lapply() function in R Programming Language is used to apply a function over a list of elements.
lapply() function is used with a list and performs the following operations:
lapply(List, length): Returns the length of objects present in the list, List.
lapply(List, sum): Returns the sum of elements held by objects in the list, List.
lapply(List, mean): Returns the mean of elements held by objects in the list, List.
lapply(List, cumsum): Returns the cumulative sum of elements held by objects present inside the list, List.
Syntax: lapply(list, func)
Parameters:
- list: list of elements
R - Apply a Function over a List of elements
Example 1: Basic example of lapply() Function in R programming
# R program to illustrate
# lapply() function
# Creating a matrix
A = matrix(1:9, 3, 3)
# Creating another matrix
B = matrix(10:18, 3, 3)
# Creating a list
myList = list(A, B)
# applying lapply()
determinant = lapply(myList, det)
print(determinant)
Output:
[[1]] [1] 0 [[2]] [1] 5.329071e-15
Example 2: Apply a Function over a List of elements in R
# R program to illustrate
# lapply() function
# Creating a matrix
A = matrix(1:9, 3, 3)
# Creating another matrix
B = matrix(10:18, 3, 3)
# Creating a list
myList = list(A, B)
# applying lapply()
sum = lapply(myList, sum)
print(sum)
Output:
[, 1] [, 2] [, 3] [1, ] 1 4 7 [2, ] 2 5 8 [3, ] 3 6 9 [1] 28 80 162 [1] 6 120 504