Is there any way to modify this pie chart ?

Question

[ohtang7]

Hello,

I am just curious if there is any function in R that I can use to create the pie chart graph shown in the figure?

I want to draw lines that connect the assigned labels to each segment of the pie chart, similar to what is depicted in the figure.

Could you please let me know if there is a package or another method to achieve this in R?

Thanks.

FYI my code is as

library(ggplot2)
library(readxl)
data2 <- read_excel("Pigeon_RelativeAbundance.xlsx", sheet = "Sheet1")

genus_colors <- c("#FF0000", "#FF7F00", "#FFFF00", "#00FF00", "#00FFFF", "#0000FF", "#8B00FF", "#FF00FF",
                  "#FF4500", "#FF8C00", "#FFD700", "#ADFF2F", "#00FF7F", "#40E0D0", "#00BFFF", "#8A2BE2",
                  "#9932CC", "#FF1493", "#FF69B4", "#FFC0CB", "#FFE4B5", "#008888", "#0CCCCC", "#009900",
                  "#FAFAD2")

# Create pie chart
plot_a <- ggplot(data2, aes(x = "", y = RelativeAbundance, fill = Taxa)) +
  geom_bar(width = 1, stat = "identity") +
  coord_polar(theta = "y") +  # Convert to polar coordinate system
  scale_fill_manual(values = genus_colors) +
  theme_void() +  # Remove background and gridlines
  theme(legend.position = "bottom") +  # Move legend to bottom
  guides(fill = guide_legend(title = "Taxa")) +  # Customize legend title
  labs(title = "A")  # Add title

print(plot_a)

Answer 1

[marco.barr]

Hi, you can add the labels outside chart using geom_label_repel from ggrepel package. Check out this guide

https://r-charts.com/part-whole/pie-chart-labels-outside-ggplot2/

[ohtang7]

Thank you, I've tried but I see only some appear in the chart in wrong segments. Could you help me to solve this how ?

My code is as this.

plot_a <- ggplot(data, aes(x = "", y = Proportion, fill = Taxa)) +
  geom_bar(width = 1, stat = "identity") +
  coord_polar(theta = "y") +  # Convert to polar coordinate system
  scale_fill_manual(values = genus_colors) +
  theme_void() +  # Remove background and gridlines
  theme(legend.position = "bottom") +  # Move legend to bottom
  guides(fill = guide_legend(title = "Taxa")) +  # Customize legend title
  labs(title = "A") +  # Add title
  geom_label_repel(aes(label = Taxa), 
                   show.legend = FALSE,
                   box.padding = 0.001, 
                   point.padding = 0.001,
                   point.size = 1,  # 
                   min.segment.length = 0.001, 
                   angle = 45)  # Rotate labels if necessary

[marco.barr]

Try following the same logic as the guide which adds the labels about halfway through each pie slice value. Check column's name in script because i don''t know you data :

library(ggplot2)
library(ggrepel)
library(tidyverse)

data2 <- read_excel("Pigeon_RelativeAbundance.xlsx", sheet = "Sheet1")

genus_colors <- c("#FF0000", "#FF7F00", "#FFFF00", "#00FF00", "#00FFFF", "#0000FF", "#8B00FF", "#FF00FF",
              "#FF4500", "#FF8C00", "#FFD700", "#ADFF2F", "#00FF7F", "#40E0D0", "#00BFFF", "#8A2BE2",
              "#9932CC", "#FF1493", "#FF69B4", "#FFC0CB", "#FFE4B5", "#008888", "#0CCCCC", "#009900",
              "#FAFAD2")

df2 <- data2 %>% mutate(csum = rev(cumsum(rev(RelativeAbundance))), 
     pos = RelativeAbundance/2 + lead(csum, 1),
     pos = if_else(is.na(pos), RelativeAbundance/2, pos))

plot_a <- ggplot(data2, aes(x = "", y = RelativeAbundance, fill = fct_inorder(Taxa))) +
geom_bar(width = 1, stat = "identity") +
coord_polar(theta = "y") +  
scale_fill_manual(values = genus_colors) +
theme_void() +  
theme(legend.position = "bottom") +  
guides(fill = guide_legend(title = "Taxa")) + 
labs(title = "A") +
geom_label_repel(data = df2,
               aes(y = pos, label = Taxa),
               size = 4.5, nudge_x = 1, show.legend = FALSE)