Day 4- R Data Structure

Data Structures

• Collection of data elements
• Grouped under one name
• Container

Homogeneouse data structure 
Atomic vector, Matrix, Array

Hetrogeneous data structure 
List, Data Frame

• Atomic vector
• 1 Dimension
• Matrix
• 2 Dimension
• Array
• n Dimension
• List
• 1 Dimension
• Data frame
• 2 Dimension

Basic Classes of Objects

Atomic Classes

Character

“A”, “c”

Numeric

4.36, 7.42

Integer

3,5

Logical

True, False

Complex

1 + 7i , 8 - 2i

Atomic Vector

•  Commonly knows as vectors
•  Homogeneous data structure

# Character

student.names <‐ c("Raj","Rahul","Priya","Poonam")

# Numeric

student.weights <‐ c( 60.5, 72.5 , 45.2, 47.5)

# Integer

student.physics.marks <‐ c( 70L , 75L , 80L, 85L)

# Logical

student.physics.interest <‐ c(FALSE, F, TRUE, T)

Common Operations on Atomic Vectors

• Arithmetic & logical Subsetting Coercion

Factor

• Special case of vector used to store nominal values

student.genders <‐ c(“Male",“Male",“Female",“Female")

student.genders <‐ factor(c(“Male",“Male",“Female",“Female"))

List

• Heterogeneous data structure
• Can contain items of different classes
• 1-Dimensional arrangement