Conference Agenda

Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).

Please note that all times are shown in the time zone of the conference. The current conference time is: 21st June 2021, 01:17:00pm UTC

Session Overview
Tutorials - Track 2
Wednesday, 07/July/2021:
7:00am - 11:59pm

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7:00am - 10:00am
ID: 316 / 2-Tut: 1
Topics: Other, Efficient programming
Keywords: testing, vcr, testthat, mocking, fixtures

GET better at testing your R package!

Maëlle Salmon, Scott Chamberlain

Are you a package developer who wants to improve your understanding and practice of unit testing?

You've come to the right place: This tutorial is about Advanced testing of R packages, with HTTP testing as a case study.

Unit tests have numerous advantages like preventing future breakage of your package and helping you define features (test-driven development).

In many introductions to package development you learn how to set up testthat infrastructure, and how to write a few “cute little tests” ( with only inline assertions.

This might work for a bit but soon you will encounter some practical and theoretical challenges: e.g. where do you put data and helpers for your tests? If your package is wrapping a web API, how do you test it independently from any internet connection? And how do you test the behavior of your package in case of API errors?

In this tutorial we shall use HTTP testing with the vcr package as an opportunity to empower you with more knowledge of testing principles (e.g. cleaning after yourself, testing error behavior) and testthat practicalities (e.g. testthat helper files, testthat custom skippers).

After this tutorial, you will be able to use the handy vcr package for your package wrapping a web API or any other web resource, but you will also have gained skills transferable to your other testing endeavours!

Come and learn from rOpenSci expertise!

Related materials

10:00am - 10:15am
ID: 327 / 2-Tut: 2


useR! 2021

10:15am - 2:15pm
ID: 317 / 2-Tut: 3
Topics: Other, R in production

Systematic data validation with the validate package

Mark van der Loo, Edwin de Jonge

Statistics Netherlands, Netherlands, The

- Language: English

- Duration: 240 mn

- N° Participants: 30

- Level: Intermediate

Checking the quality of data is a task that pervades data analyses. It does not matter whether you are working with raw data, cleaned data, or with the results of an analyses. It is always important to convince yourself that the data you are using is fit for its intended purpose. Since it is such a common task, why not automate it? The 'validate' package is designed for exactly this task: it implements a domain specific language for data checking that aims to encompass any check you might wish to perform. In this course you will will learn to define and measure data quality in a precise way with the validate package. We will focus on the main workflow, and show you how you can involve domain experts directly with your work, even if they do not know R. You will learn the main principles of data validation, both from the point of view of organizing a data processing work flow, as well as from a more formal perspective. You will exercise data validation tasks that range from checking input format and types to complex checks that involve data from multiple sources. You will learn how to follow the evolution of data quality as it is processed using the lumberjack package. And you will learn how to flush out redundant or contradictory quality demands using the validatetools package. The course will consist of hands-on work, based on a prepared tutorial that will be published on GitHub. There will be break-out sessions with assignments where you can discuss the materials with other course participants. The presentations will include some Kahoot quizzes to keep things interactive, fun, and focused.

2:15pm - 2:30pm
ID: 330 / 2-Tut: 4


useR! 2021

2:30pm - 6:00pm
ID: 318 / 2-Tut: 5
Topics: R in production, Web Applications (Shiny/Dash)

Production-grade Shiny Apps with {golem} - French

Vincent GUYADER, Cervan Girard

- Language: French

- Duration: 120 mn

- N° Participants: 30

- Level: Intermediate

This tutorial is aimed at intermediate or advanced shiny application developers who want to design "clean" applications following best practices. We will present the different steps necessary to obtain an application deployed in production. An active participation of the participants is expected, with screen sharing, microphone (and if possible webcam).

6:00pm - 6:15pm
ID: 331 / 2-Tut: 6


useR! 2021

6:15pm - 7:15pm
ID: 319 / 2-Tut: 7
Topics: Data mining / Machine learning / Deep Learning and AI

Penguins in a Box: Interactive Data Science Tutorial with Penguins.

Maria Dermit, Susana Escobar

- Language: English

- Duration: 60 mn

- N° Participants: 100

- Level: Intermediate

Penguins in a Box is a learnr package that covers the topics of R for Data Science book and uses the widely used dataset penguins to explore book's concepts. The package currently contains one tutorial for each chapter of the book and will be introduced during the presentation. In addition, you will join breakout rooms to work on modules on the book's main sections (e.i. Explore, Wrangle, Program, Model and Communicate; 6 sections in total) according to your learning objectives. This tutorial is aimed at both students who want to improve their data science skills in an interactive way and teachers who want to access additional learnr resources similar to Rstudio Primers ( The tutorial is aimed to be interactive and peer-instruction between attendees is aimed to guide learning at breakout rooms.

7:15pm - 8:00pm
ID: 329 / 2-Tut: 8


useR! 2021

8:00pm - 11:00pm
ID: 320 / 2-Tut: 9
Topics: Teaching R/R in Teaching, Other

Professional, Polished, Presentable: Making Great Slides with xaringan

Garrick Aden-Buie, Silvia Canelón

- Language: English

- Duration: 180mn

- N° Participants: 60

- Level: Intermediate

The xaringan package brings professional, impressive, and visually appealing slides to the powerful R Markdown ecosystem. Through our hands-on tutorial, you will learn how to design highly effective slides that support presentations for teaching and reporting alike. Over three hours, you will learn how to create an accessible baseline design that matches your institution or organization’s style guide. Together we’ll explore the basics of CSS—the design language of the internet—and how we can leverage CSS to produce elegant slides for effective communication. Finally, we’ll deploy our slides online where they can be shared and discovered by others long after they support our presentations. The tutorial will demonstrate how to use the skills learned to incorporate principles of accessible design into their presentations. The tutorial will feature live-coding and interactive question and answer periods,

interspersed with small-group break out sessions for guided hands-on experience. The tutorial will be supported by a repository of materials.

11:00pm - 11:15pm
ID: 328 / 2-Tut: 10


useR! 2021

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