R ggplot2：在分面图中为轴标题添加边框和彩色背景

我可能会通过使用拼图在主图的左侧添加一个细长的纯文本gggraph来实现此目的

library(ggh4x)
library(patchwork)

p2 <- pdf %>%
  ggplot(aes(x = value, fill = xx)) +
  geom_histogram(alpha=0.6, position="identity") +
  facet_grid(selected_site ~ name, scale = 'free_y') + 
  scale_fill_manual(name = '', values = c('red', 'blue')) +
  facetted_pos_scales(
    y = list(selected_site == 'n' ~ scale_y_continuous(limits = c(0,5)),
             selected_site == 'y' ~ scale_y_continuous(limits = c(0,2)))) +
  xlab('') + ylab(NULL) +
  theme_bw() + 
  theme(legend.position = 'none',
        strip.background.y = element_blank(),
        strip.text.y = element_blank(),
        panel.spacing=unit(0.2, "lines"))

p1 <- ggplot(data.frame(x = 1, y = 1, label = "THIS IS A TEST"), aes(x, y)) +
  geom_text(aes(label = label), angle = 90) +
  coord_cartesian(clip = "off") +
  theme_void() +
  theme(panel.background = element_rect(fill = "gray"),
        plot.margin = margin(5, 5, 5, 5))

p1 + p2 + plot_layout(widths = c(1, 30))