• Familiarity with R and RStudio
• Reading and writing data in various formats
• Data manipulation with tidyverse
• Aggregating and summarizing
• Data visualization

We will try to combine these topics with a focus on survey sampling and estimation.

• All up-to-date info and material on webpage: (https://peterstoltze.github.io/R_Accra_2024/)
• Two sessions per day (except Monday and Friday)
  • 09.00-13.00 (with break 10.45-11.15)
  • 14.00-16.00
• Lecture - Exercise - Repeat

In this lecture we will look at:

• R and RStudio IDE
• Working environment
• Objects and assignment
• Writing code and executing

• Created in New Zealand to teach statistics in 1993

• R is a language and environment made for statistical computing and for graphics

• GNU project (100% free software)

• Managed by the R Foundation for Statistical Computing, Vienna, Austria.

• Community-driven

• Based on the object-oriented language S (1975)

• Aggregates all convenient information and procedures into one single place
• Allows you to work in projects
• Manages your code with highlighting
• Gives extra functionality (Shiny, knitr, markdown, LaTeX)
• Allows for integration with version control systems, such as Git.

• Editor is for scripting
  • Can write multiple commands
  • You can easily run the commands again
  • Does not execute until you tell it to (Ctrl + Enter)
• Console is for executing
  • One command at a time
  • Good for commands you only need to run once (like inspecting objects)
  • Not good for writing long commands

• R works with objects that consist of elements. The smallest elements are numbers and characters.

  • These elements are assigned to objects.
  • A set of objects can be used to perform calculations
  • Calculations can be presented as functions
  • Functions are used to perform calculations and return new objects, containing calculated (or estimated) elements.

• Assigning things in R is very straightforward:

  • you just use <-

• For example, if you assign the value 100 (an element) to object a, you would type

a <- 100

• Life hack: In RStudio learn to use the shortcut “alt + -” (hyphen) to produce the left arrow <- in an R file

• Calling things in R is also very straightforward:

  • you just use type the name you have given to the object

• For example, we assigned the value 100 to object a. To call object a, we would type

a

## [1] 100

This is why we use R-Studio.

• Everything that is published on the Comprehensive R Archive Network (CRAN) and is aimed at R users, must be accompanied by a help file.

• If you know the name of the function that performs an operation, e.g. mean(), then you just type ?mean or help(mean) in the console.

• If you do not know the name of the function: type ?? followed by your search criterion. For example ??mean returns a list of all help pages that contain the word ‘mean’

• Alternatively, the internet will tell you almost everything you’d like to know (and then some)

• Sites such as http://www.stackoverflow.com and http://www.stackexchange.com, as well as Google can be of tremendous help.

  • If you google R related issues; use ‘R:’ as a prefix in your search term