Publications by Jonathan Carroll
Adelaide Traffic – Part I
Have you seen the little shark-fins on top of some traffic light control boxes? Have you seen the new ‘x minutes to y road‘ signs? Did you know they’re connected? DPTI installed a heap of bluetooth sensors around Adelaide and they capture mobile phone signals when you’re stopped at traffic lights; correlate them in real-time; and figure ...
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Is it crowded in here?
This was a neat graphic that someone made. It shows the population at a given latitude or longitude as a bar chart, overlayed on a map of the world itself. It shows where people live; the bigger the bar, the more people living at that latitude/longitude. “I can do that.” I said. In R of course. So here it is; I love that such a small amount...
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Image marginal histograms
Another day, another interesting challenge. I follow Bob Rudis’ (a.k.a. hrbrmstr’s) blog, typically via R-bloggers, and this post caught my eye. Partly because I thought I knew of an existing way to do this. As usual, actually getting that to work took a little longer than I might have hoped, but I think the end result is pretty neat. His p...
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Bring on the ROpenSci #auunconf 2016!
I’ll be heading to the 2016 ROpenSci un-conference (hackathon) in Brisbane later this month to smash out a heap of open-science R code. Ideas are already flowing quite nicely, and I’m confident that any ideas we don’t end up officially working on will get their chance in the very near future. One thing I noticed from the organisers was tha...
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52vis Week 2 Challenge
From Bob Rudis’ blog comes a weekly data/coding challenge. I didn’t quite get the time to tackle last week’s but I thought this one offered up a pretty good opportunity. Half the challenge is of course data processing/tidying, which is a big part of data science anyway (“75% of data science is getting the data in the right format, the ot...
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52vis Week 2 Challenge — Australian Version
I mapped out the USA homelessness rate in my last post as a challenge and noted at the end that it would be interesting to do the same for Australia. That was the first comment I received in person, too. “Let’s do it!” I said. What I found may shock you (click-bait title; check). Most of the code carried over. Of course, lacking hrbrmstr�...
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Simpler isn’t always faster
My name is Jonathan, and I have a coding obsession. I’ll admit it, the Hadleyverse has ruined me. I can no longer read a blog post or stackoverflow question in base R and leave it be. There are improvements to make, and I’m somewhat sure that I know what they are. Most of them involve dplyr. Many involve data.table. Some involve purrr. This ...
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#auunconf slack users’ timezone locations
I had never used slack before, but had read a heap of tech articles extolling its virtues. Apparently this is what our current Prime Minister advocates within Cabinet. The upcoming #auunconf organising team set up a channel and invited the participants, so I checked it out. Slack is pretty awesome as far as a unified workspace/messaging protocol ...
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Solving Inequality (the math kind)
This neat approach showed up recently as an answer to a FiveThirtyEight puzzle and of course I couldn’t help but throw it at dplyr as soon as I could. Turns out that’s not a terrible idea. The question posed is optimise 200a + 100b + 50c + 25d under the constraints 400a + 400b + 150c + 50d ≤ 1000, b ≤ a, a ≤ 1, c ≤ 8, d ≤ 4, and (a...
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Solving Inequality (the math kind)
This neat approach showed up recently as an answer to a FiveThirtyEight puzzle and of course I couldn’t help but throw it at dplyr as soon as I could. Turns out that’s not a terrible idea. The question posed is optimise 200a + 100b + 50c + 25d under the constraints 400a + 400b + 150c + 50d ≤ 1000, b ≤ a, a ≤ 1, c ≤ 8, d ≤ 4, and (a...
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