有没有一种方法可以用一个单独的饼图作为R中的标记来制作折线图？

library(ggplot2)
library(gridExtra)

# 创建数据集
data <- data.frame(
  time = seq(as.Date("2023-01-01"), as.Date("2023-01-05"), by="days"),
  category = c("A", "B", "C", "D", "E"),
  value = c(10, 20, 30, 40, 50)
)

# 创建饼图函数
pie_func <- function(x) {
  pie_data <- data.frame(value = x$value, category = x$category)
  pie_data$value <- pie_data$value / sum(pie_data$value)
  pie <- ggplot(pie_data, aes(x = "", y = value, fill = category)) +
    geom_bar(stat = "identity", width = 1) +
    coord_polar("y", start=0) +
    theme_void() +
    labs(title = paste("Category Proportions for", x$time))
  return(pie)
}

# 创建折线图
line_plot <- ggplot(data, aes(x = time, y = value)) +
  geom_line() +
  geom_point()

# 将饼图作为标记添加到折线图上
plot_list <- lapply(data$time, function(t) {
  p <- line_plot + geom_text(aes(label = paste("(", round(value, 2), ")")), x = t, y = data$value[which(data$time == t)], size = 4)
  grid.arrange(p, pie_func(data[which(data$time == t), ]), ncol = 2)
})

# 显示图表
grid.arrange(grobs = plot_list, layout_matrix = matrix(1:length(plot_list), nrow = 1))