2 Easy ways to convert a dataframe to a matrix in R

Hello, readers! In this article, we will be focusing on exploring 2 Easy Ways to convert a Dataframe to a matrix in R programming, in detail.

So, let us begin!

1. R data.matrix() function to convert a dataframe to a matrix

R provides us with a built-in function to perform the conversion of a data frame to a matrix. The

With data.matrix() function, we manipulate the structure of the data frame to fit in the schema of a matrix.

That is, as discussed above, a data frame deals with multiple data types in a multi-column structure, while a matrix solely occupies data with fixed rows and columns in a rectangular format.

To comply with this schema, the data.matrix() function internally converts the multi-column structure into a rectangular matrix format and converts the character or factor type data to numeric form.

Syntax:

data.matrix(dataframe)

The data.frame() function converts all the data values of the data frame into a numeric format and then it binds all the values to form a rectangular matrix structure.

Example:

rm(list = ls())

data = data.frame( 
  "Name" = c("Jose", "Chris", "Akash"), 
  "City" = c("Rajasthan", "Texas", "California")
) 

print(data) 

mat <- data.matrix(data) 
print(mat)

Output:

As seen below, prior to applying the function, the data frame happens to have factor data. After applying the data.matrix() function, the data frame gets converted into a matrix format with all the factor values being altered to numeric form.

> print(data) 
   Name       City
1  Jose  Rajasthan
2 Chris      Texas
3 Akash California
> 
> mat <- data.matrix(data) 
> print(mat)
     Name City
[1,]    3    2
[2,]    2    3
[3,]    1    1

2. R as.matrix() function to convert data frame to matrix

With as.matrix() function, we can convert any R object or data structure to a matrix type. By this, we mean to say that a list of values or even a data frame can be manipulated to matrix type.

Unlike data.matrix() function, R

Example 1:

In this example, we have converted a vector into a matrix form.

rm(list = ls())

data <- c(1:10) 

as.matrix(data)

Output:

> as.matrix(data)
      [,1]
 [1,]    1
 [2,]    2
 [3,]    3
 [4,]    4
 [5,]    5
 [6,]    6
 [7,]    7
 [8,]    8
 [9,]    9
[10,]   10

Example 2:

In this example, we have converted a data frame to a matrix format. Unlike the data.matrix() function, here we do not witness any manipulation of factor values to numeric format. Only the structure of the data frame gets converted to a matrix form.

rm(list = ls())

data = data.frame( 
  "Name" = c("Jose", "Chris", "Akash"), 
  "City" = c("Rajasthan", "Texas", "California")
) 

print(data) 

mat <- as.matrix(data) 
print(mat)

Output:

> print(data) 
   Name       City
1  Jose  Rajasthan
2 Chris      Texas
3 Akash California
> 
 
> print(mat)
     Name    City        
[1,] "Jose"  "Rajasthan" 
[2,] "Chris" "Texas"     
[3,] "Akash" "California"

Conclusion

By this, we have come to the end of this topic. Feel free to comment below, in case you come across any question.

For more such posts related to R programming, Stay tuned!

Till then, Happy Learning!! 🙂