R 如何使用ggplot2根据绘图中生成的斜率对小平面进行排序

如何使用ggplot2按图中生成的斜率对小平面进行排序？我的印象是，after_stat(slope)应该做的工作，但它似乎没有效果，因为下面的截图显示，负斜率显然不是最后一个情节的小面.

library(tidyverse)
set.seed(123)
n <- 100

data_filtered <- data.frame(
  start_date = rep(seq(as.Date("2022-01-01"), by = "days", length.out = n), each = 5),
  value = rnorm(n * 5, mean = 10, sd = 3),
  id = rep(letters[1:5], each = n)
)

data_filtered$slope <- ifelse(data_filtered$id == "a", 0.5, -0.5)
data_filtered$value <- data_filtered$value + data_filtered$slope * as.numeric(data_filtered$start_date) / 100
slope <- coef(lm(value ~ as.numeric(start_date), data = data_filtered))[2]

data_filtered %>% 
  ggplot(aes(x = start_date, y = value)) + 
  geom_line() + 
  geom_smooth(method = "lm", se = FALSE) +
  facet_wrap(~fct_reorder(id, after_stat(slope), .desc = TRUE), scales = "free_y") +
  theme_minimal() +
  theme(strip.text.x = element_text(hjust = 1), 
        strip.background = element_blank(),
        strip.placement = "outside", 
        legend.position = "bottom") +
  theme(panel.spacing = unit(1, "lines"))

值得一提的是，我也try 了单独计算斜率，并使用fct_reorder重新排序，但没有成功.

fct_reorder(data_filtered, factor(id), slope, na.rm = TRUE, .desc = TRUE)