自行编写的survival curve的function，旨在画出生存曲线和曲线下的no at risk表。
结果运行后报错，求帮助。
报错trackback如下：
Error in parse(text = x, keep.source = FALSE) :
  <text>:2:0: unexpected end of input
1: srv~
   ^
7.
parse(text = x, keep.source = FALSE)
6.
eval(parse(text = x, keep.source = FALSE)[[1L]])
5.
formula(eval(parse(text = x, keep.source = FALSE)[[1L]]))
4.
formula.character(object, env = baseenv())
3.
formula(object, env = baseenv())
2.
as.formula(paste("srv~", marker))
1.
ggsrv(time = "RFS", event = "resultR", data = data)

Error in parse(text = x, keep.source = FALSE) :
  <text>:2:0: unexpected end of input
1: srv~
   ^
7.
parse(text = x, keep.source = FALSE)
6.
eval(parse(text = x, keep.source = FALSE)[[1L]])
5.
formula(eval(parse(text = x, keep.source = FALSE)[[1L]]))
4.
formula.character(object, env = baseenv())
3.
formula(object, env = baseenv())
2.
as.formula(paste("srv~", marker))
1.
ggsrv(time = "RFS", event = "resultR", data = data)



原代码如下：