This tutorial will discuss converting an object to a numeric by using the as.numeric()
function in the R programming language. If you are interested in this topic, read the end of this article now.
What is the as.numeric in R?
The as.numeric()
function returns a numeric value in R. The as.numeric()
function takes a R object and converts it to a numeric value.
We will use the as.numeric()
function to convert a factorial value to a numeric number and use the is.numeric()
function to examine if an object may be interpreted as numbers.
The numeric()
function is the same as the double()
method that generates a double-precision vector of the specified length, with each item having the value 0. The numeric()
method accepts a non-negative integer describing the required length as an argument. Double values will be limited to integers, which is an error if you offer a parameter with a length different than one.
The default is.numeric()
function returns TRUE if its parameter is of type “double” or “integer” and mode “numeric” else, it returns FALSE.
Now, you can follow the syntax of this function below to see how this function works.
The syntax of as.numeric function in R:
as.numeric(x)
is.numeric(x)
Parameter:
- x: An object which you want to convert to numeric.
How to use the as.numeric in R?
Convert character vector to numeric values
First, we will create a character vector for this example as below:
# Create a character vector vec <- c("10", "20", "7.5", "-9") # View a vector cat("The vector is:\n") vec
Output
The vector is:
[1] "10" "20" "7.5" "-9"
Now, we will use the as.numeric()
function in R to convert all elements in the vector to numeric values, and then you can check the convert above success or not success by using the is.numeric()
function.
# Create a character vector vec <- c("10", "20", "7.5", "-9") # Convert to numeric value res <- as.numeric(vec) # View a vector cat("The vector after conversion is:\n") res # Check a numeric value is.numeric(res)
Output
The vector after conversion is:
[1] 10.0 20.0 7.5 -9.0
[1] TRUE
Convert factors to numeric values
We will convert factors to numeric values using the as.numeric() function in this example. If the input is a character vector, use the factor() function to convert it to a factor and the as.numeric() function to convert the factor to numeric values. Follow the code example.
# Create a character vector vec <- c("Bray", "Seachains", "Amee", "Wowy") # Convert a vector into a factor vf <- factor(vec) # Convert a factor into a numeric value res <- as.numeric(vf) # View a the numeric value cat("The vector after conversion is:\n") res # Check a numeric value is.numeric(res)
Output
The vector after conversion is:
[1] 2 3 1 4
[1] TRUE
Another example similarly you can convert a number factor to a numeric value. Check out the code example below.
# Create a vector vec <- c(8, 9, 12, -5, 20, -19) # Convert a vector into a factor vf <- factor(vec) # Convert a factor into a numeric value res <- as.numeric(as.character(vf)) # View a the numeric value cat("The vector after conversion is:\n") res # Check a numeric value is.numeric(res)
Output
The vector after conversion is:
[1] 8 9 12 -5 20 -19
[1] TRUE
Summary
So, this tutorial will demonstrate how to use the as.numeric()
function in the R programming language to convert a vector to a numeric value. If you have any questions, please leave a comment below.
Good luck!
Maybe you are interested:
- iqr in R: Calculate the interquartile range of the numeric dataset
- cumsum() Function In R: Sum of a Numeric Object’s Cumulative Value
- quantile() function in R: Calculate the sample quantiles of the numeric dataset

Hi, guys! My name’s Scott Miller. My current job is a software developer and I have shared a lot of quality articles about Javascript, C, C++, C#, Python, PHP, R, Java programming languages. I’m hoping they can assist you.
Name of the university: HCMUS
Major: IT
Programming Languages: C, C++, Python, R, Java, JavaScript