mjfrigaard

Hi! I'm Martin Frigaard.

I'm a Senior Application Developer at BioMarin Pharmaceutical. I like to
develop Shiny applications, R packages, and create training materials and
workshops on data management, visualizations, and reproducible research.

This is my personal blog where I write about projects I'm currently working
on (or topics I'm thinking about). Thanks for visiting!

Shiny, {R6}, and R Packages

As a Shiny app-package grows, I’ve found it’s easy to end up with state scattered across reactives, observers, and module arguments. Shiny’s reactive model is naturally…

Create GitHub README with R Markdown

GitHub README files allow users to introduce themselves, share interests, projects, status, etc.¹ I love working in RMarkdown, so I wrote a small package that allows me to…

glockr: An R Wrapper around Succinct Code Counter

Last week I built glockr, an R package that wraps scc, a “very fast accurate code counter with complexity calculations.” Code metrics are a fascination of mine, and now that…

Who is this for?

I’ve written and discarded several drafts of this post out of concern that they sounded overly alarmist. For this version, I chose to step back from the technical details of…

Posit on Pop!_OS

I recently purchased a System76 laptop, which comes with Pop!_OS, an Ubuntu-flavored operating system. This post covers installing R, Python, and Quarto and setting up…

plumber vs `plumber2`

I’ve been working through the exercises in Alex K Gold’s DevOps for Data Science and this week I finished the API labs. When the book was written, plumber2 hadn’t been…

Shiny (for Python) & APIs

This is the second post demonstrating how to use Shiny apps with a database and an API (see previous post here). Both of these solutions are inspired by the exercises in the …

Quarto Shiny Apps in R Packages

This post was prompted by a new chapter I’ve been working on for Shiny App-Packages. I’ve recently been building a Shiny application in a Quarto document¹, and noticed quite…

Positron

I’ve been trying out Posit’s new Positron IDE for a few weeks, so I put together a post covering my initial impressions of developing Shiny apps and R packages.

Python Apps

This is the second post on working in VS Code with Python. I’ll cover developing and publishing Python applications using Bokeh, Streamlit, and Dash.

VS Code, meet Quarto.

I’ve been using VS Code to write more and more Python code lately, so I’ve decided make some notes on 1) installing Python, 2) working in VS Code, and 3) using Python code…

Shiny system tests with `shinytest2`

This post has been shortened from the original version. I felt it was too long and duplicative of other resources written better elsewhere. If you’d like to read the…

Testing Shiny modules

This is the third post in a series on testing shiny applications. I’ll cover testing shiny module server functions using the testhat package and shiny’s testServer() function.

Debugging in RStudio

In this post I’ll cover using the browser() function with RStudio’s debugger. RStudio’s debugging tools are built into the IDE, which provides a seamless transition between…

Testing Non-Package Shiny Apps

This is the second post in a series on testing Shiny applications. I’ll cover testing Shiny module server functions using the testhat package outside of an R package…

Behavior Driven Unit Tests

This post is the first in a series on testing Shiny applications. We’ll cover developing and testing a set of utility functions for a Shiny app-package using testhat. If…

Writing modular code with `box`

box provides a precise and concise method for using add-on packages and functions. box also doesn’t require bundling your code into R packages to make it reusable. This post…

purrr updates (v1.0.0)

This post is going to cover the recent updates to the purrr package. The release of version 1.0.0 (and dev version v1.0.1) had some breaking changes, which I will cover…