How to create a factor in R?
Overview
A factor in R is used to categorize data. For example:
- Temperature: Cold/Hot
- Sex: Male/Female
- Height: Tall/Average/Short
The above are simple examples of factors.
Creating a factor in R
To create a factor in R, we make use of the factor() function.
Syntax
factor(level(s))
Parameter value
The factor() function takes the level(s) corresponding to the factor variable as its parameters.
Return value
The factor() function returns an object class factor.
Code example
# creating a factorHeight <- factor(c("Tall", "Average", "Short"))# printing the factorHeight
Code explanation
- Line 2: We create a factor variable
Heightusing thefactor()function. - Line 5: We print the factor object
Height.
Printing only the levels of the factor
To print only the levels corresponding to a factor variable, we use the levels() function.
Syntax
levels(factor)
Parameter value
The levels() function takes the factor variable as its single parameter value.
Code example
# creating a factorHeight <- factor(c("Tall", "Average", "Short", "Average", "Short"))# printing the levelslevels(Height)