remove all variables except functions

Question

I have loaded in a R console different type of objects. I can remove them all using

rm(list=ls())

or remove only the functions (but not the variables) using

rm(list=lsf.str())

My question is: is there a way to remove all variables except the functions

Josh O'Brien · Accepted Answer · 2011-11-29T04:57:15.340

158

Here's a one-liner that removes all objects except for functions:

rm(list = setdiff(ls(), lsf.str()))

It uses setdiff to find the subset of objects in the global environment (as returned by ls()) that don't have mode function (as returned by lsf.str())

edited Nov 29 '11 at 04:57

answered Nov 29 '11 at 04:27

Josh O'Brien

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If you also want to remove objects whose names start with a period, use this instead: `rm(list=setdiff(ls(all.names=TRUE), lsf.str(all.names=TRUE)))` – Josh O'Brien Nov 29 '11 at 05:21
1

Thanks a lot for this answer. May I know what is a period? – RockScience Nov 30 '11 at 04:18
1

Sure. A period (in American English) is another name for a dot, like this: `.` To see what I'm talking about, try `.j <- 5; ls(); ls(all.names=TRUE)` – Josh O'Brien Nov 30 '11 at 05:14
great, thank you. I already noticed that .j was not affected by ls() but could explain that. – RockScience Nov 30 '11 at 08:52

score 7 · Answer 2 · answered Nov 29 '11 at 12:48

7

The posted setdiff answer is nice. I just thought I'd post this related function I wrote a while back. Its usefulness is up to the reader :-).

lstype<-function(type='closure'){ 
    inlist<-ls(.GlobalEnv)
    if (type=='function') type <-'closure'
    typelist<-sapply(sapply(inlist,get),typeof)
    return(names(typelist[typelist==type]))
}

answered Nov 29 '11 at 12:48

Carl Witthoft

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Thanks for posting that. It makes for an interesting comparison with the code for `ls.str()` which, however, tests the `mode` rather than the `typeof` of objects. (On a side note, I'll be darned if I can figure the difference between those two from their documentation). – Josh O'Brien Nov 29 '11 at 17:04
I always use class instead of typeof – RockScience Nov 30 '11 at 04:19

score 1 · Answer 3 · answered Oct 25 '17 at 20:47

1

You can use the following command to clear out ALL variables. Be careful because it you cannot get your variables back.

rm(list=ls(all=TRUE))

answered Oct 25 '17 at 20:47

lwileczek

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Good to know but that's not the not the question – RockScience Oct 26 '17 at 01:54
I guess I should have left that as a comment since it was more of an FYI. Sorry. – lwileczek Oct 26 '17 at 16:16

Rich Scriven · Answer 4 · 2014-06-23T05:50:19.997

Here's a pretty convenient function I picked up somewhere and adjusted a little. Might be nice to keep in the directory.

list.objects <- function(env = .GlobalEnv) 
{
    if(!is.environment(env)){
        env <- deparse(substitute(env))
        stop(sprintf('"%s" must be an environment', env))
    }
    obj.type <- function(x) class(get(x, envir = env))
    foo <- sapply(ls(envir = env), obj.type)
    object.name <- names(foo)
    names(foo) <- seq(length(foo))
    dd <- data.frame(CLASS = foo, OBJECT = object.name, 
                     stringsAsFactors = FALSE)
    dd[order(dd$CLASS),]
}

> x <- 1:5
> d <- data.frame(x)
> list.objects()
#        CLASS       OBJECT
# 1 data.frame            d
# 2   function list.objects
# 3    integer            x 
> list.objects(env = x)
# Error in list.objects(env = x) : "x" must be an environment

GiantShoulder · Answer 5 · 2020-04-08T12:19:05.837

I wrote this to remove all objects apart from functions from the current environment (Programming language used is R with IDE R-Studio):

    remove_list=c()                             # create a vector

      for(i in 1:NROW(ls())){                   # repeat over all objects in environment
        if(class(get(ls()[i]))!="function"){    # if object is *not* a function
         remove_list=c(remove_list,ls()[i])     # ..add to vector remove_list
         }    
      }

    rm(list=remove_list)                        # remove all objects named in remove_list

Notes-

The argument "list" in rm(list=) must be a character vector.

The name of an object in position i of the current environment is returned from ls()[i] and the object itself from get(ls()[i]). Therefore the class of an object is returned from class(get(ls()[i]))

Please add more information about "current environment", e.g. whether this is shell or certain programming language — DiveIntoML, Mar 27 '20 at 15:05

remove all variables except functions

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