从标签数据帧中提取标签

Question

我想从数据库中的标签列中提取标签。因此，在这里，我想从数据df中从所有列、vs1、am1中提取标签。

输出可以是标签列表("all“、"version”、"amp")

library(expss)     
df <- mtcars 
df$vs<-factor(df$vs, levels=c(1,0), labels = c("version","others")) 
df$am<-factor(df$am, levels=c(1,0), labels = c("AMP","others")) 
 
 
df$all<- 1 
df$vs1<-ifelse(df$vs=='version',1,NA) 
df$am1<-ifelse(df$am == 'AMP', 1, NA) 
 
 
#"Cuts will be labelled like below definition" 
 
val_lab(df$all)<-c("All"=1) 
val_lab(df$vs1)<-c("version"=1) 
val_lab(df$am1)<-c("AMP"=1) 
 
dfl <- list(df$all,df$vs1,df$am1)

Answer 1

使用sapply，您可以：

library(expss)

dfl <- df[c("all", "vs1", "am1")]

sapply(dfl, function(x) names(val_lab(x)))
#>       all       vs1       am1 
#>     "All" "version"     "AMP"