R: How to Use lapply() with Multiple Arguments

---

The lapply() function in R can be used to apply a function to each element of a list, vector, or data frame and obtain a list as a result.

To use the lapply() function with multiple arguments, you can use the following basic syntax:

#define function
my_function <- function(var1,var2,var3){
  var1*var2*var3
}

#apply function to list using multiple arguments
lapply(my_list, my_function, var2=3, var3=5)

The following example shows how to use this syntax in practice.

Example: How to Use lapply() with Multiple Arguments in R

Suppose we have the following list in R:

#create a list
my_list <- list(A=1, B=2, C=3, D=4)

#view list
my_list

$A
[1] 1

$B
[1] 2

$C
[1] 3

$D
[1] 4

The following code defines a function that accepts three variables and multiplies all three variables together, then uses the lapply() function to apply this function to each value in our list:

#define function
my_function <- function(var1,var2,var3){
  var1*var2*var3
}

#apply function to list using multiple arguments
lapply(my_list, my_function, var2=3, var3=5)

$A
[1] 15

$B
[1] 30

$C
[1] 45

$D
[1] 60

Notice that the lapply() function multiplies each value in the list by 3 and then by 5.

For example:

• First value in list: 1 * 3 * 5 = 15
• Second value in list: 2 * 3 * 5 = 30
• Third value in list: 3 * 3 * 5 = 45
• Fourth value in list: 4 * 3 * 5 = 60

Using similar syntax, you can supply as many arguments as you’d like to the lapply() function.

The following tutorials explain how to perform other common tasks in R: