# 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```
| | Category: R

# R: Numbers

In general, numbers in R are treated as numeric objects.

For example,

 ``` 3 # numeric object [1] 3 3L # explicitly gives an integer [1] 3 Inf # a special number which represents infinity [1] Inf 1/0 [1] Inf 1/Inf # can be used in calculations [1] 0 0/0 # NaN ("not a number"); also, seen as a missing number [1] NaN```

Numerics are also decimal values in R. This happens by default, so that if you create a decimal value for x that is will be of the numeric type.

 ``` x = 8.3 # create x which a decimal value x # print the value of x [1] 8.3 class(x) # what is the class of x? [1] "numeric"```

Even when assigning an integer to a variable such as N, it is still being retained as a numeric value.

 ``` N = 43 N #print the value of N [1] 43 class(N) # what is the class of N? [1] "numeric"```

You can further confirm that N is not an integer by using the is.integer function.

 ``` is.integer(N) # is N an integer? [1] FALSE is.numeric(N) # is N numeric? [1] TRUE```
| | Category: R