geom_text labels repeating in a stacked bar-CodePudding

I suspect I'm missing something obvious here, but am very confused by the behavior in this plot. Rather than trying to dput() the data here I provide a direct download link to the .csv

library(ggplot2)
library(dplyr)
library(magrittr)

variant_url <- "https://data.cdc.gov/api/views/jr58-6ysp/rows.csv"

variant_data <- read.csv("C:/<your download path here>/SARS-CoV-2_Variant_Proportions.csv", header = TRUE,
                         stringsAsFactors = FALSE)

variant_data$week_ending <- as.Date(variant_data$week_ending, format = "%m/%d/%Y")

USA_variant_data <- variant_data %>% filter(usa_or_hhsregion == "USA", week_ending >= "2022-06-01") %>%
  select(week_ending, variant, share)

USA_variant_bar <- USA_variant_data %>% ggplot(aes(fill=variant, y=share, x=week_ending))  
  geom_bar(position="fill", stat="identity")  
  geom_text(aes(label=ifelse(share >0.1, variant,"")), position=position_fill(vjust=0.5), size = 2)  
  labs(x = "",
       y = "Percent of genomes sequenced")  
  theme(plot.title = element_text(size = rel(1), face = "bold"),
        plot.subtitle = element_text(size = rel(0.7)),
        plot.caption = element_text(size = rel(1)),
        axis.text.y = element_text(color='forestgreen'),
        axis.title.y = element_text(color="forestgreen"),
        axis.text.x = element_text(angle = 45,hjust = 1))

print(USA_variant_bar)

This produces the following plot

And I don't understand why the labels are repeating?

CodePudding user response：

Your data contains multiple observations per variant and date. Hence you end up with multiple labels. To fix that I would suggest to aggregate your data before passing it to ggplot:

library(ggplot2)
library(dplyr)

USA_variant_data <- USA_variant_data %>%
  group_by(week_ending, variant) %>%
  summarise(share = sum(share), .groups = "drop")

ggplot(USA_variant_data, aes(fill = variant, y = share, x = week_ending))  
  geom_col(position = "fill")  
  geom_text(aes(label = ifelse(share > 0.1, variant, "")), position = position_fill(vjust = 0.5), size = 2)  
  labs(
    x = "",
    y = "Percent of genomes sequenced"
  )  
  theme(
    plot.title = element_text(size = rel(1), face = "bold"),
    plot.subtitle = element_text(size = rel(0.7)),
    plot.caption = element_text(size = rel(1)),
    axis.text.y = element_text(color = "forestgreen"),
    axis.title.y = element_text(color = "forestgreen"),
    axis.text.x = element_text(angle = 45, hjust = 1)
  )