ggplot2分面仪表图主标题与副标题显示位置异常问题

问题描述 #

绘制分面仪表图时，主标题和副标题显示在第一个分面子图内部，而非图表顶部；尝试添加inherit.aes = FALSE参数修复时，触发unused argument (inherit.aes = FALSE)报错。

问题原因 #

1. 主副标题错位：代码中同时用geom_text在子图内插入了名为title的文本，又在labs()中设置全局标题，加上facet_wrap(~title)把数据框的title列作为分面依据，导致ggplot混淆了全局标题和子图文本；再加上theme_void()默认布局压缩了顶部空间，最终让全局标题挤入第一个子图。
2. 参数报错：inherit.aes = FALSE是给图层（如geom_*）使用的参数，element_text()（主题文本设置）不支持该参数，因此会报错。

修正后的代码 #

library(showtext) 
library(tidyverse)

# 添加字体
font_add_google(name = "Bebas Neue", family = "Bebas Neue")
showtext_auto()

# 数据准备
df <- data.frame(matrix(nrow=5, ncol = 2))
names(df) <- c("variable", "percentage")
df$variable <- c("Carbohydrates", "Warming", "NGTnotPresent", "DrainNotPresent", "DrEaMing")
df$percentage <- c(0.67,0.33,0.86,0.78,0.58)

# 重命名title列为subplot_title，避免和全局标题冲突
df <- df %>% 
  mutate(group=ifelse(percentage <0.6, "red",
                      ifelse(percentage>=0.6 & percentage<0.8, "orange","green")),
         label=paste0(percentage*100, "%"),
         subplot_title=dplyr::recode(variable, 
                                     `Carbohydrates`="Preoperative\ncarbohydrate loading",
                                     `Warming`="Intraoperative\nwarming",
                                     `NGTnotPresent`="\nPatients without a\nnasogastric tube\non arrival in recovery",
                                     `DrainNotPresent`="\nPatients without an\nabdominal drain\non arrival in recovery",
                                     `DrEaMing`="Patients DrEaMing on\npostoperative day 1"))

# 全局标题、副标题、说明文本
title <- "pomVLAD risk-adjustment model"
subtitle <- 'The model is being used to produce a variable life-adjusted display plot for each of the 10 pilot hospitals showing their expected against observed postoperative morbidity outcomes' %>% 
  str_wrap(width = 50)
caption <- "Data: pomVLAD | Viz: @stepminer2"

# 绘图代码
gg<- ggplot(df, aes(fill = group, ymax = percentage, ymin = 0, xmax = 2, xmin = 1)) +
  geom_rect(aes(ymax=1, ymin=0, xmax=2, xmin=1), fill ="#ece8bd") +
  geom_rect() + 
  coord_polar(theta = "y",start=-pi/2) + 
  xlim(c(0, 2)) + 
  ylim(c(0,2)) +
  # 修正字体名称拼写错误，调整引号格式
  geom_text(aes(x = 0, y = 0, label = label, colour=group), 
            size=25.5, family="Bebas Neue", face= "bold") +
  # 移除子图内的冗余title文本，避免布局混乱
  facet_wrap(~subplot_title, ncol = 5) +
  theme_void() +
  scale_fill_manual(values = c("red"="#C9146C", "orange"="#DA9112", "green"="#129188")) +
  scale_colour_manual(values = c("red"="#C9146C", "orange"="#DA9112", "green"="#129188")) +
  theme(strip.background = element_blank(),
        strip.text.x = element_text(family="Bebas Neue", size=12), # 可选：显示分面标题，不需要可设为element_blank()
        plot.margin = margin(t = 100, r = 20, b = 20, l = 20, unit = "pt") # 增加顶部边距，给全局标题留空间
  ) +
  guides(fill=FALSE) +
  guides(colour=FALSE)

gg+
  labs(
    title = title,
    subtitle = subtitle,
    caption = caption)+
  theme(
    plot.title = element_text(family = "Bebas Neue", size = 50, colour = "black",
                              margin = margin(t = 20, b = 10), hjust = 0.5),
    plot.subtitle = element_text(family = "Bebas Neue", size = 30, colour = "black",
                                 margin = margin(b = 20), hjust = 0.5),
    plot.caption = element_text(color = "black", size = 20, hjust = 0.5)
  )

关键修改说明 #

1. 重命名冲突列：将数据框中的title列改为subplot_title，避免和全局标题变量混淆，同时修正facet_wrap的分面依据。
2. 移除冗余文本：删掉子图内插入全局标题的geom_text代码，消除布局冲突。
3. 修复字体错误：修正字体名称拼写（Bebas Neuel改为Bebas Neue）和引号嵌套问题。
4. 移除无效参数：删掉element_text()中的inherit.aes = FALSE，该参数不适用于主题文本设置。
5. 调整绘图边距：添加plot.margin增加顶部空间，确保全局标题能显示在图表顶部。
6. 分面标题控制：可通过strip.text.x设置是否显示子图的分面标题，按需调整。

内容的提问来源于stack exchange，提问作者Patrick Stephenson