ggplot2:如何在geom_text标签中将字符变量(例如x < - ".35")解析为字符,而不是数字

Question

我正在研究一个出版的数字,并希望用一些beta和p值来注释它; 我所在区域的风格指南要求这些数字的格式不带前导零(例如,".003",而不是"0.003").我遇到了似乎是Catch-22的东西; 我从模型中提取了beta和p值,并进行了一些预处理以正确格式化它们,以便它们现在是字符而不是数字:

fake.beta.vals <- c(".53", ".29", ".14")
fake.p.vals <- c(".034", ".001", ".050")

但是,当我尝试在我的图中使用这些值时,parse = TRUE将它们转回数值,失去我需要的格式.

fake.beta.vals <- c(".53", ".29", ".14")
fake.p.vals <- c(".034", ".001", ".050")

p <- ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width))
p <- p + 
  geom_smooth(method = "lm") +
  geom_point() +
  facet_wrap( ~ Species)
p

len <-length(levels(iris$Species))
vars <- data.frame(expand.grid(levels(iris$Species)))
colnames(vars) <- c("Species")
betalabs <- as.data.frame(fake.beta.vals)
plabs <- as.data.frame(fake.p.vals)
dat <- data.frame(
  x = rep(7, len),
  y = rep(4, len),
  vars,
  betalabs,
  plabs)
dat$fake.beta.vals <- as.factor(dat$fake.beta.vals)
dat$fake.p.vals <- as.factor(dat$fake.p.vals)

p <- p +
  geom_text(
    aes(x     = x,
        y     = y,
        label = paste("list(beta ==",
                      fake.beta.vals,
                      ", italic(p) ==",
                      fake.p.vals,
                      ")"),
        group = NULL),
    size  = 5,
    data  = dat,
    parse = TRUE)
p

我一直在讨论这个问题一段时间但是补充说as.character():

        label = paste("list(beta ==",
                      as.character(fake.beta.vals),
                      ", italic(p) ==",
                      as.character(fake.p.vals),
                      ")"),

显然也被取消了 parse = TRUE

并添加我以前用于格式化我的值的函数:

statformat <- function(val,z){
  sub("^(-?)0.", "\\1.", sprintf(paste("%.",z,"f", sep = ""), val))
}

更糟糕的是:

        label = paste("list(beta ==",
                      statformat(fake.beta.vals, 2),
                      ", italic(p) ==",
                      statformat(fake.p.vals, 3),
                      ")"),

最后一团糟.

救命？

Answer 1

使用bquote创建的标签,然后使用强制转换为字符表示deparse

例如

# create a list of labels using bquotw
labs <- Map(.beta = fake.beta.vals, 
            .p = fake.p.vals, 
          f = function(.beta,.p) bquote(list(beta == .(.beta), italic(p) == .(.p))))
# coerce to a character representation for parse=TRUE to work within 
# geom_text
dat <- data.frame(
  x = rep(7, len),
  y = rep(4, len),
  vars,
  labels = sapply(labs,deparse))


p <- ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width)) + 
  geom_smooth(method = "lm") +
  geom_point() +
  facet_wrap( ~ Species) +
  geom_text(data = dat, aes(x=x,y=y,label=labels), parse=TRUE)
p

Answer 2

回到我的电脑并重新阅读你的问题后,我发现我误解了这个问题.试用这个I功能,我发现它似乎没有用parse.

我找到了一种让它工作的方法,这是通过在你的调用解析中包含你的fake.beta.vals和fake.p.vals'字符或'字符来实现的.

p <- p +
  geom_text(
    aes(x     = x,
        y     = y,
        label = paste("list(beta ==",
                      "`", fake.beta.vals, "`",
                      ", italic(p) ==",
                      "`", fake.p.vals, "`",
                      ")", 
                      sep=""),
        group = NULL),
    size  = 5,
    data  = dat,
    parse = TRUE)

这应该工作.