ggplot2中堆叠条上方的总标签

Question

我想构建一个堆积条形图，每个堆积条都有标签，条形上方有一个总标签。

我应该如何解决这个问题？

在此处查看示例代码：

library(dplyr)
library(ggplot2)
set.seed(19)
df <- data.frame(class = rep(c("Math", "History", "Language"), 5),
                 task = rep(c("Reading", "Lecture", "Exercises", "Seminar", "Exam"), 3),
                 time = sample(1:6, size = 15, replace = TRUE))

total <- df %>%
    group_by(class) %>%
    summarise(time_total = sum(time))

# Plot
ggplot(data = df, aes(x = class, y = time, fill = task)) +
    geom_bar(stat = "identity") +
    geom_text(aes(label = time), position = position_stack(vjust = 0.5), colour = "white") +
    geom_text(aes(x = class, y = time_total + .5, label = time_total), data = total)

此代码为我生成此错误： eval 中的错误（expr、envir、enclos）：找不到对象“任务”

我不能为我的绘图使用多个数据源吗？或者我应该如何获得总标签？

Answer 1

试试这个

ggplot() +
geom_bar(data = df, aes(x = class, y = time, fill = task), stat = "identity") +
geom_text(data = df, aes(x = class, y = time, label = time), position = position_stack(vjust = 0.5), colour = "white") +
geom_text(aes(x = class, y = time_total + .5, label = time_total), data = total)