* R
1.1 - Initial Setup and Navigation 1.2 - Calculations and Variables 1.3 - Create and Work With Vectors 1.4 - Character and Boolean Vectors 1.5 - Vector Arithmetic 1.6 - Building and Subsetting Matrices 1.7 - Section 1 Review and Help Files 2.1 - Loading Data and Working With Data Frames 2.2 - Loading Data, Object Summaries, and Dates 2.3 - if() Statements, Logical Operators, and the which() Function 2.4 - for() Loops and Handling Missing Observations 2.5 - Lists 3.1 - Managing the Workspace and Variable Casting 3.2 - The apply() Family of Functions 3.3 - Access or Create Columns in Data Frames, or Simplify a Data Frame using aggregate() 4.1 - Basic Structure of a Function 4.2 - Returning a List and Providing Default Arguments 4.3 - Add a Warning or Stop the Function Execution 4.4 - Passing Additional Arguments Using an Ellipsis 4.5 - Make a Returned Result Invisible and Build Recursive Functions 4.6 - Custom Functions With apply()