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

numeric_vector <- as.numeric(as.character(factor_vector))

We must first convert the factor vector to a character vector, then to a numeric vector. This ensures that the numeric vector contains the actual numeric values instead of the factor levels.

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

**Example 1: Convert a Vector from Factor to Numeric**

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

#define factor vector factor_vector <- factor(c(1, 5, 7, 8)) #convert factor vector to numeric vector numeric_vector <- as.numeric(as.character(factor_vector)) #view class class(numeric_vector) [1] "numeric"

**Example 2: Convert a Column from Factor to Numeric**

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

#create data frame df <- data.frame(a = factor(c(1, 5, 7, 8)), b = c(28, 34, 35, 36)) #convert column 'a' from factor to numeric df$a <- as.numeric(as.character(df$a)) #view new data frame df a b 1 1 28 2 5 34 3 7 35 4 8 36 #confirm class of numeric vector class(df$a) [1] "numeric"

**Example 3: Convert Several Columns from Factor to Numeric**

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

#create data frame df <- data.frame(a = factor(c(1, 5, 7, 8)), b = factor(c(2, 3, 4, 5)), c = c('A', 'B', 'C', 'D'), d = c(45, 56, 54, 57)) #display classes of each column sapply(df, class) a b c d "factor" "factor" "character" "numeric" #identify all factor columns x <- sapply(df, is.factor) #convert all factor columns to numeric df[ , x] <- as.data.frame(apply(df[ , x], 2, as.numeric)) #display classes of each column sapply(df, class) a b c d "numeric" "numeric" "character" "numeric"

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

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

By using the apply() and sapply() functions, we were able to convert only the factor columns to numeric columns and leave all other columns unchanged.

**Additional Resources**

How to Convert Character to Factor in R

How to Convert Factor to Character in R

How to Convert a Character to a Timestamp in R