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rlistnaming

Use object names as list names in R


Of course I could name the objects in my list all manually like this:

    #create dfs
    df1<-data.frame(a=sample(1:50,10),b=sample(1:50,10),c=sample(1:50,10))
    df2<-data.frame(a=sample(1:50,9),b=sample(1:50,9),c=sample(1:50,9))
    df3<-data.frame(a=sample(1:50,8),b=sample(1:50,8),c=sample(1:50,8))

    #make them a list
    list.1<-list(df1=df1,df2=df2,df3=df3)

But it makes a lot of work if I have let's say 50 objects with long names. So is there any way to automate this and make the names inside the list the same as the outside objects?


Solution

  • Find the names, then call mget.
    If there is a pattern to the names of each individual variable, then this is straightforward.

    var_names <- paste0("df", 1:3)
    mget(var_names, envir = globalenv())  #or maybe envir = parent.frame()
    

    If the naming system is more complicated, you can use regular expressions to find them, using something like

    var_names <- ls(envir = globalenv(), pattern = "^df[[:digit:]]+$")