如何在 R 中生成生存曲線時添加“>”符號？

Question

有沒有辦法在ggsurvplot中添加大於符號“>”？ 在圖例中？

這是我針對此問題的示例數據集和代碼：

structure(list(X = 1:26, OS = c(59, 115, 156, 421, 431, 448,  464,
475, 477, 563, 638, 744, 769, 770, 803, 855, 1040, 1106,  1129, 1206,
1227, 268, 329, 353, 365, 377), OS_event = c(1, 1,  1, 0, 1, 0, 1, 1,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,  1, 1, 0), age = c("> 50
years", "> 50 years", "> 50 years", "> 50 years",  "> 50 years", "> 50
years", "> 50 years", "> 50 years", "> 50 years",  "> 50 years", "> 50
years", "> 50 years", "> 50 years", "< 50 years",  "< 50 years", "< 50
years", "< 50 years", "< 50 years", "< 50 years",  "< 50 years", "< 50
years", "< 50 years", "< 50 years", "< 50 years",  "< 50 years", "< 50
years"), resid.ds = c(2L, 2L, 2L, 2L, 2L,  1L, 2L, 2L, 2L, 1L, 1L, 1L,
2L, 2L, 1L, 1L, 2L, 1L, 1L, 2L, 1L,  2L, 2L, 1L, 2L, 1L), rx = c(1L,
1L, 1L, 2L, 1L, 1L, 2L, 2L, 1L,  2L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L,
2L, 2L, 2L, 1L, 1L, 2L, 2L,  2L), ecog.ps = c(1L, 1L, 2L, 1L, 1L, 2L,
2L, 2L, 1L, 2L, 2L,  1L, 2L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 2L, 2L, 1L,
2L, 1L, 1L)), row.names = c(NA, 
-26L), class = "data.frame")
Load data and packages
pacman::p_load(pacman, party, rio, tidyverse) 
library(survival) 
library(survminer) 
library(ggtext)

ovarian <- read.csv("~/Desktop/ovarian.csv", stringsAsFactors = FALSE)
 

ovarian$OS = as.numeric(ovarian$OS) ovarian$OS_event =
as.numeric(ovarian$OS_event)

# Run KM plot: 
ggsurvplot(survfit(Surv(OS, OS_event) ~ ovarian$age,
                    data = ovarian), 
            risk.table = TRUE,
            pval = TRUE,
            pval.coord = c(72,0.8),
            legend.labs = c("< 55 years", "> 55 years"), 
            title = "                              OS by binarised median age",
            legend = "right",
            legend.title = "Binarised median age", 
            break.x.by=24,
            palette = c("red", "blue"), 
            xlab="Time (Months)",
            xlim=c(0,96))

但是，這會產生以下錯誤：

錯誤：gridtext 遇到了尚不支持的標記：

目前只支持非常有限數量的標簽。

Answer 1

值得回顧一下實際發生的事情。 ggtext函數嘗試使用標簽解析標簽，但不支持ggtext標簽 ( > )。 所以我們需要一些方法來轉義標簽。 我找不到記錄的方式。

這是一個黑客攻擊的一位，但我添加了一個零寬度空間Unicode字符（ \​前） >打破標簽：

ggsurvplot(survfit(Surv(OS, OS_event) ~ ovarian$age,
                    data = ovarian), 
            risk.table = TRUE,
            pval = TRUE,
            pval.coord = c(72,0.8),
            legend.labs = c("< 55 years", "\u200B> 55 years"), 
            title = "                              OS by binarised median age",
            legend = "right",
            legend.title = "Binarised median age", 
            break.x.by=24,
            palette = c("red", "blue"), 
            xlab="Time (Months)",
            xlim=c(0,96))

順便說一句，您不必手動將標題居中。 您可以將以下參數添加到ggsurvplot ：

ggtheme = theme_survminer() + theme(plot.title = element_text(hjust = 0.5))