Lesson 1: Intro to R

Episode 2: Data Structures

Videos Credits: Claudiu Forgaci (Introduction), Javier San Millán Tejedor, Aleksandra Wilczynska

In this episode you’re going to start learning about the data structures such as Vectors in the R environment.

Vectors

Here the data vectors are explained.

Character Vectors

Here the character vectors are explained.

Str Vectors

str() function is explained.

Question about str function

What does structure function do?

Answer to the question

Combining Vectors

The combine function, c(), is introduced here.

Tip: Mixed Vectors

Tip on Mixed Vectors and str()

Additional tips on the Mixed Vectors

Question about mixed vectors

What is the underlying rule behind it?

Logical Values

Vectors can also have logical values.

Question about mixing values

What happens when we mix two different types of values?

Missing Values

There will be missing values.

Challenge: Missing Values

Missing Values Part 2

Missing Values Part 3

Factors

Factor is another important data structure.

Creating Factors

Here’s how to create factors.

Inspect Factors

The levels() function is introduced.

Tip: Summary function

A tip on using the summary() function

Reorder levels

fct_relevel() function is explained.

Questions regarding the syntax

Question about exclamation mark

What is the use of an exclamation mark inside the syntax?

Is it okay to have whitespaces or new lines in R programming?

Episode 3: Exploring Data Frames & Data Frame Manipulation with dplyr

Check the information of data frame basics and explore the dataset.

Reading data

Exploring dataset

First look at the dataset

The dollar sign

See how to use the dollar sign ($) in your script.

Using dollar sign

Question about factor function

Can we use factor function to convert character vector?

Answer

Tip: Intro to ncol & nrow

An introduction to ncol and nrow functions.

Question about summaries

Can we get the summaries for all countries?

Dataframe manipulation with dplyr

Select function

Introducing the select function.

Tip: select function errors

When choosing the select function, you may face error saying tidyverse is not installed.

Pipes

Introducing the pipe

Tip: read indentations when using pipes

A tip when you’re using pipes is to read your code with indentations.

Question about the pipe

Why use a pipe instead of doing things step by step?

Filter

Introduction to filter

Question about the order operation

What is the order of operation if we write it based on that structure?

A follow-up question from the previous question

Challenge: Filtered data frame

Challenge description

Challenge solution

You can also check the alternative solution

Question about the challenge

how to get all info about a country?

Group and summarize

Check the detailed descriptions from the carpentries regarding group and summarize with a challenge.

Multiple groups and summary variables

Frequencies

Introduction to frequencies

Mutate

Mutate function

Data Visualization

Introduction to data visualization

Don’t forget to take a quick look at the cheatsheet

Second part of the data visualization

Third part of the data visualization. Creating a summary plot for the data using the mutate function.

Question about a continent in the dataset

How did we know there’s the continent of America in the dataset?

fourth part of data visualization, coloring.

Color scale

Color scale and viridis function

Writing data

Saving the plot

Using help documentation

Saving the data

write.csv function description.

Also, check the cheatsheet.