获取绘图区域 ggplot2 的笛卡尔坐标

问题描述

我想将标签放置在靠近图例的位置。

在下面的代码中，我在 (x,y) 中硬编码了 geom_label 值以获得当前数据帧的所需结果：

#  Creating dataframe
library(ggplot2)
values <- c(rep(0,2),rep(2,3),rep(3,rep(4,5,rep(6,8,9,rep(11,2) )
obs_number <- c(rep(18,18))
value_1 <- c(rep(4,18))
value_2 <- c(rep(7,18))
value_3 <- c(rep(3,18))
  
data_to_plot <- data.frame(values,obs_number,value_1,value_2,value_3)

#  Calculate max frequency value for using in `geom_label`

frequency_count <- data_to_plot %>% group_by(values) %>% count()%>% arrange(n)
max_frequency <- max(frequency_count$n)

# Plot
ggplot(data_to_plot,aes(x = values)) +
  geom_histogram(aes(y = ..count..),binwidth = 1,colour= "black",fill = "white") +
  geom_density(aes(y=..count..),fill="blue",alpha = .25)+
  
  
  geom_vline(aes(xintercept = value_1),color="red",linetype = "dashed",size = 0.5,alpha = 1) +
  
  geom_vline(aes(xintercept = value_1),color="forestgreen",linetype="dashed",alpha = 1) +
  
  
  geom_vline(aes(xintercept = value_3),color="purple",alpha = 1) +
  
  
  geom_label(aes(label = obs_number,y = max_frequency*0.87,x = (max(values) - 2.2),color = 'blue'),size = 3.5,alpha = 1) +
  geom_label(aes(label = value_1,y = max_frequency * 0.83,x = (max(values) - 2.2 ),color = 'forestgreen'),alpha = 1) +
  geom_label(aes(label = value_2,y = max_frequency * 0.79,color = 'purple'),alpha = 1) +
  geom_label(aes(label = value_3,y = max_frequency * 0.75,color = 'red'),alpha = 1) +
  
  
  scale_color_manual(name="Values",labels = c("Observations number","value_1","value_2","value_3"
                     ),values = c( "blue","forestgreen","purple","red")) +
  
  labs(title = "relevant_title",y = "distribution fors DLT values",x = "DLT for the route: average values per batch") +
  theme(plot.title = element_text(hjust = 0.5),axis.title.x = element_text(colour = "darkblue"),axis.text.x = element_text(face="plain",color="black",size=10,angle=0),axis.title.y = element_text(colour = "darkblue"),axis.text.y = element_text(face="plain",legend.position = c(.90,.80)
  )+
  
  
  labs(title="DLT values",y = "frequency",x = "days")+
  scale_x_continuous(breaks = seq(0,max(data_to_plot$values),1))

这是想要的结果：

但这不适用于所有数据集。

问题：

如何获得绘图区域的笛卡尔坐标，因此我将替换 max_frequency 中的 max(values) 和 geom_label，并将标签与图例对齐，假设为 legend.position = c(.90,.80)。

也欢迎其他替代方案。

解决方法

在“也欢迎替代品”的旗帜下：为什么不为 geom_vline() 使用文本字形并覆盖实际标签？

为了我自己的理解，我重新排列了代码，但这里有一个例子：

library(tidyverse)
#> Warning: package 'tibble' was built under R version 4.0.3
#> Warning: package 'tidyr' was built under R version 4.0.3
#> Warning: package 'readr' was built under R version 4.0.3
#> Warning: package 'dplyr' was built under R version 4.0.3
values <- c(rep(0,2),rep(2,3),rep(3,rep(4,5,rep(6,8,9,rep(11,2) )
obs_number <- c(rep(18,18))
value_1 <- c(rep(4,18))
value_2 <- c(rep(7,18))
value_3 <- c(rep(3,18))

data_to_plot <- data.frame(values,obs_number,value_1,value_2,value_3)

# Extra dataframe for storing the xintercepts and labels
vals <- data.frame(xintercept = c(18,4,7,label = c("Observations number","value_1","value_2","value_3"))


frequency_count <- data_to_plot %>% group_by(values) %>% count()%>% arrange(n)
max_frequency <- max(frequency_count$n)

ggplot(data_to_plot,aes(x = values)) +
  geom_histogram(aes(y = ..count..),binwidth = 1,colour= "black",fill = "white") +
  geom_density(aes(y=..count..),fill="blue",alpha = .25)+
  geom_vline(aes(xintercept = xintercept,color = label),data = vals[2:nrow(vals),],linetype = "dashed",size = 0.5,alpha = 1,# Give different legend glyph for vlines
             key_glyph = draw_key_text) +
  scale_color_manual(
    name= "Values",limits = vals$label,values = c("blue","forestgreen","purple","red"),# Override the labels and set size to something sensible
    guide = guide_legend(override.aes = list(label = vals$xintercept,size = 3.88))
  ) +
  labs(title = "relevant_title",y = "Distribution fors DLT values",x = "DLT for the route: average values per batch") +
  theme(plot.title = element_text(hjust = 0.5),axis.title.x = element_text(colour = "darkblue"),axis.text.x = element_text(face="plain",color="black",size=10,angle=0),axis.title.y = element_text(colour = "darkblue"),axis.text.y = element_text(face="plain",legend.position = c(.90,.80)
  )+
  labs(title="DLT values",y = "frequency",x = "days")+
  scale_x_continuous(breaks = seq(0,max(data_to_plot$values),1))

^{由 reprex package (v0.3.0) 于 2021 年 1 月 8 日创建}