如何用patchwork的inset_element调整插图大小并定位至右上角？

我有两张生存分析图，其中big图作为背景图，small图作为插图。请问如何调整该插图的大小？以及如何将其定位在背景图的右上角？

原绘图代码 #

library(survminer)
library(survival)
library(patchwork)

fit <- survfit(Surv(time, status) ~ sex, data = lung)

# Big plot
big <- ggsurvplot(
  fit,  
  size = 1,  
  legend.labs = c("A", "B"),
  ylim = c(0, 1),
  linetype = "strata", 
  break.time.by = 365, 
  palette = c("#E7B800", "#2E9FDF"), 
  risk.table = TRUE,
  risk.table.title = "No. at risk",
  risk.table.height = 0.2,
  fontsize = 6,
  tables.theme = theme_cleantable()
)

# Small plot (inset)
small <- ggsurvplot(
  fit,  
  size = 1,  
  legend.labs = c("A", "B"),
  legend = "none",
  ylab = "",
  ylim = c(0.7, 1),
  linetype = "strata", 
  xlim = c(0, 365),
  break.time.by = 365, 
  palette = c("#E7B800", "#2E9FDF"), 
  fontsize = 6,
  tables.theme = theme_cleantable()
)

我的尝试代码 #

big_plot <- big$plot / big$table + plot_layout(heights = c(3, 0.5))
small_plot <- small$plot

combined <- big_plot + inset_element(small_plot, left = 0.2, bottom = 1, right = 0.95, top = 1, align_to = 'plot')

ggsave("combined.pdf", combined)

解决方案 #

你当前的inset_element参数设置存在问题（bottom和top都设为1，导致插图高度为0，无法正常显示）。要实现插图的右上角定位与大小调整，只需修改inset_element的四个位置参数：

• left/right：控制插图在背景图上的横向位置与宽度，取值范围为0（最左/最下）到1（最右/最上）
• bottom/top：控制插图在背景图上的纵向位置与高度

修改后的完整代码 #

library(survminer)
library(survival)
library(patchwork)

fit <- survfit(Surv(time, status) ~ sex, data = lung)

# Big plot
big <- ggsurvplot(
  fit,  
  size = 1,  
  legend.labs = c("A", "B"),
  ylim = c(0, 1),
  linetype = "strata", 
  break.time.by = 365, 
  palette = c("#E7B800", "#2E9FDF"), 
  risk.table = TRUE,
  risk.table.title = "No. at risk",
  risk.table.height = 0.2,
  fontsize = 6,
  tables.theme = theme_cleantable()
)

# Small plot (inset)
small <- ggsurvplot(
  fit,  
  size = 1,  
  legend.labs = c("A", "B"),
  legend = "none",
  ylab = "",
  ylim = c(0.7, 1),
  linetype = "strata", 
  xlim = c(0, 365),
  break.time.by = 365, 
  palette = c("#E7B800", "#2E9FDF"), 
  fontsize = 6,
  tables.theme = theme_cleantable()
)

# 组合主图与风险表
big_plot <- big$plot / big$table + plot_layout(heights = c(3, 0.5))
small_plot <- small$plot

# 调整插图位置与大小：定位右上角
combined <- big_plot + 
  inset_element(
    small_plot, 
    left = 0.6,   # 插图左边界位于背景图60%宽度处
    bottom = 0.6, # 插图下边界位于背景图60%高度处
    right = 0.95, # 插图右边界位于背景图95%宽度处
    top = 0.95,   # 插图上边界位于背景图95%高度处
    align_to = 'plot'
  )

ggsave("combined.pdf", combined)

参数调整说明 #

• 若想让插图更大：缩小left值、增大bottom值（比如left=0.5, bottom=0.5），保持right和top不变即可增加插图的宽高
• 若想让插图更靠近右上角：增大left和bottom值（比如left=0.7, bottom=0.7），缩小插图在背景图上的覆盖范围

内容的提问来源于stack exchange，提问作者geek45