Data Transformation with dplyr

CVEN 5837 - Summer 2022

Lars Schöbitz

Data Organisation in Spreadsheets

Think, Pair, Share

Questions

  1. Why should you not leave a blank cell in a spreadsheet used for data collection?
  2. Which of the 12 rules for data organization was the least comprehensible to you?
  • Think for 2 minutes
  • Pair with in break-out rooms for 4 minutes
  • Share your answer with the class
02:00

Learning Objectives (for this week)

  1. Learners can apply ten functions from the dplyr R Package to generate a subset of data for use in a table or plot

Data wrangling with dplyr

A grammar of data wrangling…

… based on the concepts of functions as verbs that manipulate data frames

  • select: pick columns by name
  • arrange: reorder rows
  • slice: chooses rows based on location
  • filter: pick rows matching criteria
  • relocate: changes the order of the columns
  • mutate: add new variables
  • summarise: reduce variables to values
  • group_by: for grouped operations
  • … (many more)

dplyr rules

Rules of dplyr functions:

  • First argument is always a data frame
  • Subsequent arguments say what to do with that data frame
  • Always return a data frame
  • Don’t modify in place

Live Coding Exercise: SDG 6.2.1

live-03a-data-transformation

  1. Head over to rstudio.cloud
  2. Open the workspace for the course (cven5837-ss22)
  3. Open “Projects”
  4. Open the “course-materials” project
  5. Follow along with me

Break

10:00

Pair Programming Exercise

Pair Programming Exercises

  • Two learners work together in a break out session
  • One person (the driver) shares the screen and does the typing
  • The other person (the navigator) offers comments and suggestions
  • Roles get switched

hw-03a-data-visualiation

  1. Head over to rstudio.cloud
  2. Open the workspace for the course (cven5837-ss22)
  3. Open “Projects”
  4. Open the “course-materials” project

Homework week 3

Homework late submission

  • 25% 10% each day that a homework is submitted late

Homework due dates

  • All material on course website
  • Homework assignment due: Friday, 22th July
  • Learning reflection due: Monday, 25th July

Thanks! 🌻

Slides created via revealjs and Quarto: https://quarto.org/docs/presentations/revealjs/ Access slides as PDF on GitHub

All material is licensed under Creative Commons Attribution Share Alike 4.0 International.

https://cven5837-ss22.github.io/website/