How to Convert Character to Numeric in R (With Examples)

---

We can use the following syntax to convert a character vector to a numeric vector in R:

numeric_vector <- as.numeric(character_vector)

This tutorial provides several examples of how to use this function in practice.

Example 1: Convert a Vector from Character to Numeric

The following code shows how to convert a character vector to a numeric vector:

#create character vector
chars <- c('12', '14', '19', '22', '26')

#convert character vector to numeric vector
numbers <- as.numeric(chars)

#view numeric vector
numbers

[1] 12 14 19 22 26

#confirm class of numeric vector
class(numbers)

[1] "numeric"

Example 2: Convert a Column from Character to Numeric

The following code shows how to convert a specific column in a data frame from character to numeric:

#create data frame
df <- data.frame(a = c('12', '14', '19', '22', '26'),
                 b = c(28, 34, 35, 36, 40))

#convert column 'a' from character to numeric
df$a <- as.numeric(df$a)

#view new data frame
df

   a  b
1 12 28
2 14 34
3 19 35
4 22 36
5 26 40

#confirm class of numeric vector
class(df$a)

[1] "numeric"

Example 3: Convert Several Columns from Character to Numeric

The following code shows how to convert all character columns in a data frame from character to numeric:

#create data frame
df <- data.frame(a = c('12', '14', '19', '22', '26'),
                 b = c('28', '34', '35', '36', '40'),
                 c = as.factor(c(1, 2, 3, 4, 5)),
                 d = c(45, 56, 54, 57, 59))

#display classes of each column
sapply(df, class)

          a           b           c           d 
"character" "character"    "factor"   "numeric" 

#identify all character columns
chars <- sapply(df, is.character)

#convert all character columns to numeric
df[ , chars] <- as.data.frame(apply(df[ , chars], 2, as.numeric))

#display classes of each column
sapply(df, class)

        a         b         c         d 
"numeric" "numeric"  "factor" "numeric" 

This code made the following changes to the data frame columns:

• Column a: From character to numeric
• Column b: From character to numeric
• Column c: Unchanged (since it was a factor)
• Column d: Unchanged (since it was already numeric)

By using the and functions, we were able to convert only the character columns to numeric columns and leave all other columns unchanged.