R Tutorial

• Introduction to R Programming Language
• R vs Python
• Environments in R Programming
• Introduction to R Studio
• How to Install R Studio on Windows and Linux?
• Creation and Execution of R File in R Studio
• Clear the Console and the Environment in R Studio
• Hello World in R Programming

Fundamentals of R

• Basic Syntax
• Comments
• Operators
• Keywords
• Data Types

Variables

• Introduction to Variables
• Scope of Variable
• Dynamic Scoping
• Lexical Scoping
• Lexical Scoping vs Dynamic Scoping

Input and Output

• Taking Input from User
• Printing Output of R Program
• Print the Argument to the Screen - print() Function

Decision Making

• Decision Making - if, if-else, if-else-if ladder, nested if-else, and switch
• if statement
• if-else statement
• Switch case

Control Flow

• Introduction to Control Statements
• Loops (for, while, repeat)
• For loop
• while loop
• Repeat loop
• goto statement
• Break and Next statements
• Next Statement

Functions

• Introduction to Functions
• Function Arguments
• Types of Functions
• Recursive Functions
• Conversion Functions

Strings

• Introduction to Strings
• Working with Text
• String Manipulation
• Concatenate Two Strings
• String Matching
• How to find a SubString?
• Finding the length of string - nchar() method
• Adding elements in a vector - append() method
• Convert string from Lowercase to Uppercase - toupper() function
• Convert String from Uppercase to Lowercase - tolower() method
• Splitting Strings - strsplit() method
• Print a Formatted string - sprintf() Function

Vectors

• Introduction to Vectors
• Operations on Vectors
• Append Operation on Vectors
• Dot Product of Vectors
• Types of Vectors
• Assigning Vectors 
• Getting and Setting Length of the Vectors - length() Function
• Creating a Vector of sequenced elements - seq() Function
• Get the Minimum and Maximum element of a Vector - range() Function
• Formatting Numbers and Strings - format() Function
• Replace the Elements of a Vector - replace() Function
• Sorting of a Vector - sort() Function
• Convert elements of a Vector to Strings - toString() Function
• Extracting Substrings from a Character Vector - substring() Function

Lists

• Introduction to Lists
• Two Dimensional List
• Operations on Lists
• List of Vectors
• List of Dataframes
• Named List
• Check if the Object is a List - is.list() Function
• Convert an Object to List - as.list() Function
• Check if an Object of the Specified Name is Defined or not - exists() Function
• Apply a Function over a List of elements - lapply() Function
• Performing Operations on Multiple Lists simultaneously - mapply() Function

Arrays

• Introduction to Arrays
• Multidimensional Array
• Array Operations
• Sorting of Arrays
• Convert values of an Object to Logical Vector - as.logical() Function
• Performing different Operations on Two Arrays - outer() Function
• Intersection of Two Objects - intersect() Function
• Get Exclusive Elements between Two Objects - setdiff() Function

Matrices

• Introduction to Matrices
• Create Matrix from Vectors
• Operations on Matrices
• Matrix Multiplication
• Algebraic Operations on a Matrix
• Combining Matrices
• Matrix Transpose
• Inverse of Matrix
• Working with Sparse Matrices
• Check if the Object is a Matrix - is.matrix() Function
• Convert an Object into a Matrix - as.matrix() Function
• Get or Set Dimensions of a Matrix - dim() Function
• Calculate Cumulative Sum of a Numeric Object - cumsum() Function
• Compute the Sum of Rows of a Matrix or Array - rowSums Function

Factors

• Introduction to Factors
• Level Ordering of Factors
• Convert Factor to Numeric and Numeric to Factor
• Check if a Factor is an Ordered Factor - is.ordered() Function
• Convert an Unordered Factor to an Ordered Factor  - as.ordered() Function
• Checking if the Object is a Factor - is.factor() Function
• Convert a Vector into Factor - as.factor() Function

DataFrames

• Introduction to Data Frames
• Matrix vs Dataframe
• DataFrame Operations
• DataFrame Manipulation
• Joining of Dataframes
• The Factor Issue in a DataFrame
• Data Reshaping
• Creating a Data Frame from Vectors
• Data Wrangling - Data Transformation
• Data Wrangling - Working with Tibbles
• Melting and Casting
• Subsetting of DataFrames
• Handling Missing Values
• Convert an Object to Data Frame - as.data.frame() Function
• Get the number of columns of an Object - ncol() Function
• Get the number of rows of an Object - nrow() Function
• Get Addition of the Objects passed as Arguments - sum() Function
• Create Subsets of a Data frame - subset() Function

Object Oriented Programming

• Introduction to Object-Oriented Programming
• Classes
• Objects
• Encapsulation
• Polymorphism
• Inheritance
• Abstraction
• Looping over Objects
• Creating, Listing, and Deleting Objects in Memory
• S3 class
• Explicit Coercion
• R6 Classes
• Getting attributes of Objects - attributes() and attr() Function
• Get or Set names of Elements of an Object - names() Function
• Get the Minimum element of an Object - min() Function
• Get the Maximum element of an Object - max() Function

Error Handling

• Introduction to Error Handling
• Condition Handling
• Debugging in R Programming

File Handling

• Introduction to File Handling
• Reading Files
• Writing to Files
• Read Lines from a File - readLines() Function
• Working with Binary Files

Packages in R

• Introduction to Packages
• dplyr Package
• ggplot2 package
• Grid and Lattice Packages
• Shiny Package
• tidyr Package
• What Are the Tidyverse Packages?
• Data Munging

Data Interfaces

• Data Handling
• Importing Data in R Script
• How To Import Data from a File?
• Exporting Data from scripts 
• Working with CSV files 
• Working with XML Files
• Working with Excel Files
• Working with JSON Files 
• Reading Tabular Data from files
• Working with Databases
• Database Connectivity
• Manipulate Data Frames Using SQL

Data Visualization

• Graph Plotting
• Graphical Models
• Plotting Graphs using Two Dimensional List
• Data Visualization
• Charts and Graphs
• Add Titles to a Graph
• Adding Colors to Charts
• Adding Text to Plots
• Adding axis to a Plot
• Set or View the Graphics Palette
• Plotting of Data using Generic plots
• Bar Charts
• Line Graphs
• Adding Straight Lines to a Plot
• Addition of Lines to a Plot
• Histograms
• Pie Charts
• Scatter plots
• Create One Dimensional Scatterplots
• Create a Plot Matrix of Scatterplots
• Create Dot Charts
• Boxplots in R Language
• Stratified Boxplot
• Create a Heatmap
• Pareto Chart
• Waffle Chart
• Draw a Quantile-Quantile Plot
• Creating 3D Plots
• Describe Parts of a Chart in Graphical Form
• Principal Component Analysis
• Social Network Analysis

Statistics

• Introduction to Statistics
• Calculate the Mean, Median, and Mode
• Calculate the Average, Variance, and Standard Deviation
• Homogeneity of Variance Test
• Covariance and Correlation 
• Correlation Matrix
• Visualize correlation matrix using correlogram 
• Distance Matrix by GPU 
• Descriptive Analysis
• Normal Distribution 
• Binomial Distribution 
• Compute the Negative Binomial Density
• Poisson Functions
• ANOVA Test
• MANOVA Test
• Naive Bayes Classifier
• K-NN Classifier
• Central Tendency
• Variability
• Skewness and Kurtosis
• Absolute and Relative Frequency
• Permutation Hypothesis Test
• AB Testing
• Completely Randomized Design
• Randomized Block Design
• Bartlett’s Test
• Tree Entropy
• Compute Summary Statistics of Subsets
• Hypothesis Testing
• Bootstrapping
• Time Series Analysis
• T-Test Approach

Machine Learning with R

• Introduction to Machine Learning
• Setting up Environment for Machine Learning
• Supervised and Unsupervised Learning
• Classification
• Regression and its Types
• Regression Analysis
• Decision Tree
• Random Forest Approach
• Root-Mean-Square Error
• Clustering
• Hierarchical Clustering
• DBScan Clustering
• Deep Learning
• Building a Simple Neural Network
• How Neural Networks are used for Regression?
• Multi Layered Neural Networks
• Survival Analysis
• Stem and Leaf Plots

Exporting Data from scripts in R

Exporting data is a common task when working with R scripts. Depending on the format you want, there are multiple ways to export data from R to external files like CSV, Excel, or databases.

In this tutorial, we'll explore the basics of exporting data from R scripts to different file formats.

1. Exporting to CSV:

The write.csv() function is an easy way to export data frames to CSV.

# Create a data frame
data <- data.frame(Name = c("John", "Jane", "Doe"),
                   Age = c(28, 34, 45),
                   Gender = c("Male", "Female", "Male"))

# Export to CSV
write.csv(data, "data.csv", row.names = FALSE)

2. Exporting to Excel:

The writexl package provides a simple way to write data to Excel.

install.packages("writexl")
library(writexl)

write_xlsx(data, "data.xlsx")

3. Exporting to Text:

You can export data to a plain text file using write.table().

write.table(data, "data.txt", sep = "\t", row.names = FALSE)

4. Exporting to SPSS, Stata, or SAS:

The haven package supports exporting to SPSS, Stata, or SAS formats.

install.packages("haven")
library(haven)

# To SPSS
write_sav(data, "data.sav")

# To Stata
write_dta(data, "data.dta")

# To SAS
write_sas(data, "data.sas7bdat")

5. Exporting to Databases:

You can export data frames to databases using the DBI and corresponding database-specific packages.

For SQLite (as an example):

install.packages("DBI")
install.packages("RSQLite")

library(DBI)
library(RSQLite)

# Create a connection
con <- dbConnect(RSQLite::SQLite(), "database.sqlite")

# Write data to database
dbWriteTable(con, "table_name", data)

# Close connection
dbDisconnect(con)

6. Exporting to RDS (R Binary Format):

For saving and loading objects in R's binary format:

# Save to RDS
saveRDS(data, "data.rds")

# To load back
data2 <- readRDS("data.rds")

7. Exporting to RData:

You can save multiple R objects to .RData format.

var1 <- "hello"
var2 <- 123

# Save multiple objects
save(var1, var2, file = "data.RData")

# To load back
load("data.RData")

8. Exporting to JSON:

Using the jsonlite package, you can export data to JSON format.

install.packages("jsonlite")
library(jsonlite)

write_json(data, "data.json")

Conclusion:

Exporting data from R allows you to share your results, use them in other software or applications, or simply archive them for later use. Depending on the target software or the intended use-case, R provides various ways to export your data efficiently. Always ensure that the export format aligns with the requirements of your subsequent tasks or workflows.

1. Exporting data to CSV in R:

   • Description: The CSV (Comma-Separated Values) format is widely used for exporting data. Show how to use write.csv() to export a data frame to a CSV file.
   • Code:

     # Create a sample data frame
     my_data <- data.frame(
       Name = c("Alice", "Bob", "Charlie"),
       Age = c(25, 30, 22)
     )
     
     # Export data frame to CSV
     write.csv(my_data, "my_data.csv", row.names = FALSE)
     

2. R saveRDS function example:

   • Description: Introduce the saveRDS() function, which allows you to save a single R object to a file in a binary format, preserving its structure.
   • Code:

     # Save a data frame using saveRDS
     saveRDS(my_data, file = "my_data.rds")
     

3. Write.xlsx or writexl in R:

   • Description: Show how to use the writexl or WriteXLS package to export data to Excel format.
   • Code:

     # Install and load the writexl package
     install.packages("writexl")
     library(writexl)
     
     # Export data frame to Excel
     write_xlsx(my_data, path = "my_data.xlsx")
     

4. Exporting data to text files in R:

   • Description: Illustrate exporting data to text files using functions like write.table() or writeLines(), depending on the desired format.
   • Code:

     # Export data frame to a text file
     write.table(my_data, "my_data.txt", sep = "\t", row.names = FALSE)
     

5. Exporting data to Excel in R:

   • Description: Demonstrate exporting data to Excel using additional packages like openxlsx or writexl.
   • Code:

     # Install and load the openxlsx package
     install.packages("openxlsx")
     library(openxlsx)
     
     # Export data frame to Excel
     write.xlsx(my_data, "my_data_excel.xlsx")
     

6. Save data frames as RDS files in R:

   • Description: Revisit the saveRDS() function, specifically highlighting its use for saving and later loading entire data frames in a binary format.
   • Code:

     # Save and load a data frame using saveRDS and readRDS
     saveRDS(my_data, file = "my_data.rds")
     loaded_data <- readRDS("my_data.rds")