R Objects: Data Types

  • OBJECTS
  • R has five basic classes of objects:
  1. Character
  2. Numeric
  3. Integer
  4. Complex
  5. Logical

However, the most basic object is a vector.

  • There are two things which you should remember when dealing with vectors.
    1. A vector can only contain objects of the same class.
    2. AND there is an exception to this, a list. A list looks like a vector, but can have different classes.

To create an empty vector use the following function:

vector()
Vectors can be created by using the following:
c() # used to concatenate individual values together
: # to create a sequence, such as 1:10
seq() # to create more complex sequences
rep() # replicates values
sort() # ordering elements in a vector
order() # ordering elements in a vector

 

An example of using rep()

rep(5,2) #a vector of two fives
[1] 5 5

 

An example of using c()

c(3,2,1) # vector of three numeric elements in that order
[1] 3 2 1

 

An example of using seq()

seq(4,20, by = 2)
[1]  4  6  8 10 12 14 16 18 20
seq(1,length = 20, by =4)
 [1]  1  5  9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77