在ggplot中为文本标签添加下划线

Question

我正在尝试制作一个由书名和书籍作者组成的标签.我想在标签中强调标题,但不是作者.

这是MWE数据:

Title,Author,Pages,Date Started,Date Finished
underline('Time Travel'),'James Gleick',353,1/1/17,1/27/17
underline('The Road'),'Cormac McCarthy',324,1/28/17,3/10/17

此代码有效,但不允许标题和作者

library(ggplot2)
library(tidyverse)
library(ggrepel)
library(ggalt)

books.2017 <- read_csv('books_2017.csv')
books.2017$`Date Started` <- as.Date(books.2017$`Date Started`, "%m/%d/%y")
books.2017$`Date Finished` <- as.Date(books.2017$`Date Finished`, "%m/%d/%y")

ggplot(books.2017, aes(x=`Date Started`, xend=`Date Finished`)) +
  geom_dumbbell(aes(size=Pages),size_x=0, size_xend=0) +
  geom_text_repel(aes(label=paste(Title)), parse=TRUE)

当我尝试改为geom_text_repel:

geom_text_repel(aes(label=paste(Title,Author)), parse=TRUE)

我收到此错误:

Error in parse(text = as.character(lab)) : 
  <text>:1:26: unexpected string constant
1: underline('Time Travel') 'James Gleick'
                             ^

编辑标签看起来应该是这样的

Answer 1

你需要形成一个有效的plotmath表达式,qplot(1,1,geom="blank") + annotate("text", x=1, y=1, label='underline("this")*" and that"', parse = TRUE)

适用于你的数据集,这可能看起来像label=paste(Title, Author, sep="~"),这里~是一个非打破空间plotmath分离.在修复了不可重现的示例之后,这给出了

Answer 2

看起来您正在尝试下拉您的goodreads数据,并根据开始数据,结束数据和图书大小绘制您一年中阅读的图书数量.

要执行您的建议,您可以使用parse选项on geom_text*(,要执行此操作,您必须创建一个解析字符串,sprintf()并将其geom_text*(作为label输入传递到哪里parse = TRUE.

要添加换行,您可以考虑使用 plotmath::over()

parseLabel <- sprintf("over(%s,%s)",
                 gsub(" ", "~", books.2007$Title, fixed = TRUE),
                 gsub(" ", "~", books.2007$Author, fixed = TRUE))
parseLabel

或者,您可以使用下划线,但添加换行很棘手,因为plotmath()不直接支持在解析公式中使用换行符.

parseLabel <- sprintf("underline(%s)~\n~%s",
                      gsub(" ", "~", books.2007$Title, fixed = TRUE),
                      gsub(" ", "~", books.2007$Author, fixed = TRUE))
parseLabel

注意:Baptiste在他的回答中正确地说明了这一点我只是使用我创建的示例数据集扩展他的工作.

好的,这是基于上述假设的快速示例.我希望这能指出你正确的方向.

注意:我附加了一个示例数据集供人们使用.

添加下划线

为了在文本中添加下划线,您可以通过在调用中设置来利用plotmath.parse=truegeom_label*()

使用plotmath和geom_label的简单示例

library(tidyverse) # Loads ggplot2
library(graphics)
library(ggrepel)
library(gtable)
library(ggalt)

# load test dataset
# ... See example data set
# books.2007 <- structure...

gp <- ggplot(books.2007)
gp <- gp + geom_dumbbell( aes(x = `Date Started`, 
                              xend = `Date Finished`, 
                              y = ISBN, 
                              size = as.numeric(Pages)), 
                          size_x = 0, size_xend = 0)

# Construct parseLabel using sprintf
parseLabel <- sprintf("underline(%s)~\n~%s",
                  gsub(" ", "~", books.2007$Title, fixed = TRUE),
                  gsub(" ", "~", books.2007$Author, fixed = TRUE))

gp <- gp + geom_label(aes(x = `Date Started`,
                          y = ISBN), 
                      label = parseLabel,
                      vjust = 1.5, hjust = "inward", parse = TRUE)
gp <- gp + labs(size = "Book Size")
gp

绘图输出示例

使用plotmath和geom_label_repel的简单示例

NB.我个人的感觉是geom_text更容易使用,因为geom_label_repel需要计算开销来计算标签的位置.

## Construct parse string
##
##
parseLabel <- sprintf("underline(%s)~\n~%s",
                      gsub(" ", "~", books.2007$Title, fixed = TRUE),
                      gsub(" ", "~", books.2007$Author, fixed = TRUE))
parseLabel

rm(gp)
gp <- ggplot(books.2007)
gp <- gp + geom_dumbbell( aes(x = `Date Started`,
                              xend = `Date Finished`,
                              y = ISBN,
                              size = as.numeric(Pages)),
                          size_x = 0, size_xend = 0)
gp <- gp + geom_label_repel(aes(x = `Date Started`,
                                y = ISBN),
                            label = parseLabel,
                            # max.iter = 100,
                            parse = TRUE)
gp <- gp + labs(size = "Book Size")
gp

示例使用geom_text_repel绘制输出

示例数据集:

books.2007 <- structure(list(Title = c("memoirs of a geisha", "Blink: The Power of Thinking Without Thinking", 
"Power of One", "Harry Potter and the Half-Blood Prince (Book 6)", 
"Dune (Dune Chronicles Book 1)"), Author = c("arthur golden", 
"Malcolm Gladwell", "Bryce Courtenay", "J.K. Rowling", "Frank Herbert"
), ISBN = c("0099498189", "0316172324", "034541005X", "0439785960", 
"0441172717"), `My Rating` = c(4L, 3L, 5L, 4L, 5L), `Average Rating` = c(4, 
4.17, 5, 4.38, 4.55), Publisher = c("vintage", "Little Brown and Company", 
"Ballantine Books", "Scholastic Paperbacks", "Ace"), Binding = c("paperback", 
"Hardcover", "Paperback", "Paperback", "Paperback"), `Year Published` = c(2005L, 
2005L, 1996L, 2006L, 1990L), `Original Publication Year` = c(2005L, 
2005L, 1996L, 2006L, 1977L), `Date Read` = c(NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_), `Date Added` = structure(c(13558, 
13558, 13558, 13558, 13558), class = "Date"), Bookshelves = c("fiction", 
"nonfiction marketing", "fiction", "fiction fantasy", "fiction scifi"
), `My Review` = c(NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_), `Date Started` = structure(c(13577, 
13610, 13634, 13684, 13722), class = "Date"), `Date Finished` = structure(c(13623, 
13647, 13660, 13689, 13784), class = "Date"), Pages = c("522", 
"700", "300", "145", "700")), .Names = c("Title", "Author", "ISBN", 
"My Rating", "Average Rating", "Publisher", "Binding", "Year Published", 
"Original Publication Year", "Date Read", "Date Added", "Bookshelves", 
"My Review", "Date Started", "Date Finished", "Pages"), row.names = c(NA, 
-5L), spec = structure(list(cols = structure(list(Title = structure(list(), class = c("collector_character", 
"collector")), Author = structure(list(), class = c("collector_character", 
"collector")), ISBN = structure(list(), class = c("collector_character", 
"collector")), `My Rating` = structure(list(), class = c("collector_integer", 
"collector")), `Average Rating` = structure(list(), class = c("collector_double", 
"collector")), Publisher = structure(list(), class = c("collector_character", 
"collector")), Binding = structure(list(), class = c("collector_character", 
"collector")), `Year Published` = structure(list(), class = c("collector_integer", 
"collector")), `Original Publication Year` = structure(list(), class = c("collector_integer", 
"collector")), `Date Read` = structure(list(), class = c("collector_character", 
"collector")), `Date Added` = structure(list(), class = c("collector_character", 
"collector")), Bookshelves = structure(list(), class = c("collector_character", 
"collector")), `My Review` = structure(list(), class = c("collector_character", 
"collector"))), .Names = c("Title", "Author", "ISBN", "My Rating", 
"Average Rating", "Publisher", "Binding", "Year Published", "Original Publication Year", 
"Date Read", "Date Added", "Bookshelves", "My Review")), default = structure(list(), class = c("collector_guess", 
"collector"))), .Names = c("cols", "default"), class = "col_spec"), class = c("tbl_df", 
"tbl", "data.frame"))

简单示例 - 没有格式化

为了完整起见,我将如何处理避免公式构造问题的问题.

gp <- ggplot(books.2007)
gp <- gp + geom_dumbbell( aes(x = `Date Started`, 
                              xend = `Date Finished`, 
                              y = ISBN, 
                              size = as.numeric(Pages)), 
                          size_x = 0, size_xend = 0)
t <- paste(books.2007$Title, "\n", books.2007$Author)
gp <- gp + geom_label(aes(x = `Date Started`,
                               y = ISBN),
                      label = t,
                      vjust = 1.5, hjust = "inward", parse = FALSE)
gp <- gp + labs(size = "Book Size")
gp

绘图输出