var(if (is.vector(x) || is.factor(x)) x else as.double(x) 中的错误

如何解决var(if (is.vector(x) || is.factor(x)) x else as.double(x) 中的错误

只是试图在我的研究中复制 Callaway 和 Sant'Anna 平均治疗组效应，我想看看与从未治疗过的州（对照组）相比，特定法律的实施如何影响所有治疗过的州的工资工资。

但我得到的错误是 -

var(if (is.vector(x) || is.factor(x)) x else as.double(x),na.rm = na.rm) 中的错误： 对因子 x 调用 var(x) 已失效。 使用类似 'all(duplicated(x)[-1L])' 的东西来测试一个常数向量。

谁能告诉我这是什么问题？我的代码如下

## Cleaning treated and never treated 

dat$treat = ifelse(is.na(dat$law_effective_year),1)

dat$nevertreated = ifelse(dat$treat==0,1,0)

## Command for CSDID 

out1 <- att_gt(yname="ln_incwage",tname="year",gname="law_effective_year",xformla=~male + age + age2 + age3 + age4 + black + asian + hispanic + lths + hsdegree + somecollege,data=dat,est_method = "dr",# "dr" is doubly robust. "ipw" is inverse probability weighting. "reg" is regression
               control_group = "nevertreated",# set the comparison group which is either "nevertreated" or "notyettreated" 
               print_details = FALSE,# if TRUE,print detailed results
               clustervars = "statefip",# cluster level
               panel = FALSE) # wh)

summary(out1)