R Convert Integer & Numeric Range into Categorical Variable (Example Code)

data(iris)                                # Loading iris
head(iris)
#   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
# 1          5.1         3.5          1.4         0.2  setosa
# 2          4.9         3.0          1.4         0.2  setosa
# 3          4.7         3.2          1.3         0.2  setosa
# 4          4.6         3.1          1.5         0.2  setosa
# 5          5.0         3.6          1.4         0.2  setosa
# 6          5.4         3.9          1.7         0.4  setosa

data(iris) # Loading iris head(iris) # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 1 5.1 3.5 1.4 0.2 setosa # 2 4.9 3.0 1.4 0.2 setosa # 3 4.7 3.2 1.3 0.2 setosa # 4 4.6 3.1 1.5 0.2 setosa # 5 5.0 3.6 1.4 0.2 setosa # 6 5.4 3.9 1.7 0.4 setosa

iris$SW_cat <- rep(NA, nrow(iris))        # Create empty variable
iris$SW_cat[iris$Sepal.Width < 3] <- 1    # Filling categories based on Sepal.Width
iris$SW_cat[iris$Sepal.Width >= 3 & iris$Sepal.Width < 3.5] <- 2
iris$SW_cat[iris$Sepal.Width >= 3.5 & iris$Sepal.Width < 4] <- 3
iris$SW_cat[iris$Sepal.Width >= 4] <- 4
iris$SW_cat <- as.factor(iris$SW_cat)     # Convert numeric to factor
head(iris)                                # Head of updated iris data set
#   Sepal.Length Sepal.Width Petal.Length Petal.Width Species SW_cat
# 1          5.1         3.5          1.4         0.2  setosa      3
# 2          4.9         3.0          1.4         0.2  setosa      2
# 3          4.7         3.2          1.3         0.2  setosa      2
# 4          4.6         3.1          1.5         0.2  setosa      2
# 5          5.0         3.6          1.4         0.2  setosa      3
# 6          5.4         3.9          1.7         0.4  setosa      3

iris$SW_cat <- rep(NA, nrow(iris)) # Create empty variable iris$SW_cat[iris$Sepal.Width < 3] <- 1 # Filling categories based on Sepal.Width iris$SW_cat[iris$Sepal.Width >= 3 & iris$Sepal.Width < 3.5] <- 2 iris$SW_cat[iris$Sepal.Width >= 3.5 & iris$Sepal.Width < 4] <- 3 iris$SW_cat[iris$Sepal.Width >= 4] <- 4 iris$SW_cat <- as.factor(iris$SW_cat) # Convert numeric to factor head(iris) # Head of updated iris data set # Sepal.Length Sepal.Width Petal.Length Petal.Width Species SW_cat # 1 5.1 3.5 1.4 0.2 setosa 3 # 2 4.9 3.0 1.4 0.2 setosa 2 # 3 4.7 3.2 1.3 0.2 setosa 2 # 4 4.6 3.1 1.5 0.2 setosa 2 # 5 5.0 3.6 1.4 0.2 setosa 3 # 6 5.4 3.9 1.7 0.4 setosa 3