Data types and logical functions

Basic data types

There are many kinds of data types in R. We will introduce them gradually through the semester. Let’s start with the basic two data types:

  1. numeric: numeric values such as 7.9.
  2. character: text/string such as "roberto" or "281928" (notice the quotes!).

You can check the data type of a given variable by using the class() function. Now that you have the different columns of our dataframe stored as separate variables, you can check the class each variable belong to.

class(______) # column 1
class(______) # column 2
class(______) # column 3

Details about each variable/column of a given dataset is also available in bulk in the str() function. Let’s read it together.

str(_____)

Logical functions (I)

You can check if a given variable is of a given data type by using the is.-type functions. The console will return a logical (TRUE/FALSE) depending on whether the variable is of that type (TRUE) or not (FALSE).

  1. is.numeric()
  2. is.character()
is.numeric(______) # is column 1 numeric?
is.character(______) # is column 1 character?

is.numeric(______) # is column 2 numeric?
is.character(______) # is column 2 character?

is.numeric(______) # is column 3 numeric?
is.character(______) # is column 3 character?

Throughout the course, we will keep adding up on these functions as we discover new data types.