R：在ggplot2中将指南/图例的顺序从排序字符串更改为排序数字

我正在尝试使用ggplot2创建等值线图。我成功地使用cut（）函数分组填充了geom_tile（）函数的瓷砖。使用这种方法，中断将被解释为字符串，而不是值，这给我设置指南的顺序带来了麻烦。这样，例如，值20将被解释为大于180的数字，从而导致情节中出现致命的误导性颜色，例如故意丑恶的颜色：

为了创建这个丑陋的图像，我使用了以下代码：

plot.isoline <- function(data, dbr=20, n_interp=200){

  library(akima)
  library(ggplot2)
  library(fields)

  data <- read.table(file = "http://s000.tinyupload.com/download.php?file_id=90687695741432763217&t=9068769574143276321730276", header = T)

  dint <- interp(x = data$x, y = data$y, z = data$z,
                 xo = seq(min(data$x), max(data$x), length = n_interp),
                 yo = seq(min(data$y), max(data$y), length = n_interp))

  dat_interp <- data.frame(expand.grid(x=dint$x,y=dint$y), z=c(dint$z))

  br <- seq(floor(min(dat_interp$z)/dbr)*dbr, ceiling(max(dat_interp$z)/dbr)*dbr, dbr)

  breaks <- cut(dat_interp$z, breaks = br)
  breaks <- gsub(","," - ",breaks,fixed=TRUE)

  dat_interp$breaks <- sapply(breaks, function(x){strsplit(x, "[( ]")[[1]][[2]]})

  ret <- ggplot(dat_interp) + 
    aes(x=x, y=y, z=z) +
    geom_tile(aes(fill=breaks)) +
    scale_fill_manual("TEMP", values=tim.colors(length(br)), guide = guide_legend(reverse=TRUE)) +
    stat_contour(breaks=br) +
    scale_x_continuous(expand=c(0,0)) +
    scale_y_continuous(expand=c(0,0))

  return(ret)        
}

---

plot.isoline
ggplot2
将
字符
值作为字符串排序，并将
因子
值按其级别排序。在代码中

breaks <- gsub(","," - ",breaks,fixed=TRUE)

在@krlmlr的帮助下，我成功地解决了这个问题。正如他所说，关键的部分是编辑标高（）。对于任何感兴趣的人来说，这是重要的部分：

  breaks <- cut(dat_interp$z, breaks = br)
  levels(breaks) <- gsub(","," - ", levels(breaks),fixed=TRUE)
  dat_interp$breaks <- breaks
  levels(dat_interp$breaks) <- as.numeric(sapply(levels(breaks), function(x){strsplit(x, "[( ]")[[1]][[2]]}))

中断，但在使用
dat_interp$breaks@oepix之后：哦，我错过了那一行。尝试在
dat_interp
数据框中使用
cut
返回的中断，并仅在必要时修改级别。（我认为
strsplit
也可以使用
gsub
实现。）好的，这帮我弄明白了，非常感谢@krlmlr！
levels(breaks) <- gsub(",", " - ", levels(breaks), fixed=TRUE)

  breaks <- cut(dat_interp$z, breaks = br)
  levels(breaks) <- gsub(","," - ", levels(breaks),fixed=TRUE)
  dat_interp$breaks <- breaks
  levels(dat_interp$breaks) <- as.numeric(sapply(levels(breaks), function(x){strsplit(x, "[( ]")[[1]][[2]]}))

plot.isoline <- function(data, dbr=20, n_interp=200){

  library(akima)
  library(ggplot2)
  library(fields)

  data <- read.table(file = "http://s000.tinyupload.com/download.php?file_id=90687695741432763217&t=9068769574143276321730276", header = T)

  dint <- interp(x = data$x, y = data$y, z = data$z,
                 xo = seq(min(data$x), max(data$x), length = n_interp),
                 yo = seq(min(data$y), max(data$y), length = n_interp))

  dat_interp <- data.frame(expand.grid(x=dint$x,y=dint$y), z=c(dint$z))

  br <- seq(floor(min(dat_interp$z)/dbr)*dbr, ceiling(max(dat_interp$z)/dbr)*dbr, dbr)

  breaks <- cut(dat_interp$z, breaks = br)
  levels(breaks) <- gsub(","," - ", levels(breaks),fixed=TRUE)
  dat_interp$breaks <- breaks
  levels(dat_interp$breaks) <- as.numeric(sapply(levels(breaks), function(x){strsplit(x, "[( ]")[[1]][[2]]}))

  ret <- ggplot(dat_interp) + 
    aes(x=x, y=y, z=z) +
    geom_tile(aes(fill=breaks)) +
    scale_fill_manual("TEMP", values=tim.colors(length(br)), guide = guide_legend(reverse=TRUE)) +
    stat_contour(breaks=br) +
    scale_x_continuous(expand=c(0,0)) +
    scale_y_continuous(expand=c(0,0))

  return(ret)        
}