Basic Commands

Help & Documentation

help(function) # Show documentation for a function
?function # Shortcut for help
help.search("topic") # Search for functions on a topic

Workspace

getwd() # Show the current working directory
setwd("path") # Change working directory
ls() # Show objects in the workspace
rm(object) # Remove an object
rm(list = ls()) # Clear the workspace

Packages

install.packages("package") # Install a package
library(package) # Load a package
update.packages() # Update all installed packages

Data Structures

Vectors

c(1, 2, 3) # Create a vector
seq(1, 10, by = 2) # Create a sequence
rep(1, times = 5) # Repeat elements
length(vector) # Length of a vector

Matrices

matrix(1:6, nrow = 2, ncol = 3) # Create a matrix
t(matrix) # Transpose a matrix

Lists

list(a = 1, b = 2) # Create a list

Data Frames

data.frame(a = 1:3, b = c("X", "Y", "Z")) # Create a data frame
head(df) # Show the first few rows of a data frame
tail(df) # Show the last few rows
str(df) # Structure of a data frame
summary(df) # Summary of a data frame

Factors

factor(c("A", "B", "A")) # Create a factor
levels(factor) # Show levels of a factor

Data Manipulation

Indexing

vector[2] # Access the second element of a vector
matrix[1, 2] # Access the element at row 1, column 2
dataframe$column # Access a column in a data frame

Filtering

subset(df, column > 10) # Filter rows based on a condition

Sorting

sort(vector) # Sort a vector
order(df$column) # Get sorted indices based on a column

Merging

merge(df1, df2, by = "column") # Merge two data frames by a common column

Statistics & Calculations

Basic Operations

mean(vector) # Calculate the mean
median(vector) # Calculate the median
sd(vector) # Calculate the standard deviation
sum(vector) # Sum of the elements

Tables

table(vector) # Create a frequency table

Random Numbers

runif(10, min = 0, max = 1) # Generate random numbers from a uniform distribution
rnorm(10, mean = 0, sd = 1) # Generate random numbers from a normal distribution

Plotting & Visualization

Basic Plots

plot(x, y) # Create a scatter plot
hist(vector) # Create a histogram
boxplot(vector) # Create a box plot

Labels & Titles

plot(x, y, main = "Title", xlab = "X-Axis", ylab = "Y-Axis")

Colors & Layout

barplot(vector, col = "blue") # Create a bar plot with color

Programming

Loops

for (i in 1:10) { print(i) } # For loop
while (condition) { ... } # While loop

Functions

my_function <- function(x) { return(x^2) } # Create a function
my_function(2) # Call the function