交错轴标签，ggplot2中的新功能

Question

您好：我需要绘制81个不同类别的因子，每个类别具有不同的频率计数。每个因子名称都是一个4个字母的类别。看起来像这样。如您所见，阅读因子标签非常困难。我想根据this建议错开y轴。但是，github上的this问题表明ggplot2中的某些内容发生了变化，并且hjust和vjust选项不再起作用。有没有人有任何建议让这个情节看起来更好，特别是要使因子水平可读。

#libraries
# install.packages('stringi')
library(ggplot2)
library(stringi)
#fake data
var<-stri_rand_strings(81, 4, pattern='[HrhEgeIdiFtf]')
var1<-rnorm(81, mean=175, sd=75)
#data frame
out<-data.frame(var, var1)

#set levels for plotting
out$var<-factor(out$var, levels=out$var[order(out$var1, decreasing=FALSE)])
#PLot
out.plot<-out %>%
ggplot(., aes(x=var, y=var1))+geom_point()+coord_flip()
#Add staggered axis option
out.plot+theme(axis.text.y = element_text(hjust = grid::unit(c(-2, 0, 2),     "points")))

Answer 1

要错开标签，可以在数据框中为标签添加空格。

# Libraries
library(ggplot2)
library(stringi)

# fake data
set.seed(12345)
var <- stri_rand_strings(81, 4, pattern = '[HrhEgeIdiFtf]')
var1 <- rnorm(81, mean = 175, sd = 75)

out <- data.frame(var, var1)

# Add spacing, and set levels for plotting
out = out[order(out$var1), ]
out$var = paste0(out$var, c("", "       ", "            "))
out$var <- factor(out$var, levels = out$var[order(out$var1, decreasing = FALSE)])

# Plot
out.plot <- ggplot(out, aes(x = var, y = var1)) +
   geom_point() + coord_flip()
out.plot

或者，绘制原始图，然后编辑。在这里，我使用grid函数editGrob()进行编辑。

# Libraries
library(ggplot2)
library(gtable)
library(grid)
library(stringi)

# fake data
set.seed(12345)

var <- stri_rand_strings(81, 4, pattern = '[HrhEgeIdiFtf]')
var1 <- rnorm(81, mean = 175, sd = 75)

out <- data.frame(var, var1)

# Set levels for plotting
out$var <- factor(out$var, levels = out$var[order(out$var1, decreasing = FALSE)])

# Plot
out.plot <- ggplot(out, aes(x = var, y = var1)) +
   geom_point() + coord_flip()

# Get the ggplot grob
g = ggplotGrob(out.plot)

# Get a hierarchical list of component grobs
grid.ls(grid.force(g))

查看列表以查找涉及左轴的部分。相关的一点是：

   axis-l.6-3-6-3   
     axis.line.y..zeroGrob.232   
     axis   
       axis.1-1-1-1   
         GRID.text.229   
       axis.1-2-1-2   

您需要设置从＆＃39; axis-l＆＃39;，到＆＃39;轴＆＃39;，到＆＃39;轴＆＃39;的路径，尽管到＆＃39; GRID。文本＆＃39;

# make the relevant column a little wider
g$widths[3] = unit(2.5, "cm")

# The edit
g = editGrob(grid.force(g), 
      gPath("axis-l", "axis", "axis", "GRID.text"), 
      x = unit(c(-1, 0, 1), "npc"), 
      grep = TRUE)

# Draw the plot
grid.newpage()
grid.draw(g)

另一种选择是找到通过结构到相关grob的方式进行编辑。

# Get the grob
g <- ggplotGrob(out.plot)

# Get the y axis
index <- which(g$layout$name == "axis-l")  # Which grob
yaxis <- g$grobs[[index]]   

# Get the ticks (labels and marks)
ticks <- yaxis$children[[2]]

# Get the labels
ticksL <- ticks$grobs[[1]]

# Make the edit
ticksL$children[[1]]$x <- rep(unit.c(unit(c(1,0,-1),"npc")), 27)

# Put the edited labels back into the plot
ticks$grobs[[1]] <- ticksL
yaxis$children[[2]] <- ticks
g$grobs[[index]] <- yaxis

# Make the relevant column a little wider
g$widths[3] <- unit(2.5, "cm")

# Draw the plot
grid.newpage()
grid.draw(g)

Answer 2

Sandy提到在标签上添加空格。 对于离散轴，您也可以简单地在其他情况下添加换行符。就我而言，我想交错其他选项：

scale_x_discrete(labels=paste0(c("","\n"),net_change$TZ_t)

net_change$TZ_t是我的排序因素。借助c("","\n","\n\n")，它可以轻松扩展到“三重”级别。