为 ggsurvplot 中的 plot 和表格设置不同的 x 轴中断（R 中的 survminer package）

Question

I can set different x-axis breaks in ggplot and survminer::ggsurvplot. I am currently setting this by using break.time.by = 365.25 / 12 (monthly). However, I need to set axis labels for the table every 12 months (to meet formatting requirements that I can't change). I tried formatting just the table component of the overall plot and using scale_x_continuous(breaks = c(values here)) but that didn't work. I get a message saying that Scale for 'x' is already present. Adding another scale for 'x', which will replace the existing scale. Scale for 'x' is already present. Adding another scale for 'x', which will replace the existing scale.

Answer 1

You can substitute a scale in the object created by ggsurvplot , which is a list-like object containing two ggplot objects (among other things). One of these ggplot objects is called table . You can either add a second scale_x_continuous to that (and get the warning about adding a second scale), or just over-write the original.

As an example, we'll use one of the built in data sets from the survival package:

library(survival)
library(survminer)

fit3 <- survfit( Surv(time, status) ~ sex, data = colon)

ggsurv <- ggsurvplot(fit3, data = colon,
  fun = "cumhaz", conf.int = TRUE,
  risk.table = TRUE, risk.table.col="strata",
  ggtheme = theme_bw())

ggsurv

We can find out which scale object is the x-scale by doing:

x <- which(ggsurv$table$scales$find("x"))

And over-write it with our own scale. For example, we can make breaks every 200 rather than every 1000 units:

ggsurv$table$scales$scales[[x]] <- scale_x_continuous(breaks = 0:15 * 200)

And our plot is now as we want it, with the new scale in the table's x axis:

ggsurv

^{Created on 2022-01-26 by the reprex package (v2.0.1)}