Convert an Object to List in R Programming – as.list() Function

as.list() function in R Programming Language is used to convert an object to a list. These objects can be Vectors, Matrices, Factors, and dataframes.

Syntax: as.list(object)

Parameters:

object: Vector, Matrix, factor, or data frame 

R – as.list() Function Example

Example 1: Converting Vector to list using as.list() function in R Language

R

# R program to convert object to list

# Creating vector
x < - c(1, 2, 3, 4, 5)

# Calling as.list() Function
as.list(x)

Output:

[[1]]
[1] 1

[[2]]
[1] 2

[[3]]
[1] 3

[[4]]
[1] 4

[[5]]
[1] 5

Example 2: Converting data frame to list using as.list() function in R Language

R

# R program to convert object to list

# Calling pre-defined data set
BOD

# Calling as.list() Function
as.list(BOD)

Output:

  Time demand
1    1    8.3
2    2   10.3
3    3   19.0
4    4   16.0
5    5   15.6
6    7   19.8
$Time
[1] 1 2 3 4 5 7

$demand
[1]  8.3 10.3 19.0 16.0 15.6 19.8

attr(, "reference")
[1] "A1.4, p. 270"

Example 3: Converting matrix to list using as.list() function in R Language

R

# R program to create a matrix
# and then convert into list

A = matrix(

# Taking sequence of elements
c(1, 2, 3, 4, 5, 6, 7, 8, 9),

# No of rows
nrow = 3,

# No of columns
ncol = 3,

# By default matrices are in column-wise order
# So this parameter decides how to arrange the matrix
byrow = TRUE
)

# Naming rows
rownames(A) = c("a", "b", "c")

# Naming columns
colnames(A) = c("c", "d", "e")

cat("The 3x3 matrix:\n")
print(A)


lst = as.list(A)
lst

Output:

The 3x3 matrix:
  c d e
a 1 2 3
b 4 5 6
c 7 8 9
[[1]]
[1] 1

[[2]]
[1] 4

[[3]]
[1] 7

[[4]]
[1] 2

[[5]]
[1] 5

[[6]]
[1] 8

[[7]]
[1] 3

[[8]]
[1] 6

[[9]]
[1] 9