Lesson - 2A1

R has 5 basic or "atomic" data structures which are classified as objects
They are as follows:

character - (a-zA-Z0-9) - can be a combination of alpha-numeric combinations
numeric - (decimal) - double precision real numbers
integers - (basic numerical) - 0-9
complex - (complex numerical) - 1.0i
logic - (boolean) - T/F - TRUE/FALSE - 0=FALSE/1+=TRUE

The most basic object is a vector and has a specific rule to follow:

The vector can only contain objects of like similarity 
ie: a vector can only have objects of like objects 
ie: complex objects can only contain complex vectors

You can not mix two vector types inside the same object. 
However there is an exception to these rules and that is:

List - represented as a vector but containing objects from different classes
which is a sequence of objects contained inside a list and may as well
that can have a list inside a previous list of different objects

Empty vectors can be created with function: vector()

The vector function takes 2 parameters as follows:

        ie: vector(numeric, length=value)
        ie: vector(0, length=10)

If you want to have a specific numeric value to be classified a integer rather then a double precision number you must include the suffix "L". 

R would classify 1 as a numeric object, but 1L would be classified an integer

There is also a special number Inf, of infinity or "∞" as a symbolic representation that most of the world knows Inf as. Inf can be used in ordinal calculations.

ie: 1/0 = Inf
ie: 1/Inf = 0

As well there is NaN that stands for Not a Number, or commonly known as an unified value, or thought of as "the missing value"

ie: 0/0 = NaN

Objects in R which have attributes are as follows:

names, dimnames
dimensions(array, matrice)
user defined attributes and metadata

Attributes of an object can be accessed through the attributes() function