Add a legend to a ggplot pointrange figure

user_14452324 0
Viewed 53

I developed this point range graph and want to add a legend to explain what the black dots (median) and horizontal lines (range) represents as well as what the vertical dashed line (overall median) means.

    data = diamonds %>%
      group_by(cut) %>%
      summarise(min = min(depth), max = max(depth), 
                median = median(depth))
    
    h_line <- 61  
    
    ggplot(data, aes(x = cut, y = median, ymin = min, ymax = max)) + 
      geom_linerange() + 
      geom_hline(yintercept=h_line, linetype="dashed", colour="#0ab58f") +
      geom_pointrange() +   coord_flip()

preview the figure developed

ggplot2 legend figure r visualization
1 Answers

Thanks for clarifying your intended outcome. Here is a potential solution:

library(tidyverse)

data = diamonds %>%
  group_by(cut) %>%
  summarise(min = min(depth), max = max(depth), 
            median = median(depth))

h_line <- 61  

ggplot(data, aes(x = cut, y = median, ymin = min, ymax = max)) +
  geom_linerange(aes(linetype = "Range"),
                 key_glyph = "path") +
  geom_hline(aes(yintercept = h_line, colour="#0ab58f"), 
             lty = 2) +
  geom_point(aes(fill = "Median"),
             key_glyph = "point",
             size = 3) +
  coord_flip() +
  scale_fill_discrete(name = "") +
  scale_linetype_discrete(name = "") +
  scale_color_identity(name = "",
                       breaks = "#0ab58f",
                       label = "Group Median",
                       guide = guide_legend()) +
  theme(legend.position = "top")

Created on 2022-07-20 by the reprex package (v2.0.1)

user_129573400
Related