,main = substitute(italic(x),list(x = a)))
When I make a map using ggplot2
and attempt to italicize part of the figure title using a combination of expression()
and italic()
using a string, my map comes out as desired:
plottitle <- expression(paste('Example map with ', italic('italics')))
crimes <- data.frame(state = tolower(rownames(USArrests)), USArrests)
states_map <- map_data("state")
map <- ggplot(crimes, aes(map_id = state)) +
geom_map(aes(fill = Murder),
map = states_map) +
expand_limits(x = states_map$long,
y = states_map$lat) +
labs(title = plottitle)
map
However, when I try to do the same thing, but use an object instead of a string, the object does not evaluate to the desired string:
word <- 'italics'
plottitle2 <- expression(paste('Example map with ', italic(word)))
map <- ggplot(crimes, aes(map_id = state)) +
geom_map(aes(fill = Murder),
map = states_map) +
expand_limits(x = states_map$long,
y = states_map$lat) +
labs(title = plottitle2)
map
How can I get the vector word
to evaluate before applying italic()
?
bquote or substitute should work,
a = 'text'
plot(1,1, main=bquote(italic(.(a))))
plot(1,1, main=substitute(italic(x), list(x=a)))
这篇关于在ggplot2标题表达式中使用italic()和一个变量的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!