ggsurvplot风险表与K-M曲线X轴对齐问题求助

需求 #

实现K-M曲线从(0,0)位置起始，同时让风险表的x=0位置与图表X轴刻度完全对齐。

初始代码（存在对齐问题） #

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

f <- survfit(Surv(time, status) ~ 1, data = lung)

Figure <- ggsurvplot(
  fit = f,
  fun = function(s) s * 100,
  pval = FALSE,
  conf.int = FALSE,
  cumcensor = FALSE,
  censor = FALSE,
  axes.offset = FALSE,
  size = 1.5,
  break.time.by = 365,
  risk.table = TRUE,
  risk.table.title = "No. at risk",
  risk.table.height = 0.18,
  risk.table.y.text = FALSE,
  risk.table.col = "strata",
  tables.theme = theme_cleantable(),
  palette = c("#0072B2"),
  ggtheme = theme_classic())

Figure$plot <- Figure$plot + 
  coord_cartesian(xlim = c(0, 800), clip = 'on', expand = FALSE)

Figure$table <- Figure$table + 
  coord_cartesian(xlim = c(0, 800), clip = 'on', expand = FALSE) +
  theme(legend.position = "null")

(Figure$plot / Figure$table) + plot_layout(heights = c(6,1))

尝试过的无效方法 #

方法1：设置axes.offset = TRUE #

风险表第一列直接缺失，无法实现对齐：

Figure <- ggsurvplot(
  fit = f,
  fun = function(s) s * 100,
  pval = FALSE,
  conf.int = FALSE,
  cumcensor = FALSE,
  censor = FALSE,
  axes.offset = TRUE,
  size = 1.5,
  break.time.by = 365,
  risk.table = TRUE,
  risk.table.title = "No. at risk",
  risk.table.height = 0.18,
  risk.table.y.text = FALSE,
  risk.table.col = "strata",
  tables.theme = theme_cleantable(),
  palette = c("#0072B2"),
  ggtheme = theme_classic())

Figure$plot <- Figure$plot + 
  coord_cartesian(xlim = c(0, 800), clip = 'on', expand = FALSE)

Figure$table <- Figure$table + 
  coord_cartesian(xlim = c(0, 800), clip = 'on', expand = FALSE) +
  theme(legend.position = "null")

(Figure$plot / Figure$table) + plot_layout(heights = c(6,1))

方法2：调整风险表axis.text.y边距 #

对X轴对齐无任何效果：

Figure <- ggsurvplot(
  fit = f,
  fun = function(s) s * 100,
  pval = FALSE,
  conf.int = FALSE,
  cumcensor = FALSE,
  censor = FALSE,
  axes.offset = TRUE,
  size = 1.5,
  break.time.by = 365,
  risk.table = TRUE,
  risk.table.title = "No. at risk",
  risk.table.height = 0.18,
  risk.table.y.text = FALSE,
  risk.table.col = "strata",
  tables.theme = theme_cleantable() +
theme(axis.text.y = element_text(margin = margin(r = 1.5, unit = "cm"))),
  palette = c("#0072B2"),
  ggtheme = theme_classic())

Figure$plot <- Figure$plot + 
  coord_cartesian(xlim = c(0, 800), clip = 'on', expand = FALSE)

Figure$table <- Figure$table + 
  coord_cartesian(xlim = c(0, 800), clip = 'on', expand = FALSE) +
  theme(legend.position = "null")

(Figure$plot / Figure$table) + plot_layout(heights = c(6,1))

有效解决方案 #

核心是让绘图区域和风险表的X轴缩放参数完全统一，同时保留曲线从(0,0)起始的设置：

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

f <- survfit(Surv(time, status) ~ 1, data = lung)

Figure <- ggsurvplot(
  fit = f,
  fun = function(s) s * 100,
  pval = FALSE,
  conf.int = FALSE,
  cumcensor = FALSE,
  censor = FALSE,
  axes.offset = FALSE, # 确保曲线从(0,0)起始
  size = 1.5,
  break.time.by = 365,
  risk.table = TRUE,
  risk.table.title = "No. at risk",
  risk.table.height = 0.18,
  risk.table.y.text = FALSE,
  risk.table.col = "strata",
  tables.theme = theme_cleantable() + 
    theme(legend.position = "none"), # 提前隐藏图例
  palette = c("#0072B2"),
  ggtheme = theme_classic()
)

# 统一设置绘图和风险表的X/Y轴范围与扩展参数，确保对齐
Figure$plot <- Figure$plot + 
  scale_x_continuous(limits = c(0, 800), expand = c(0, 0)) +
  scale_y_continuous(limits = c(0, 100), expand = c(0, 0)) # 强制Y轴从0起始

Figure$table <- Figure$table + 
  scale_x_continuous(limits = c(0, 800), expand = c(0, 0))

# 组合图形并设置高度比例
(Figure$plot / Figure$table) + plot_layout(heights = c(6,1))

原理说明 #

1. axes.offset = FALSE：确保K-M曲线的起点直接贴合(0,0)坐标，不产生偏移。
2. 替换coord_cartesian为scale_x_continuous：前者仅限制显示范围，后者直接定义轴的实际范围和扩展量，让绘图区域和风险表的X轴起点、刻度完全匹配。
3. 统一expand = c(0,0)：取消X轴两端的默认留白，确保x=0位置完全对齐。

内容的提问来源于stack exchange，提问作者Hyun Seok Kwak