Non-numeric argument to binary operator error in R

Non-numeric argument to binary operator error

The R error, "non-numeric argument to binary operator" occurs when you try to perform a binary, or arithmetic, operation (+, −, ×, ÷) on two vectors, and one of the vectors is non-numeric, or on variables that are non-numeric. Use as.numeric() to convert numbers formatted as a character into a number.

Binary operations:

• Addition (+)
• Subtraction (-)
• Multiplication (× or *)
• Division (÷ or /)

The error occurs when one of the vectors is a character vector.

Here is an example of how the error occurs.

# ⛔️ Error: non-numeric argument to binary operator
1 + "one"

# ✅ this runs
1 + 1

To solve this, check if you are adding, subtracting, multiplying or dividing by a something that is not a number — it is usually a character. Change the character into a number and rerun your code.

Use as.numeric()

If your number is formatted as a character, you can manually change it to a number: "one" to 1 or use the function as.numeric().

char <- "5"
number <- as.numeric(char) + 3
>> 8

Vectors

If you are performing arithmetic operations (+, −, ×, ÷) on two vectors and one of the vectors contains non-numeric variables, you will get the "non-numeric argument to binary operator". Use as.numeric() on the non-numeric vector to solve this problem.

Here is an example.

# 👇️ create a data frame
store <- data.frame(revenue = c(50, 35, 46, 98),
                                costs = c("23", "12", "23", "49"))

# view the data frame
store

revenue   costs
     50      23
     35      12
     46      23
     98      49

Let's try to create a new column called profit by subtracting costs from revenue.

# ⛔️ Error: non-numeric argument to binary operator
store$profit = store$revenue - store$costs

It yields an error because the numbers in costs are stored as a character, not as numbers. We cannot subtract a character from a number. You can check the class type of each column.

# 👇️ check the class type of each column
class(store$revenue)
>> "numeric"

class(store$costs)
>> "character"

The solution is to convert the characters in costs into numbers by using as.numeric().

# 👇️ convert `costs` into a numeric class

# ✅ this runs
store$profit <- store$revenue - as.numeric(store$costs)

Conclusion

The R error, "non-numeric argument to binary operator" occurs when you try to perform a binary, or arithmetic, operation (+, −, ×, ÷) on two vectors, and one of the vectors is non-numeric, or on variables that are non-numeric. Use as.numeric() to convert numbers formatted as a character into a number.