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Question

我试图使用facet plot绘制数据子集.它是2列x4行图.第一列的值介于120和150之间,第二列的值介于180和250之间,变量在数据文件中指定为较小或较大.我在向列变量("Lesser","Greater")添加特定标签('120 <=希腊符号(alpha)<= 150','180 <=希腊符号(alpha)<= 250)时遇到问题.我尝试这样做:

require(graphics)
library(ggplot2)
hp <- ggplot2(data) + ....
xlow <- paste("120 <", expression(alpha), " < 150") 
xhi <- paste("180 <", expression(alpha), " < 250")
mf_labeller <- function(var, value){
  value <- as.character(value)
  if (var=="regime") {
  value[value=="Lesser"] <- xlow
  value[value=="Greater"]  <- xhi
}
  return(value) 
}
(hp %+% data) + facet_grid(param~regime,  scales="free", labeller=mf_labeller)

我得到"错误值=="更大":表达式不允许比较".我也尝试过强制数据.如果我以任何方式进行标记:

data2 <- transform(data, regime = factor(regime, levels=c("Lesser", "Greater"), labels=c(expression(paste("120 <", alpha," < 150")), expression("180 < alpha < 250"))))

我逐字逐句地得到了整个表达式,而不是所需的情节.我可能会遗漏一些东西.任何帮助真的很感激!! 先感谢您..

我的样本摘录如下:

regime,param,line,XX,Var,sner
Lesser,Rise,VII,AA,4.968624,0.1275248
Lesser,Rise,VII,BB,3.719405,0.08470305
Lesser,Rise,VII,CC,7.608773,0.177848
Lesser,Rise,VII,DD,9.874395,0.1367159
Lesser,Text,VII,AA,4.968624,0.1275248
Lesser,Text,VII,BB,3.719405,0.08470305
Lesser,Text,VII,CC,7.608773,0.177848
Lesser,Text,VII,DD,9.874395,0.1367159
Lesser,Chant,VII,AA,0.1771826,0.186758
Lesser,Chant,VII,BB,0.3611497,0.5484656
Lesser,Chant,VII,CC,0.7719002,0.8864444
Lesser,Chant,VIII,DD,1.829022,0.2639881
Greater,Rise,VII,AA,4.968624,0.1275248
Greater,Rise,VII,BB,3.719405,0.08470305
Greater,Rise,VII,CC,7.608773,0.177848
Greater,Rise,VII,DD,9.874395,0.1367159
Greater,Text,VII,AA,4.968624,0.1275248
Greater,Text,VII,BB,3.719405,0.08470305
Greater,Text,VII,CC,7.608773,0.177848
Greater,Text,VII,DD,9.874395,0.1367159
Greater,Chant,VII,AA,0.1771826,0.186758
Greater,Chant,VII,BB,0.3611497,0.5484656
Greater,Chant,VII,CC,0.7719002,0.8864444
Greater,Chant,VIII,DD,1.829022,0.2639881

和我使用的代码:我在帖子中以错误的方式写了早期的表达式,但我确实在代码中使用了正确的表达式.

x <- read.table("sample.csv", header=T, sep=',')
require(graphics)
library(ggplot2)
ppi <- 300
png("figure.png", width=6*ppi, height=6*ppi, res=ppi)
hp <- ggplot(data=x,aes(x=XX, y=Var, colour=line, group = line)) + geom_errorbar(aes(ymin=Var-sner, ymax=Var+sner, colour=line), width=.3) + geom_line(aes(ymax=Var+sner), size=0.7) + geom_point(aes(ymax=Var+sner), shape=21, size=2,fill="white") + theme_bw() + theme(axis.text.x = element_text(angle=90,vjust=0.25), panel.grid.minor=element_blank(), panel.grid.major=element_blank(), panel.background =element_blank(), legend.position="none" ) + scale_colour_hue(l=40) 
xlow <- expression(paste("120 <",alpha," < 150"))
xhi <- expression(paste("180 <", alpha," < 250"))
.. earlier code block as alternative here...
data2 <- transform(x, regime = factor(regime, levels=c("Lesser", "Greater"), labels=c( bquote(120<.(alpha)~phantom()<150), bquote(180<.(alpha)~phantom()<250) )
(hp %+% data2) + facet_grid(param~regime,  scales="free", labeller=label_bquote)

我也和mf_labeller一样尝试过..提前谢谢你

Answer 1

你想要用于plotmath表达式的形式是

expression(120 <= alpha~phantom() <= 150)
expression(180 <= alpha~phantom() <= 250)

您可以通过这种方式或间接获得

parse(text="120 <= alpha~phantom() <= 150")
parse(text="180 <= alpha~phantom() <= 250")

最简单的方法是将因子的级别设置为这些字符串并使用该label_parsed函数.

用mtcars数据模拟,因为你没有提供可重复的例子:

dat <- mtcars   
dat$regime <- factor(dat$am)
levels(dat$regime) <- list("120 <= alpha~phantom() <= 150" = "0",
                           "180 <= alpha~phantom() <= 250" = "1")

ggplot(aes(x=wt, y=mpg), data=dat) +
  geom_point() +
  facet_grid(cyl ~ regime, labeller=label_parsed)

如果您真的想使用自己的贴标机,并且不想更改基础数据的因子级别,那么您也可以这样做.从具有"较小"和"较大"级别的模拟数据开始:

dat <- mtcars   
dat$regime <- factor(dat$am, levels=c(0,1), labels=c("Lesser", "Greater"))

那么贴标机功能和ggplot代码将是:

mf_labeller <- function(var, value){
  value <- as.character(value)
  if (var=="regime") {
    value[value=="Lesser"] <- "120 <= alpha~phantom() <= 150"
    value[value=="Greater"]  <- "180 <= alpha~phantom() <= 250"
    value <- lapply(value, function(x) parse(text=x))
  }
  return(value) 
}

ggplot(aes(x=wt, y=mpg), data=dat) +
  geom_point() +
  facet_grid(cyl ~ regime, labeller=mf_labeller)

该图看起来一样.

Answer 2

我们没有您的数据可供测试（也没有您正在使用的代码），但之前的点阵绘图经验告诉我，可能需要和中bquote的一个或某些组合。尝试 ：sapplyas.expression

..., labels=c( bquote(120<.(alpha)~phantom()<150), bquote(180<.(alpha)~phantom()<250) )

在代码的第一部分中，我不认为您应该expression在内部使用paste，而是首先构建标签，然后构建表达向量。

如果你感到绝望，你可以先构建情节，然后强迫标签变得不同。如何使用网格编辑 ggplot2 对象以将数学表达式添加到构面标签？