Clean Up Memory in R

In this R article, we will discuss how to clean up memory with its working example in the  R programming language. Let’s first discuss removing objects from our workspace first.

rm() function in R Language is used to delete objects from the workspace. It can be used with ls() function to delete all objects. remove() function is also similar to rm() function.

Syntax: rm(x)

Parameters:

x: Object name

Example:

In this example, we are creating some data and remove from the workspace.

R

# R Program to remove
# objects from Memory

# Creating a vector
vec <- c(1, 2, 3, 4)
vec

# Creating a list
list1 = list("Number" = c(1, 2, 3),
            "Characters" = c("a", "b", "c"))
list1

# Creating a matrix
mat <- matrix(c(1:9), 3, 3)
mat

# Calling rm() Function
rm(list1)

# Calling ls() to check object
# list
ls()

Output:

[1] 1 2 3 4
$Number
[1] 1 2 3

$Characters
[1] "a" "b" "c"

     [,1] [,2] [,3]
[1,]    1    4    7
[2,]    2    5    8
[3,]    3    6    9
[1] "mat" "vec"

Using gc() function to remove all objects that are used from memory:

gc() is used to remove all objects that are used from memory.

Syntax:

gc(reset = TRUE)

reset is an optional parameter.

It will return the maximum memory used in Mb.

Example:

In this example, we are creating some data and remove from memory.

R

# R Program to remove
# objects from Memory

# Creating a vector
vec <- c(1, 2, 3, 4)
vec

# Creating a list
list1 = list("Number" = c(1, 2, 3),
            "Characters" = c("a", "b", "c"))
list1

# Creating a matrix
mat <- matrix(c(1:9), 3, 3)
mat

# remove from memory
gc()

Output:

[1] 1 2 3 4
$Number
[1] 1 2 3

$Characters
[1] "a" "b" "c"

     [,1] [,2] [,3]
[1,]    1    4    7
[2,]    2    5    8
[3,]    3    6    9
         used (Mb) gc trigger (Mb) max used (Mb)
Ncells 271233 14.5     654180   35   448093 24.0
Vcells 458584  3.5    8388608   64  1770431 13.6