I’m house-hunting, and while I’d love to buy a 5-bedroom house with a pool 10 minutes walk from Flinders Street Station I probably can’t afford that. So I need to take a broader look at Melbourne. One of the main constraints is commute time. I built a choropleth of commute times to the University of Melbourne and put it on top of a map of Melbourne. The rough idea is to create a fine hexagonal grid across the city using the sf package, and then to pass the centre of each hexagon through the Google Maps Directions Matrix API with the help of the (Melbourne-made) googleway package.

I’ve been playing around with an idea for a new R package. I call it exemplar and here’s how it works: I provide an example of what data should look like — an exemplar. The package gives a function that checks to make sure that any new data looks the same. The generated function checks — for each column — duplicate values, missing values, ranges, and more. The validation function doesn’t have any dependencies at all.

When I train a machine learning model in a blog post, I edit out all the mistakes. I make it seem like I had the perfect data I needed from the very start, and I never add a useless feature. This time, I want to train a model with all the mistakes and fruitless efforts included. My goal here is to describe my process of creating a model rather than just presenting the final code.

Advent of Code is an advent calendar for programming puzzles. I decided to tackle this year’s set of 50 puzzles in Julia and journal my experiences along the way. I’m a beginner in Julia so I thought this would help me improve my skills. This post covers days 9 through 16. Day 9: Bracket matching Syntax error in navigation subsystem on line: all of them I over-engineered the heck out of this puzzle.

Advent of Code is an advent calendar for programming puzzles. I decided to tackle this year’s set of 50 puzzles in Julia and journal my experiences along the way. I’m a beginner in Julia so I thought this would help me improve my skills. This post covers days 1 through 8. All of my solutions are available on GitHub. Day 1: Increasing sequences Count the number of times a depth measurement increases from the previous measurement

I love Julia’s UnicodePlots.jl, a package for making pretty, colourful plots directly in the terminal. While playing around for Advent of Code I wrote a function to animate a sequence of Unicode plots. It’s not much, but I couldn’t find anything similar on Google so I thought I’d share. The move_up helper function is the fiddly part; it moves the cursor to the start of where the plot begins so that a new plot can be printed right on top.

I have a URL with a colour parameter, like “https://example.com/diamonds?colour=H”. When I go to this URL in my browser, an AWS Lambda instance takes that parameter and passes it to rmarkdown::render, which knits a customised R Markdown report. My Lambda returns the knitted report as HTML, which my browser displays. If I change the parameter to “colour=G”, I get a different report, knitted on-demand. This is all serverless, so I only pay each time a report is requested (around $0.

Metaflow is one of my favourite R packages. Actually, it’s a Python module, but the R package provides a set of bindings for running R code through Metaflow. Recently I’ve spent a good amount of effort trying to improve the way that R data is translated to the Python side of Metaflow, but I just can’t get it to work. So I thought I’d post about what I’ve learnt. Maybe someone will have an answer.

One of the joys of keeping a personal blog is that I don’t have to justify a post. If I want to hook up 4 Raspberry Pis into a Kubernetes cluster just to monitor the humidity of my living room, then I can. And it’s pretty cool to open up a browser and go to starfleet:30001 to see this: I’ve explored Kubernetes once before, when I used it to host an R API made with Plumber.

In case this saves anyone some time, here’s a quick bit of regex and Python code for identifying if a given licence plate is standard or custom (personalised) in a given state. I can’t promise that this logic is correct or up to date. Some of the rules used are a bit more general than they need to be. I also tended to ignore rules before 1970. The rules come from: