R objects are the basic building blocks of R programming. They are used to store data, functions, and other objects. R has a variety of different types of objects, each with its own unique properties.
The five basic or “atomic” classes of objects in R are:
- Character: Objects of this class store text data.
- Numeric: Objects of this class store numbers.
- Integer: Objects of this class store integers.
- Complex: Objects of this class store complex numbers.
- Logical: Objects of this class store logical values, such as TRUE and FALSE.
The most basic type of R object is a vector. A vector is a one-dimensional array of objects of the same class. Vectors are created using the `c()` function. For example, the following code creates a vector of integers:
x <- c(1, 2, 3, 4, 5)
R also supports other types of objects, such as lists, matrices, factors, and data frames. Lists are similar to vectors, but they can store objects of different classes. Matrices are two-dimensional arrays of objects. Factors are used to store categorical data. Data frames are a special type of list that is used to store tabular data.
R objects are a powerful tool for storing and manipulating data. They are used in a variety of different tasks, such as data analysis, statistical modeling, and machine learning.
Empty Vector
Empty vectors can be created with the `vector()` function. The `vector()` function takes two arguments: the class of the vector and the length of the vector. For example, the following code creates an empty vector of integers:
x <- vector(mode="integer", length=0)
The `mode` argument specifies the class of the vector. In this case, the mode is "integer", so the vector will contain only integers. The `length` argument specifies the length of the vector. In this case, the length is 0, so the vector will be empty.
The one rule about vectors in R is that a vector can only contain objects of the same class. This means that a vector cannot contain a mixture of integers, characters, and logical values. For example, the following code will not work:
x <- c(1, "hello", TRUE)
This code will try to create a vector that contains an integer, a character, and a logical value. However, R will not allow this because a vector can only contain objects of the same class.
The exception to this rule is lists. Lists can contain objects of different classes. For example, the following code creates a list that contains an integer, a character, and a logical value:
x <- list(1, "hello", TRUE)
This code will work because lists can contain objects of different classes.
