remove all variables except functions

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

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())

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]))
}

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))

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

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]))