How can I remove all objects but one from the workspace in R?

Question

I have a workspace with lots of objects and I would like to remove all but one. Ideally I would like to avoid having to type rm(obj.1, obj.2... obj.n). Is it possible to indicate remove all objects but these ones?

Answer 1

Here is a simple construct that will do it, by using setdiff:

rm(list=setdiff(ls(), "x"))

And a full example. Run this at your own risk - it will remove all variables except x:

x <- 1
y <- 2
z <- 3
ls()
[1] "x" "y" "z"

rm(list=setdiff(ls(), "x"))

ls()
[1] "x"

Answer 2

Using the keep function from the gdata package is quite convenient.

> ls()
[1] "a" "b" "c"

library(gdata)
> keep(a) #shows you which variables will be removed
[1] "b" "c"
> keep(a, sure = TRUE) # setting sure to TRUE removes variables b and c
> ls()
[1] "a"

Answer 3

I think another option is to open workspace in RStudio and then change list to grid at the top right of the environment(image below). Then tick the objects you want to clear and finally click on clear.

Answer 4

I just spent several hours hunting for the answer to a similar but slightly different question - I needed to be able to delete all objects in R (including functions) except a handful of vectors.

One way to do this:

rm(list=ls()[! ls() %in% c("a","c")])

Where the vectors that I want to keep are named 'a' and 'c'.

Hope this helps anyone searching for the same solution!

Answer 5

To keep all objects whose names match a pattern, you could use grep, like so:

to.remove <- ls()
to.remove <- c(to.remove[!grepl("^obj", to.remove)], "to.remove")
rm(list=to.remove)

Answer 6

Replace v with the name of the object you want to keep

rm(list=(ls()[ls()!="v"]))

hat-tip: http://r.789695.n4.nabble.com/Removing-objects-and-clearing-memory-tp3445763p3445865.html

Answer 7

This takes advantage of ls()'s pattern option, in the case you have a lot of objects with the same pattern that you don't want to keep:

> foo1 <- "junk"; foo2 <- "rubbish"; foo3 <- "trash"; x <- "gold"  
> ls()
[1] "foo1" "foo2" "foo3" "x"   
> # Let's check first what we want to remove
> ls(pattern = "foo")
[1] "foo1" "foo2" "foo3"
> rm(list = ls(pattern = "foo"))
> ls()
[1] "x"

Answer 8

To keep a list of objects, one can use:

rm(list=setdiff(ls(), c("df1", "df2")))

Answer 9

From within a function, rm all objects in .GlobalEnv except the function

initialize <- function(country.name) {

  if (length(setdiff(ls(pos = .GlobalEnv), "initialize")) > 0) {
    rm(list=setdiff(ls(pos = .GlobalEnv), "initialize"), pos = .GlobalEnv)
  }

}

Answer 10

require(gdata)
keep(object_1,...,object_n,sure=TRUE)
ls()

Answer 11

let's think in different way, what if we wanna remove a group? try this,

 rm(list=ls()[grep("xxx",ls())]) 

I personally don't like too many tables, variables on my screen, yet I can't avoid using them. So I name the temporary things starting with "xxx", so I can remove them after it is no longer used.

Answer 12

How about this?

# Removes all objects except the specified & the function itself.

rme <- function(except=NULL){
  except = ifelse(is.character(except), except, deparse(substitute(except)))
  rm(list=setdiff(ls(envir=.GlobalEnv), c(except,"rme")), envir=.GlobalEnv)
}

Answer 13

assuming you want to remove every object except df from environment:

rm(list = ls(pattern="[^df]"))

Answer 14

# remove all objects but selected
rm(list = ls()[which("key_function" != ls())])

Answer 15

The following will remove all the objects from your console

rm(list = ls())