获取函数或在R中传递字符变量名称

Question

我有数据框名称MC_df，我需要在MC_df中获取一些变量列表才能通过我的函数访问，所以如果我通过vari_names_MCdf <- list(MC_df$Age, MC_df$Year, MC_df$Education, MC_df$City, MC_df$Country)手动执行，它会起作用，但是由于数据集很大，我将要包含的所有变量名称都写入csv文件中。现在我读csv文件来访问所有变量，我卡住了。这是数据MC_df

MC_df <- data.frame(ID=c(1:5),Age=c(18,25,30,22,19),
                Year=c(2003,2010,2008,2010,2015),
                Education = c("<12","13-15",">15","<12",">15"),
                City = c("SD","MS","LA","CV","SD"),
                Country=c("US","CA","CA","CA","US"),
                Group=c(rep("group",5)))

我手动操作，只需调用列表我想要的所有变量，它可以正常工作

vari_names_MCdf <- list(MC_df$Age, MC_df$Year, MC_df$Education, MC_df$City, MC_df$Country)
vari_group_MCdf <- list(MC_df$Group,MC_df$Group,MC_df$Group,MC_df$Group,MC_df$Group)

现在我将变量写入csv文件和read.csv文件，它有助于我的未来，我需要在csv文件中编辑，我不需要从MC_df访问

df <- data.frame(names=c("Age","Year","Education","City","Country"),
             text=c("Age Continuos","Year Category","Eduaction Group","City Category","Country Group"))
write.csv(df,"vari.csv")
var <- read.csv("vari.csv", stringsAsFactors = FALSE)
var
  X     names            text
1 1       Age   Age Continuos
2 2      Year   Year Category
3 3 Education Eduaction Group
4 4      City   City Category
5 5   Country   Country Group

我试试

vari_names <- as.list(var$names) vari_text <- as.list(var$text)

get("MC_df")$vari_names[[1]]  
vari_names_new <- lapply(vari_names, function(i) paste0("MC_df$",i, sep=""))
get(vari_names_new[[1]])

一切都不起作用，所以我如何在CSV文件和数据集名称中激活变量名称