COX回归最后一个代码出现问题

rm(list=ls())

setwd('D:/R language')
library(survival)
library(plyr)
library(readxl)

BaseLine<-read_excel("./clinic.xlsx",sheet = '原数据',col_names = TRUE)
View(BaseLine)

1.Cox回归分析

levels(BaseLine$Gender)

BaseLine$Gender<-factor(BaseLine$Gender)
BaseLine$Pathologic.differentiation<-factor(BaseLine$Pathologic.differentiation)
BaseLine$Obesity<-factor(BaseLine$Obesity)
BaseLine$Metastasis<-factor(BaseLine$Metastasis)
BaseLine$vital.states<-factor(BaseLine$vital.states)

1.1.2 因子（等级资料）要注意，注意排序
BaseLine$Pathologic.differentiation<-factor(BaseLine$Pathologic.differentiation,ordered = T,levels=c('low','middle','high'))
levels(BaseLine$Pathologic.differentiation)

1.1.3 批量更改为字符串
BaseLine[,c(1,3,6,7,10)]<-lapply(BaseLine[,c(1,3,6,7,10)],as.numeric)

2.0单因素Cox回归

BaSurv<- Surv(BaseLine$Follow.up.m.,BaseLine$vital.states)

BaseLine$BaSurv<-with(BaseLine,BaSurv)

BaSurv

2.2 第一个单因素分析(coxph(生存信息，风险因素))
GCox<-coxph(BaSurv~Gender,data=BaseLine)
GSum<-summary(GCox)
HR<-round(GSum$coefficients[,2],2) #HR值[coefficients，第2列]
PValue<-round(GSum$coefficients[,5],3) #P值【coefficients，第5列】
CI<-paste0(round(GSum$conf.int[,3:4],2),collapse='-')

2.2.2 整合到数据框中
Unicox<-data.frame('characteristic'='Gender',
'Hazard Ratio'=HR,
'CI95'=CI,
P value=PValue)

2.3循环
memory.size(102400)

UniCox<-function(x){
FML<-as.formula(paste0('BaSurv~',x))
GCox<-coxph(FML,data=BaseLine)
GSum<-summary(GCox)
HR<-round(GSum$coefficients[,2],2)
PValue<-round(GSum$coefficients[,5],3)
CI<-paste0(round(GSum$conf.int[,3:4],2),collapse='-')
Unicox<-data.frame('characteristic'='x',
'Hazard Ratio'=HR,
'CI95'=CI,
P value=PValue)
return(Unicox)
}

2.3.1试用这个function
UniCox('Treatment')

2.3.2 提取变量名称
VarNames<-colnames(BaseLine)[c(1:8,11)]

用Unicox运算lappy(前面是变量，后面是公式)
Univar<-lapply(VarNames,UniCox)

6.
str2lang(x)
5.
formula.character(object, env = baseenv())
4.
formula(object, env = baseenv())
3.
as.formula(paste0("BaSurv~", x))
2.
FUN(X[[i]], ...)
1.
lapply(VarNames, UniCox)

错误信息文本发一下，不要截图。

错误符号，把~去掉