data.matrix() and as.matrix() functions in R is used to convert a data frame to matrix. The data.matrix() function converts all data frame variables to numeric and displays them as columns of the matrix. The as.matrix() is a generic function and returns a character matrix.

In this tutorial, we will discuss how to convert a data frame to a matrix using the data.matrix and as.matrix method.

## Convert a Data Frame to Matrix using as.matrix

**as.matrix** function is generic and converts data frame data into a character matrix.

as.matrix syntax:

```
as.matrix(x, ...)
where x is R object
```

Let’s understand converting a data frame to a matrix using the as.matrix function.

Let’s create a student_info data frame. It has a name, age, gender, and marks columns.

# Create a data frame student_info <- data.frame( name = c("Tom","Kim","Sam","Julie","Emily","Chris"), age = c(20,21,19,20,21,22), gender = c('M','F','M','F','F','M'), marks = c(72,77,65,80,85,87) ) # Print the data frame student_info

To convert a data frame to the matrix using as.matrix, use the following code.

# Convert a data frame to character matrix using as.matrix data <- as.matrix(student_info) # Print the data frame data

In the above R code, as.matrix takes the data frame as input parameter and converts a data frame to a character matrix.

The output of the above R code is:

```
name age gender marks
[1,] "Tom" "20" "M" "72"
[2,] "Kim" "21" "F" "77"
[3,] "Sam" "19" "M" "65"
[4,] "Julie" "20" "F" "80"
[5,] "Emily" "21" "F" "85"
[6,] "Chris" "22" "M" "87"
```

## Convert a Data Frame to a Numeric Matrix using data.matrix

data.matrix function in R converts data frame to the numeric matrix.

data.matrix syntax:

```
data.matrix(frame, rownames.force = NA)
Where,
frame = data frame
rownames.force = logical indicating if output matrix should have character (rather than NULL)
```

If the data frame contains logical or factor columns, it will be converted to an integer. Character columns are converted to factors and later converted to an integer.

Let’s understand converting a data frame to a numeric matrix using data.matrix function with an example.

Use the above student_info data frame to understand the conversion of a data frame to the matrix.

# Convert a data frame to numeric matrix using data.matrix function matrix_data <- data.matrix(student_info) # Print the data frame matrix_data

The output of the above R code is:

```
name age gender marks
[1,] 6 20 2 72
[2,] 4 21 1 77
[3,] 5 19 2 65
[4,] 3 20 1 80
[5,] 2 21 1 85
[6,] 1 22 2 87
```

In the above resultant matrix, data.matrix converts character columns such as name and gender to factor and later factor to an integer.

data.matrix converts data frame to the numeric matrix.

## Conclusion

I hope the above article on how to convert a data frame to a matrix is helpful to you.

Use as.matrix() function to convert a data frame to the character matrix and data.matrix() function for converting a data frame to a numeric matrix.