A Complete Guide - Running Your First R Language

Basic Commands and Syntax

1. Simple Arithmetic:

   • You can perform basic arithmetic operations directly in the console.

     5 + 3 # Addition
     10 - 4 # Subtraction
     6 * 7 # Multiplication
     21 / 3 # Division
     

2. Creating Variables:

   • Variables are used to store data. You can create a variable using the assignment operator <-.

     x <- 10
     y <- 20
     z <- x + y # z will hold the value 30
     

3. Data Types in R:

   • R supports various data types, including numeric, character, logical, and complex.

     num_var <- 5.5 # Numeric
     char_var <- "Hello" # Character
     logical_var <- TRUE # Logical
     complex_var <- 1+2i # Complex
     

4. Basic Data Structures:

   • Vector: A vector is a sequence of elements of the same type.

     numbers <- c(1, 2, 3, 4, 5) # Numeric vector
     chars <- c("apple", "banana", "orange") # Character vector
     

   • Matrix: A matrix is a two-dimensional array that holds data of the same type.

     mat <- matrix(c(1, 2, 3, 4, 5, 6), nrow = 2, ncol = 3)
     

   • Data Frame: A data frame is a table-like structure where each column can contain different types of data.

     df <- data.frame(name = c("John", "Doe"), age = c(25, 30))
     

5. Basic Functions:

   • Functions perform specific tasks. Examples include mean(), sum(), length().

     nums <- c(5, 10, 15, 20, 25)
     mean_value <- mean(nums) # Calculates the mean of the vector
     total_value <- sum(nums) # Calculates the sum of the vector
     length_value <- length(nums) # Calculates the length of the vector
     

6. Control Structures:

   • if-else statements: Used for conditional execution.

     x <- 10
     if(x > 5){ print("x is greater than 5")
     } else { print("x is not greater than 5")
     }
     

   • Loops: Repeatedly executes a block of code.

     for(i in 1:5) { print(i)
     } i <- 1
     while(i <= 5) { print(i) i <- i + 1
     }
     

Important Information

1. Comments:

   • Use # to add comments in your R code for documentation.

     # This is a comment
     x <- 10 # Assign value 10 to variable x
     

2. Packages:

   • R relies on packages to extend its functionality. Install packages using install.packages("package_name") and load them using library(package_name).

     install.packages("ggplot2")
     library(ggplot2)
     

3. Getting Help:

   • Use ?function_name to get help on any function.

     ?mean
     

4. Debugging:

   • Use debug(function_name) to debug functions.

     debug(mean)
     

5. Saving Your Work:

   • Save your R script using File > Save in RStudio or save the workspace using save.image("workspace.RData").

Conclusion