R Programming 101 Lecture Notes

Introduction to R Programming

• Purpose of R: Programming language for statistical and data analysis.
• Audience: Beginners with no prior experience in R.
• Goal: Understand basics of R, comfortable using R for data analysis.

R Environment Overview

Console and Source

• Source: Area where you write code.
• Console: Displays outputs, like a sophisticated calculator.

Basic Operations

• Arithmetic: R can perform basic calculations, e.g., 5 + 6 = 11.

Assigning Values

Variables

• Assignment Operator: Use <- to assign values.
  • Example: a <- 5, b <- 6.
• Using Variables: a + b will result in 11.

Functions in R

Sum Function

• Using Functions: Functions take arguments within brackets.
  • Example: sum(a, b) results in 11.

Working with Multiple Values

Vectors

• Creating Vectors: Use c() to concatenate values.
  • Example: name <- c('Greg', 'Jill').

Data Structures

Data Frames

• Creating Data Frames: Combine vectors into a data frame.
  • Example: friends <- data.frame(name, age, gender).
• Environment: Data frames and variables show up in the environment pane.

Subsetting Data

Accessing Data

• Dollar Sign Operator: To access specific variables in a data frame.
  • Example: friends$name.

Subsetting with Square Brackets

• Rows and Columns: Use [rows, columns] to subset data.
  • Example: friends[1, ] gives the first row.
• Conditional Subsetting: Use conditions to extract parts of data.
  • Example: friends[friends$age < 50, 1:2].

Introduction to Tidyverse

Packages

• Tidyverse: A collection of R packages for data manipulation.
• Installing: install.packages('tidyverse').
• Loading: library(tidyverse).

Simplifying Operations

• Pipe Operator: %>% simplifies chaining commands.
  • Example: friends %>% select(name, age) %>% filter(age < 50).

Conclusion

• Ease of Use: R is user-friendly with practice.
• Future Learning: Tidyverse and other packages make R intuitive and expand its capabilities.

Final Remarks

• Encouragement to continue learning and exploring R.
• Motivating closing message: Stay curious and persistent.